Cytotoxic, Antioxidant and Antimicrobial Activities and Phenolic Contents of Eleven Salvia Species from Iran

The plants of the genus Salvia synthesize several types of secondary metabolites with antimicrobial, cytotoxic, and radical scavenging activities and are used in the folk medicine of different countries. Eleven Salvia species including S. aegyptiaca, S. aethiopis, S. atropatana, S. eremophila, S. hypoleuca, S. limbata, S. nemorosa, S. santolinifolia, S. sclarea, S. syriaca, and S. xanthocheila were collected from different localities in Iran and screened for their cytotoxic activity using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. The antioxidant potential and total phenol contents of the plant extracts were assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and Folin- Ciocalteu reagent respectively and finally antimicrobial activity of the above extracts were determined by using agar disc diffusion (ADD) and nutrient broth micro-dilution (NBMD) bioassays. Cytotoxic activity of methanol, 80% methanol and dichloromethane extracts of these plants were assessed on 3 human cancer cell lines. All of the extracts of S. eremophila and S. santolinifolia were active at IC50 values of 10.5-75.2 μg extract/mL, while the methanol and dichloromethane extracts of S. limbata, S. hypoleuca and S. aethiopis showed considerable cytotoxic activity against the tested cell lines. Among the tested plants for their antioxidant activity, S. nemorosa, S. atropatana, S. santolinifolia, and S. eremophila were the most active radical scavengers with higher total phenol contents while, S. limbata, S. xanthocheila and S. aegyptiaca were the weakest ones. The methanol extracts of S. santolinifolia, S. eremophila, S. sclarea and S. limbata inhibited the growth of all tested bacterial strains.