IN-VITRO ANTIOXIDANT AND CYTOTOXIC ACTIVITY OF EXTRACTS OF BACCHARIS-CORIDIFOLIA DC

The in vitro antioxidant and cytotoxic activities in different extract s of Baccharis coridifolia DC. (Compositae) were studied using differe nt bioassays. Antioxidant activity was tested using hydroperoxide-init iated chemiluminescence (CL) in rat liver homogenates. The aqueous ext ract showed antioxidant activity (IC50 = 141 mu g/ml), while the dichl oromethane and methanol extracts were prooxidant. Activity in the aque ous extract was confirmed by determination of thiobarbituric acid-reac tive substances (TBARS), showing an IC50 = 556 mu g/ml. On the other h and, studies on the cytotoxic activity demonstrated a 78% crown gall t umour inhibition and an ED50 = 4.2 mu g/ml in KB cells growth for the dichloromethane extract. A. 56% decrease in the initial absorbance of DNA-Methyl Green complex could also be observed at 1000 mu g/ml, sugge sting the presence of compounds that interact with DNA. (C) 1997 Elsev ier Science Ireland Ltd.