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    Moacir Pizzolatti

    We report the electrochemical oxidation of rutin in acetonitrile-sodium phosphate (4:1 (v/v); pH 2.0) in the presence of p-toluenesulfinic acid. Cyclic voltammetry and controlled potential electrolysis were used to study rutin... more
    We report the electrochemical oxidation of rutin in acetonitrile-sodium phosphate (4:1 (v/v); pH 2.0) in the presence of p-toluenesulfinic acid. Cyclic voltammetry and controlled potential electrolysis were used to study rutin electro-oxidation and to prepare the sulfone derivatives. Chromatographic methods were employed to separate the products and IR, 1H NMR, 13C NMR, MS and microanalysis to their characterization. Data from
    This study was conducted to investigate the anti-inflammatory efficacy of Esenbeckia leiocarpa against the inflammation caused by the carrageenan using a murine air pouch model. Material and methods: The effects of the crude... more
    This study was conducted to investigate the anti-inflammatory efficacy of Esenbeckia leiocarpa against the inflammation caused by the carrageenan using a murine air pouch model. Material and methods: The effects of the crude hydroalcoholic extract (CHE), fractions (n-hexane (Hex) and ethyl acetate (AcOEt)), subfractions (polar (Pol) and nonpolar (Nonpol)), or isolated compounds (dihydrocorynantheol (DHC) and beta-sitosterol (β-Sit)) isolated from CHE
    Page 1. J. CHEM. SOC. PERKIN TRANS. 2 1990 759 Azoxybenzene Formation from Nitrosobenzene and Phenylhydroxylamine. A Unified View of the Catalysis and Mechanisms of the Reactions Moacir Geraldo Pizzolatti and ...
    The effect of 3β-hidroxihop-22(29)ene (3-BHO) on insulin and glucagon-like peptide 1 (GLP-1) secretion as well as the mechanism of action of the compound in pancreatic islet on glucose homeostasis was investigated. The data from in vivo... more
    The effect of 3β-hidroxihop-22(29)ene (3-BHO) on insulin and glucagon-like peptide 1 (GLP-1) secretion as well as the mechanism of action of the compound in pancreatic islet on glucose homeostasis was investigated. The data from in vivo treatment show that 3-BHO significantly reduces the hyperglycemia by increasing the insulin and GLP-1 secretion, as well as by accumulating hepatic glycogen in hyperglycemic rats. In rat pancreatic β-cell, 3-BHO stimulates the glucose uptake, insulin vesicles translocation to the plasma membrane and thus the insulin secretion through the involvement of potassium channels (ATP- and Ca(2+)-dependent K(+) channels) and calcium channels (L-type voltage-dependent calcium channels (L-VDCC)). Furthermore, this study also provides evidence for a crosstalk between intracellular high calcium concentration, PKA and PKC in the signal transduction of 3-BHO to stimulate insulin secretion. In conclusion, 3-BHO diminishes glycaemia, stimulates GLP-1 secretion and po...
    The present study investigates the mechanisms related to the endogenous nitric oxide synthase (eNOS) activation in the relaxant effects of a proanthocyanidin-rich fraction (PRF), obtained from Croton celtidifolius Baill barks, in rat... more
    The present study investigates the mechanisms related to the endogenous nitric oxide synthase (eNOS) activation in the relaxant effects of a proanthocyanidin-rich fraction (PRF), obtained from Croton celtidifolius Baill barks, in rat thoracic aorta rings with endothelium. In vessels pre-contracted with phenylephrine (Phe), PRF (0.1 - 100 microg/mL) induced a concentration-dependent relaxation. This effect was significantly reduced by endothelium denudation, by N(omega)-nitro-L-arginine, and by 1H[1,2,3]oxadiazolo[4,3-alpha]quinoxalin. However, the vasorelaxant effect was not altered by indomethacin, atropine, tetraethylammonium, and charybdotoxin plus apamin. In thoracic aorta rings pre-contracted with phorbol-12,13-dibuyrate, PRF also induced a concentration-dependent relaxation. The PRF-induced relaxation disappeared in the absence of extracellular calcium in the medium and decreased significantly in the presence of lanthanum. A sulfhydryl alkylating agent, N-ethylmaleimide, and a...
