Antioxidant activities of different Teucrium montanum L. extracts

The sequential extraction of Teucrium montanum L. was realised with five solvents of different polarities (70% methanol, petroleum ether, chloroform, ethyl acetate, and n-butanol) and HPLC method was used for identification of phenolic compounds. The total phenolic content of the extracts was determined spectrophotometrically according to the Folin-Ciocalteau procedure and range from 0 to 296 mg g(-1). The antioxidant activity of extracts was tested by measuring their ability to scavenge reactive hydroxyl radical during the Fenton reaction, using electron spin resonance (ESR) spectroscopy. Moreover, the influence of these extracts on lipid peroxyl radicals obtained during lipid peroxidation of: (1) sunflower oil (37 degrees C, 3 h) induced by 4,4'-azobis(4-cyanovaleric acid) (ACVA) and (2) liposomes induced by 2,2'-azobis(2-amidino-propane)dihydrochloride (AAPH) was studied. n-Butanol extract, because of the highest content of total phenolic compounds (296 mg g(-1)) had the best antioxidant activity (100% at 0.16 mg mL(-1) in Fenton reaction system; 90.57% at 5 mg mL(-1) in system I; 100% at 5 mg mL(-1) in system II).