RESUMO
ABSTRACT Mansoa hirsuta (Bignoniaceae) is a native plant from caatinga in Brazilian semiarid. This plant has been locally used as antimicrobial and hypoglycemiant agents, but their action mechanisms and toxicity remain largely unknown. Therefore, we evaluated the composition and antioxidant, cytoprotective and hypoglycemiant effects of raw extract, fractions and compounds from leaves of M. hirsuta. The cytogenotoxic effects of ursolic and oleanolic acids, the main phytotherapic components of this plant, were assessed. The raw extract and fractions presented steroids, saponins, flavonols, flavanonols, flavanones, xanthones, phenols, tannins, anthocyanins, anthocyanidins and flavonoids. The ethyl acetate fraction inhibited efficiently the cascade of lipid peroxidation while the hydroalcoholic fraction was richer in total phenols and more efficient in capturing 2,2-diphenyl-1-picrylhydrazyl (·DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS·+) radicals. The isolated fraction of M. hirsuta also inhibited the α-amylase activity. Cytotoxic effects were absent in both raw extract and fractions while ursolic+oleanolic acids were efficient in protecting cells after exposure to hydrogen peroxide. Moreover, this mixture of acid shad no significant interference on the mitotic index and frequency of nuclear and/or chromosomal abnormalities in Allium cepa test. Therefore, M. hirsuta represents a potential source of phytochemicals against inflammatory and oxidative pathologies, including diabetes.
Assuntos
Animais , Extratos Vegetais/farmacologia , Bignoniaceae/química , Hipoglicemiantes/farmacologia , Antioxidantes/farmacologia , Valores de Referência , Triterpenos/química , Brasil , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Reprodutibilidade dos Testes , Cricetinae , Folhas de Planta/química , Cebolas/efeitos dos fármacos , Citoproteção , Etanol/química , alfa-Amilases/química , Fibroblastos/efeitos dos fármacos , Hipoglicemiantes/isolamento & purificação , Antioxidantes/isolamento & purificaçãoRESUMO
A "carqueja", Baccharis trimera (Less) DC (Asteraceae), é uma espécie vegetal característica de regiões tropicais, muito utilizada na medicina popular como antiinflamatória, hipoglicemiante e em tratamento de problemas digestivos. A avaliação da atividade antiúlcera do extrato bruto liofilizado e do extrato liofilizado da "resina" (porção que durante a concentração dos extratos ficava depositada no fundo do recipiente com aspecto viscoso e pegajoso) foi realizada através de indução aguda por etanol acidificado. O extrato bruto liofilizado, na dose de 400 mg/ kg, reduziu a área de lesão em 90 por cento, 200 mg/kg, 87 por cento, 100 mg/kg, 66 por cento e o fármaco controle (lansoprazol), 66 por cento. O extrato liofilizado da "resina", administrado na dose de 400 mg/kg, reduziu a área de lesão em 82 por cento, 200 mg/kg, 82 por cento, 100 mg/kg, 53 por cento e o fármaco controle (lansoprazol), 70 por cento. A atividade antioxidante foi ensaiada com extrato bruto liofilizado, extrato liofilizado da "resina", pó da droga e frações clorofórmica, acetato de etila, etanol e etanol 50 por cento através do método que reduz o radical 2,2'-difenil-1-picril-hidrazil (DPPH), permitindo após o equilíbrio da reação, calcular a quantidade de antioxidante gasta para reduzir 50 por cento do DPPH, apresentando resultado evidente, comparado à vitamina E. Não foram verificados sinais de alteração aparente no ensaio de toxicidade na dose única de 5g/kg, em camundongos.
Baccharis trimera (Less) DC (Asteraceae) is a medicinal Brazilian plant well-known by "carqueja". Natural from tropical regions, used as home-made medicine as anti-inflammatory, hypoglycemiant and for the treatment of digestive problems. The evaluation of the antiulcer activity of the extract and the "resin" (portion which during the extracts concentration was settled at the bottom of the recipient, showing a viscous and clammy aspect), was accomplished through the acute induction by acidified ethanol. The lyophilized extract, at a dose of 400 mg/kg, reduced the lesion area at 90 percent; 200 mg/kg, at 87 percent; 100 mg/kg, at 66 percent; and the control (lansoprazol) at 66 percent. The "resin" administered at the 400 mg/kg dose reduced the lesion area at 82 percent; 200 mg/kg, at 82 percent, 100 mg/kg, at 53 percent and the control (lansoprazol), at 70 percent. The antioxidant activity of the lyophilized extract, of the "resin" of the powdered drug, of the chloroform, ethyl acetate, ethanol and 50 percent ethanol fractions was tested following the method which reduces the 2,2-dipheny l-1 -picrylhydrazyl (DPPH) radical, permitting after the reaction balance, to calculate the amount of antioxidant spent to reduce 50 percent of the DPPH. The result was meaningful, when compared with the vitamin E result. The acute toxicity test performed in mice showed no apparent alteration.