    A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (1HNMR,... more
    A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (1HNMR, {1H}-13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete 1H and 13C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated.
    Schinus molle L. (Anacardiaceae), among other uses, is popularly employed for the treatment of depression. In this study, the antidepressant-like effect of the hexanic extract from leaves of S. molle was investigated in the mouse tail... more
    Schinus molle L. (Anacardiaceae), among other uses, is popularly employed for the treatment of depression. In this study, the antidepressant-like effect of the hexanic extract from leaves of S. molle was investigated in the mouse tail suspension test (TST), a predictive model of depression. The immobility time in the TST was significantly reduced by the extract (dose range 30-600 mg/kg, p.o.), without accompanying changes in ambulation when assessed in an open-field test. The efficacy of extract was found to be comparable to that of fluoxetine (10 mg/kg, p.o.). The anti-immobility effect of the extract (100 mg/kg, p.o.) was prevented by pretreatment of mice with p-chlorophenylalanine methyl ester (PCPA, 100 mg/kg, i.p., an inhibitor of serotonin synthesis, for four consecutive days), NAN-190 (0.5 mg/kg, i.p., a 5-HT(1A) receptor antagonist), WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist), ketanserin (5 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), MDL72222 ...
    Chalcones are an important class of natural compounds that have been widely applied as synthons in synthetic organic chemistry and possess diverse and interesting biological properties. We conducted tests with the synthetic substances... more
    Chalcones are an important class of natural compounds that have been widely applied as synthons in synthetic organic chemistry and possess diverse and interesting biological properties. We conducted tests with the synthetic substances 6-quinolinyl N-oxide chalcones 4c and 4e to determine their antifungal activity against several isolates of Paracoccidioides spp. and their activity in a murine model. We also determined whether the chalcones interacted with other drugs or interfered with the morphology of Paracoccidioides brasiliensis (Pb18) yeast cells. We verified that the substances were active against Paracoccidioides spp., but we did not show an interaction with the drugs tested when only the fractional inhibitory concentration index values were considered individually. We observed that the substances induced in vitro morphological changes. Compounds 4c and 4e showed activity similar to itraconazole in treated mice, as demonstrated by their ability to reduce the number of cfu rec...
    The effect of in vivo treatment with ursolic acid (UA) on glycemia in hyperglycemic rats and its mechanism of action on muscle were studied. The UA effects on glycemia, glycogen, LDH, calcium and on insulin levels were evaluated after... more
    The effect of in vivo treatment with ursolic acid (UA) on glycemia in hyperglycemic rats and its mechanism of action on muscle were studied. The UA effects on glycemia, glycogen, LDH, calcium and on insulin levels were evaluated after glucose tolerance curve. The β-cells were evaluated through the transmission electron microscopy. UA mechanism of action was studied on muscles through the glucose uptake with/without specific insulin signaling inhibitors. The nuclear effect of UA and the GLUT4 expression on muscle were studied using thymidine, GLUT4 immunocontent, immunofluorescence and RT-PCR. UA presented a potent antihyperglycemic effect, increased insulin vesicle translocation, insulin secretion and augmented glycogen content. Also, UA stimulates the glucose uptake through the involvement of the classical insulin signaling related to the GLUT4 translocation to the plasma membrane as well as the GLUT4 synthesis. These were characterized by increasing the GLUT4 mRNA expression, the activation of DNA transcription, the expression of GLUT4 and its presence at plasma membrane. Also, the modulation of calcium, phospholipase C, protein kinase C and PKCaM II is mandatory for the full stimulatory effect of UA on glucose uptake. UA did not change the serum LDH and serum calcium balance. The antihyperglycemic role of UA is mediated through insulin secretion and insulinomimetic effect on glucose uptake, synthesis and translocation of GLUT4 by a mechanism of cross-talk between calcium and protein kinases. UA is a potential anti-diabetic agent with pharmacological properties for insulin resistance and diabetes therapy.
