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Diabetes mellitus is a life-threatening non-communicable disease that affects all age groups. Despite the increased attention it has received in recent years, the number of diabetic patients has grown exponentially. These increased cases... more
Diabetes mellitus is a life-threatening non-communicable disease that affects all age groups. Despite the increased attention it has received in recent years, the number of diabetic patients has grown exponentially. These increased cases are attributed to essential enzymes involved in blood glucose regulation. In this study, we attempt to reveal the aldose reductase inhibitory potential of xanthones isolated from African medicinal plants. Ensemble docking, molecular dynamics simulation, density functional theory (DFT), and ADMET methods were employed to identify drug candidates as aldose reductase inhibitors. The ensemble docking results identified mangostenone B, bangangxanthone A, smeathxanthone B, mangostenone A, and allanxanthone B as potent inhibitors against the aldose reductase enzyme. Molecular dynamics studies showed the xanthones established better binding mode and affinities against the enzyme. Moreover, the electronic properties of the xanthones explained their good phar...
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Summary of compounds separated and identified in F. umbellata aqueous extract by UHPLC-ESI-HRMS analysis in the negative ion mode. Figure S1. Microphotographs of HE-stained sections (400×) of liver, lungs, kidneys and femur from different... more
Summary of compounds separated and identified in F. umbellata aqueous extract by UHPLC-ESI-HRMS analysis in the negative ion mode. Figure S1. Microphotographs of HE-stained sections (400×) of liver, lungs, kidneys and femur from different experimental rat groups in postmenopausal-like condition after 3 weeks of treatment. SHAM = Sham operated rats treated with vehicle as normal control; OVX = Ovariectomized rats treated with vehicle as negative control; E2V = Ovariectomized rats treated with estradiol valerate at the dose of dose 1 mg/kg BW as positive control; FU 50 and 200 = Ovariectomized rats treated with F. umbellata aqueous extract at the doses of 50 and 200 mg/kg BW, respectively; MC = Ovariectomized rats treated with 7-methoxycoumarin at the dose of 1 mg/kg BW. Vp = portal veine, H = Hepatocyte; S = sinusoids; A = alveol; Ba = Aveolar bag; TB = Trabecular bone; MB = marrow bone; Mi = microglie; Ne = Neurone; Co = Cortex. G = Glomerula; Dt = Distal tube; Pt = Proximal tube. (...
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Background Despite the considerable advances made in the treatment of cancer, it remains a global threat. Tartrazine (E102) is a synthetic dye widely used in food industries; it has recently been shown to induce oxidative stress (a well... more
Background Despite the considerable advances made in the treatment of cancer, it remains a global threat. Tartrazine (E102) is a synthetic dye widely used in food industries; it has recently been shown to induce oxidative stress (a well known risk factor of cancer) in rat tissues. The present work therefore aimed to assess the impact of a regular consumption of tartrazine on the incidence of breast cancer in rats. Methods Forty (40) Wistar rats aged 55 to 60 days were randomly assigned into 5 groups (n = 8) including two groups serving as normal controls and receiving distilled water (NOR) or tartrazine (NOR + TARZ). The three remaining groups were exposed to the carcinogen DMBA (50 mg/kg) and treated for 20 weeks with either distilled water (DMBA), tartrazine 50 mg/kg (DMBA + TARZ) or a natural dye (DMBA + COL). The parameters evaluated were the incidence, morphology and some biomarkers (CA 15–3, estradiol and α-fetoprotein) of breast cancer. The oxidative status and histomorpholog...
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Cyclic and polycyclic compounds containing moieties such as imidazole, pyrazole, isoxazole, thiazoline, oxazine, indole, benzothiazole and benzoxazole benzimidazole are prized molecules because of the various pharmaceutical properties... more
Cyclic and polycyclic compounds containing moieties such as imidazole, pyrazole, isoxazole, thiazoline, oxazine, indole, benzothiazole and benzoxazole benzimidazole are prized molecules because of the various pharmaceutical properties that they display. This led Prof. Landor and co-workers to engage in the synthesis of several of them such as alkylimidazolenes, oxazolines, thiazolines, pyrimidopyrimidines, pyridylpyrazoles, benzoxazines, quinolines, pyrimidobenzimidazoles and pyrimidobenzothiazolones. This review covers the synthesis of biologically active heterocyclic compounds by the Michael addition and the double Michael addition of various amines and diamines on allenic nitriles, acetylenic nitriles, hydroxyacetylenic nitriles, acetylenic acids and acetylenic aldehydes. The heterocycles were obtained in one step reaction and in most cases, did not give side products. A brief discussion on the biological activities of some heterocycles is also provided.
