Antioxidative responses of Piper betle, L. (daun sirih) under paraquat stress

Abstract

Antioxidants include enzymatic and non-enzymatic antioxidant as well as bioactive plant phenols. The health benefits of this Piper betle are largely due to antioxidant vitamin supported by large number of phytochemicals, some with greater antioxidant properties. The objective of this study is to determine the effects of oxidative stress induced by paraquat (PQ) on the level of antioxidative constituents (carotenoid, ascorbic acid, and a.-tocopherol) in Piper betle. Leaf disc of Piper betle were treated with different concentrations of PQ (0, 15, 30, 60 µM) for 7 days. At the earlier stages of PQ treatment, increasing of PQ concentrations enhanced the level of non-enzymatic antioxidants compared to control. Excess PQ application (60µM) lowered the ascorbic acid, carotenoid, and a.-tocopherol concentration. Results revealed that PQ induced the oxidative stress in Piper betle.