Antioxidant activity of mimonosides isolated from In vitro regenerated plants of Mimosa hamata willd.

Plants are major source for the discovery of new products of medicinal value for drug development. Different strategies including use of in vitro system, have been extensively studied to improve the production of plant chemicals. The present study is focused on the application of tissue culture technology for the production of some important plant pharmaceuticals. Under this, biosynthetic potentialities of in vitro regenerated plants of Mimosa hamata Willd. on Murashige and Skoog's (MS) medium have been evaluated for their phytochemicals and antioxidant activity. Three mimonosides A, B and C were isolated and identified on the basis of physical and spectral data from the n-butanol fraction of in vitro regenerated roots, using column chromatography. Similarly, in both in vivo and in vitro plant parts (root, stem and leaves) free radical scavenging activity was also studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and compared with standard antioxidants (quercetin and ascorbic acid). The extract of in vivo roots was found to be a good scavenger of DPPH radicals (RC₅₀ 5 g/ml) as compared to in vitro root extract (RC₅₀ 9 g/ml) comparable to the standards. It is evident from the results that M. hamata synthesizes useful bioactive metabolites and a potential source of natural antioxidant(s).