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The phytochemical investigation on the chemical constituents of dichloromethane-methanol (1:1) stem-bark extract ofCola lateritiaK. Schum. (Sterculiaceae) led to the isolationand characterization of five pentacyclic triterpenoids, one... more
The phytochemical investigation on the chemical constituents of dichloromethane-methanol (1:1) stem-bark extract ofCola lateritiaK. Schum. (Sterculiaceae) led to the isolationand characterization of five pentacyclic triterpenoids, one fatty acid and two phytosteroids. Thecompounds were identified as heptadecanoic acid (1), maslinic acid (2), betulinic acid (3), lupenone(4), lupeol (5), friedelin (6),b-stigmasterol (7) andß-sitosterol-3-O-ß-D-glucoside (8). Their struc-tures were determined by NMR analysis (1H,13C, DEPT-135, COSY, HMBC and HSQC), high-resolution mass spectrometry (HR-ESI-MS) and comparisons with published data in the literature.This work, to the best of our knowledge, is the first isolation and identification of these compoundsin pure forms fromCola lateritia. Also, compounds1–3are reported for the first time fromColagenus.In vitroantibacterial activity of the isolated compounds (1–8) and the crude extract wereevaluated againstBacillus subtilis,Staphylococcus epidermidis,Enterococcus faecalis,Mycobacterium smegmatis,Staphylococcus aureus,Enterobacter cloacae,Klebsiella oxytoca,Proteusvulgaris,Klebsiella pneumonia,Escherichia coli, Proteus mirabilisandKlebsiella aerogeneswithstreptomycin, nalidixic acid and ampicillin as standard antibacterial drugs. Compound2was activeagainstE. faecalis(MIC = 18.5mg/mL), and it was 6.9 and 28 times lower and active than that ofstreptomycin (MIC 128mg/mL) and nalidixic acid (MIC>512mg/mL) respectively. All the isolatedcompounds and crude extract showed significant activities against the tested bacterial strains.National Research Foundatio
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Medicinal plants are indispensable source of therapeutic agents, and have proved to be “warehouse” of lead drug candidates. Lecaniodiscus cupanioides Planch. ex Benth is a medicinal tree plant that is extensively distributed in both Asia... more
Medicinal plants are indispensable source of therapeutic agents, and have proved to be “warehouse” of lead drug candidates. Lecaniodiscus cupanioides Planch. ex Benth is a medicinal tree plant that is extensively distributed in both Asia and Africa. The species has many ethnomedicinal uses in the treatment of fever, cough, typhoid, wound, skin infection, measles, jaundice, diabetes, sexual dysfunction, cancer, bone fracture, and as galactogogues. In the recent decades, the extracts and phytochemicals of L. cupanioides have been investigated to possess antibacterial, anticancer, aphrodisiac, antifungal, cytotoxic, antidiabetic, antiprotozoal, antioxidant, antidiarrhoeal, analgesic and ameliorative properties. However, triterpenoids which have been linked to its anticancer and antifungal actions, are the only isolated active constituents identified from the species despite the results of the phytochemical screenings and reported biological activities. Moreover, the mechanisms of actio...
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Antifungal and antibacterial activities of crude extracts of 3 tropical mushrooms including Pleurotus sajor-caju, Pleurotus tuber-regium and Lentinus squarrosulus were investigated on eleven species of bacterial and three of fungal human... more
Antifungal and antibacterial activities of crude extracts of 3 tropical mushrooms including Pleurotus sajor-caju, Pleurotus tuber-regium and Lentinus squarrosulus were investigated on eleven species of bacterial and three of fungal human pathogens. For the pathogenic fungi, the Minimal Inhibitory Concentration (MIC) of carpophore extracts ranged from 0.39 mg/mL to 6.25 mg/mL for Candida albicans, 0.78 mg/mL to 6.25 mg/mL for Aspergillus fumigetus, and 1.56 mg/mL to 6.25 mg/mL for Aspergillus ochraceus. For bacteria, the MIC values ranged from 6.25 mg/mL to 12.5 mg/mL on most Gram positive strains including Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and Mycobacterium smegmatis. This MIC value was the same (12.5 mg/mL) for the 3 crude extracts tested on Staphylococcus epidermidis for the Gram positive strains. Gram negative bacteria were generally less sensitive to crude extracts with higher MIC values ranging from 6.25 mg/mL to 12.5 mg/mL for Escherichia coli and...
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Abstract A series of 2-substituted vinylidene-1,1-bisphosphonate esters and their acids were synthesized and tested in vitro for activity against Plasmodium falciparum and Trypanosoma brucei. For each compound, % parasite viability in... more
Abstract A series of 2-substituted vinylidene-1,1-bisphosphonate esters and their acids were synthesized and tested in vitro for activity against Plasmodium falciparum and Trypanosoma brucei. For each compound, % parasite viability in treated wells was calculated relative to untreated controls for both P. falciparum and T. brucei. Fifty percentage inhibitory concentration (IC50) was also determined for the compounds. Chloroquine and pentamidine were used as positive control drug standards for activity against P. falciparum and T. brucei, respectively. The esters had better antiparasitic activity compared to their corresponding acids. Some of the compounds reduced % parasite viability to as low as 24.3% for P. falciparum and down to 0.602% for T. brucei. Tetraethyl-2-(o-tolyl)-ethene-1,1-bisphosphonate (3b) recorded the best IC50 against T. brucei which was 0.0345 µmol/mL. GRAPHICAL ABSTRACT
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Erythrina abyssinica is one of over 100 species that belongs to the genus Erythrina and that is widely used in traditional medicine. It is used in the treatment of various ailments, one of which is the management and treatment of type 2... more
Erythrina abyssinica is one of over 100 species that belongs to the genus Erythrina and that is widely used in traditional medicine. It is used in the treatment of various ailments, one of which is the management and treatment of type 2 diabetes. The increasing prevalence of diabetes worldwide and especially in Africa has become a serious public health concern. The need to develop novel therapies with mechanisms of action that are mimetic of the insulin-signaling pathway is necessary in face of the high rates of secondary failure and side effects of existing therapies. One of these potential targets that has emerged is protein tyrosine phosphate 1B, which recently was identified as a major negative regulator in the insulin-signaling pathway. Cohort studies showed reduced risk of type 2 diabetes associated with high intakes of dietary flavonoids. In this study, we described the isolation and protein tyrosine phosphate inhibitory activity of various flavonoids from Erythrina abyssinica. Sixty-eight flavonoids were identified and 43 were found to inhibit protein tyrosine phosphate 1B in a dose dependent manner, with inhibition values ranging from 4.2 to 40 μM.
