Comparison of the antioxidant activity and total phenolic contents in some Stachys species

The methanolic extracts of the aerial parts of nine Stachys species: S. persica Gmel., S. fruticulosa M. B., S. laxa Boiss. & Buhse., S. inflata Benth., S. turcomanica Trautv., S. subaphylla Rech. F., S. setiferaC. A. Mey., S. byzantina C. Koch and S. trinervis Aitch. & Hemsl. were investigated for their antioxidant activity and total phenolic content using FRAP and Folin-Ciocalteu assays respectively. S. persica Gmel. and S. fruticulosa M. B. had the highest antioxidant activity (61.42 and 62.02 mmol FeII/100g) and total phenolic content (3294.96 and 4450.36 mg gallic acid/100 g) among these nine species. There was a direct correlation between total phenol and antioxidant activity (R2 = 0.9446, p 0.001) which indicates that polyphenols are the main antioxidants