    The effect of betulinic acid on glycemia and its mechanism of action compared with 1,25(OH)2 vitamin D3 in rat muscle were investigated. Betulinic acid improved glycemia, induced insulin secretion and increased the glycogen content and... more
    The effect of betulinic acid on glycemia and its mechanism of action compared with 1,25(OH)2 vitamin D3 in rat muscle were investigated. Betulinic acid improved glycemia, induced insulin secretion and increased the glycogen content and glucose uptake in muscle tissue. Additionally, the integrity of both PI3K and the cytoskeleton is necessary for the stimulatory action of betulinic acid in glucose uptake. The genomic effect was apparent, since cycloheximide and PD98059 nullified the stimulatory effect of betulinic acid on glucose uptake. Therefore, although this compound did not modify the DNA transcription, the protein translation was significantly improved. Also, betulinic acid increased the GLUT4 immunocontent and its translocation was corroborated by GLUT4 localization at the plasma membrane (after 180 min). On the other hand, the effect of 1,25(OH)2 vitamin D3 on glucose uptake is not mediated by PI3K and microtubule activity. In contrast, the nuclear activity of 1,25(OH)2 vitamin D3 is necessary to trigger glucose uptake. In addition, the increased DNA transcription and GLUT4 immunocontent provide evidence of a mechanism by which 1,25(OH)2 vitamin D3 contributes to glycemia. In conclusion, betulinic acid acts as an insulin secretagogue and insulinomimetic agent via PI3K, MAPK and mRNA translation and partially shares the genomic pathway with 1,25(OH)2 vitamin D3 to upregulate the GLUT4. In summary, betulinic acid regulates glycemia through classical insulin signaling by stimulating GLUT4 synthesis and translocation. In addition, it does not cause hypercalcemia, which is highly significant from the drug discovery perspective.
    Polygala sabulosa, a folk medicine, presents dihydrostyryl-2-pyrones (DST) and styryl-2-pyrones (STY), compounds structurally similar to kavalactones. Our previous study showed that the ethyl acetate fraction (EA) and these constituents... more
    Polygala sabulosa, a folk medicine, presents dihydrostyryl-2-pyrones (DST) and styryl-2-pyrones (STY), compounds structurally similar to kavalactones. Our previous study showed that the ethyl acetate fraction (EA) and these constituents present anxiolytic-like, hypno-sedative, and anticonvulsant effects in mice. This study investigated the role of benzodiazepine binding site (BDZ-bs) in the central effects of either EA or three DST (1, 2, and 3) and three STY (4, 5, and 7), using in vivo and in vitro assays. In the elevated plus-maze (EPM), flumazenil (FMZ), a BDZ antagonist, partially blocked the anxiolytic-like effect of DST-3 or STY-4 and STY-7, but not DST-1. Using electroencephalogram (EEG), EA protected against pentylenetetrazole (PTZ)-induced convulsion in rats, an effect partially blocked by FMZ, suggesting the participation of the BDZ-bs in this action. EA also protected against the maximal electroshock (MES)-induced convulsions in mice, a profile distinct from diazepam (DZP). DST and STY compounds inhibited the [(3)H]-flunitrazepam ([(3)H]-FNZ) binding to BDZ-bs in rat cortical synaptosomes with K (i) higher than 100 microM (DST-1), 41.7 microM (DST-2), 35.8 microM (DST-3), 90.3 microM (STY-4), 31.0 microM (STY-5) and 70.0 microM (STY-7). In the saturation assay, DST-3 and STY-7 competitively inhibited the binding of [(3)H]-FNZ to BDZ-bs with a significant decrease in apparent affinity (K (d)) and no change in maximal binding (B (max)). The present data support a partial BDZ-bs mediation of the anxiolytic-like and anticonvulsant effects of EA of P. sabulosa and its main isolated constituents, DST and STY.