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A complementary application of three analytical techniques, viz. multidimensional nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), and single-crystal X-ray diffractometry was required to identify and refine two... more
A complementary application of three analytical techniques, viz. multidimensional nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), and single-crystal X-ray diffractometry was required to identify and refine two natural products isolated from Millettia versicolor and solvent of crystallization. The two compounds, namely 3-(2H-1,3-benzodioxol-5-yl)-6-methoxy-8,8-dimethyl-4H,8H-pyrano[2,3-h]chromen-4-one, or durmillone, (I), and (2E)-1-(4-{[(2E)-3,7-dimethylocta-2,6-dien-1-yl]oxy}-2-hydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one, (II), could not be separated by routine column chromatography and cocrystallized in a 2:1 ratio with 0.13 molecules of ethanol solvent. Compound (II) and ethanol could not be initially identified by single-crystal X-ray analysis due to complex disorder in the aliphatic chain region of (II). Mass spectrometry ensured that (II) represented only one species disordered over several positions in the solid state, rather than several species ...
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Despite the significant developments occurring in the treatment of cancer, it still remains the second deadly disease, responsible for 8.2 million deaths every year. Various natural substances have been studied for active molecules of... more
Despite the significant developments occurring in the treatment of cancer, it still remains the second deadly disease, responsible for 8.2 million deaths every year. Various natural substances have been studied for active molecules of tumor suppression in the past and the tropical flora, by its diversity, continues to provide new antitumor drugs. Acacia seyal is a plant used in Cameroonian traditional system to treat cancer. It exhibited cytotoxic effects towards human breast adenocarcinoma cells. The present work was therefore designed to elucidate the underlying mechanisms by which A. seyal extract induced its cytotoxic effect. The cell death mechanism (apoptosis or necrosis) and cell cycle analyses were assessed using flow cytometry. The levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), caspases activities as well as Bcl-2 and Bcl-xL protein contents were assessed in MDA-MB-231 cells. Afterwards, cell migration/invasion was also assessed. The A. sey...
Research Interests: Chemistry, Complementary and Alternative Medicine, Plant Biology, Flow Cytometry, Biology, and 14 moreCell Cycle, Ethnopharmacology, Apoptosis, Medicine, Caspases, Humans, Reactive Oxygen Species, Ethanol, Programmed cell death, Acacia, Plant extracts, Solvents, Breast Neoplasms, and Pharmacology and pharmaceutical sciences
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Crateva adansonii DC is a plant traditionally used in Cameroon to treat constipation, asthma, snakebites, postmenopausal complaints and cancers. The anticancer potential of the dichloromethane/methanol extract of C. adansonii stem barks... more
Crateva adansonii DC is a plant traditionally used in Cameroon to treat constipation, asthma, snakebites, postmenopausal complaints and cancers. The anticancer potential of the dichloromethane/methanol extract of C. adansonii stem barks was investigated using human breast cancer cell and 7,12 dimethylbenz(a)anththracene (DMBA)-induced mammary tumorigenesis model in rats. The cytotoxicity of C. adansonii extract was assessed in vitro towards breast carcinoma (MCF-7 and MDA-MB-231) and non-tumoral cell lines (NIH/3T3 and HUVEC) by Alamar Blue assay. Furthermore, in vivo studies were performed on female Wistar rats treated either with C. adansonii extract at a dose of 75 or 300mg/kg body weight or with tamoxifen (3.3mg/kg body weight), starting 1 week prior DMBA treatment and lasted 12 weeks. The investigation focused on tumour burden, tumor DNA fingerprint, morphological, histological, hematological, and biochemical parameters. CC50 values for the in vitro assays were 289µg/mL against...
