The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in ... more The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in the isolation and identification of two new proaporphine alkaloids; (+)-scortechiniine A (1) and (+)-scortechiniine B (2) together with two known proaporphines; (−)-hexahydromecambrine A (3), (−)-norhexahydromecambrine A (4), and one aporphine; norboldine (5). Structural elucidations of these alkaloids were performed using spectroscopic methods especially 1D and 2D
Methods and findings in experimental and clinical pharmacology, Oct 1, 2008
The protective effect of methanol extracts of Cassia fistula (flowers, leaves and bark) was exami... more The protective effect of methanol extracts of Cassia fistula (flowers, leaves and bark) was examined in vitro in human umbilical vein endothelial cells (HUVEC) against toxicity induced by glycated protein (GFBS) in vitro. The experiments consisted of eight groups of HUVEC with five flasks in each group. Group I was treated with 15% FBS, group II with GFBS (70 microM) alone, and the other six groups were treated with GFBS plus 25 and 50 microg of each of the three types of C. fistula extracts. After 72 h of incubation, cells were collected ...
Columbin, a diterpenoid furanolactone, was isolated purely for the first time from the plant spec... more Columbin, a diterpenoid furanolactone, was isolated purely for the first time from the plant species Tinspora bakis. The anti-inflammatory effects of columbin were studied in vitro, in silico and in vivo. The effect of columbin on nitric oxide was examined on lipopolysaccharide–interferon-gamma (LPS/IFN) induced RAW264. 7 macrophages. In vitro and in silico cyclooxygenase-1 and cyclooxygenase-2 inhibitory activities of columbin using biochemical kit and molecular docking, respectively, were investigated. Mechanism of columbin in ...
Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus ... more Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus species that have been studied, β-bungarotoxin has never been isolated from Bungarus fasciatus venom. It was hypothesized that the absence of β-bungarotoxin in this species was due to divergence during evolution prior to evolution of β-bungarotoxin. In this study, we have isolated a β-bungarotoxin isoform we named P-elapitoxin-Bf1a by using gel filtration, cation-exchange and reverse-phase chromatography from Malaysian B. fasciatus venom. The toxin consists of two heterogeneous subunits, subunit A and subunit B. LCMS/MS data showed that subunit A was homologous to acidic phospholipase A2 subunit A3 from Bungarus candidus and B. multicinctus venoms, whereas subunit B was homologous with subunit B1 from B. fasciatus venom that was previously detected by cDNA cloning. The toxin showed concentration- and time-dependent reduction of indirect-twitches without affecting contractile responses to ACh, CCh or KCl at the end of experiment in the chick biventer preparation. Toxin modification with 4-BPB inhibited the neurotoxic effect suggesting the importance of His-48. Tissue pre-incubation with monovalent B. fasciatus (BFAV) or neuro-polyvalent antivenom (NPV), at the recommended titer, was unable to inhibit the twitch reduction induced by the toxin. This study indicates that Malaysian B. fasciatus venom has a unique β-bungarotoxin isoform which was not neutralized by antivenoms. This suggests that there might be other presynaptic neurotoxins present in the venom and there is a variation in the enzymatic neurotoxin composition in venoms from different localities.
Kraits (Bungarus spp.) are highly venomous elapids that are only found in Asia. In the current st... more Kraits (Bungarus spp.) are highly venomous elapids that are only found in Asia. In the current study, 103 and 86 different proteins were identified from Bungarus candidus and Bungarus fasciatus venoms, respectively. These proteins were classified into 18 different venom protein families. Both venoms were found to contain a high percentage of three finger toxins, phospholipase A2 enzymes and Kunitz-type inhibitors. Smaller number of high molecular weight enzymes such as L-amino acid oxidase, hyaluronidases, and acetylcholinesterase were also detected in the venoms. We also detected some unique proteins that were not known to be present in these venoms. The presence of a natriuretic peptide, vespryn, and serine protease families was detected in B. candidus venom. We also detected the presence of subunit A and B of β-bungarotoxin and α-bungarotoxin which had not been previously found in B. fasciatus venom. Understanding the proteome composition of Malaysian krait species will provide useful information on unique toxins and proteins which are present in the venoms. This knowledge will assist in the management of krait envenoming. In addition, these proteins may have potential use as research tools or as drug-design templates.
To date, plants have been the major source of anticancer drugs. Boldine is a natural alkaloid com... more To date, plants have been the major source of anticancer drugs. Boldine is a natural alkaloid commonly found in the leaves and bark of Peumus boldus. In this study, we found that boldine potently inhibited the viability of the human invasive breast cancer cell lines, MDA-MB-231 (48-hour IC50 46.5±3.1 μg/mL) and MDA-MB-468 (48-hour IC50 50.8±2.7 μg/mL). Boldine had a cytotoxic effect and induced apoptosis in breast cancer cells as indicated by a higher amount of lactate dehydrogenase released, membrane permeability, and DNA fragmentation. In addition, we demonstrated that boldine induced cell cycle arrest at G2/M phase. The anticancer mechanism is associated with disruption of the mitochondrial membrane potential and release of cytochrome c in MDA-MB-231. Boldine selectively induced activation of caspase-9 and caspase-3/7, but not caspase-8. We also found that boldine could inhibit nuclear factor kappa B activation, a key molecule in tumor progression and metastasis. In addition, protein array and Western blotting analysis showed that treatment with boldine resulted in downregulation of Bcl-2 and heat shock protein 70 and upregulation of Bax in the MDA-MB-231 cell line. An acute toxicity study in rats revealed that boldine at a dose of 100 mg/kg body weight was well tolerated. Moreover, intraperitoneal injection of boldine (50 or 100 mg/kg) significantly reduced tumor size in an animal model of breast cancer. Our results suggest that boldine is a potentially useful agent for the treatment of breast cancer.
New research and development efforts using computational chemistry in studying an assessment of t... more New research and development efforts using computational chemistry in studying an assessment of the validity of different quantum chemical methods to describe the molecular and electronic structures of some corrosion inhibitors were introduced. The standard and the highly accurate CCSD method with 6-311++G(d,p), ab initio calculations using the HF/6-31G++(d,p) and MP2 with 6-311G(d,p), 6-31++G(d,p), and 6-311++G(2df,p) methods as well as DFT method at the B3LYP, BP86, B3LYP*, MO6L, and M062x/6-31G++(d,p) basis set level were performed on some triazole derivatives and sulfur containing compounds used as corrosion inhibitors. Quantum chemical parameters, such as the energy of the highest occupied molecular orbital energy (E-HOMO), the energy of the lowest unoccupied molecular orbital energy (E-LUMO), energy gap (Delta E), dipole moment (mu), sum of total negative charges (TNC), chemical potential (Pi), electronegativity (X), hardness (eta), softness (sigma), local softness (s), Fukui functions (f(+),f(-)), electrophilicity (omega), the total energy change (Delta E-T) and the solvation energy (S.E), were calculated. Furthermore, the accuracy and the applicability of these methods were estimated relative to the highest accuracy and standard CCSD with 6-311++G(d,p) method. Good correlations between the quantum chemical parameters and the corresponding inhibition efficiency (IE%) were found.
