[Show abstract][Hide abstract] ABSTRACT: Abstract This paper describes the seasonal phytochemical variation and the antimicrobial potential of V. zizanioides roots collected in Brazil. Considering the high levels of chemical constituents and their biological activity in dichloromethane fraction, the plants were grown in different seasons and the respective dichloromethane fractions were analyzed by gas chromatography-mass spectrometry. The antimicrobial activity was evaluated against several pathogenic microorganisms by determining the minimum inhibitory concentration (MIC) using the agar dilution method. Yields of dichloromethane fractions from plants collected in the autumn and spring occurred in a higher proportion than in other seasons. Khusimol (2) was isolated by column chromatography and identified by NMR and CG-MS, along with other sesquiterpenes, including β-vetivenene (1), vetiselinenol (3), isovalencenol (4), vetivenic acid (5), α-vetivone (6) and β-vetivone (7). Some extracts showed promising antimicrobial effects, with MICs ranging from 31.25 to 500 μg mL-1. Kushimol was slightly active against the tested microorganisms.
[Show abstract][Hide abstract] ABSTRACT: Objectives
Litchi chinensis has been traditionally used in folk medicine to treat several ailments. In this study, we investigated the chemical composition, antioxidant and antinociceptive activity of L. chinensis leaves.Methods
The antioxidant capacity of the extract, fraction and compounds was evaluated using the 1,1-diphenyl-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, and the liposome model with peroxyl radicals generated by 2,2′-azobis (2-amidinopropane) dihydrochloride radical. The pharmacological models of acute nociception used in mice were: writhing test with acetic acid (AA), hotplate (HP), glutamate (GLU), capsaicin (CP) and formalin (FM) tests.Key findingsThe main compounds isolated were procyanidin A2 (PA2), procyanidin B2 (PB2) and (–)-epicatechin. The biochemical features of the crude extracts and their ethyl acetate fraction (EtOAcFR) presented high antioxidant activity, and the antioxidant activity of PA2 and PB2 was remarkably high, with DPPH and ABTS. The crude methanol extract (MeOHEXTR), EtOAcFR and PB2 were effective in reducing nociception in FM and HP models. MeOHEXTR and EtOAcFR treatments also reduced pain induced by GLU and AA. In the CP model, only EtOAcFR and PB2 were effective.Conclusions
The results demonstrate the antinociceptive and antioxidant of MeOHEXTR, EtOAcFR and PB2.
[Show abstract][Hide abstract] ABSTRACT: Previous phytochemical studies carried out with Rubus imperialis Chum. Schl. (Rosaceae) have demonstrated the presence of triterpenes (niga-ichigoside F1 and 2β,3β,19α-trihydroxyursolic acid) in this species. The literature indicates that triterpenes are closely related to some pharmacological activities, including antiulcer activity. Therefore, in view of the previous promising results with this species, this work extends the phytochemical studies, as well as investigates its gastroprotective action in different models using rodents. The hydroalcoholic extract was tested using the following protocols in mice: ethanol/HCl and nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer, acetic acid-induced chronic ulcer, ligature pylorus model, and free mucus quantification in mucosa. Isolated triterpenes were investigated in the ethanol/HCl-induced ulcer model. The results of this study show that R. imperialis extract (100, 250, or 500 mg) displays gastroprotective activity in the ethanol-induced ulcer model with a percentage of inhibition of gastric lesions of 70, 71, and 86 %, respectively. The extract also significantly reduced the ulcerative lesions in the indomethacin-induced ulcer. In this model, the percentage of inhibition of ulcer was 41, 44, and 70 %, respectively. Regarding the model of gastric secretion, a reduction of gastric juice volume and total acidity was observed, as well as an increase in gastric pH; however, gastric mucus production was not altered by treatment with the extract. It was also observed that the ethyl acetate fraction presented higher activity, leading to the isolation of niga-ichigoside F1 and 2β,3β-19-α-trihydroxyursolic acid, which presented antiulcer activity comparable to that of omeprazole, with an inhibition percentage of 98 and 99 %, respectively. These results demonstrate that R. imperialis extract and isolated compounds (niga-ichigoside F1 and 2β,3β-19-α-trihydroxyursolic acid) produce gastroprotective effects, and this activity seems, at least in part, to be related to antisecretory effects.
