Antioxidant activity of Hedychium spicatum Buch.- Ham. rhizomes

Abstract

The different extracts of Hedychium spicatum Buch.-Ham. (Zingiberaceae) were evaluated for antioxidant activity by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and reducing power determination method. Total phenol and total flavonoid content in each extracts were also determined. Gallic acid and ascorbic acid were used as reference standards. They exhibited strong antioxidant DPPH radical scavenging activity with IC50 value of 0.43, 259.1, 386.7, 414.3, 77.01 and 51.54 μg/mL for gallic acid, petroleum ether, benzene, chloroform, methanol and aqueous extracts of rhizomes of H. spicatum, respectively. The absorbance for reducing power was found to be 0.540, 0.036, 0.042, 0.046, 0.050 and 0.072 for ascorbic acid, petroleum ether, benzene, chloroform, methanol and aqueous extracts of rhizomes of H. spicatum, respectively. Total phenol content was found to be 13, 33, 24, 32 and 35 mg equivalent to gallic acid per gram of petroleum ether, benzene, chloroform, methanol and aqueous extracts of rhizomes of H. spicatum, respectively. Total flavonoid content was found to be 4.6, 7, 7.5, 34.5 and 40 mg equivalent to rutin per gram of petroleum ether, benzene, chloroform, methanol and aqueous extracts of rhizomes of H. spicatum, respectively. The strongest antioxidant activity of the methanol and aqueous extracts could be due to the presence of flavonoids and phenols.