Antioxidant properties of Rubus discolor leaf extracts

In this work were examined aqueous, methanol, ethanol and acetone leaf extracts of Rubus discolor, wild growing blackberry, for their antioxidant properties and total phenol and flavonoid content. The total phenol content (TPC) varried from 250.05 to 446.61 mg GAE/g of dry extract, while total flavonoid content (TFC) was in range between 22.44 and 61.15 mg QE/g of dry extract. Aqueous extracts were the richest in phenols, as well as in flavonoids. In vitro antioxidant capacity of leaf extracts was evaluated by 2,2-diphenyl-1-picrylhydrazil (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging procedures and ferric reducing ability of plasma (FRAP) assay. Aqueous extracts were the most effective through all antioxidant tests. The total phenol content highly correlated with antioxidant activity of extracts. Moreover, weak correlation was established between total phenol and total flavonoid content. The results presented in this work indicate that phenol compounds contribute to antioxidant ability of extracts. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173029