Research Interests: Pharmacology, Chemistry, Ethnobotany, Complementary and Alternative Medicine, Africa, and 15 moreEthnopharmacology, Oxidative Stress, DNA damage, Medicine, Humans, Mice, Female, Animals, In Vivo, Lethal Dose, DMBA, Molecular Structure, Capparaceae, Breast Neoplasms, and Human Umbilical Vein Endothelial Cells
The 100 K structures of two salts, namely 2-amino-1H-benzimidazolium 3-phenylpropynoate, C7H8N3+·C9H5O2−, (I), and 2-amino-1H-benzimidazolium oct-2-ynoate, C7H8N3+·C8H11O2−, (II), both have monoclinic symmetry (space groupP21/c) and... more
The 100 K structures of two salts, namely 2-amino-1H-benzimidazolium 3-phenylpropynoate, C7H8N3+·C9H5O2−, (I), and 2-amino-1H-benzimidazolium oct-2-ynoate, C7H8N3+·C8H11O2−, (II), both have monoclinic symmetry (space groupP21/c) and display N—H...O hydrogen bonding. Both structures show packing with corrugated sheets of hydrogen-bonded molecules lying parallel to the [001] direction. Two hydrogen-bonded ring motifs can be identified and described with graph setsR22(8) andR44(16), respectively, in both (I) and (II). Computational chemistry calculations performed on both compounds show that the hydrogen-bonded ion pairs are more energetically favourable in the crystal structure than their hydrogen–bonded neutral molecule counterparts.
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Two different procedures were compared for the preparation of cellulose nanofibres from flax and microcrystalline cellulose (MCC). The first involved a combination of high energy ball milling, acid hydrolysis and ultrasound, whilst the... more
Two different procedures were compared for the preparation of cellulose nanofibres from flax and microcrystalline cellulose (MCC). The first involved a combination of high energy ball milling, acid hydrolysis and ultrasound, whilst the second employed a high pressure homogenisation technique, with and without various pre-treatments of the fibrous feedstock. The geometry and microstructure of the cellulose nanofibres were observed by SEM and TEM and their particle size measured using image analysis and dynamic light scattering. Aspect ratios of nanofibres made by microfluidisation were orders of magnitude greater than those achieved by acid hydrolysis. FTIR, XRD and TGA were used to characterise changes to chemical functionality, cellulose crystallinity and thermal stability resulting from the approaches used for preparing the cellulose nanofibres. Hydrolysis using sulphuric acid gave rise to esterification of the cellulose nanofibres, a decrease in crystallinity with MCC, but an increase with flax, together with an overall reduction in thermal stability. Increased shear history of flax subjected to multiple passes through the microfluidiser, raised both cellulose nanofibril crystallinity and thermal stability, the latter being strongly influenced by acid, alkaline and, most markedly, silane pretreatment.
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Additional file 1: Fig. S1. FTIR spectrum of Schiff base Compound 3.a. Fig. S2. FTIR spectrum of Schiff base Compound 3.b. Fig. S3. FTIR spectrum of Schiff base Compound 3.c. Fig. S4. FTIR spectrum of Schiff base Compound 3.d. Fig. S5.... more
Additional file 1: Fig. S1. FTIR spectrum of Schiff base Compound 3.a. Fig. S2. FTIR spectrum of Schiff base Compound 3.b. Fig. S3. FTIR spectrum of Schiff base Compound 3.c. Fig. S4. FTIR spectrum of Schiff base Compound 3.d. Fig. S5. FTIR spectrum of Schiff base Compound 3.e. Fig. S6. FTIR spectrum of Schiff base Compound 3.f. Fig. S7. Normalized UV-vis absorption spectrum of Schiff base 3.a. Fig. S8. Normalized UV-vis absorption spectrum of Schiff base 3.b. Fig. S9. Normalized UV-vis absorption spectrum of Schiff base 3.c. Fig. S10. Normalized UV-vis absorption spectrum of Schiff base 3.d. Fig. S11. Normalized UV-vis absorption spectrum of Schiff base 3.e. Fig. S12. Normalized UV-vis absorption spectrum of Schiff base 3.f. Fig. S13. 1H NMR spectrum of Schiff base Compound 3.a. Fig. S14. 13C NMR spectrum of Schiff base Compound 3.a. Fig. S15. 1H NMR spectrum of Schiff base Compound 3.b. Fig. S16. 13C NMR spectrum of Schiff base Compound 3.b. Fig. S17. 1H NMR spectrum of Schiff bas...
Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the... more
Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively....
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Various diseases associated with oxidative stress have necessitated the need to investigate plants for antioxidant agents. This study aims to investigate the antioxidant potential of the extract and fractions of C. pulcherrima and... more
Various diseases associated with oxidative stress have necessitated the need to investigate plants for antioxidant agents. This study aims to investigate the antioxidant potential of the extract and fractions of C. pulcherrima and estimate the quantum chemical properties of polyphenolic compounds isolated from its most active antioxidant fraction. Methanolic extract and partition fractions of the pods of the plant were assayed for their antioxidant activity using four models: 1,1-diphenyl-2-dipicrylhydrazyl radical scavenging, ferric reducing antioxidant power, total antioxidant capacity and hydroxyl radical scavenging activity. Total phenolic and flavonoid contents of the extract and fractions were also investigated. Furthermore, the quantum chemical properties of two polyphenolic compounds were calculated to predict the antioxidant potential. The extract exhibited good antioxidant activity with IC50 = 45.63 µg/ml comparable to ascorbic acid of IC50 = 37.94 µg/ml, high reducing pow...
