Terminalia chebula Retz. Stem Bark Extract: A Potent Natural Antioxidant

In vitro antioxidant activities and preliminary phytochemical profiling of the methanol extract of the stem bark of Terminalia chebula Retz. (METC) of Combretaceae family were investigated. Total reducing power of the extract increased with increasing concentration which indicated that the plant has inherent antioxidant potential. The extract at a concentration of 500μg/ml showed maximum activity (85.72%) for 2, 2-diphenyl-2-picryl-hydrazyl (DPPH) followed by nitric oxide (82.28%), superoxide (79.12%) and hydroxyl (77.28%) radicals. The IC50 values of DPPH, nitric oxide, superoxide and hydroxyl radicals were 72μg/ml, 73μg/ml, 69μg/ml and 80μg/ml respectively. METC had 28.6mg phenols per gram. METC showed the presence of phytoconstituents such as alkaloids, terpenoids, saponins, quinines, anthroquinones, tannins, carbohydrates, volatile oils, and phenolics. However, glycoside, coumarins, reducing sugars and resins were absent. Thin layer chromatogram showed two spots (Rf: 0.41, 0.56) under visible light and five spots (Rf: 0.41, 0.49, 0.56, 0.62, 0.71) on exposure to Iodine vapour. The findings suggest that the methanol extract of T. chebula possesses significant free radical scavenging activities in different in vitro models and could be a potent source of natural antioxidants.