Archiv für Experimentelle Pathologie und Pharmakologie 01/2014; · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chrysophyllum cainito, popularly known as "star apple", caimito, "abiu-roxo" or "abiu-do-Pará", is a tree of about 25m in height. Besides its culinary use, it is also used in fork medicine for the treatment of diabetes mellitus and several inflammatory diseases.
The crude methanolic extract (CME) was submitted to phytochemical studies for obtaining fractions and isolated compounds. They were monitored by thin-layer-chromatography (TLC). The biological activity was evaluated in mice using the carrageenan-induced mechanical hypersensitivity and paw oedema. Biochemical assays, such as myeloperoxidase (MPO) and activity and cytokines levels quantification, were carried out to analyse the involvement of neutrophil migration and IL-1β and TNFα production. Some adverse effects were investigated using the open-field and rota-rod tests, and it was also measured the rectal temperature.
This study demonstrates, for the first time, the anti-hypersensitivity and anti-inflammatory effects of CME, fractions and two isolated triterpenes obtained from the leaves of C. cainito on carrageenan-induced hypersensitivity and paw-oedema. The mice treated with CME or chloroform fraction (CHCl3) presented reduction in mechanical hypersensitivity. The effect of the CME seemed to be partially related to the anti-inflammatory activity, as the paw-oedema and MPO activity were also significantly inhibited. The isolated compound Lup-20(29)-en-3β-O-hexanoate demonstrated more reduction of the hypersensitivity than 3β-Lup-20(29)-en-3-yl acetate, suggesting that this molecule might be partially responsible for the biological effects obtained with CME and CHCl3 fractions. Finally, animals treated with CME and CHCl3 did not present changes in locomotor activity, motor performance or body temperature.
Our data demonstrates, for the first time, that the crude extract, fractions and pure compounds obtained from the C. cainito leaves possess important anti-hypersensitive properties against inflammatory pain in mice. The mechanisms through which C. cainito exerts its anti-hypersensitive actions are still unclear, and require further investigation; however, this could well constitute a new and attractive alternative for the management of persistent inflammatory and neuropathic pain in humans.
Journal of ethnopharmacology 12/2013; · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: As part of the program of our research group to search for new and effective substances from the Brazilian biodiversity, the present work evaluates the antibacterial activity of four species from the Brazilian flora (Garcinia achachairu, Macrosiphonia velame, Rubus niveus and Pilea microphylla) against Bacillus subtilis, Staphylococcus aureus and S. saprophyticus (Gram-positive bacteria), Escherichia coli (Gram-negative bacterium) and Candida albicans (yeast). The extracts of R. niveus and M. velame showed promising antibacterial activity with MICs, ranging from 1000 to 125 microg/mL. Bio-guided fractionation of M. velame yielded four compounds, with the highest inhibition being observed for compound 3, with a MIC of 125 microg/mL against S. aureus. The combinations of fractions 2 and 4 showed beneficial effect against Gram-positive bacteria (additive effect), suggesting a possible synergistic effect.
[Show abstract][Hide abstract] ABSTRACT: This paper evaluates CHCl3 and CH3OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl3 and CH3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC50 ) values ranging from 39-100 µg/mL. The CHCl3 extract of the stem bark returned IC50 values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-β-(p-coumaroyloxy)-polygodial produced IC50 values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-β-(p-methoxycinnamoyl)-polygodial, which produced respective IC50 values of 15.85 and 17.80 µM. The CHCl3 extract demonstrated activity (IC50 of 3.0 µg/mL) against P. falciparum. The IC50 values of 1-β-(p-cumaroyloxyl)-polygodial and 1-β-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents.