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Shrimps, including Pestarella tyrrhena , are highly susceptible to deterioration whereas odour production has been indicated as one of the factors determining the perishability and bait potential of shrimps. In this study, volatile... more
Shrimps, including Pestarella tyrrhena , are highly susceptible to deterioration whereas odour production has been indicated as one of the factors determining the perishability and bait potential of shrimps. In this study, volatile components generated from fresh egg, adult female and male of P. tyrrhena were assessed using two-dimensional gas chromatography coupled to time-of-flight mass spectrometry to understand their contribution to odour production. Alkenes, alkynes, alcohols, aldehydes, a ketone, acids, esters, an amine, sulphur-containing and miscellaneous compounds were detected. Meanwhile, adult females and males of P. tyrrhena had a higher number of these volatile compounds. The detection of 2-methyl propan-1-ol with pungent odour only in the male sample of P. tyrhenna suggests that the male of this shrimp species may not completely attract fishes to hooks. Overall, the study established shrimp developmental stage and sex as additional factors influencing the production of...
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A series of aryl and alkyl pyrimido[1,2-a]benzimidazole derivatives was synthesized according to published procedures. All synthesized compounds were fully characterized by spectral and microanalytical data. The compounds (1a, 1b, 2a, 2b... more
A series of aryl and alkyl pyrimido[1,2-a]benzimidazole derivatives was synthesized according to published procedures. All synthesized compounds were fully characterized by spectral and microanalytical data. The compounds (1a, 1b, 2a, 2b and 2c) were screened for their antimicrobial activity against Gram-positive and Gram-negative bacteria and only compound 2b showed moderate to good activity with respect to minimum inhibitory concentrations and by disc diffusion assays. Apart from Proteus vulgaris, which showed resistance against all the compounds, Enterobacter cloacae, Escherichia coli and Proteus mirabilis were the most susceptible Gram-negative bacteria with MIC of 1 μg/ml, 4 μg/ml and 2 μg/ml respectively. On the other hand, Staphylococcus epidermis, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis and Mycobacterium smegmatis all showed susceptibility with MIC’s of 15.62 μg/ml, 31.25 μg/ml, 62.5 μg/ml, 3.9 μg/ml, 62.5 μg/ml and 7.81 μg/ml respect...
Medicinal plants contain bioactive compounds that have the potentials to cure many human ailments without unnecessary side effects like most of the chemotherapeutic drugs used today. Therefore, the need for phytochemicals in medicinal... more
Medicinal plants contain bioactive compounds that have the potentials to cure many human ailments without unnecessary side effects like most of the chemotherapeutic drugs used today. Therefore, the need for phytochemicals in medicinal plants for potentials application in the treatments of these human ailments as alternatives.1 Drug resistance parasite has rendered most of the drugs used in treating many human diseases ineffective.2 Therefore, the urgent need and continuous search for new drugs from natural sources because most of the drugs used are either derived from plant or endproduct of the natural source.2-4 Boswellia dalzielii from Burseraceae family, it is known as frankincense tree. The plant which is called “Hannu” in the Hausa language is a plant that is used medically by the West Africa people especially Northern part of Nigeria, Ivory Coast and Cameroon where the plant is found in abundance.5-8 The decoction of the plants part is used in treating many ailments such as tr...
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Mn(II), Co(II) and Ni(II) complexes of hexamethylen etetramine (HMTA) have been synthesized in water and ethanol. All the complexes are hydroge n-bonded, except the cobalt complex [Co(HMTA)2(NO3)2(H2O)2] which is polymeric. These... more
Mn(II), Co(II) and Ni(II) complexes of hexamethylen etetramine (HMTA) have been synthesized in water and ethanol. All the complexes are hydroge n-bonded, except the cobalt complex [Co(HMTA)2(NO3)2(H2O)2] which is polymeric. These complexes have been cha ra terized by elemental analyses, infrared and visible spectrosco py as well as conductivity. The results suggest octahedral coordination in which the central metal ion is bonded to aqua ligands and the HMTA is bonded to the aqua ligands through hydrogen-bond ing. Antibacterial activities of the ligand and its complexes show that the ligand is active ag ainst 1 out of 10 tested bacteria species; the cobalt complexes [Co(H 2O)6](HMTA)2(NO3)2. 4H2O, and [Co(HMTA)2(NO3)2(H2O)2] are the most active, showing activity against all the micro organisms. These cobalt complexes also show greater activity than the reference antibiotic gent amycin against Klebsiella pneumonia.
Vitex doniana Sweet is an African medicinal species that is prescribed as an aqueous bark extract to be applied topically or orally to achieve anti-infective outcomes. In select regions it is also taken orally as an antimalarial agent.... more
Vitex doniana Sweet is an African medicinal species that is prescribed as an aqueous bark extract to be applied topically or orally to achieve anti-infective outcomes. In select regions it is also taken orally as an antimalarial agent. The aim of the current study was to explore the biological properties of V. doniana and isolated compounds in the context of pathogenic bacteria and the protozoan parasite Plasmodium falciparum. Three compounds were isolated and assigned by nuclear magnetic resonance spectroscopy as ecdysteroids: (1) 20-hydroxyecdysone, (2) turkesterone, and (3) ajugasterone C. Interestingly, two of these compounds had not previously been identified in V. doniana, providing evidence of chemical variability between regions. The bark extract and three ecdysteroids were screened for activity against a panel of pathogenic bacteria associated with skin, stomach and urinary tract infections, and the protozoan parasite P. falciparum. The crude extract of the bark inhibited a...
