Evaluation of in vitro antioxidant and cardioprotective properties of selected plant methanolic extracts from Sarawak, Malaysia

This study assessed the antioxidant properties of ten aqueous alcoholic extracts of edible leafy plants using various in vitro methods, including cell culture-based assays. Half of the extracts contained very high total phenolic contents (>4 mg GAE/100 mg dry plant powder), often associated with high antioxidant properties. Of these, Dillenia suffruticosa and Eugenia polyantha consistently showed high antioxidant activities. Both extracts afforded protection against H2O2-induced oxidative damage on H9c2(2-1) rat myoblast cell line, with E. polyantha (LD50 = 60 mg/L) being a better candidate for antioxidative cardioprotective agent than D. suffruticosa (LD50 = 650 mg/L), due to its lower cytotoxicity.