In vitro antioxidant activity of dewberry (Rubus caesius L. var. aquáticus Weihe. & Nees.) leaf extracts

In this study, the antioxidant properties and total phenolic and flavonoid contents of Rubus caesius L. var. aquaticus Weihe & Nees leaf extracts were examined. The radical scavenging capacity of four leaf extracts (methanol, ethanol, acetone and aqueous) was estimated against 2,2-diphenyl-1-picrylhydrazil (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assays. Total antioxidant capacity was tested by ferric reducing ability of plasma (FRAP) and total reducing capacity (TRC) procedures. Total contents of phenols and flavonoids were also determined. Total phenol content in the extracts was determined using Folin-Ciocalteu reagent and amounts ranged between 263.74 for ethanol to 366.27 mg gallic acid (GA)/g for acetone extracts. The amounts of flavonoids varied from 10.73 mg quercetin equivalent (QE)/g for aqueous to 75.83 mg QE/g for acetone extract. The highest antioxidant activity against DPPH and ABTS●+ radicals was that of the acetone extract. Values for FRAP varied between 3.00 μmol Fe+2/mg for the ethanol extract and 5.31 μmol Fe+2/mg for the methanol extract. The results obtained for total reducing capacity indicate that the acetone extract has the highest antioxidant potential. [Projekat Ministarstva nauke Republike Srbije, br. 173029]