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For years, the focus on the lipid–atherosclerosis relationship has limited the consideration of the possible contribution of other key dietary components, such as amino acids (AAs), to cardiovascular disease (CVD) development.... more
For years, the focus on the lipid–atherosclerosis relationship has limited the consideration of the possible contribution of other key dietary components, such as amino acids (AAs), to cardiovascular disease (CVD) development. Notwithstanding, the potential of plant-based diets, some AAs and phytochemicals to reduce CVDs’ risk has been reported. Therefore, in this study, the phytochemical and AA profiles of different medicinal plants’ (MPs) parts used for CVDs’ treatment in sub-Saharan Africa were investigated. Fourier-transform infrared analysis confirmed the presence of hydroxyl, amino and other bioactive compounds’ functional groups in the samples. In most of them, glutamic and aspartic acids were the most abundant AAs, while lysine was the most limiting. P. biglobosa leaf, had the richest total branched-chain AAs (BCAAs) level, followed by A. cepa bulb. However, A. cepa bulb had the highest total AAs content and an encouraging nutraceutical use for adults based on its amino acid...
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A series of Schiff bases (3.a–f) bearing benzimidazole moiety was successfully synthesized in ethanol by refluxing Oct-2-ynoic acid (1,3-dihydrobenzimidazole-2-ylidene)amide with substituted amines. Fourier transform infrared (FTIR),... more
A series of Schiff bases (3.a–f) bearing benzimidazole moiety was successfully synthesized in ethanol by refluxing Oct-2-ynoic acid (1,3-dihydrobenzimidazole-2-ylidene)amide with substituted amines. Fourier transform infrared (FTIR), ultra violet light (UV–VIS), elemental analysis, proton (1H) and carbon (13C) nuclear magnetic resonance spectroscopy were used to characterize the newly synthesized Schiff bases. Micro dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the Schiff bases, against 14 human pathogenic bacteria (8 Gram negative and 6 Gram positive) and against 7 fungal strains (5 Aspergillus and 2 Fusarium) representatives. Antimalarial activity against Plasmodium falciparum and antitrypanosomal property against Trypanosoma brucei was studied in vitro at a single dose concentration of the Schiff bases. Cytotoxicity of the Schiff bases was assessed against human cervix adenocarcinoma (HeLa) cells. Re...
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In this work, we report the identification and quantification of catechins by electrochemistry and UV-Vis spectroscopy in Elephantorrhiza elephantina (Fabaceae) and Pentanisia prunelloides (Rubiaceae), both of which are medicinal plants... more
In this work, we report the identification and quantification of catechins by electrochemistry and UV-Vis spectroscopy in Elephantorrhiza elephantina (Fabaceae) and Pentanisia prunelloides (Rubiaceae), both of which are medicinal plants that are widely used in Southern Africa to remedy various ailments. A comparative study of the catechin content as (-)-epicatechin equivalent is reported for the first time, with E. elephantina exhibiting a higher concentration relative to P. prunelloides in both aqueous and methanol extracts.
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A Ficus umbellata is used to treat cancer. The present work was therefore designed to assess antitumor potentials of F. umbellata extracts in nine different cell lines. Cell cycle, apoptosis, cell migration/invasion, levels of reactive... more
A Ficus umbellata is used to treat cancer. The present work was therefore designed to assess antitumor potentials of F. umbellata extracts in nine different cell lines. Cell cycle, apoptosis, cell migration/invasion, levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), caspases activities as well as Bcl-2 and Bcl-xL protein content were assessed in MDA-MB-231 cells. The 7,12-dimethylbenz(a)anthracene (DMBA)-induced carcinogenesis in rats were also used to investigate antitumor potential of F. umbellata extracts. The F. umbellata methanol extract exhibited a CC50 of 180 μg/mL in MDA-MB-231 cells after 24 h. It induced apoptosis in MCF-7 and MDA-MB-231 cells, while it did not alter their cell cycle phases. Further, it induced a decrease in MMP, an increase in ROS levels and caspases activities as well as a downregulation in Bcl-2 and Bcl-xL protein contents in MDA-MB-231 cells. In vivo, F. umbellata aqueous (200 mg/kg) and methanol (50 mg/kg) extracts signi...
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Purpose The purpose of this study was to composite maize, a cereal grain with low protein and lysine content, with groundnut a rich source of protein, to improve the nutritional quality of maize–groundnut composite flours and their... more
Purpose The purpose of this study was to composite maize, a cereal grain with low protein and lysine content, with groundnut a rich source of protein, to improve the nutritional quality of maize–groundnut composite flours and their resultant porridges. Design/methodology/approach Defatted and full fat groundnut flours were used to prepare maize–groundnut composite flours and porridges at the ratio of 100:0, 55:45, 70:30 and 85:15, respectively. They were analyzed for proximate composition, energy value, amino acid and fatty acid profiles. Findings Compositing maize with groundnut significantly (p ≤ 0.05) increased proteins from 10 per cent in maize flour to up to 21 per cent in composite porridge (denoted DFC1). The energy values for composite porridges were 434 Kcal/100 g when compared with 398 Kcal/100 g established for maize porridge alone. Lysine content was three times higher in composite flours than for maize flour, while for composite porridges, lysine was four times higher t...
