Abstract

Background: There are most studies on the antioxidant activity of Ribes nigrum and R. rubrum; however, this activity has been restricted on the other species. In the present study, the phenolic contents and antioxidant activities of different extracts prepared with methanol (MeOH), dichloromethane (DCM), ethyl acetate (EtOAc), n-buthanol (BuOH) and water from the leaf and branch of Ribes alpinum, R. anatolica, R. biebersteinii, R. multiflorum, R. nigrum, R.orientale, R.rubrum and R. uva-crispa, (Grossulariaceae) of Turkish origin were investigated by using in vitro methods.
Methods:The phenolic contents of the samples were determined using Folin-Ciocalteu's phenol reagent. Antioxidant activities of the extracts were studied by qualitative and quantitative DPPH^● (1,1-diphenyl- 2-picrylhydrazyl radical) assays to detect the free radical scavenging activity and thiobarbituric acid (TBA) assay for determining the amount of liposome lipid peroxidation.
Results:The highest total phenolic contents in investigated of leaf extracts were found in the EtOAc ranging from 1067,19 to 345,31mg/g in dry weight expressed in gallic acid equivalents (GAE). All extracts showed a strong antioxidant activity with the both DPPH^● test. The highest activity was observed in the water extracts of leaf and branch (0.30 and 0.44 μg/mL, respectively)of R.orientale when compared to the other plant extracts in the TBA test.
Conclusion: Ribes orientale leaf and branch of water extracts showed good antioxidant activity on both in vitro assays. These results revealed that R. orientalemay be a good antioxidant source of natural origin.