    The present study describes the occurrence of two ellagitannins in the ethanolic extract of the leaves and stems of Phyllanthus sellowianus (Euphorbiaceae). Their preliminary antinociceptive properties were also evaluated. The two... more
    The present study describes the occurrence of two ellagitannins in the ethanolic extract of the leaves and stems of Phyllanthus sellowianus (Euphorbiaceae). Their preliminary antinociceptive properties were also evaluated. The two ellagitannins were identified on the basis of 1H- and 13C-NMR spectra data and by mixed co-TLC and co-HPLC injection with an authentic sample of furosin and geraniin. Preliminary pharmacological analysis revealed that both furosin and geraniin (3 to 30 mg/kg, i.p.), given 30 min before testing, exhibited significant and dose-related antinociceptive properties against acetic acid-induced abdominal constrictions in mice. Geraniin and furosin were about six- to seven-fold more potent at the ID50 level (micromol/kg) as analgesics than aspirin and acetaminophen, respectively, although they were less efficacious when compared with the standard drugs. These data extend our previous studies and indicate that the two ellagitannins isolated from P.sellowianus, identified as furosin and geraniin are, at least in part, responsible for the antinociceptive actions reported previously for the hydroalcoholic extract of P.sellowianus and other plants belonging to the genus Phyllanthus.
    The hydroalcoholic extract (HE) obtained from stems and leaves of Hedyosmum brasiliense, given i.p., produced significant inhibition of acetic acid-induced abdominal constriction in mice, with a mean ID50 of 12.7 mg/kg. This effect... more
    The hydroalcoholic extract (HE) obtained from stems and leaves of Hedyosmum brasiliense, given i.p., produced significant inhibition of acetic acid-induced abdominal constriction in mice, with a mean ID50 of 12.7 mg/kg. This effect installed rapidly (0.5 h) and lasted for up to 2 h. Given orally up to 1000 mg/kg, the HE was ineffective. When assessed in the formalin response the HE, given i.p., inhibited the first and second phase, with ID50s of 31.1 and 21.7 mg/kg for the first and the second phases, respectively. The HE also inhibited capsaicin-induced neurogenic pain with ID50 of 69.0 mg/kg, but, in contrast to morphine, failed to cause analgesia in either the tail-flick or hot-plate models of pain. In addition, its antinociception was not reversed by naloxone. The sesquiterpene lactone 13-hydroxy-8,9-dehydroshizukanolide, isolated from H. brasiliense and already reported in other plant species (given by i.p., i.t., or i.c.v. routes) exhibited graded antinociception against acetic-acid writhing and capsaicin-induced licking. Additionally, we have corrected some physico-chemical data already reported for this compound. It is concluded that both the extract and the sesquiterpene lactone isolated from H. brasiliense produced marked antinociception in different models of chemical pain. The site of action involved in the antinociception of the 13-hydroxy-8,9-dehydroshizukanolide remains unclear, but the opioid pathway seems unlikely to be involved in its action.
    The antinociceptive actions of the steroid compounds isolated from the leaves, stems, and roots of P. corcovadensis have been investigated in mice. Stigmasterol, stigmasterol acetate, beta-sitosterol, and aspirin (3-100 mk/kg, i.p.)... more
    The antinociceptive actions of the steroid compounds isolated from the leaves, stems, and roots of P. corcovadensis have been investigated in mice. Stigmasterol, stigmasterol acetate, beta-sitosterol, and aspirin (3-100 mk/kg, i.p.) inhibited, in a dose-related manner, acetic acid-induced abdominal constriction in mice with ID50s of 16, 11, 9, and 24 mg/kg, respectively. In the formalin test, stigmasterol and stigmasterol acetate (10-100 mg/kg, i.p.) caused graded inhibition of both the neurogenic (first phase) and inflammatory phases (second phase) of formalin-induced pain. However, both compounds were more effective in relation of the second phase of the formalin test with ID50 values of 26 and 41 mg/kg, respectively. Furthermore, both steroids failed to affect the edematogenic response of the formalin test. Given orally, stigmasterol and stigmasterol acetate (50-200 mg/kg) also exhibited significant though less potent analgesic action against both acetic acid- and formalin-induced nociception in mice. In addition, stigmasterol (up to 100 mg/kg, i.p.), in contrast to morphine (10 mg/kg, s.c.), had no analgesic effect in either tail-flick or hot-plate models. These findings suggest that stigmasterol and beta-sitosterol may account, at least in part, for the antinociceptive actions reported previously for the hydroalcoholic extract of Phyllanthus corcovadensis.
