963 resultados para plant extracts


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of gastric ulcers. Several folk medicinal plants and herbs have been used to treat gastrointestinal disorders, including gastric ulcers. Mammea americana L. (Guttiferae) fruit is very common in the diet of the population of northern South America. Our research interest in this plant arose because of its potential medicinal value as a tonic and against stomachache, as used in folk medicine. In this paper we evaluated three different extracts (ethanolic/EtOH, methanolic/MeOH and dichloromethane/DCM) obtained from M. americana L., for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCI/60% EtOH), hypothermic restraint stress, nonsteroidal anti-inflammatory drugs (NSAID, indomethacin) and pylorus ligation. In the HCI/EtOH-induced gastriculcer model, EtOH and DCM extracts demonstrated significant inhibition of the ulcerative lesion index by 54% (12.0 +/- 2.6 mm) and 86% (3.7 +/- 1.8 mm), respectively, in relation to the control value (26.0 +/- 1.4 mm) (p < 0.000 1). In the NSAID/cholinomimetic-induced lesion model, both EtOH and DCM extracts showed antiulcerogenic effects with significant reduction in the damage to these gastric lesions of 36% (8.3 +/- 2.0 mm) and 42% (7.5 +/- 1.4 mm), respectively, as compared to the control group (13.0 +/- 0.9 mm) (p < 0.0001). In the gastric ulcer induced by hypothermic-restraint stress, both extracts also showed significant activity, and inhibited the gastric lesion index by 58% and 75%, respectively. The EtOH and DCM extracts also changed gastric juice parameters as well as those of cimetidine, decreased gastric acid secretion significantly (p < 0.0001), increased pH values and promoted reduced acid output (p < 0.0001). In all gastric-ulcer-induced models, MeOH extract did not show any significant antiulcerogenic activity, nor did it change gastric-juice parameters (p > 0.05). The results suggest that EtOH and DCM extracts obtained from M. americana possess excellent antisecretory and/or gastrotective effect in all gastric ulcer models. These results suggest that the antiulcerogenic compound(s) present in M. americana may be clustered in the apolar fraction, which will be investigated by our group for the probable mechanisms of action. (c) 2004 Elsevier GmbH. All rights reserved.

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A rapid analytical approach suitable to achieve a comprehensive characterization of the compounds present in the infusion prepared from the leaves of Byrsonima fagifolia Niedenzu (Malpighiaceae), a Brazilian plant used as an infusion to treat gastric disorders, was developed. The method was based on high-performance liquid chromatography coupled to electrospray negative ionisation multistage ion trap mass spectrometry (HPLC/ESI-ITMSn). The main ions in the ESI-ITMS spectra were attributed to a quinic acid core containing from one to five galloyl units. Quercetin derivatives containing one and two sugar moieties as well as galloyl esterification were also detected. These results indicated that HPLC/ESI-ITMSn is easily applicable to infusions of this plant and allows the rapid and direct identification of these compounds in crude plant extracts. Copyright (C) 2007 John Wiley & Sons, Ltd.

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Extracts of Acanthospermum hispidum and Cajanus cajan have been used by Brazilian people in an attempt to produce abortion. In order to evaluate the possible abortive and/or teratogenic effect of these plant extracts, female Wistar rats were treated with the aqueous extract (infusion, proportion C. cajan and A. hispidum 1:1.3). Doses of 0, 150, 300 and 600 mg/kg were daily administered by gavage during the organogenic period. The animals were sacrificed at term. There was no significant change in the mean weight of the fetuses, and no change in the percentage of post implantation loss in the treated groups. However, there was an increase in the number of external malformations, and this was related to dose. No internal malformations were observed in fetuses at term, but there was a significant incidence of fetuses with visceral anomalies. The tendency of the pregnancy to continue or terminate did not change with the treatment.

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"Isolation and evaluation of the biological activity related to the major alkaloids in Tabernaemontana angulata Mart. ex Mull Arg., Apocynaceae." Introducing-new chemotherapeutic agents is a, great demand. in the control of infections diseases.' Brazil is one of the richest countries in biodiversity and the Laboratorio de Extracao at UNIP has been collecting plants from. the Amazon and Atlantic Rain Forests with the aim of screening for new antibacterial and antitumor plant extracts. Previous studies demonstrated that the ethanol fraction obtained from the crude extract of Tabernaemontana angulata stems showed antibacterial activity against Staphylococcus aureus (ATCC 6538 in the microdilution broth assay. Two alkaloids were the major compounds in the active fraction, verified by thin layer chromatography analysis. In the present study, the total alkaloids were obtained from the crude extract and were fractionated by preparative thin layer chromatography for the isolation of the main components. The isolated. compounds were identified by GC/MS and (1)H-NMR as coronaridine,e and voacangine. The alkaloid fractions obtained from the isolation procedure were tested for antibacterial activity, but no activity was detected.

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The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC50 of 572.2 mu g/mL and LC99 of 1137.8 mu g/mL in the EHT, and LC50 of 0.7 mu g/mL and LC99 of 60.81 mu g/mL in the LDT. In turn, the T. claussenii extract presented a LC50 of 263.8 mu g/mL and LC99 of 522.5 mu g/mL in the EHTand LC50 of 1.11 mu g/mL and LC99 of 26.4 mu g/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers. (C) 2011 Elsevier B.V. All rights reserved.

