In vitro and in vivo Antioxidant Properties of Extracts from the Root of Curcuma longa Linn

Many plants possess antioxidants that exhibit additive or synergistic activities. The antioxidant activities of the root of Curcuma longa Linn extracts extracted different solvents were investigated by using several established in vitro systems: α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen Peroxide scavenging activity (HPSA), nitric oxide radical scavenging activity (NOSA) and ferric reducing antioxidant power (FRAP). The result showed that methanol extract exhibited greater antioxidant activity in vitro which was statistically significant compared to the other extracts. Based on the in vitro results, the methanol extract was subjected to column chromatography. Six pooled fractions (FI-FVI) were evaluated for in vivo antioxidant activity in liver and kidney of alloxan-induced diabetic rats using a total of forty-five (45) rats which were grouped into nine (9) groups of five (5) rats. The in vivo antioxidants showed a significant decrease in superoxide dismutase (SOD), catalase (CAT) and gluthatione peroxidase (GPx) levels in both liver and kidney of Alloxan-induced diabetic rats. These changes were significantly reversed after treatment with methanol fraction II and the standard drug. Thus, Curcuma longa Linn may be useful in the management of diabetes and oxidative stress.