Memórias do Instituto Oswaldo Cruz 04/2013; 108(2):140-4. · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Protein tyrosine phosphatase B (PtpB) is one of the virulence factors secreted into the host cell by Mycobacterium tuberculosis. PtpB attenuates host immune defenses by interfering with signal transduction pathways in macrophages and, therefore, it is considered a promising target for the development of novel anti-tuberculosis drugs. Here we report the discovery of natural compound inhibitors of PtpB among an in house library of more than 800 natural substances by means of a multidisciplinary approach, mixing in silico screening with enzymatic and kinetics studies and MS assays. Six natural compounds proved to inhibit PtpB at low micromolar concentrations (< 30 µM) with Kuwanol E being the most potent with K i = 1.6 ± 0.1 µM. To the best of our knowledge, Kuwanol E is the most potent natural compound PtpB inhibitor reported so far, as well as it is the first non-peptidic PtpB inhibitor discovered from natural sources. Compounds herein identified may inspire the design of novel specific PtpB inhibitors.
PLoS ONE 01/2013; 8(10):e77081. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study was undertaken to evaluate the gastroprotective properties of seed, leaf, and branch methanolic extracts and guttiferone A obtained from Garcinia achachairu (Clusiaceae). Mice were used in all the models, and treatments were administered orally only in pylorus-ligated model of the extracts, and drugs were administered intraduodenally. Treatment with different extracts (500 mg/kg) significantly reduced the ulcerative lesions in the ethanol/HCl-induced model; however, the seed extract was most active. When tested in different doses (50, 250, or 500 mg/kg), the seed extract of G. achaicharu showed a dose-dependent effect with a percentage of inhibition of gastric lesions of 41, 49, and 85 %, respectively. The seed extract also significantly reduced the ulcerative lesions in the indomethacin/bethanechol-induced ulcer. In this model, the percentage of inhibition of ulcer was 24, 58, and 90 %, respectively. Regarding the model of gastric secretion, a reduction of gastric juice volume and total acidity was observed, as well as an increase in gastric pH. Considering that the seed extract was the most active, it was subjected to silica gel column chromatography, leading to the isolation of guttiferone A. The isolated compound and omeprazole were evaluated in the HCl/ethanol-induced ulcer model. In this assay, both compounds at a dose of 30 mg/kg reduced the ulcerative lesions by about 75 %. These results demonstrate, for the first time, that extracts obtained from G. achachairu and guttiferone A produce gastroprotective effects, corroborating ethnomedicinal use of this plant.
Archiv für Experimentelle Pathologie und Pharmakologie 08/2012; 385(11):1103-9. · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In a search for new and effective analgesic substances from the Brazilian biodiversity, the present study evaluates the chemical composition and antinociceptive potential of the methanol extract and a pure compound obtained from the seeds of Garcinia achachairu Rusby (Clusiaceae). The methanolic seed extract was directly subjected to purification by column chromatography and the purification was monitored by thin-layer chromatography. The main isolated compound was identified as Guttiferone A by comparison of conventional spectroscopic data (IR, NMR-(1)H and (13)C) to the literature data which was isolated for the first time from this plant. When evaluated in the acetic acid-induced nociception model in mice, the methanolic seed extract had an ID(50) (Inhibitory dose) of 13.1 (11.23-14.91) mg/kg and a maximal inhibition of 72 ± 4%. In the same model, Guttiferone A had an ID(50) of 4.54 (3.29-6.24) mg/kg and a maximal inhibition of 73 ± 5%. The methanolic seed extract and Guttiferone A were also active in pain models induced by formalin, capsaicin, glutamate and carrageenan. These data suggest that the antinociceptive effect of Guttiferone A partly depends on its interference with the synthesis or activity of the cytokine TNF-α, the keratinocyte-derived chemokine KC, and/or PGE(2). These data support, at least in part, the use of G. achachairu in folk medicine and suggest that this plant is an important source of compounds with a suitable profile for development as new and effective medicinal agents to treat pain processes.