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The effect of a lyophilized mistletoe infusion (LMI) was studied on isolated guinea-pig vas deferens. LMI caused a contraction which was partially blocked by phentolamine but not by atropine. LMI caused a shift to the left of the norepinephrine concentration-effect curve (CEC), an effect which appeared to be blocked by atropine and was absent in animals previously treated with reserpine and α-methyl-para-tyrosine. The increase of the norepinephrine maximal response induced by LMI was not blocked by atropine or pharmacological denervation. LMI caused a shift to the right of the acetylcholine CEC and had no effect on the acetylcholine maximal response. These results suggest that the effects seem to be due mainly to the presence of potassium ion in the LMI; however, the participation of muscarinic agonist(s) of reduced intrinsic activity or some tyramine-like substance could not be ruled out.

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A new naphthopyrone dimer was isolated from the capitula of Paepalanthus bromelioides by chromatographic procedures. Its structure was deduced from spectrometric data. On colorimetric assay for cytotoxicity the new dimer showed IC50 of 55.9 μM. (C) 2000 Elsevier Science B.V.

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The hexane extract of the stems of Raulinoa echinata afforded the sesquiterpenes germacrene D (6), 1β,6α-dihydroxy-4-(15)-eudesmene (4) and oplopanone (5); the triterpenes squalene, isomultiflorenol (7), isobauerenol (8) and friedelin (9); the protolimonoids melianone (2) and melianodiol (3); and the pyranocoumarin 3-(1′-1′-dimethylallyl)-lomatin (1), which has not been reported previously as a natural product; together with β-sitosterol. The hexane extract and some of these compounds were assayed in vitro against trypomastigote forms of Trypanosoma cruzi. Brine shrimp lethality and antimicrobial activities of the crude extract and pure compounds were also evaluated.

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Propolis is a resinous material collected by bees from the buds or other parts of plants. It is known for its biological properties, having antibacterial, antifungal and healing properties. The antifungal activity of propolis was studied in sensitivity tests on 80 strains of Candida yeasts: 20 strains of Candida albicans, 20 strains of Candida tropicalis, 20 strains of Candida krusei and 15 strains of Candida guilliermondii. The yeasts showed a clear antifungal activity with the following order of sensitivity: C. albicans > C. tropicalis > C. krusei > C. guilliermondii. Patients with full dentures who used a hydroalcoholic propolis extract showed a decrease in the number of Candida.

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Wilbrandia ebracteata (Cogn.) Cogn. is a medicinal plant belonging to the Cucurbitaceae family used popularly as an antiulcer and analgesic medicine. The hydromethanol extract of leaves was investigated to determine its anti-ulcerogenic (ethanol and indomethacin induced gastric damage) and analgesic (writhing and tail-flick tests) activities in mice (efficacy), its acute toxicity (safety), and its phytochemistry (quality control). Oral administration of leaf extract at a dose of 1000 mg/kg body wt. significantly reduced 73.3% of the total area of lesion in ethanol-induced gastric damage, but was inactive in an indomethacin-induced gastric damage test. The hydromethanol extract was also inactive in both analgesic tests. Oral administration of the leaf extract did not produce mortality in mice, while the LD50 value of the roots was 22.10 mg/kg body wt. in female mice and 58.31 mg/kg body wt. in male mice. Leaves of W. ebracteata reacted positively for steroids, flavonols, flavanones, saponins, tannins and xanthones and negative for other compounds, including cucurbitacins. Leaf extract of W. ebracteata was active as an anti-ulcerogenic, probably through increasing gastric defensive factors, and flavonoids might be the main constituent responsible for this activity.

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The infusion of the aerial parts of Turnera diffusa was phytochemically examined. Chromatographic procedures led to the isolation of a new flavone glycoside, five known flavonoids and p-arbutin. Structures were determined by 1D- and 2D NMR experiments, as well as ES-MS and UV spectra.

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The natural naphthopyranones paepalantine (1), paepalantine-9O-β-D-glucopyranoside (2) and paepalantine-9-O-β-D-allopyranosyl-(1→6)-O-β-D-glucopyranoside (3) were separated in a preparative scale from the ethanolic extract of the capitula of Paepalanthus bromelioides by high-speed counter-current chromatography (HSCCC). The solvent system used was composed of water-ethanol-ethyl acetate-hexane (10:4:10:4, v/v/v/v). This technique led to the separation of the three different naphthopyranone glycosides in pure form in approximately 7 hours. Paepalantine showed a good antioxidant activity when assayed by the DPPH radical spectrophotometric assay.

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From the hexane-soluble fraction of an ethanol extract from leaves and stems of Stemodia foliosa (Scrophulariaceae), the new stearic acid 4-[(n-pentoxy)phenethyl] ester (1) was isolated. This compound exhibited antibacterial properties at 10μg/mL concentration by using disc diffusion method against Gram-positive bacteria Bacillus cereus and Bacillus subtilis and fast-acid bacterium Mycobacterium fortuitum. The structure of the new compound was elucidated by spectroscopic methods and by chemical conversion.