The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic aci... more The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic acid (QA) on a STZ-induced diabetic rat model to determine their potential role in alleviating diabetes and its associated complications. In our study design, diabetic rats were treated with single and combined doses of QE and QA for 45 days to analyse their effects on liver, kidney and pancreas tissues. The study result showed that QE and QA treated groups down-regulated hyperglycaemia and oxidative stress by up-regulating insulin and C-peptide levels. Moreover, histological observations of the liver, kidney and pancreas of diabetic rats treated with single and combined doses of QE and QA showed a significant improvement in the structural degeneration. Interestingly, the combination dose of QE and QA (50 mg/kg) exhibited maximum inhibition of the pro-apoptotic protein Bax expression and demonstrate enhancement of the anti-apoptotic protein BcI-2 expression in the kidney tissues, suggesting a protective role in the kidneys of diabetic rats. Taken together, these results indicates the synergistic effects of QE and QA in ameliorating hyperglycaemia, hyperlipidemia and insulin resistance in diabetic rats and therefore, open a new window of research on the combinatorial therapy of flavonoids. (C) 2014 Elsevier Ltd. All rights reserved.
Ethnopharmacological relevance: Paeonol is a phenolic compound isolated mainly from Moutan cortex... more Ethnopharmacological relevance: Paeonol is a phenolic compound isolated mainly from Moutan cortex, root bark of Chinese Peony tree. Moutan cortex holds a significant value in traditional Chinese medicine for alleviating various oxidative stress-related diseases mainly atherosclerosis and myocardial infarction. The present study seeks to identify the protective mechanisms of paeonol in oxidative stress-induced premature senescence in endothelial cells. Materials and methods: HUVECs were pretreated with paeonol or DMSO control at different doses for 24 h prior to an exposure of 200 mu M of reactive oxygen species (ROS) inducer, hydrogen peroxide (H2O2). The protective effects of paeonol against H2O2-induced senescence were evaluated and the activation of Sirtuin 1 pathway by paeonol pretreatment was investigated in HUVECs. Results: Paeonol attenuated H2O2-induced cell growth arrest at GO/G1 phase, reduced the percentage of SA-beta-Gal positive cells and increased BrdU incorporation. In addition, enzymatic Sirtl activation assay indicated that paeonol significantly increased lysyl deactylase activity of Sirtl enzyme with a fold change of 2.4 +/- 0.195 (p < 0.05). Furthermore, pretreatment with paeonol significantly decreased the levels of p53, acetyl H3K14 and H4K16 protein expression upregulated by H2O2 stimulation. The changes in the histone protein levels were accompanied with an increase in Sirtl protein expression level. Conclusion: These findings suggest that paeonol protects endothelial cells against oxidative stress-induced premature senescence by modulating the expressions of Sirtl protein and its substrates. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
Background: The biological properties of thiosemicarbazone have been widely reported. The incorpo... more Background: The biological properties of thiosemicarbazone have been widely reported. The incorporation of some transition metals such as Fe, Ni and Cu to thiosemicarbazone complexes is known to enhance its biological effects. In this study, we incorporated nickel(II) ions into thiosemicarbazone with N4-substitution groups H3L (H; H3L1, CH3; H3L2, C6H5; H3L3 and C2H5; H3L4) and examined its potential anti-inflammatory activity. Methodology/Principal Findings: Four ligands (1-4) and their respective nickel-containing complexes (5-8) were synthesized and characterized. The compounds synthesized were tested for their effects on NF-kappa B nuclear translocation, pro-inflammatory cytokines secretion and NF-kappa B transactivation activity. The active compound was further evaluated on its ability to suppress carrageenan-induced acute inflammation in vivo. A potential binding target of the active compound was also predicted by molecular docking analysis. Conclusions/Significance: Among all synthesized compounds tested, we found that complex [Ni(H2L1)(PPh3)]Cl (5) (complex 5), potently inhibited I kappa B alpha degradation and NF-kappa B p65 nuclear translocation in LPS-stimulated RAW264.7 cells as well as TNF alpha-stimulated HeLa S3 cells. In addition, complex 5 significantly down-regulated LPS- or TNF alpha-induced transcription of NF-kappa B target genes, including genes that encode the pro-inflammatory cytokines TNF alpha, IFN beta and IL6. Luciferase reporter assays confirmed that complex 5 inhibited the transactivation activity of NF-kappa B. Furthermore, the anti-inflammatory effect of complex 5 was also supported by its suppressive effect on carrageenan-induced paw edema formation in wild type C57BL/6 mice. Interestingly, molecular docking study showed that complex 5 potentially interact with the active site of IKK beta. Taken together, we suggest complex 5 as a novel NF-kappa B inhibitor with potent anti-inflammatory effects.
Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L... more Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L1–H3L4) have been synthesized and characterized with the aim of evaluating the effect of N4 substitution in the thiosemicarbazone moiety on their coordination behavior and biological activities. Two series of nickel(II) complexes with the general formulae [Ni(H3L)(H2L)]ClO4 and [Ni2(HL)2] were characterized by analytical and spectral techniques. The molecular structure of one of the complexes, namely, [Ni(H3L4)(H2L4)]ClO4 was established by single crystal X-ray diffraction studies. The crystal structure of this complex revealed that two H3L4 ligands are coordinated to nickel(II) in different modes; one as a neutral tridentate ONS ligand and the other is as a monoanionic tridentate (ONS−) ligand. The antimicrobial activities of the compounds were tested against 25 bacterial strains via the disc diffusion method, and their minimum inhibitory concentration (MIC) and minimum microbicidal concentration were evaluated using microdilution methods. With a few exceptions, most of the compounds exhibited low-to-moderate inhibitory activities against the tested bacterial strains. However, the complexes [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) indicated higher inhibitory activity against Salmonella enterica ATCC 9068 (MIC values 15.7 and <15.7 μg/ml, respectively), compared with gentamicin as the positive control (MIC 25 μg/ml). Complex (7) also inhibited Streptococcus pneumoniae more efficiently (MIC 31.2 μg/ml), compared with gentamicin (MIC > 50 μg/ml). The toxicities of the compounds were tested on brine shrimp (Artemia salina), where no meaningful toxicity level was noted for both the free ligands and the complexes. The cytotoxicities of the compounds on cell viability were determined on MCF7, PC3, A375, and H413 cancer cells in terms of IC50; complexes [Ni(H3L3)(H2L3)]ClO4 (3), [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) exhibited significant cytotoxicity on the tested cell lines.
Evidence-Based Complementary and Alternative Medicine, Jan 2013
Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coron... more Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coronary artery disease, heart failure, and peripheral vascular disease. The increase in oxidative stress has been associated with the pathogenesis of hypertension. Increase of blood pressure is due to an imbalance between antioxidants defence mechanisms and free radical productions. Excessive production of reactive oxygen species reduces nitric oxide bioavailability leading to an endothelial dysfunction and a subsequent increase in total peripheral resistance. Hypertension can cause few symptoms until it reaches the advanced stage and poses serious health problems with lifelong consequences. Hypertensive patients are required to take drugs for life to control the hypertension and prevent complications. Some of these drugs are expensive and may have adverse reactions. Hence, it is timely to examine scientifically, complimentary therapies that are more effective and with minimal undesirable effects. Nigella sativa (NS) and its active constituents have been documented to exhibit antioxidant, hypotensive, calcium channel blockade and diuretic properties which may contribute to reduce blood pressure. This suggests a potential role of NS in the management of hypertension, and thus more studies should be conducted to evaluate its effectiveness.
Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Enveno... more Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Envenoming by these snakes is often characterized by neurotoxicity and, without treatment, causes considerable morbidity and mortality. In this study, the in vitro neurotoxicity of each species, and the effectiveness of two monovalent antivenoms and a polyvalent antivenom, against the neurotoxic effects of the venoms, were examined in a skeletal muscle preparation. Both venoms caused concentration-dependent inhibition of indirect twitches, and attenuated responses to exogenous nicotinic receptor agonists, in the chick biventer preparation, with B. candidus venom being more potent than B. fasciatus venom. SDS-PAGE and western blot analysis indicated different profiles between the venoms. Despite these differences, most proteins bands were recognized by all three antivenoms. Antivenom, added prior to the venoms, attenuated the neurotoxic effect of the venoms. Interestingly, the respective monovalent antivenoms did not neutralize the effects of the venom from the other Bungarus species indicating a relative absence of cross-neutralization. Addition of a high concentration of polyvalent antivenom, at the t90 time point after addition of venom, partially reversed the neurotoxicity of B. fasciatus venom but not B. candidus venom. The monovalent antivenoms had no significant effect when added at the t90 time point. This study showed that B. candidus and B. fasciatus venoms display marked in vitro neurotoxicity in the chick biventer preparation and administration of antivenoms at high dose is necessary to prevent or reverse neurotoxicity
Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus... more Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus results in neurotoxicity due to the presence of presynaptic and postsynaptic neurotoxins. Antivenom, either monovalent or polyvalent, is the treatment of choice in systemically envenomed patients. In this study, we have isolated a postsynaptic neurotoxin which we named α-elapitoxin-Bf1b. This toxin has an approximate molecular weight of 6.9 kDa, with LCMS/MS data showing that it is highly homologous with Neurotoxin 3FTx-RI, a toxin identified in the Bungarus fasciatus venom gland transcriptome. α-Elapitoxin-Bf1b also shared similarity with short-chain neurotoxins from Laticauda colubrina and Pseudechis australis. α-Elapitoxin-Bf1b produced concentration- and time-dependent neurotoxicity in the indirectly-stimulated chick biventer cervicis muscle preparation, an effect partially reversible by repetitive washing of the preparation. The pA2 value for α-elapitoxin-Bf1b of 9.17 ± 0.64, determined by examining the effects of the toxin on cumulative carbacol concentration-response curves, indicated that the toxin is more potent than tubocurarine and α-bungarotoxin. Pre-incubation of Bungarus fasciatus monovalent and neuro polyvalent antivenom failed to prevent the neurotoxic effects of α-elapitoxin-Bf1b in the chick biventer cervicis muscle preparation. In conclusion, the isolation of a postsynaptic neurotoxin that cannot be neutralized by either monovalent and polyvalent antivenoms may indicate the presence of isoforms of postsynaptic neurotoxins in Malaysian B. fasciatus venom.
BMC Complementary and Alternative Medicine, Jul 10, 2013
Background: Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica;... more Background: Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica; black cumin) is one of the ingredients of an Ayurvedic preparation, called “Kayakalp”, commonly applied to treat skin disorders in India and Southeast Asia. Despite its well known anti-inflammatory property on skin diseases, the anti-cancer effect of C. anthelminticum seeds on skin cancer is less documented. The present study aims to investigate the anti-cancer effect of Centratherum anthelminticum (L.) seeds chloroform fraction (CACF) on human melanoma cells and to elucidate the molecular mechanism involved.
Methods: A chloroform fraction was extracted from C. anthelminticum (CACF). Bioactive compounds of the CACF were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human melanoma cell line A375 was treated with CACF in vitro. Effects of CACF on growth inhibition, morphology, stress and survival of the cell were examined with MTT, high content screening (HSC) array scan and flow cytometry analyses. Involvement of intrinsic or extrinsic pathways in the CACF-induced A375 cell death mechanism was examined using a caspase luminescence assay. The results were further verified with different caspase inhibitors. In addition, Western blot analysis was performed to elucidate the changes in apoptosis-associated molecules. Finally, the effect of CACF on the NF-κB nuclear translocation ability was assayed.
Results: The MTT assay showed that CACF dose-dependently inhibited cell growth of A375, while exerted less cytotoxic effect on normal primary epithelial melanocytes. We demonstrated that CACF induced cell growth inhibition through apoptosis, as evidenced by cell shrinkage, increased annexin V staining and formation of membrane blebs. CACF treatment also resulted in higher reactive oxygen species (ROS) production and lower Bcl-2 expression, leading to decrease mitochondrial membrane potential (MMP). Disruption of the MMP facilitated the release of mitochondrial cytochrome c, which activates caspase-9 and downstream caspase-3/7, resulting in DNA fragmentation and up-regulation of p53 in melanoma cells. Moreover, CACF prevented TNF-α-induced NF-κB nuclear translocation, which further committed A375 cells toward apoptosis.
Conclusions: Together, our findings suggest CACF as a potential therapeutic agent against human melanoma malignancy.
The therapeutic potential of plants varies according to their parts. The present study was aimed ... more The therapeutic potential of plants varies according to their parts. The present study was aimed to ascertain the antioxidant and antidiabetic potential of crude fractions obtained from different parts of 6 medicinal plants, Centratherum anthelminticum, Cissus quadrangularis, Terminalia bellerica, Terminalia chebula, Terminalia arjuna and Woodfordia fruticosa. Total phenolic (TPC), total flavonoid (TFC) and total tannin content (TTC) were determined. In vitro antioxidant abilities were showed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing/antioxidant Power (FRAP) assays. Furthermore, anti-diabetic potential was determined using in vitro protein tyrosine phosphatase-1B (PTP-1B) inhibition assay and blood glucose lowering effects were evaluated on streptozotocin (STZ)-induced diabetic rats. The result of our study showed that T. chebula fruit exhibited highest amount of TPC (910.43±37.45 mg GAE g-1) and TTC (65.6±6.83 mg Catechin g-1), respectively. Whereas C. anthelminticum seeds contained highest amount of TFC (98.2±27.6 mg Quercetin g-1). The free radical scavenging capacity of T. chebula fruits was the highest among the six plants as determined by DPPH (3.6±0.13 μg mL-1) and FRAP (109.6±2.5 μg mL-1) assays. C. anthelminticum seeds (9.16±0.62 μM mL-1) demonstrated highest oxygen radical absorbance capacity in ORAC test. In addition, C. anthelminticum seeds (38±5.8 μM) showed highest PTP-1B inhibitory effects and maximum blood glucose lowering effects in STZ-induced diabetic rats. Altogether, our findings suggest that T. chebula fruit is potent in ameliorating oxidative damage whereas, C. anthelminticum seeds possess highest antidiabetic and antioxidant properties.
Background and Purpose
Boldine is a potent natural antioxidant present in the leaves and bark of... more Background and Purpose
Boldine is a potent natural antioxidant present in the leaves and bark of Chilean boldo tree. The present study investigated the endothelial protective effect of boldine in arteries of db/db diabetic mice and in cultured mouse aortic endothelial cells receiving high glucose treatment.
