摘要:Problem statement: Free radical stress leads to tissue injury and progression of disease conditions such as arthritis, hemorrhagic shock, atherosclerosis, diabetes, hepatic injury, aging and ischemia, reperfusion injury of many tissues, gastritis, tumor promotion, neurodegenerative diseases and carcinogenesis. Safer antioxidants suitable for long term use are needed to prevent or stop the progression of free radical mediated disorders. Approach: Many plants possess antioxidant ingredients that provided efficacy by additive or synergistic activities. A. polystachya bark was a strong astringent, used for the treatment of liver and spleen diseases, rheumatism and tumors. Antioxidant activity of the crude extracts of bark of A. polystachya were assessed using NBT, DPPH, ABTS and FRAP assays. The potent fraction (AP-110/82C) was tested for in vivo efficacy Results: The methanol, aqueous methanol and water extracts exhibited potent antioxidant activity compared to known antioxidants. In vivo studies on potent fraction AP-110/82C demonstrated dose dependent reduction in hepatic malondialdehyde (320.6, 269.3 and 373.69 μM mg-1 protein) with simultaneous improvement in hepatic glutathione (6.9, 17.1 and 5.8 μg mg-1 protein) and catalase levels (668.9, 777.0 and 511.94 μg mg-1 protein) respectively for 50, 100 mg kg-1 doses and control) compared to control group. Conclusion: Due to its natural origin and potent free-radical scavenging ability A. polystachya could be used as a potential preventive intervention for free radical-mediated diseases.