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Research Interests: Complementary and Alternative Medicine, Data Analysis, Plant Biology, Biology, Ethnopharmacology, and 15 morePharmacognosy, Medicinal Plants, Medicine, Conservation of aromatic and medicinal plants, Phytotherapy, Humans, Gabon, Phytochemical, Bacteria, Plant extracts, Euphorbiaceae, Antimicrobial agents, Phyllanthus, Pharmacology and pharmaceutical sciences, and HIV infections
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To provide ethnopharmacological information on the use of medicinal plants for central nervous system (CNS) disorders in the Sinai Peninsula region (Egypt). To collect, analyze and evaluate the ethnobotanical knowledge about these... more
To provide ethnopharmacological information on the use of medicinal plants for central nervous system (CNS) disorders in the Sinai Peninsula region (Egypt). To collect, analyze and evaluate the ethnobotanical knowledge about these medicinal plants in the Sinai Peninsula region with 61,000 km (2) and 379,000 inhabitants. Field work was concluded between March 2006 and May 2011, using semi-structured questionnaire with 700 informants (mean age: 59; 100% men) from 117 settlements of 17 Bedouin tribes. Transects walks in wild herbal plant collection areas and bibliographical review on the collected plants were also conducted. The Interview/ Inhabitant index (I/P), relative importance value of the species and informant consensus factor (FIC) were calculated. More than 300 species were traditionally used in folk medicine in the Sinai Peninsula; 101 of these species belonging to 40 families were reported as useful in different CNS disorders. Only 5 species are endemic of the studied area. All different part plants were used, leaves and aerial parts being the most frequent. Most of the remedies were prepared as infusion or decoction, while oral administration was the most common way to be used. Gastrointestinal (67.3%) and respiratory disorders (42.57%) were also reported as frequently treated by Bedouins with herbal remedies. Only a few species were found where the traditional use is supported by pharmacological studies (Acacia nilotica, Achillea fragrantissima, Ajuga iva or Mentha longifolia). No bibliographical references in the scientific literature were found for 22 species (21.78%); finally, several studies were published with different pharmacological activities than those provided by Bedouins.
Research Interests: Ethnobotany, Complementary and Alternative Medicine, Traditional Medicine, Plant Biology, Biology, and 14 moreEgypt, Ethnopharmacology, Medicinal Plants, Medicine, Phytotherapy, Humans, Male, Data Collection, Middle Aged, Questionnaires, Arabs, Species Specificity, peninsula, and Pharmacology and pharmaceutical sciences
Cellulose nanofibers (diameter=10-70 nm) were produced using chemical treatments (alkali treatment and bleaching) and high pressure homogenization from de-pectinated sugar beet pulp (DSBP). Chemical analysis and Fourier transform infrared... more
Cellulose nanofibers (diameter=10-70 nm) were produced using chemical treatments (alkali treatment and bleaching) and high pressure homogenization from de-pectinated sugar beet pulp (DSBP). Chemical analysis and Fourier transform infrared spectroscopy (FTIR) indicated that the chemical treatments greatly removed the hemicellulose and lignin from the DSBP and significantly increased the cellulose content. The crystallinity of the cellulose nanofibers increased from 35.67% to 69.62% after alkali treatment and bleaching. The thermal degradation temperature of DSBP cellulose nanofibers was 271.7 °C which was found to be 47.3 °C higher than that of the untreated DSBP. The DSBP cellulose nanofibers can be preferably used as reinforcement in the biocomposite material at high temperature.
Research Interests: Materials Science, Chemistry, Organic Chemistry, Nanofibers, Scanning Electron Microscopy, and 15 moreMorphology, Medicine, Cellulose, Nanofiber, Biocomposite, Lignin, Crystallinity, Thermogravimetry, X ray diffraction, Fourier transform infrared spectroscopy, Food Sciences, Hemicellulose, Pectins, Beta Vulgaris, and Carbohydrate Polymers
Figure S1. 1H NMR (600 MHz, CD3OD) spectrum of compound 6. Figure S2. ESI-MS (negative mode ionization) spectrum of compound 6. Figure S3. 1H NMR (600 MHz, CD3OD) spectrum of compound 13. Figure S4. ESI-MS (positive mode ionization)... more
Figure S1. 1H NMR (600 MHz, CD3OD) spectrum of compound 6. Figure S2. ESI-MS (negative mode ionization) spectrum of compound 6. Figure S3. 1H NMR (600 MHz, CD3OD) spectrum of compound 13. Figure S4. ESI-MS (positive mode ionization) spectrum of compound 13. (DOC 112 kb)
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Despite significant developments occurring in the treatment of cancer, it still remains the second deadly disease, responsible for 8.2 million deaths every year. Various natural substances have been studied for active molecules of tumor... more
Despite significant developments occurring in the treatment of cancer, it still remains the second deadly disease, responsible for 8.2 million deaths every year. Various natural substances have been studied for active molecules of tumor suppression in the past and the tropical flora, by its diversity, continues to provide new antitumor drugs. Crateva adansonii dichloromethane-methanol (DCM/MeOH) extract was previously reported to prevent breast tumors in Wistar rats. However, it exhibited weak cytotoxic effect in human MCF-7 cells. The present study, therefore, deals with the investigation of its estrogenic and antiestrogenic effects. In vitro estrogenicity and antiestrogenicity of C. adansonii DCM/MeOH extract were performed by E-screen assay. In vivo, the investigation was carried out using the 3 days uterotrophic assay in ovariectomized rats, a classical tool for the prediction of estrogenicity of chemicals. As a result, C. adansonii extract did not induce MCF-7 cells proliferati...
