Studies on the antioxidant activity of Indian Laburnum (Cassia fistula L.):: a preliminary assessment of crude extracts from stem bark, leaves, flowers and fruit pulp

The antioxidant properties of 90% ethanol extracts of leaves, and 90% methanol extracts of stem bark, pulp and flowers from Indian Laburnum (Cassia fistula L.) were investigated. The antioxidant activity power was in the decreasing order of stem bark, leaves, flowers and pulp and was well correlated with the total polyphenolic content of the extracts. The reason for low antioxidant activity in the flower and pulp fractions could be the presence of some prooxidants, such as chrysophanol and reducing sugars which dominate the antioxidant compounds present in the extracts. Thus, the stem bark had more antioxidant activity in terms of reducing power, inhibition of peroxidation, O-2(-). DPPH radical scavenging ability. (C) 2002 Elsevier Science Ltd. All rights reserved.