Antioxidant activity of the methanol and ethanol extracts of endemic Thymus malyi Ronninger

Abstract

The genus Thymus L. from the family Lamiaceae consists of about 215 species of herbaceous perennials and sub-shrubs widespread in the arid parts of the Mediterranean region. Thymus malyi Ronninger is an endemic species from the central Balkan which grows on serpentine hills, spreaded on dry, rocky, from the lowland to the mountains. Essential oils of many Thymus species are well known for their antioxidant activity. Since there are no data about antioxidant activitity of extracts of T. malyi, in the present study we have investigated and compared possible antioxidant activity of the methanol and ehtanol extracts from T.malyi among each other and with artificial food additive BHT using 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Free radical scavenging activity was IC50=0,0370 mg/ml for the methanol extract, and IC50=0,0336 mg/ml for the ethanolextract. The results showed that the methanol and ethanol extracts of Thymus malyi Ronninger have significant antioxidant activity, almost the same among each other, and stronger than artificial antioxidant BHT (IC50=0.310 mg/ml), and suggest the use of alcoholic extracts, not only essential oils, for food preserving purpose.