EVALUATION OF ANTI-OXIDANT ACTIVITY AND ACUTE TOXICITY OF BAUHINIA STRYCHNIFOLIA STEMS

Abstract

Bauhinia strychnifolia Craib. is one of the Bauhinia plants that has been traditionally used in Thai folk medicine. The present study aimed to investigate the anti-oxidant activity and acute toxicity of B. strychnifolia stems by DPPH radical scavenging assay and acute toxicity test in mice, respectively. The ethanolic extract of B. strychnifolia effectively neutralized harmful extracellular free radicals in the DPPH assay with an IC₅₀ value of 2.2 µg/mL. Moreover, the ethyl acetate fraction obtained from fractionation of the ethanolic extract also exhibited the same effect with the IC₅₀ value of 2.5 µg/mL. The acute toxicity of the ethanolic extract and ethyl acetate fraction of B. strychnifolia was found to be greater than 2.0 g/kg of body weight in both male and female Swiss albino mice.  In addition, during the day of the observation period, the animals were observed with no significant signs of toxicity, adverse pharmacological effects or abnormal behavior. The ethanolic extract of B. strychnifolia had total phenolic and total flavonoid contents with 550.3 µg GAE/mg extract and 337.0 µg catechin/mg extract, respectively, while the ethyl acetate fraction had those contents with 655.6 GAE/mg extract and 441.0 µg catechin/mg extract, respectively. The results indicated that the ethanolic extract and ethyl acetate fraction of B. strychnifolia had high anti-oxidant activity and were safe. From this study, the stem of B. strychnifolia was found to contain phenolic and flavonoid compounds which might be responsible for the anti-oxidant activity of this plant.