    This study was undertaken to evaluate the psychopharmacological effects in mice of the hydroethanolic extract (HE), aqueous, hexane and ethyl acetate (EA) fractions, and 6-methoxy-7-prenyloxycoumarin, three dihydrostyryl-2-pyrones and... more
    This study was undertaken to evaluate the psychopharmacological effects in mice of the hydroethanolic extract (HE), aqueous, hexane and ethyl acetate (EA) fractions, and 6-methoxy-7-prenyloxycoumarin, three dihydrostyryl-2-pyrones and three styryl-2-pyrones isolated from Polygala sabulosa (Polygalaceae), a folk medicine used as a topical anesthetic. In the elevated plus-maze test (EPM), the HE of P. sabulosa and its EA induced an increase in the percentage of time spent on, and in the frequency of entries into the open arms, as well as in the number of unprotected head-dipping, besides a reduction in protected stretch-attend postures, thus indicating an anxiolytic-like profile of action for this plant species. In the hypnosis test, HE and EA enhanced the duration of pentobarbital-induced sleep, a hypnosedative effect confirmed in ethyl ether-induced hypnosis. Moreover, both preparations reduced the duration of the first convulsion induced by pentylenetetrazol, besides decreasing the severity of the seizures. The dihydrostyryl-2-pyrones (1) and (3) as well as styryl-2-pyrones (4) and (7), centrally administered, showed a similar anxiolytic-like effect in the EPM test, while the dihydrostyryl-2-pyrone (2) and styryl-2-pyrone (5) were inactive at the doses used here. These results suggest that P. sabulosa is a herbal medicine which possesses anxiolytic-like, hypnosedative and anticonvulsant effects, and these central effects can be attributed to the presence of the dihydrostyryl-2-pyrone and styryl-2-pyrone compounds.
    The present work explored the antinociceptive effects of the flavonoid myricitrin in models of overt nociception triggered by intraplantar injection of chemical algogens into the hind paw of mice. The nociception induced by bradykinin (3... more
    The present work explored the antinociceptive effects of the flavonoid myricitrin in models of overt nociception triggered by intraplantar injection of chemical algogens into the hind paw of mice. The nociception induced by bradykinin (3 nmol/paw i.pl.) was abolished by prior treatment with myricitrin (10-100mg/kg, i.p.) with ID(50) of 12.4 (8.5-18.1)mg/kg. In sharp contrast, myricitrin failed to affect the nociception elicited by prostaglandin E(2) (3 nmol/paw i.pl.). Cinnamaldehyde (10 nmol/paw i.pl.)-induced nociception was reduced by myricitrin (100mg/kg, i.p.) and camphor (7.6 mg/kg,s.c.) in 43±10% and 57±8%, respectively. Myricitrin (30-100mg/kg, i.p.) and amiloride (100mg/kg, i.p.) inhibited nociceptive responses induced by acidified saline (pH 5/paw i.pl.), with ID(50) of 22.0 (16.1-30.0)mg/kg and inhibition of 71±6% and 64±5%, respectively. Moreover, myricitrin (10-30 mg/kg, i.p.) and ruthenium red (3mg/kg, i.p.) significantly reduced the nociception induced by menthol (1.2 μmol/paw i.pl.) with the mean ID(50) of 2.4 (1.5-3.7)mg/kg and inhibition of 95±3% and 51±7%, respectively. In addition, myricitrin administration (30 and 100mg/kg, i.p.) markedly reduced menthol-induced mechanical allodynia. However, myricitrin (100mg/kg, i.p.) prevented (only in time of 60 min) cold allodynia induced by menthol. Collectively, the present results extend prior data and show that myricitrin promotes potent antinociception, an action that is likely mediated by an inhibition of the activation of nociceptors by bradykinin and TRPs agonist (i.e. cinnamaldehyde, acidified saline and menthol), probably via inhibition of PKC pathways. Thus, myricitrin could constitute an attractive molecule of interest for the development of new analgesic drugs.
