Atividade antioxidante do extrato etanólico de folhas de azeitona da terra (Syzygium Cumini L.) e seu efeito contra estresse induzido por paracetamol

Abstract

Syzygium cumini is a plant originated from India and adapted in Brazil, popularly known as black plum, jambolan and jamun. In this study, the antioxidant and protective activities of ethanolic leaves extract of Syzygium cumini (EE) were evaluated on paracetamol-induced liver damage in mice. The total antioxidant activity was determined by ABTS and DPPH methods and the content of vitamin C, extractable polyphenols, anthocyanins, yellows flavonoids and carotenoids were evaluated by different methods. The toxicity of EE was evaluated with different doses up to 1200 mg/kg administered orally for eight consecutive days. Subsequently, doses of the EE (150, 300 and 600 mg/kg weight) were administered by gavage for 7 consecutive days before treatment with single dose of paracetamol (500 mg/kg, orally) and its hepatoprotective effect has been studied by monitoring biochemical parameters. The extract presented high antioxidant activity in ABTS (2148.88 ± 140.26 mM Trolox/g of sample) and DPPH (87.11 ± 1.58 g of sample/g DPPH) assays. The extractable polyphenols prevailed among determined phytochemicals. Regarding toxicity, EE showed no toxic effects at the doses evaluated. EE (600 mg/kg) presented hepatoprotective effect that was evidenced by the decrease in the activities of alanine aminotransferase (56.94%), aspartate aminotransferase (30.14%) and alkaline phosphatase (32.68%) in the serum of animals treated with EE (600 mg/kg) and subjected to ingestion of paracetamol (EE600+ P group) compared with the group paracetamol. In liver tissue, there was a decrease of 25.68%, 31.67% and 31.97% of the malondialdehyde levels and elevation of 60.03%, 63.67% and 69.12% of the dismutase superoxide activity in EE150+ P EE300+ P and EE600+ P groups, respectively, when compared with the paracetamol group. Furthermore, non-protein sulfhydryls groups in the liver increased 56.74% and 63.61% in EE300+P and EE600 + P groups when compared with the paracetamol group. The ethanolic leaves extract of Syzygium cumini conferred hepatoprotection against stress by paracetamol, this effect may be associated to its high antioxidant activity.