Prospecção fitoquímica e avaliação dos efeitos biológicos do extrato etanólico das partes aéreas de Pilea microphylla (L.) Liebm. (Urticaceae): aspectos tóxico, mutagênico, antimutagênico e antioxidante

• Ano de defesa: 2009
• Autor(a) principal: Gomes, Tarsila Daysy Ursula Hermogenes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Biologia Vegetal; UFES; Programa de Pós-Graduação em Biologia Vegetal
• Palavras-chave em Português: Phenolic compounds; Antioxidant; Acute toxicity; Mutagenicity; Antimutagenicity; Compostos fenólicos; Mutagenicidade; Antimutagenicidade; Pilea microphylla; Fenóis; Antioxidantes; Toxicidade aguda; Agronomia; 57
• Link de acesso: http://repositorio.ufes.br/handle/10/9972

Pilea microphylla (L.) Liebm. (Urticaceae), popularly known as brilhantina in Brazil, is used as antipyretic, purifying the bladder, anti-diarrhea, anti-asthma and used for abdominal pain. Despite this medical use, there is no information about its biology and therapeutic efficacy. The objective of this work is to characterize the phytochemical, quantifying the total phenolic composition and total antioxidant capacity, and assess possible effects of the acute toxicity by LD50 (Median Lethal Dose), mutagenic and antimutagenic by micronucleus test in bone marrow and peripheral blood of mice. The dried aerial parts were subjected to maceration in absolute alcohol, resulting the crude ethanolic extract (CEE). The qualitative phytochemical prospection indicated the presence of reducing sugars, phenols and tannins, depsides and depsidons, coumarins, steroids and triterpenes. The concentration of phenolic compounds was 9.75 tannic acid equivalents and gallic acid equivalents 17.5 (reading in spectrophotometer), lower than the result found by other authors with other plant species. The antioxidant activity showed values similar or even higher than those found for other plant species. The test indicated no acute toxicity LD50, as obtained by another study. Nevertheless, the test for mutagenicity of CEE in doses 250 mg/Kg and 500 mg/Kg in bone marrow and peripheral blood of mice showed no significant increase in the frequency of micronuclei in polychromatic erythrocytes (MNPCEs) and normochromatic (MNNCEs) in marrow and peripheral blood, respectively, independent of concentration. The antimutagenic potential was evaluated in dose 250 mg/Kg in pre-treatment, post-treatment and simultaneous treatment. Only the post-treatment showed a decrease not significant in the frequency of MNPCEs on the positive control. In peripheral blood, it was found that post-treatment had lower values of MNNCEs. The results suggest that the indiscriminate and prolonged use (subchronic/chronic) preparations of Pilea microphylla may be harmful to health, due to the formation of micronuclei, but provide information for other studies to confirm the antimutagenic effect, to elucidate the mechanisms of mutagenicity and phytochemical composition, as important sources of bioactive compounds for the pharmaceutical industry for use in an isolated manner or in association with conventional treatments in various diseases such as cancer.