Iron(III) reducing and antiradical activities of three Sideritis from Turkey

Abstract

Objective: The antiradical activities of the various solvent extracts of Sideritis species are investigated here for the first time. Materials and methods: Plant samples were sequentially extracted with n-hexane, dichloromethane, methanol, and aqueous methanol (50%, v/v) in Soxhlet apparatus. The extracts of Camellia sinensis (L.) Kuntze (Theaceae) were also prepared for use as a positive control. Total phenolics, iron(III) reductive effects, and 1,1-diphenyl-2-picrylhydrazyl (DPPH<SU center dot aEuro cent</SU) radical scavenging activities of the all extracts were measured colorimetrically. Results: The aqueous MeOH and MeOH extracts contained the highest amount of total phenols, whereas the n-hexane extract contained the lowest amounts. The polar extracts of C. sinensis showed higher antiradical activity and also iron(III) reductive effects than the Sideritis species; however, the non-polar extracts of Sideritis species were found to be more active than those from C. sinensis in the iron(III) reductive assay and in the DPPH<SU center dot aEuro cent</SU assay as well. But none of the extracts was found to be as active as with positive controls, viz., ascorbic acid, butylated hydroxyanisole (BHA), and Trolox. Discussion and conclusion: These results can be shown to have antioxidant activities of these Sideritis species and support the ethnopharmacological use of these Sideritis plants.