Comparative study of the antioxidant activities of eleven Salvia species.

The lipid peroxidation-inhibiting activities of aqueous methanolic extracts of eleven Salvia species (Fam. Lamiaceae) were evaluated in an enzyme-independent biological system. The total polyphenol contents and the amounts of the most abundant phenoloids of the genus, caffeic and rosmarinic acids, were also determined. The EC50 values of the extracts displayed substantial differences. All of the investigated species except S. jurisicii (EC50 191.2 microg/mL) exhibited higher activities than that of ascorbic acid (EC50 123.8 microg/mL), the reference compound. Among the studied species, S. scabiosifolia (EC50 5.4 microg/mL) demonstrated the highest effect, followed in sequence by S. dumetorum, S. transsylvanica, S. officinalis l albiflora, S. nemorosa l albiflora and S. recognita (EC50 6.5 - 10.2 microg/mL). The close correlation was confirmed between the antioxidant activities and the total phenol contents of the extracts. For caffeic and rosmarinic acids, the correlation was much weaker, indicating the important role of other polyphenols in the antioxidant activity.