    Piperaceae is a family of tropical plants known to have antifungal, antibacterial, tumour-inhibitory, antiviral, antioxidant, molluscicidal and leishmanicidal activities. In this work, extracts and fractions from aerial parts of Piper... more
    Piperaceae is a family of tropical plants known to have antifungal, antibacterial, tumour-inhibitory, antiviral, antioxidant, molluscicidal and leishmanicidal activities. In this work, extracts and fractions from aerial parts of Piper abutiloides (Piperaceae), a traditional medicinal plant, were evaluated against the fungal species Candida albicans, C. parapsilosis, C. krusei, C. glabrata, C. tropicalis, Cryptococcus neoformans and Sporothrix schenckii. The results have shown that the antifungal activity of this plant can be concentrated in the hexanic fraction after partitioning its hydroalcoholic extract between hexane and 90% aqueous methanol. The chromatographic fractionation of the bioactive part was monitored with a bioautographic assay using C. glabrata, and allowed the isolation of three antifungal compounds: pseudodillapiol, eupomatenoid-6 and conocarpan. These compounds presented different potencies against the fungi tested, with the strongest effect being observed for eupomatenoid-6 against C. glabrata, which presented a minimal inhibitory concentration value of 0.3 microg spot(-1). Conocarpan showed antifungal activity without apparent cytotoxic effect on normal human lymphocytes, as assessed by the proliferation assay with human peripheral blood mononuclear cells stimulated with phytohaemaglutinin. This work reveals for the first time the occurrence of these compounds in P. abutiloides and justifies further studies to clarify their mechanisms of action.
    Page 1. W m II x The structure of velutinol A is (15R,16R,20S)-14,16 : 15,20 : 16,21-t:riepoxy-l5,16-seco-l4~,17a-pregn-5-ene-3~,15-diol. A combined quantitative Overhauser effect and molecular modelling study // 1-Pizzolatti,"... more
    Page 1. W m II x The structure of velutinol A is (15R,16R,20S)-14,16 : 15,20 : 16,21-t:riepoxy-l5,16-seco-l4~,17a-pregn-5-ene-3~,15-diol. A combined quantitative Overhauser effect and molecular modelling study // 1-Pizzolatti," Antonio EG SantSAnab and Rosendo A. Yunes" ...
    Proanthocyanidins are condensed tannins present in fruits, vegetables, and flowers, consumed in the human diet. These compounds are believed to decrease coronary heart disease. The present study was designed to investigate the relaxing... more
    Proanthocyanidins are condensed tannins present in fruits, vegetables, and flowers, consumed in the human diet. These compounds are believed to decrease coronary heart disease. The present study was designed to investigate the relaxing effects of a proanthocyanidin-rich fraction (PRF) obtained from Croton celtidifolius BAILL (Euphorbiaceae) barks in rat mesenteric arterial bed (MAB) and isolated mesenteric artery (MA). In the MAB pre-contracted with phenylephrine (Phe), PRF (0.1 - 100 microg) induced a concentration-dependent relaxation of 73% (compared to the control). This effect was significantly reduced by the nitric oxide (NO) synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG) or high K(+) solution and completely abolished in vessels perfused with KCl plus L-NOARG. However, the vasorelaxant effect was not altered by indomethacin, atropine, yohimbine, pyrilamine, or K(+)-channel blockers: BaCl(2), glibenclamide, ouabain, and 4-aminopyridine. In isolated MA pre-contracted with Phe, PRF also induced a concentration-dependent relaxation (0.1 - 30 microg/mL), which was in turn inhibited by endothelial removal, guanylyl cyclase inhibitor 1H[1,2,3]oxadiazolo[4,3-alpha]quinoxalin, charybdotoxin (ChTx), and ChTx plus apamin. Moreover, the relaxant effect was not altered by HOE140 and apamin given alone. The present study demonstrates that the vasorelaxing effect of PRF is dependent upon the NO-cGMP pathway in combination with hyperpolarization due to activation of Ca(2+)-dependent K(+) channels.
