In vitro antioxidant and cytotoxic activity of extracts of Baccharis coridifolia DC

The in vitro antioxidant and cytotoxic activities in different extracts of Baccharis coridifolia DC. (Compositae) were studied using different bioassays. Antioxidant activity was tested using hydroperoxide-initiated chemiluminescence (CL) in rat liver homogenates. The aqueous extract showed antioxidant activity (IC50 = 141 mu g/ml), while the dichloromethane and methanol extracts were prooxidant. Activity in the aqueous extract was confirmed by determination of thiobarbituric acid-reactive substances (TBARS), showing an IC50 = 556 mu g/ml. On the other hand, studies on the cytotoxic activity demonstrated a 78% crown gall tumour 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, suggesting the presence of compounds that interact with DNA. (C) 1997 Elsevier Science Ireland Ltd.