Comparison of total phenolic content and antioxidant activity in different Salvia species using three model systems

• In this research, total phenolic content and antioxidant activity of seven Salvia species were investigated.
• This research was the first report for S. persica and S. cereal.
• In DPPH and reducing power assay, the highest and the lowest antioxidant activity obtained for S. virgata and S. persica, respectively.
• In β-carotene/linoleic acid system, S. persica and S. virgata species had the highest antioxidant activity followed by S. officinalis.
• The strongest reducing power activity was exhibited by S. virgata.

In the present study, total phenolic content and the antioxidant activity of methanolic compounds extracted from the aerial parts of seven Salvia species (S. virgata, S. nemorosa, S. officinalis, S. sclarea, S. persica, S. reuterana and S. cereal) sampled in Iran were investigated. Total phenolic content and the antioxidant activity of S. persica and S. cereal were reported for the first time. The antioxidant activity of the samples was determined by three spectrophotometric methods, namely, DPPH, reduction of power and β-carotene/linoleic acid. Total phenolic content ranged from 33.83 to 114 mg Tannic acid/g DW. In both DPPH and reduction of power assays, the highest and lowest antioxidant activity was obtained for S. virgata (IC50 = 198 μg/ml) and S. persica (IC50 = 1810 μg/ml), respectively, while in β-carotene/linoleic acid system, S. persica and S. virgata species had the highest antioxidant activity, followed by S. officinalis. The analysis showed that there were no significant correlations between antioxidant activities and total phenolic content. Cluster analysis classified the species based on their phenolics and different antioxidant activity model systems. In all clusters, S. nemorosa and S. reuterana were put in one group and S. virgata and S. officinalis were classified in another group. Finally, the results of this study introduced the Salvia species as potential natural antioxidants with appreciable antioxidant activity.