Avaliação da atividade antiulcerogênica dos extratos e frações das folhas de Mouriri elliptica Mart. (Melastomataceae) e Byrsonima basiloba A. Juss. (Malpighiaceae)
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Data
2007
Autores
Moleiro, Fábio Cruz [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A partir da indicação popular de espécies do gênero Mouriri e Byrsonima para gastrites e distúrbios do trato gastrointestinal, foram realizados experimentos para a avaliação da atividade gastroprotetora, cicatrizante e tóxica do extrato metanólico das folhas de Mouriri elliptica (manapuçá) (EMME) e Byrsonima basiloba (murici-de-ema) (EMBB). As frações derivadas destes extratos (fração acetato de etila de M. elliptica - FAEME e fração aquosa de Byrsonima basiloba - FABB) também tiveram sua ação gastroprotetora avaliada, assim como o comportamento destas frente à expressão de PGE2 pela mucosa gástrica. Após a comprovação dos efeitos gastroprotetores de ambas espécies em modelos experimentais de indução de lesões gástricas por etanol acidificado, etanol absoluto, e piroxicam (p < 0,05), os estudos foram direcionados no intuito de se caracterizar os mecanismos de ação envolvidos. Assim, ambos os extratos apresentaram atividade gastroprotetora relacionada com os grupamentos sulfidrílicos, sendo que o EMBB também exerce proteção mediada pelo óxido nítrico. A gastroproteção conferida pelos extratos também agiu de maneira independente do efeito anti-secretório e também sem causar alterações na velocidade do trânsito intestinal. Na análise imunohistoquímica, o EMME estimula a proliferação celular na região de regeneração e a expressão de COX2, enquanto que o EMBB atua aumentando a angiogênese. No modelo de etanol absoluto, a FAEME conferiu uma dose efetiva 5 vezes menor que a do seu precursor EMME (50 e 250 mg/Kg respectivamente). Para a FABB, a menor dose efetiva foi de 200 mg/Kg contra 500 mg/Kg do EMBB neste mesmo modelo experimental. As frações também foram capazes de melhorar a expressão de PGE2 na mucosa gástrica (no entanto sem significância estatística). Porém, a expressão de PGE2 foi revertida no caso da FABB pela prévia...
The medicinal plants evaluated in this work were selected based on their brazilian folk medicine information, which appoints their use for gastritis and gastrointestinal disturbances. Thus, pre-clinical experiments were accomplished for gastroprotective activity, healing gastric mucosal evaluation and toxicity of the methanolic extracts obtained from the leaves of M. elliptica (manapuçá) (EMME) and Byrsonima basiloba (murici-de-ema) (EMBB). Fractions derived from these extracts (M. elliptica ethyl acetate fraction - FAEME and B. basiloba aqueous fraction - FABB) were investigated for their gastroprotective potential and PGE2 quantification on gastric mucosa. After the gastroprotective effect from both extracts were observed, the tests were directed to find information about the mechanisms of action involved. Then, it was found that both extracts presented a gastroprotective activity related to the sulfhydryl compounds, being EMBB also dependent of the protection mediated by nitric oxide. The gastroprotection conferred by the extracts also acted independently of the antisecretory or intestinal mobility alteration effects. At the imunohistochemical analysis, EMME seems to stimulate cell proliferation at the healing area, while EMBB apparently stimulate the local angiogenesis. For the absolute ethanol gastroprotective model, FAEME conferred an effective dose 5 times lower than its precursor EMME (50 and 250 mg/Kg respectively). For FABB, the minor effective dose was 200 mg/Kg against 500 mg/Kg obtained for its originator EMBB, at the same experimental model cited. The fractions were also capable to increase the PGE2 expression at the gastric mucosa, although without statistical significance. However, the expression of PGE2 was antagonized for FABB when a non-steroidal anti-inflammatory drug (piroxicam 60 mg/Kg) was previously administered. Polyphenolic substances (mostly flavonoids) seemed...(Complete abstract click electronic access below)
The medicinal plants evaluated in this work were selected based on their brazilian folk medicine information, which appoints their use for gastritis and gastrointestinal disturbances. Thus, pre-clinical experiments were accomplished for gastroprotective activity, healing gastric mucosal evaluation and toxicity of the methanolic extracts obtained from the leaves of M. elliptica (manapuçá) (EMME) and Byrsonima basiloba (murici-de-ema) (EMBB). Fractions derived from these extracts (M. elliptica ethyl acetate fraction - FAEME and B. basiloba aqueous fraction - FABB) were investigated for their gastroprotective potential and PGE2 quantification on gastric mucosa. After the gastroprotective effect from both extracts were observed, the tests were directed to find information about the mechanisms of action involved. Then, it was found that both extracts presented a gastroprotective activity related to the sulfhydryl compounds, being EMBB also dependent of the protection mediated by nitric oxide. The gastroprotection conferred by the extracts also acted independently of the antisecretory or intestinal mobility alteration effects. At the imunohistochemical analysis, EMME seems to stimulate cell proliferation at the healing area, while EMBB apparently stimulate the local angiogenesis. For the absolute ethanol gastroprotective model, FAEME conferred an effective dose 5 times lower than its precursor EMME (50 and 250 mg/Kg respectively). For FABB, the minor effective dose was 200 mg/Kg against 500 mg/Kg obtained for its originator EMBB, at the same experimental model cited. The fractions were also capable to increase the PGE2 expression at the gastric mucosa, although without statistical significance. However, the expression of PGE2 was antagonized for FABB when a non-steroidal anti-inflammatory drug (piroxicam 60 mg/Kg) was previously administered. Polyphenolic substances (mostly flavonoids) seemed...(Complete abstract click electronic access below)
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Plantas medicinais, Etnofarmacologia
Como citar
MOLEIRO, Fábio Cruz. Avaliação da atividade antiulcerogênica dos extratos e frações das folhas de Mouriri elliptica Mart. (Melastomataceae) e Byrsonima basiloba A. Juss. (Malpighiaceae). 2007. 100 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2007.