Antioxidant and antimutagenic activity of Curcuma caesia Roxb. rhizome extracts

• DPPH forms purple color when dissolved in solution and its color is altered to slightly yellowish color with the intervention of rhizome extracts of Curcuma caesia Roxb.at different concentrations showing the scavenging activity against the free radicals generated by DPPH. The scavenging activity of the extracts tested follows the order EECC>MECC>EaECC>AECC.
• Total phenolic and reducing ability were also found to be increased in ethanolic extract as compared to other extracts.
• EECC, MECC, AECC were selected to test the antimutagenic activity against Cyclophosphamide (CP) using Salmonella typhimurium strains TA98 and TA100. S9 mix prepared from male mice liver was used to activate the cyclophosphamide. Cyclophosphamide produces free radicals Phosphoramide and Acrolein on activation with S9 mix causing mutations inside the living system which found to be ammeliorated by the secondary metabolites present in plants. All the extracts tested were found to be non mutagenic.
• CP can also act as positive control for the strain TA98 which was not reported ealier and this can be inhibited by the used of rhizome of Curcuma caesia Roxb. Extract.

The rhizomes of Curcuma caesia Roxb. (zingiberacea) are traditionally used in treatment of various ailments and metabolic disorders like leukoderma, asthma, tumours, piles, bronchitis, etc. in Indian system of medicine. Considering the importance of natural products in modern phytomedicine, the antioxidant and antimutagenic activities of C. caesia Roxb. rhizome extract and its fractions were evaluated. The ethanolic fraction showed highest antioxidant activity by DPPH assay (86.91%) comparable to ascorbic acid (94.77%) with IC50 value of 418 μg/ml for EECC followed by MECC (441.90 μg/ml) > EAECC(561 μg/ml) > AECC(591 μg/ml). Based on the antioxidant activity, three of the rhizome extracts were evaluated for their antimutagenic properties against indirect acting mutagen cyclophosphamide (CP) using Salmonella typhimurium strains TA98 and TA100. The antimutagenic activity of the extracts against indirect acting mutagen cyclophosphamide in the presence of mammalian metabolic activation system was found to be significant (p < 0.01, p < 0.05). All the extracts showed similar antimutagenicity in dose dependent manner. The total phenolic content as well as reducing ability of the extracts was also determined.