Archives of Pharmacal Research 03/2012; 35(4):623-31. · 1.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Two regioisomeric meroterpenoids, Eugenial A and B, have been isolated from the fruits of Eugenia multiflora and their structures established on the basis of NMR evidences. They possess a phloroglucinol-monoterpene structure similar to the euglobals occurring in the sister genus Eucaliptus. A simple method to distinguish between regioisomeric pairs was pointed.
Natural product research 02/2012; · 1.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: a b s t r a c t Litsea guatemalensis Mez., a native plant of Mexico and Central America, is widely used as a food condi-ment, in the same manner as Laurus nobilis L. In folk medicine, it is used to treat several diseases such as respiratory and gastrointestinal complaints. We report here the anti-inflammatory and anti-hyperalgesic properties of ethanolic extract and the compound 5,7,3 0 ,4 0 -tetrahydroxy-isoflavone (3), which was iso-lated in addition to pinocembrin (1), and scopoletin (2). The results confirm that both the ethanolic extract and Compound 3 showed anti-inflammatory activity, by inhibiting paw oedema induced by car-rageenan, and also reduced the influx of leucocytes, particularly neutrophils, to the pleural cavity and consequently anti-hyperalgesic activity, when assessed in the model of persistent pain induced by partial sciatic nerve ligation.
[Show abstract][Hide abstract] ABSTRACT: From the stems of Croton micans Sw., five new 3,4-seco-ent-kaurene dimers: micansinoic acid (1), isomicansinoic acid (2), and the dimethyl (3), monomethyl (4) and monoethyl ester (5) of micansinoic acid were isolated. The structures of the new compounds were elucidated by spectroscopic data interpretation, mainly 1D and 2D NMR experiments and MS. These compounds are the first 3,4-seco-ent-kaurene dimers from a Croton species.
[Show abstract][Hide abstract] ABSTRACT: The increase in antibiotic resistance due to multiple factors has encouraged the search for new compounds which are active against multidrug-resistant pathogens. In this context, chalcones, dihydrochalcones, hydrazones and oxadiazoles were tested against Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus (MRSA) isolates, which were obtained from clinical laboratories and were characterized as MRSA using traditional and molecular methods. Among 65 tested compounds, two chalcones, one dihydrochalcone and two hydrazones were active against MRSA. Based on the minimal inhibitory concentration and cytotoxicity, hydrazones provided a better selectivity index than chalcones. Active hydrazones are promising antibiotic-like substances and they should be the subject of further microbiological studies.
[Show abstract][Hide abstract] ABSTRACT: Cipura paludosa (Iridaceae) is a plant that is distributed in the north region of Brazil. Its bulbs are used in folk medicine to treat inflammation and pain. Four naphthalene derivatives have been isolated from the bulbs of this plant. Three of them have been identified as the known naphthalene derivatives, eleutherine, iso-eleutherine, and hongkonin. The structure of the fourth and new component was determined as 11-hydroxyeleutherine by extensive NMR study. In addition, the IN VIVO effect of the two major compounds, eleutherine and iso-eleutherine, was evaluated in carrageenan-induced hypernociception and inflammation in mice. Eleutherine and iso-eleutherine (1.04-34.92 µmol/kg), dosed intraperitoneally (i.p.) or orally (p.o.), decreased the carrageenan-induced paw oedema (i.p. - inhibitions of 36 ± 7 % and 58 ± 14 %, respectively; p.o. - inhibitions of 36 ± 7 % and 58 ± 14 %, respectively). Iso-eleutherine, but not eleutherine, significantly reduced (inhibitions of 39 ± 4 %) the plasma extravasation induced by intradermal (i.d.) injection of carrageenan. Likewise, eleutherine and iso-eleutherine (1.04-34.92 µmol/kg, i.p. or p.o.) were also effective in preventing the carrageenan-induced hypernociceptive response (i.p. - inhibition of 59 ± 4 % and 63 ± 1 %, respectively; p.o. - inhibitions of 36 ± 7 % and 58 ± 14 %, respectively). It was also suggested that the anti-inflammatory and anti-hypernociceptive effects of eleutherine or iso-eleutherine partly depend on the interference with the synthesis or activity of mast cell products, kinins, cytokine, chemokines, prostanoids, or sympathetic amines. Our findings show that two major compounds of C. paludosa contain pharmacologically active constituents that possess antinociceptive and anti-inflammatory activity, justifying, at least in part, its popular therapeutic use for treating conditions associated with pain.