Experimental Approach
Vascular reactivity was studied in mouse aortas. Reactive oxygen species (ROS) production, angiotensin type 1 receptor (AT1R) localization and protein expression of oxidative stress markers in the vascular wall were evaluated by DHE fluorescence, lucigenin enhanced-chemiluminescence, immunohistochemistry and Western blot, respectively. The effect of boldine was also examined in high glucose (30 mmol L-1)-treated primary mouse aortic endothelial cells.
Key Results
Both oral treatment (20 mg kg-1day-1, 7 days) and incubation in vitro with boldine (1 μmol L-1, 12 hours) enhanced endothelium-dependent aortic relaxations of db/db mice. Boldine reversed the impaired relaxations induced by high glucose or angiotensin II (Ang II) in non-diabetic mouse aortas while it reduced the ROS overproduction and increased the phosphorylation of eNOS in db/db mouse aortas. The elevated expression of oxidative stress markers such bone morphogenic protein 4 (BMP4), nitrotyrosine and AT1R was reduced in boldine-treated db/db mouse aortas. The Ang II-stimulated BMP4 expression was also inhibited by treatment with boldine, tempol, noggin and losartan. Boldine inhibited high glucose-stimulated ROS production and restored the lost phosphorylation of eNOS in mouse aortic endothelial cells.
Conclusion and Implications
Boldine is effective to reduce oxidative stress and thus to improve endothelium-dependent relaxations in aortas of diabetic mice largely through inhibiting ROS over-production associated with Ang II-mediated BMP4-dependent mechanisms.
Alpha ()-tomatine, a major saponin found in tomato has been shown to inhibit the growth ofandrog... more Alpha ()-tomatine, a major saponin found in tomato has been shown to inhibit the growth ofandrogen-independent prostate cancer PC-3 cells. The effects of -tomatine in combination with thechemotherapeutic agent paclitaxel against PC-3 cells were investigated in the present study. Combinedtreatment with a sub-toxic dose of -tomatine and paclitaxel significantly decreased cell viability withconcomitant increase in the percentage of apoptotic PC-3 cells. The combined treatment, however, hadno cytotoxic effect on the non-neoplastic prostate RWPE-1 cells. Apoptosis of PC-3 cells was accompaniedby the inhibition of PI3K/Akt pro-survival signaling, an increase in the expression of the pro-apoptoticprotein BAD but a decrease in the expressions of anti-apoptotic proteins, Bcl-2 and Bcl-xL. Results froma mouse xenograft model showed the combined treatment completely suppressed subcutaneous tumorgrowth without significant side effects. Consistent with its in vitro anti-cancer effects, tumor materi-als from mice showed increased apoptosis of tumor cells with reduced protein expression of activatedPI3K/Akt. These results suggest that the synergistic anti-cancer effects of paclitaxel and -tomatine maybe beneficial for refractory prostate cancer treatment.
Evidence-Based Complementary and Alternative Medicine, 2012
This study was set to investigate antiproliferative potential of dentatin (a natural coumarin iso... more This study was set to investigate antiproliferative potential of dentatin (a natural coumarin isolated from Clausena excavata Burm. F) against prostate cancer and to delineate the underlying mechanism of action. Treatment with dentatin dose-dependently inhibited cell growth of PC-3 and LNCaP prostate cancer cell lines, whereas it showed less cytotoxic effects on normal prostate epithelial cell line (RWPE-1). The inhibitory effect of dentatin on prostate cancer cell growth was due to induction of apoptosis as evidenced by Annexin V staining and cell shrinkage. We found that dentatin-mediated accumulation of reactive oxygen species (ROS) and downregulated expression levels of antiapoptotic molecules (Bcl-2, Bcl-xL, and Survivin), leading to disruption of mitochondrial membrane potential (MMP), cell membrane permeability, and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-9, -3/7 activities, and subsequent DNA fragmentation. In addition, we found that dentatin inhibited TNF-α-induced nuclear translocation of p65, suggesting dentatin as a potential NF-κB inhibitor. Thus, we suggest that dentatin may have therapeutic value in prostate cancer treatment worthy of further development.
The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in ... more The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in the isolation and identification of two new proaporphine alkaloids; (+)-scortechiniine A (1) and (+)-scortechiniine B (2) together with two known proaporphines; (−)-hexahydromecambrine A (3), (−)-norhexahydromecambrine A (4), and one aporphine; norboldine (5). Structural elucidations of these alkaloids were performed using spectroscopic methods especially 1D and 2D
Methods and findings in experimental and clinical pharmacology, Oct 1, 2008
The protective effect of methanol extracts of Cassia fistula (flowers, leaves and bark) was exami... more The protective effect of methanol extracts of Cassia fistula (flowers, leaves and bark) was examined in vitro in human umbilical vein endothelial cells (HUVEC) against toxicity induced by glycated protein (GFBS) in vitro. The experiments consisted of eight groups of HUVEC with five flasks in each group. Group I was treated with 15% FBS, group II with GFBS (70 microM) alone, and the other six groups were treated with GFBS plus 25 and 50 microg of each of the three types of C. fistula extracts. After 72 h of incubation, cells were collected ...
Columbin, a diterpenoid furanolactone, was isolated purely for the first time from the plant spec... more Columbin, a diterpenoid furanolactone, was isolated purely for the first time from the plant species Tinspora bakis. The anti-inflammatory effects of columbin were studied in vitro, in silico and in vivo. The effect of columbin on nitric oxide was examined on lipopolysaccharide–interferon-gamma (LPS/IFN) induced RAW264. 7 macrophages. In vitro and in silico cyclooxygenase-1 and cyclooxygenase-2 inhibitory activities of columbin using biochemical kit and molecular docking, respectively, were investigated. Mechanism of columbin in ...
Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus ... more Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus species that have been studied, β-bungarotoxin has never been isolated from Bungarus fasciatus venom. It was hypothesized that the absence of β-bungarotoxin in this species was due to divergence during evolution prior to evolution of β-bungarotoxin. In this study, we have isolated a β-bungarotoxin isoform we named P-elapitoxin-Bf1a by using gel filtration, cation-exchange and reverse-phase chromatography from Malaysian B. fasciatus venom. The toxin consists of two heterogeneous subunits, subunit A and subunit B. LCMS/MS data showed that subunit A was homologous to acidic phospholipase A2 subunit A3 from Bungarus candidus and B. multicinctus venoms, whereas subunit B was homologous with subunit B1 from B. fasciatus venom that was previously detected by cDNA cloning. The toxin showed concentration- and time-dependent reduction of indirect-twitches without affecting contractile responses to ACh, CCh or KCl at the end of experiment in the chick biventer preparation. Toxin modification with 4-BPB inhibited the neurotoxic effect suggesting the importance of His-48. Tissue pre-incubation with monovalent B. fasciatus (BFAV) or neuro-polyvalent antivenom (NPV), at the recommended titer, was unable to inhibit the twitch reduction induced by the toxin. This study indicates that Malaysian B. fasciatus venom has a unique β-bungarotoxin isoform which was not neutralized by antivenoms. This suggests that there might be other presynaptic neurotoxins present in the venom and there is a variation in the enzymatic neurotoxin composition in venoms from different localities.