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Abyssinone V-4′ methyl ether (AVME) isolated from Erythrina droogmansiana was recently reported to exhibit anti-mammary tumor effect in mice. The present work was therefore aimed at elucidating its cellular and molecular mechanisms. To... more
Abyssinone V-4′ methyl ether (AVME) isolated from Erythrina droogmansiana was recently reported to exhibit anti-mammary tumor effect in mice. The present work was therefore aimed at elucidating its cellular and molecular mechanisms. To achieve our goal, the cytotoxicity of AVME against tumoral and non-tumoral cell lines was evaluated by resazurin reduction test; flow cytometry allowed us to evaluate the cell cycle and mechanisms of cell death; the mitochondrial transmembrane potential, reactive oxygen species (ROS) levels, and caspase activities as well as apoptosis-regulatory proteins (Bcl-2 and Bcl-XL) were measured in MDA-MB-231 cells. Further, the antimetastatic potential of AVME was evaluated by invasion assay. AVME exhibited cytotoxic effects in all tested tumor cell lines and induced a significant increase in the percentage of MDA-MB-231 cells at G2/M and S phases of the cell cycle in a concentration-dependent manner. AVME also induced apoptosis in MDA-MB-231 cells, which was...
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Despite the wide use of leaves of (Cecropiaceae) in several African countries including Cameroon as food and against amenorrhea and female infertility, it has never been tested for this purpose. Using immature female Wistar rats, the... more
Despite the wide use of leaves of (Cecropiaceae) in several African countries including Cameroon as food and against amenorrhea and female infertility, it has never been tested for this purpose. Using immature female Wistar rats, the impact of on the sexual maturation parameters (vaginal opening, ovarian relative weight and follicle maturation, gonadotropins and ovarian hormones serum levels) and fertility index has been evaluated through a 30-day oral administration of aqueous and methanol extracts of leaves at the doses of 20, 110 and 200 g/kg/day. Aqueous extract increased the ovarian relative weight ( < 0.001), progesterone ( < 0.001) and gonadotropins ( < 0.001) serum levels, and induced the maturation of ovarian follicles. The methanol extract additionally induced an early vaginal opening ( < 0.001), uterine growth ( < 0.01) and increased estradiol ( < 0.001) serum levels. The fertility index generally increased following treatments, while the gestation rate ...
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Ficus umbellata is a medicinal plant previously shown to endow estrogenic properties. Its major component was isolated and characterized as 7-methoxycoumarin (MC). Noteworthy, coumarins and the respective active metabolite... more
Ficus umbellata is a medicinal plant previously shown to endow estrogenic properties. Its major component was isolated and characterized as 7-methoxycoumarin (MC). Noteworthy, coumarins and the respective active metabolite 7-hydroxycoumarin analogs have shown aromatase inhibitory activity, which is of particular interest in the treatment of estrogen-dependent cancers. The present work aimed at evaluating the estrogenic/antiestrogenic effects of MC in vitro and in vivo. To do so, in vitro assays using E-screen and reporter gene were done. In vivo, a 3-day uterotrophic assay followed by a postmenopausal-like rat model to characterize MC as well as F. umbellata aqueous extract in ovariectomized Wistar rats was performed. The investigations focused on histological (vaginal and uterine epithelial height) and morphological (uterine wet weight, vagina stratification and cornification) endpoints, bone mass, biochemical parameters and lipid profile. MC induced a significant (p < 0.05) MCF...
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Since the biological properties of propolis depend to the plants that can be found in a specific region, propolis from unexplored regions attracts the attention of scientists. Ethanolic extract of Cameroonian propolis (EEP) is used to... more
Since the biological properties of propolis depend to the plants that can be found in a specific region, propolis from unexplored regions attracts the attention of scientists. Ethanolic extract of Cameroonian propolis (EEP) is used to treat various ailments including gynecological problems and amenorrhea. Since there were no scientific data to support the above claims, the present study was therefore undertaken to assess estrogenic properties of Cameroonian propolis. To achieve our goal, the ability of EEP to induce MCF-7 cells proliferation in E-screen assay as well as to activate estrogen receptors α (ERα) and β (ERβ) in cell-based reporter gene assays using human embryonic kidney cells (HEK293T) transfected with ERs was tested. Further, a 3-day uterotrophic assay was performed and the ability of EEP to alleviate hot flushes in ovariectomized adult rats was evaluated. In vitro, EEP showed an antiestrogenic activity in both HEK293T ER-α and ER-β cells. In vivo, EEP induced a signif...