Antioxcidative compounds of Stenochlaena palustris (paku mindin) at different leaf stages

Abstract

Plants possess a self-defense mechanism to counteract the oxidative stress that caused by the accumulation of reactive oxygen species (ROS). In plant, antioxidant composed of enzymatic and non-enzymatic antioxidants. Enzymatic antioxidant includes ascorbate peroxidase (APx), catalase (CAT), guaiacol peroxidase (G-POD) and superoxide dismutase (SOD) while the non-enzymatic antioxidant comprise of ascorbic acid, a-tocopherol, carotenoid and flavonoid. Stenochlaena palustris (paku midin) is a type of fems that widely distributed in Malaysia. Objectives of this study are to determine and compare the level of antioxidative compounds in S. palustris at different leaf stages, i.e. stage 1 (frond), stage 2 Guvenile leaf), stage 3 (matured leaf). The antioxidant assayed includes APx, CAT and G-POD specific activity as well as ascorbic acid, a-tocopherol and carotenoid content. Among the three stages, juvenile leaf contained the highest specific activities of APx and CAT as well as a-tocopherol and carotenoid content. On the other hand, matured leaf exhibited highest specific activity of POD and ascorbic acid concentration. The results suggest that juvenile leaf is a good source of dietary antioxidants due to high concentrations of antioxidants compared to other stages.