Kraits (Bungarus spp.) are highly venomous elapids that are only found in Asia. In the current st... more Kraits (Bungarus spp.) are highly venomous elapids that are only found in Asia. In the current study, 103 and 86 different proteins were identified from Bungarus candidus and Bungarus fasciatus venoms, respectively. These proteins were classified into 18 different venom protein families. Both venoms were found to contain a high percentage of three finger toxins, phospholipase A2 enzymes and Kunitz-type inhibitors. Smaller number of high molecular weight enzymes such as L-amino acid oxidase, hyaluronidases, and acetylcholinesterase were also detected in the venoms. We also detected some unique proteins that were not known to be present in these venoms. The presence of a natriuretic peptide, vespryn, and serine protease families was detected in B. candidus venom. We also detected the presence of subunit A and B of β-bungarotoxin and α-bungarotoxin which had not been previously found in B. fasciatus venom. Understanding the proteome composition of Malaysian krait species will provide useful information on unique toxins and proteins which are present in the venoms. This knowledge will assist in the management of krait envenoming. In addition, these proteins may have potential use as research tools or as drug-design templates.
To date, plants have been the major source of anticancer drugs. Boldine is a natural alkaloid com... more To date, plants have been the major source of anticancer drugs. Boldine is a natural alkaloid commonly found in the leaves and bark of Peumus boldus. In this study, we found that boldine potently inhibited the viability of the human invasive breast cancer cell lines, MDA-MB-231 (48-hour IC50 46.5±3.1 μg/mL) and MDA-MB-468 (48-hour IC50 50.8±2.7 μg/mL). Boldine had a cytotoxic effect and induced apoptosis in breast cancer cells as indicated by a higher amount of lactate dehydrogenase released, membrane permeability, and DNA fragmentation. In addition, we demonstrated that boldine induced cell cycle arrest at G2/M phase. The anticancer mechanism is associated with disruption of the mitochondrial membrane potential and release of cytochrome c in MDA-MB-231. Boldine selectively induced activation of caspase-9 and caspase-3/7, but not caspase-8. We also found that boldine could inhibit nuclear factor kappa B activation, a key molecule in tumor progression and metastasis. In addition, protein array and Western blotting analysis showed that treatment with boldine resulted in downregulation of Bcl-2 and heat shock protein 70 and upregulation of Bax in the MDA-MB-231 cell line. An acute toxicity study in rats revealed that boldine at a dose of 100 mg/kg body weight was well tolerated. Moreover, intraperitoneal injection of boldine (50 or 100 mg/kg) significantly reduced tumor size in an animal model of breast cancer. Our results suggest that boldine is a potentially useful agent for the treatment of breast cancer.
New research and development efforts using computational chemistry in studying an assessment of t... more New research and development efforts using computational chemistry in studying an assessment of the validity of different quantum chemical methods to describe the molecular and electronic structures of some corrosion inhibitors were introduced. The standard and the highly accurate CCSD method with 6-311++G(d,p), ab initio calculations using the HF/6-31G++(d,p) and MP2 with 6-311G(d,p), 6-31++G(d,p), and 6-311++G(2df,p) methods as well as DFT method at the B3LYP, BP86, B3LYP*, MO6L, and M062x/6-31G++(d,p) basis set level were performed on some triazole derivatives and sulfur containing compounds used as corrosion inhibitors. Quantum chemical parameters, such as the energy of the highest occupied molecular orbital energy (E-HOMO), the energy of the lowest unoccupied molecular orbital energy (E-LUMO), energy gap (Delta E), dipole moment (mu), sum of total negative charges (TNC), chemical potential (Pi), electronegativity (X), hardness (eta), softness (sigma), local softness (s), Fukui functions (f(+),f(-)), electrophilicity (omega), the total energy change (Delta E-T) and the solvation energy (S.E), were calculated. Furthermore, the accuracy and the applicability of these methods were estimated relative to the highest accuracy and standard CCSD with 6-311++G(d,p) method. Good correlations between the quantum chemical parameters and the corresponding inhibition efficiency (IE%) were found.
The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic aci... more The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic acid (QA) on a STZ-induced diabetic rat model to determine their potential role in alleviating diabetes and its associated complications. In our study design, diabetic rats were treated with single and combined doses of QE and QA for 45 days to analyse their effects on liver, kidney and pancreas tissues. The study result showed that QE and QA treated groups down-regulated hyperglycaemia and oxidative stress by up-regulating insulin and C-peptide levels. Moreover, histological observations of the liver, kidney and pancreas of diabetic rats treated with single and combined doses of QE and QA showed a significant improvement in the structural degeneration. Interestingly, the combination dose of QE and QA (50 mg/kg) exhibited maximum inhibition of the pro-apoptotic protein Bax expression and demonstrate enhancement of the anti-apoptotic protein BcI-2 expression in the kidney tissues, suggesting a protective role in the kidneys of diabetic rats. Taken together, these results indicates the synergistic effects of QE and QA in ameliorating hyperglycaemia, hyperlipidemia and insulin resistance in diabetic rats and therefore, open a new window of research on the combinatorial therapy of flavonoids. (C) 2014 Elsevier Ltd. All rights reserved.
Ethnopharmacological relevance: Paeonol is a phenolic compound isolated mainly from Moutan cortex... more Ethnopharmacological relevance: Paeonol is a phenolic compound isolated mainly from Moutan cortex, root bark of Chinese Peony tree. Moutan cortex holds a significant value in traditional Chinese medicine for alleviating various oxidative stress-related diseases mainly atherosclerosis and myocardial infarction. The present study seeks to identify the protective mechanisms of paeonol in oxidative stress-induced premature senescence in endothelial cells. Materials and methods: HUVECs were pretreated with paeonol or DMSO control at different doses for 24 h prior to an exposure of 200 mu M of reactive oxygen species (ROS) inducer, hydrogen peroxide (H2O2). The protective effects of paeonol against H2O2-induced senescence were evaluated and the activation of Sirtuin 1 pathway by paeonol pretreatment was investigated in HUVECs. Results: Paeonol attenuated H2O2-induced cell growth arrest at GO/G1 phase, reduced the percentage of SA-beta-Gal positive cells and increased BrdU incorporation. In addition, enzymatic Sirtl activation assay indicated that paeonol significantly increased lysyl deactylase activity of Sirtl enzyme with a fold change of 2.4 +/- 0.195 (p < 0.05). Furthermore, pretreatment with paeonol significantly decreased the levels of p53, acetyl H3K14 and H4K16 protein expression upregulated by H2O2 stimulation. The changes in the histone protein levels were accompanied with an increase in Sirtl protein expression level. Conclusion: These findings suggest that paeonol protects endothelial cells against oxidative stress-induced premature senescence by modulating the expressions of Sirtl protein and its substrates. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
Background: The biological properties of thiosemicarbazone have been widely reported. The incorpo... more Background: The biological properties of thiosemicarbazone have been widely reported. The incorporation of some transition metals such as Fe, Ni and Cu to thiosemicarbazone complexes is known to enhance its biological effects. In this study, we incorporated nickel(II) ions into thiosemicarbazone with N4-substitution groups H3L (H; H3L1, CH3; H3L2, C6H5; H3L3 and C2H5; H3L4) and examined its potential anti-inflammatory activity. Methodology/Principal Findings: Four ligands (1-4) and their respective nickel-containing complexes (5-8) were synthesized and characterized. The compounds synthesized were tested for their effects on NF-kappa B nuclear translocation, pro-inflammatory cytokines secretion and NF-kappa B transactivation activity. The active compound was further evaluated on its ability to suppress carrageenan-induced acute inflammation in vivo. A potential binding target of the active compound was also predicted by molecular docking analysis. Conclusions/Significance: Among all synthesized compounds tested, we found that complex [Ni(H2L1)(PPh3)]Cl (5) (complex 5), potently inhibited I kappa B alpha degradation and NF-kappa B p65 nuclear translocation in LPS-stimulated RAW264.7 cells as well as TNF alpha-stimulated HeLa S3 cells. In addition, complex 5 significantly down-regulated LPS- or TNF alpha-induced transcription of NF-kappa B target genes, including genes that encode the pro-inflammatory cytokines TNF alpha, IFN beta and IL6. Luciferase reporter assays confirmed that complex 5 inhibited the transactivation activity of NF-kappa B. Furthermore, the anti-inflammatory effect of complex 5 was also supported by its suppressive effect on carrageenan-induced paw edema formation in wild type C57BL/6 mice. Interestingly, molecular docking study showed that complex 5 potentially interact with the active site of IKK beta. Taken together, we suggest complex 5 as a novel NF-kappa B inhibitor with potent anti-inflammatory effects.
Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L... more Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L1–H3L4) have been synthesized and characterized with the aim of evaluating the effect of N4 substitution in the thiosemicarbazone moiety on their coordination behavior and biological activities. Two series of nickel(II) complexes with the general formulae [Ni(H3L)(H2L)]ClO4 and [Ni2(HL)2] were characterized by analytical and spectral techniques. The molecular structure of one of the complexes, namely, [Ni(H3L4)(H2L4)]ClO4 was established by single crystal X-ray diffraction studies. The crystal structure of this complex revealed that two H3L4 ligands are coordinated to nickel(II) in different modes; one as a neutral tridentate ONS ligand and the other is as a monoanionic tridentate (ONS−) ligand. The antimicrobial activities of the compounds were tested against 25 bacterial strains via the disc diffusion method, and their minimum inhibitory concentration (MIC) and minimum microbicidal concentration were evaluated using microdilution methods. With a few exceptions, most of the compounds exhibited low-to-moderate inhibitory activities against the tested bacterial strains. However, the complexes [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) indicated higher inhibitory activity against Salmonella enterica ATCC 9068 (MIC values 15.7 and <15.7 μg/ml, respectively), compared with gentamicin as the positive control (MIC 25 μg/ml). Complex (7) also inhibited Streptococcus pneumoniae more efficiently (MIC 31.2 μg/ml), compared with gentamicin (MIC > 50 μg/ml). The toxicities of the compounds were tested on brine shrimp (Artemia salina), where no meaningful toxicity level was noted for both the free ligands and the complexes. The cytotoxicities of the compounds on cell viability were determined on MCF7, PC3, A375, and H413 cancer cells in terms of IC50; complexes [Ni(H3L3)(H2L3)]ClO4 (3), [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) exhibited significant cytotoxicity on the tested cell lines.
Evidence-Based Complementary and Alternative Medicine, Jan 2013
Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coron... more Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coronary artery disease, heart failure, and peripheral vascular disease. The increase in oxidative stress has been associated with the pathogenesis of hypertension. Increase of blood pressure is due to an imbalance between antioxidants defence mechanisms and free radical productions. Excessive production of reactive oxygen species reduces nitric oxide bioavailability leading to an endothelial dysfunction and a subsequent increase in total peripheral resistance. Hypertension can cause few symptoms until it reaches the advanced stage and poses serious health problems with lifelong consequences. Hypertensive patients are required to take drugs for life to control the hypertension and prevent complications. Some of these drugs are expensive and may have adverse reactions. Hence, it is timely to examine scientifically, complimentary therapies that are more effective and with minimal undesirable effects. Nigella sativa (NS) and its active constituents have been documented to exhibit antioxidant, hypotensive, calcium channel blockade and diuretic properties which may contribute to reduce blood pressure. This suggests a potential role of NS in the management of hypertension, and thus more studies should be conducted to evaluate its effectiveness.
Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Enveno... more Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Envenoming by these snakes is often characterized by neurotoxicity and, without treatment, causes considerable morbidity and mortality. In this study, the in vitro neurotoxicity of each species, and the effectiveness of two monovalent antivenoms and a polyvalent antivenom, against the neurotoxic effects of the venoms, were examined in a skeletal muscle preparation. Both venoms caused concentration-dependent inhibition of indirect twitches, and attenuated responses to exogenous nicotinic receptor agonists, in the chick biventer preparation, with B. candidus venom being more potent than B. fasciatus venom. SDS-PAGE and western blot analysis indicated different profiles between the venoms. Despite these differences, most proteins bands were recognized by all three antivenoms. Antivenom, added prior to the venoms, attenuated the neurotoxic effect of the venoms. Interestingly, the respective monovalent antivenoms did not neutralize the effects of the venom from the other Bungarus species indicating a relative absence of cross-neutralization. Addition of a high concentration of polyvalent antivenom, at the t90 time point after addition of venom, partially reversed the neurotoxicity of B. fasciatus venom but not B. candidus venom. The monovalent antivenoms had no significant effect when added at the t90 time point. This study showed that B. candidus and B. fasciatus venoms display marked in vitro neurotoxicity in the chick biventer preparation and administration of antivenoms at high dose is necessary to prevent or reverse neurotoxicity
Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus... more Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus results in neurotoxicity due to the presence of presynaptic and postsynaptic neurotoxins. Antivenom, either monovalent or polyvalent, is the treatment of choice in systemically envenomed patients. In this study, we have isolated a postsynaptic neurotoxin which we named α-elapitoxin-Bf1b. This toxin has an approximate molecular weight of 6.9 kDa, with LCMS/MS data showing that it is highly homologous with Neurotoxin 3FTx-RI, a toxin identified in the Bungarus fasciatus venom gland transcriptome. α-Elapitoxin-Bf1b also shared similarity with short-chain neurotoxins from Laticauda colubrina and Pseudechis australis. α-Elapitoxin-Bf1b produced concentration- and time-dependent neurotoxicity in the indirectly-stimulated chick biventer cervicis muscle preparation, an effect partially reversible by repetitive washing of the preparation. The pA2 value for α-elapitoxin-Bf1b of 9.17 ± 0.64, determined by examining the effects of the toxin on cumulative carbacol concentration-response curves, indicated that the toxin is more potent than tubocurarine and α-bungarotoxin. Pre-incubation of Bungarus fasciatus monovalent and neuro polyvalent antivenom failed to prevent the neurotoxic effects of α-elapitoxin-Bf1b in the chick biventer cervicis muscle preparation. In conclusion, the isolation of a postsynaptic neurotoxin that cannot be neutralized by either monovalent and polyvalent antivenoms may indicate the presence of isoforms of postsynaptic neurotoxins in Malaysian B. fasciatus venom.
BMC Complementary and Alternative Medicine, Jul 10, 2013
Background: Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica;... more Background: Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica; black cumin) is one of the ingredients of an Ayurvedic preparation, called “Kayakalp”, commonly applied to treat skin disorders in India and Southeast Asia. Despite its well known anti-inflammatory property on skin diseases, the anti-cancer effect of C. anthelminticum seeds on skin cancer is less documented. The present study aims to investigate the anti-cancer effect of Centratherum anthelminticum (L.) seeds chloroform fraction (CACF) on human melanoma cells and to elucidate the molecular mechanism involved.
