Avaliação da atividade antioxidante in vitro e in vivo de extratos preparados a partir das folhas de Syzygium cumini (L.) Skeels

Abstract

Syzygium cumini (L.) Skeels, known as jambolan, is one of the most medicinal plants used in folk medicine. Although it origin in the India, this species is cultivated in many countries, including Brazil. All parts of the species (leaves, seeds, fruit and bark) have a long history of medicinal use in several popular cultures. Leaves of Syzygium cumini (L.) Skeels are used for the treatment of fever, stomachalgia, gastropathy and mainly diabetes. The present study evaluated the antioxidant activity both in vitro and in vivo of three different extracts prepared from the leaves of Syzygium cumini (L.) Skeels. Antioxidant activity in vitro of the extracts was assessed by different methodologies such as scavenger of the DPPH radical, total antioxidant capacity and reducing power of the iron (III). As an in vivo model, we used Saccharomyces cerevisiae strains proficient and deficient in superoxide dismutase (SOD). Growth of the strains and lipid peroxidation were assessed after 24 hours exposure concomitantly to paraquat (pro-oxidant) and different concentrations of the extracts. The extracts showed to have antioxidant activity in vitro through the ability to donate electrons and hydrogen. In the in vivo assays, paraquat inhibited the growth and increased lipid peroxidation in strains treated only with paraquat. The three extracts were able to assist the growth of strains and reduce lipid peroxidation even in the presence of paraquat. The contents of phenolic compounds and flavonoids could be correlated with the antioxidant activity observed in the extracts. The results indicate that leaves of Syzygium cumini (L.) Skeels possess antioxidant activity which may contribute to their traditional use in treatment of many diseases.