In vitro antioxidant activities and an investigation of neuroprotection by six Salvia species from Iran: A comparative study

Methanolic extracts of six species of Salvia (S. hydrangea, S. lachnocalyx, S. macilenta, S. multicalis, S. sclarea and S. xanthocheila) were analyzed for their antioxidant properties, ability to prevent DNA damage by free radicals, and neuroprotective effects. Several biochemical assays were used to evaluate their antioxidant properties: DPPH, FRAP, β-carotene bleaching and TEAC assays. The amounts of phenolics and flavonoids were also determined. Comparison study of Salvia species showed that extracts from S. hydrangea and S. macilenta are strong antioxidants and that from S. lachnocalyx is a weak one. Furthermore, extracts from all of these species can at high concentrations (⩾50 μg/ml) inhibit DNA damage by free radicals. Furthermore, these species not only showed no cytotoxic effects in nerve growth factor (NGF)-differentiated PC12 cells, they also protected them against H2O2-induced cell death. Thus these plants may be candidates for treating neurodegenerative diseases.