Methods: A chloroform fraction was extracted from C. anthelminticum (CACF). Bioactive compounds of the CACF were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human melanoma cell line A375 was treated with CACF in vitro. Effects of CACF on growth inhibition, morphology, stress and survival of the cell were examined with MTT, high content screening (HSC) array scan and flow cytometry analyses. Involvement of intrinsic or extrinsic pathways in the CACF-induced A375 cell death mechanism was examined using a caspase luminescence assay. The results were further verified with different caspase inhibitors. In addition, Western blot analysis was performed to elucidate the changes in apoptosis-associated molecules. Finally, the effect of CACF on the NF-κB nuclear translocation ability was assayed.
Results: The MTT assay showed that CACF dose-dependently inhibited cell growth of A375, while exerted less cytotoxic effect on normal primary epithelial melanocytes. We demonstrated that CACF induced cell growth inhibition through apoptosis, as evidenced by cell shrinkage, increased annexin V staining and formation of membrane blebs. CACF treatment also resulted in higher reactive oxygen species (ROS) production and lower Bcl-2 expression, leading to decrease mitochondrial membrane potential (MMP). Disruption of the MMP facilitated the release of mitochondrial cytochrome c, which activates caspase-9 and downstream caspase-3/7, resulting in DNA fragmentation and up-regulation of p53 in melanoma cells. Moreover, CACF prevented TNF-α-induced NF-κB nuclear translocation, which further committed A375 cells toward apoptosis.
Conclusions: Together, our findings suggest CACF as a potential therapeutic agent against human melanoma malignancy.
The therapeutic potential of plants varies according to their parts. The present study was aimed ... more The therapeutic potential of plants varies according to their parts. The present study was aimed to ascertain the antioxidant and antidiabetic potential of crude fractions obtained from different parts of 6 medicinal plants, Centratherum anthelminticum, Cissus quadrangularis, Terminalia bellerica, Terminalia chebula, Terminalia arjuna and Woodfordia fruticosa. Total phenolic (TPC), total flavonoid (TFC) and total tannin content (TTC) were determined. In vitro antioxidant abilities were showed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing/antioxidant Power (FRAP) assays. Furthermore, anti-diabetic potential was determined using in vitro protein tyrosine phosphatase-1B (PTP-1B) inhibition assay and blood glucose lowering effects were evaluated on streptozotocin (STZ)-induced diabetic rats. The result of our study showed that T. chebula fruit exhibited highest amount of TPC (910.43±37.45 mg GAE g-1) and TTC (65.6±6.83 mg Catechin g-1), respectively. Whereas C. anthelminticum seeds contained highest amount of TFC (98.2±27.6 mg Quercetin g-1). The free radical scavenging capacity of T. chebula fruits was the highest among the six plants as determined by DPPH (3.6±0.13 μg mL-1) and FRAP (109.6±2.5 μg mL-1) assays. C. anthelminticum seeds (9.16±0.62 μM mL-1) demonstrated highest oxygen radical absorbance capacity in ORAC test. In addition, C. anthelminticum seeds (38±5.8 μM) showed highest PTP-1B inhibitory effects and maximum blood glucose lowering effects in STZ-induced diabetic rats. Altogether, our findings suggest that T. chebula fruit is potent in ameliorating oxidative damage whereas, C. anthelminticum seeds possess highest antidiabetic and antioxidant properties.
Background and Purpose
Boldine is a potent natural antioxidant present in the leaves and bark of... more Background and Purpose
Boldine is a potent natural antioxidant present in the leaves and bark of Chilean boldo tree. The present study investigated the endothelial protective effect of boldine in arteries of db/db diabetic mice and in cultured mouse aortic endothelial cells receiving high glucose treatment.
Experimental Approach
Vascular reactivity was studied in mouse aortas. Reactive oxygen species (ROS) production, angiotensin type 1 receptor (AT1R) localization and protein expression of oxidative stress markers in the vascular wall were evaluated by DHE fluorescence, lucigenin enhanced-chemiluminescence, immunohistochemistry and Western blot, respectively. The effect of boldine was also examined in high glucose (30 mmol L-1)-treated primary mouse aortic endothelial cells.
Key Results
Both oral treatment (20 mg kg-1day-1, 7 days) and incubation in vitro with boldine (1 μmol L-1, 12 hours) enhanced endothelium-dependent aortic relaxations of db/db mice. Boldine reversed the impaired relaxations induced by high glucose or angiotensin II (Ang II) in non-diabetic mouse aortas while it reduced the ROS overproduction and increased the phosphorylation of eNOS in db/db mouse aortas. The elevated expression of oxidative stress markers such bone morphogenic protein 4 (BMP4), nitrotyrosine and AT1R was reduced in boldine-treated db/db mouse aortas. The Ang II-stimulated BMP4 expression was also inhibited by treatment with boldine, tempol, noggin and losartan. Boldine inhibited high glucose-stimulated ROS production and restored the lost phosphorylation of eNOS in mouse aortic endothelial cells.
Conclusion and Implications
Boldine is effective to reduce oxidative stress and thus to improve endothelium-dependent relaxations in aortas of diabetic mice largely through inhibiting ROS over-production associated with Ang II-mediated BMP4-dependent mechanisms.
Alpha ()-tomatine, a major saponin found in tomato has been shown to inhibit the growth ofandrog... more Alpha ()-tomatine, a major saponin found in tomato has been shown to inhibit the growth ofandrogen-independent prostate cancer PC-3 cells. The effects of -tomatine in combination with thechemotherapeutic agent paclitaxel against PC-3 cells were investigated in the present study. Combinedtreatment with a sub-toxic dose of -tomatine and paclitaxel significantly decreased cell viability withconcomitant increase in the percentage of apoptotic PC-3 cells. The combined treatment, however, hadno cytotoxic effect on the non-neoplastic prostate RWPE-1 cells. Apoptosis of PC-3 cells was accompaniedby the inhibition of PI3K/Akt pro-survival signaling, an increase in the expression of the pro-apoptoticprotein BAD but a decrease in the expressions of anti-apoptotic proteins, Bcl-2 and Bcl-xL. Results froma mouse xenograft model showed the combined treatment completely suppressed subcutaneous tumorgrowth without significant side effects. Consistent with its in vitro anti-cancer effects, tumor materi-als from mice showed increased apoptosis of tumor cells with reduced protein expression of activatedPI3K/Akt. These results suggest that the synergistic anti-cancer effects of paclitaxel and -tomatine maybe beneficial for refractory prostate cancer treatment.