    The leaves of the pantropical genus Bauhinia (Fabaceae) are popularly known as cow's-paw or cow's hoof due to their unique characteristic... more
    The leaves of the pantropical genus Bauhinia (Fabaceae) are popularly known as cow's-paw or cow's hoof due to their unique characteristic bilobed aspect. The species Bauhinia forficata (Brazilian Orchid-tree) is widely used in folk medicine as an antidiabetic. This article deals with the quantitative analysis of kaempferitrin from B. forficata medicinal extract (aqueous and hydro alcoholic) using the LC method, and the comparison of kaempferitrin content in leaves collected from two different regions in the south Brazil. The total flavonoid content assessed by LC was also compared with the classical spectrophotometric determination. Kaempferitrin was found in different amounts, in samples from two geographical areas (Telêmaco Borba/PR and Itajaí/SC), for aqueous (368.68 and 77.91 microg/mL) and hydro alcoholic extracts (1952.59 and 211.61 microg/mL), respectively. The method was subjected to recovery assay, to determine its accuracy. A marked difference in total flavonoid concentration was observed in relation to kaempferitrin content: 2759.95 and 2188.20 microg/mL for the fluidextract and 863.35 and 856.77 microg/mL for the aqueous extract (Telêmaco Borba/PR and Itajaí/SC). The spectrophotometric assay overestimated the total flavonoid content (3620 microg/mL) in relation to the LC assay.
    In vivo and in vitro treatments were carried out to investigate the effects of kaempferol-3,7-O-(alpha)-dirhamnoside (kaempferitrin), a major flavonoid compound of the n-butanol fraction from Bauhiniaforficata leaves, on serum glucose... more
    In vivo and in vitro treatments were carried out to investigate the effects of kaempferol-3,7-O-(alpha)-dirhamnoside (kaempferitrin), a major flavonoid compound of the n-butanol fraction from Bauhiniaforficata leaves, on serum glucose levels, as well as its antioxidant potential. Oral administration of kaempferitrin led to a significant hypoglycemic effect in normal and in alloxan-induced diabetic rats. In normal rats, blood glucose lowering was observed only with the higher dose of kaempferitrin (200 mg/kg) at 1 h after treatment. However, the hypoglycemic effect of kaempferitrin in diabetic rats was evident at all doses tested (50, 100, and 200 mg/kg), and this profile was maintained throughout the period studied for both higher doses. Additionally, in glucose-fed hyperglycemic normal rats, the kaempferitrin failed to decrease blood glucose levels. In vitro antioxidant properties or action against reactive oxygen species of this compound was also evaluated. The compound showed high reactivity with 1,1-diphenyl-2-picryl hydrazyl (DPPH), IC(50) of 84.0 +/- 7.8 microM, inhibited myeloperoxidase activity with K(0.5) = 86 +/- 9.9 microM, and decreased lipid peroxidation, induced by ascorbyl radical either in microsomes or in asolectin and phosphatidylcholine liposomes, with IC(50)'s of 320 +/- 14.1, 223 +/- 8.3, and 112 +/- 8.8 microM, respectively.
    In the methanolic extract of Croton urucurana Baillon (Euphorbiaceae) a number of known compounds, such as acetyl aleuritolic acid, stigmasterol, β-sitosterol, campesterol, β-sitosterol-O-glucoside, sonderianin, catechin and gallocatechin... more
    In the methanolic extract of Croton urucurana Baillon (Euphorbiaceae) a number of known compounds, such as acetyl aleuritolic acid, stigmasterol, β-sitosterol, campesterol, β-sitosterol-O-glucoside, sonderianin, catechin and gallocatechin were isolated and identified by MS and NMR spectroscopy, HRGC and data from literature. The antibacterial activity of the aqueous–EtOH extract, some fractions of the methanolic extract and some of the isolated compounds,

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