[Show abstract][Hide abstract] ABSTRACT: This study reports the cytotoxicity screening of 33 coumarins in a panel of human tumor cell lines (Caco-2: human colorectal adenocarcinoma, HCT-8: human ileocecal adenocarcinoma, and HEp-2: human larynx epidermoid carcinoma). The classic MTT assay was employed to evaluate the influence of samples on cellular viability. Following continuous incubation with cells for 72 h, all tested coumarins exhibited CC50 values ≥ 0.34 mM for all three cell lines. These findings indicate that all samples were notable to reduce the viability of tumor cell lines used in this study in clinically relevant concentrations. Some structure-activity relationships were established and could be used for the synthesis of derivatives with improved cytotoxic potential.
LATIN AMERICAN JOURNAL OF PHARMACY 01/2011; 30(9):1669-1674. · 0.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
[Show abstract][Hide abstract] ABSTRACT: The diastereoselective synthesis of (+/-)-trans-4-hydroxy-6-propyl-1-oxocyclohexan-2-one, as a mixture trans:cis (3:1), was accomplished using a protocol that combine the Prins cyclization and RuO(4) oxidation. The synthesis this lactone allowed the elucidation of the correct structure of the substance isolated from the barks of Vitex cymosa. The delta-lactones mixture showed significant antinociceptive properties in preliminary tests using the tail flick model assay.
[Show abstract][Hide abstract] ABSTRACT: The antinociceptive properties of some fractions and two pure compounds, conocarpan and orientin, obtained from P. solmsianum leaves were investigated in several models of pain in mice. The results indicated that this plant exhibits a promising antinociceptive profile, as it produces active principles which are several times more active than some reference drugs used for comparison. The main compound tested, orientin, caused potent and dose-dependent effects against acetic acid-induced writhing and capsaicin- and glutamate-induced nociception, being more effective against the first one, with an ID(50) value of 6.5 mg/kg (14.5 micromol/kg). Orientin was about 20-fold more potent than acetylsalicylic acid and 3.5-fold more active than indomethacin. The antinociceptive effects of this plant may be attributed, at least partially, to the presence of conocarpan and, in particular, to the flavonoid orientin.
Journal of Natural Medicines 10/2010; 64(4):402-8. · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Echinodorus macrophyllus leaf has been used in Brazilian folk medicine to treat inflammatory conditions and kidney dysfunctions. The present study evaluated the effects of leaf ethanolic extract from E. macrophyllus (EEEm) in acute and subchronic models of inflammation. The EEEm was found to cause significant and potent inhibition of carrageenan- and dextran-induced paw edema in rats and marked decreases in the exudate volume and leukocyte migration in rats with carrageenan-induced pleurisy, the vascular permeability increase induced by intraperitoneal acetic acid, and the croton oil-induced topical ear edema in mice. On the other hand, the EEEm was not active in the test model of cotton pellet-induced granuloma in rats. Phytochemical analysis with E. macrophyllus leaves revealed the presence of triterpenoids, steroids, flavones, flavonols, and xanthones. Two flavonoids were isolated from the ethyl acetate fraction and identified as isovitexin and vitexin. Our results support the traditional use of E. macrophyllus leaves in the treatment of acute inflammatory conditions.
Journal of medicinal food 10/2010; 13(5):1161-6. · 1.39 Impact Factor