Evidence-Based Complementary and Alternative Medicine, 2012
This study was set to investigate antiproliferative potential of dentatin (a natural coumarin iso... more This study was set to investigate antiproliferative potential of dentatin (a natural coumarin isolated from Clausena excavata Burm. F) against prostate cancer and to delineate the underlying mechanism of action. Treatment with dentatin dose-dependently inhibited cell growth of PC-3 and LNCaP prostate cancer cell lines, whereas it showed less cytotoxic effects on normal prostate epithelial cell line (RWPE-1). The inhibitory effect of dentatin on prostate cancer cell growth was due to induction of apoptosis as evidenced by Annexin V staining and cell shrinkage. We found that dentatin-mediated accumulation of reactive oxygen species (ROS) and downregulated expression levels of antiapoptotic molecules (Bcl-2, Bcl-xL, and Survivin), leading to disruption of mitochondrial membrane potential (MMP), cell membrane permeability, and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-9, -3/7 activities, and subsequent DNA fragmentation. In addition, we found that dentatin inhibited TNF-α-induced nuclear translocation of p65, suggesting dentatin as a potential NF-κB inhibitor. Thus, we suggest that dentatin may have therapeutic value in prostate cancer treatment worthy of further development.
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Papers by Mohd Rais Mustafa
Methods: A chloroform fraction was extracted from C. anthelminticum (CACF). Bioactive compounds of the CACF were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human melanoma cell line A375 was treated with CACF in vitro. Effects of CACF on growth inhibition, morphology, stress and survival of the cell were examined with MTT, high content screening (HSC) array scan and flow cytometry analyses. Involvement of intrinsic or extrinsic pathways in the CACF-induced A375 cell death mechanism was examined using a caspase luminescence assay. The results were further verified with different caspase inhibitors. In addition, Western blot analysis was performed to elucidate the changes in apoptosis-associated molecules. Finally, the effect of CACF on the NF-κB nuclear translocation ability was assayed.
Results: The MTT assay showed that CACF dose-dependently inhibited cell growth of A375, while exerted less cytotoxic effect on normal primary epithelial melanocytes. We demonstrated that CACF induced cell growth inhibition through apoptosis, as evidenced by cell shrinkage, increased annexin V staining and formation of membrane blebs. CACF treatment also resulted in higher reactive oxygen species (ROS) production and lower Bcl-2 expression, leading to decrease mitochondrial membrane potential (MMP). Disruption of the MMP facilitated the release of mitochondrial cytochrome c, which activates caspase-9 and downstream caspase-3/7, resulting in DNA fragmentation and up-regulation of p53 in melanoma cells. Moreover, CACF prevented TNF-α-induced NF-κB nuclear translocation, which further committed A375 cells toward apoptosis.
Conclusions: Together, our findings suggest CACF as a potential therapeutic agent against human melanoma malignancy.
Boldine is a potent natural antioxidant present in the leaves and bark of Chilean boldo tree. The present study investigated the endothelial protective effect of boldine in arteries of db/db diabetic mice and in cultured mouse aortic endothelial cells receiving high glucose treatment.
Experimental Approach
Vascular reactivity was studied in mouse aortas. Reactive oxygen species (ROS) production, angiotensin type 1 receptor (AT1R) localization and protein expression of oxidative stress markers in the vascular wall were evaluated by DHE fluorescence, lucigenin enhanced-chemiluminescence, immunohistochemistry and Western blot, respectively. The effect of boldine was also examined in high glucose (30 mmol L-1)-treated primary mouse aortic endothelial cells.
Key Results
Both oral treatment (20 mg kg-1day-1, 7 days) and incubation in vitro with boldine (1 μmol L-1, 12 hours) enhanced endothelium-dependent aortic relaxations of db/db mice. Boldine reversed the impaired relaxations induced by high glucose or angiotensin II (Ang II) in non-diabetic mouse aortas while it reduced the ROS overproduction and increased the phosphorylation of eNOS in db/db mouse aortas. The elevated expression of oxidative stress markers such bone morphogenic protein 4 (BMP4), nitrotyrosine and AT1R was reduced in boldine-treated db/db mouse aortas. The Ang II-stimulated BMP4 expression was also inhibited by treatment with boldine, tempol, noggin and losartan. Boldine inhibited high glucose-stimulated ROS production and restored the lost phosphorylation of eNOS in mouse aortic endothelial cells.
Conclusion and Implications
Boldine is effective to reduce oxidative stress and thus to improve endothelium-dependent relaxations in aortas of diabetic mice largely through inhibiting ROS over-production associated with Ang II-mediated BMP4-dependent mechanisms.
Methods: A chloroform fraction was extracted from C. anthelminticum (CACF). Bioactive compounds of the CACF were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human melanoma cell line A375 was treated with CACF in vitro. Effects of CACF on growth inhibition, morphology, stress and survival of the cell were examined with MTT, high content screening (HSC) array scan and flow cytometry analyses. Involvement of intrinsic or extrinsic pathways in the CACF-induced A375 cell death mechanism was examined using a caspase luminescence assay. The results were further verified with different caspase inhibitors. In addition, Western blot analysis was performed to elucidate the changes in apoptosis-associated molecules. Finally, the effect of CACF on the NF-κB nuclear translocation ability was assayed.
Results: The MTT assay showed that CACF dose-dependently inhibited cell growth of A375, while exerted less cytotoxic effect on normal primary epithelial melanocytes. We demonstrated that CACF induced cell growth inhibition through apoptosis, as evidenced by cell shrinkage, increased annexin V staining and formation of membrane blebs. CACF treatment also resulted in higher reactive oxygen species (ROS) production and lower Bcl-2 expression, leading to decrease mitochondrial membrane potential (MMP). Disruption of the MMP facilitated the release of mitochondrial cytochrome c, which activates caspase-9 and downstream caspase-3/7, resulting in DNA fragmentation and up-regulation of p53 in melanoma cells. Moreover, CACF prevented TNF-α-induced NF-κB nuclear translocation, which further committed A375 cells toward apoptosis.
Conclusions: Together, our findings suggest CACF as a potential therapeutic agent against human melanoma malignancy.
Boldine is a potent natural antioxidant present in the leaves and bark of Chilean boldo tree. The present study investigated the endothelial protective effect of boldine in arteries of db/db diabetic mice and in cultured mouse aortic endothelial cells receiving high glucose treatment.
Experimental Approach
Vascular reactivity was studied in mouse aortas. Reactive oxygen species (ROS) production, angiotensin type 1 receptor (AT1R) localization and protein expression of oxidative stress markers in the vascular wall were evaluated by DHE fluorescence, lucigenin enhanced-chemiluminescence, immunohistochemistry and Western blot, respectively. The effect of boldine was also examined in high glucose (30 mmol L-1)-treated primary mouse aortic endothelial cells.
Key Results
Both oral treatment (20 mg kg-1day-1, 7 days) and incubation in vitro with boldine (1 μmol L-1, 12 hours) enhanced endothelium-dependent aortic relaxations of db/db mice. Boldine reversed the impaired relaxations induced by high glucose or angiotensin II (Ang II) in non-diabetic mouse aortas while it reduced the ROS overproduction and increased the phosphorylation of eNOS in db/db mouse aortas. The elevated expression of oxidative stress markers such bone morphogenic protein 4 (BMP4), nitrotyrosine and AT1R was reduced in boldine-treated db/db mouse aortas. The Ang II-stimulated BMP4 expression was also inhibited by treatment with boldine, tempol, noggin and losartan. Boldine inhibited high glucose-stimulated ROS production and restored the lost phosphorylation of eNOS in mouse aortic endothelial cells.
Conclusion and Implications
Boldine is effective to reduce oxidative stress and thus to improve endothelium-dependent relaxations in aortas of diabetic mice largely through inhibiting ROS over-production associated with Ang II-mediated BMP4-dependent mechanisms.