Free radical-scavenging activity of acetone extract/fractions of Acacia auriculiformis A. Cunn.

The antioxidant potency of acetone extract/fractions of Acacia auriculiformis A. Cunn. was investigated by employing various in vitro systems, such as DPPH, deoxyribose (site- and non-site-specific), reducing power, chelating power and lipid peroxidation in rat liver homogenate. The bark powder of the plant was extracted with different solvents by a maceration method in order of increasing and decreasing polarities and then partitioned (Flow Charts I and 2). It was observed that the fractions were comparatively more effective than the crude acetone extract in all the assays. Maximum inhibitory activities noticed were 72.3%, 91.7%, 1.63, 83.3%, and 70.9% in DPPH, deoxyribose, reducing power, chelating power and lipid peroxidation assays, respectively. The inhibitory potential was compared with known antioxidants (ascorbic acid and BHT) and correlated with the total phenolic content in crude extract and fractions. Fractions rich in polyphenolic content were more effective than crude extract. Further studies are underway to isolate and elucidate the structures of the active principles. (c) 2006 Elsevier Ltd. All rights reserved.