Elite genotypes/chemotypes, with high contents of madecassoside and asiaticoside, from sixty accessions of Centella asiatica of south India and the Andaman Islands: for cultivation and utility in cosmetic and herbal drug applications.

摘要

Centella asiatica is a perennial herb with high utility in traditional medicines, herbal drugs and cosmeceutics. In India, owing to its high domestic and export demands, C. asiatica populations in the wild are overexploited at an uncontrolled rate. The aim of this study was to identify potential genotypes/chemotypes of C. asiatica from a wide geographical region in Peninsular India and the Andaman Islands, so as to emphasize cultivation of its high-yielding genotypes for commercial purposes. Sixty C. asiatica accessions collected from various locations in south India and the Andaman Islands were grown in a Field Gene Bank under identical environmental conditions. Potential ursane-type triterpene glycosides, madecassoside and asiaticoside, in the third generation vegetatively propagated progenies of these C. asiatica accessions were estimated simultaneously by precise HPTLC-densitometry. Methanol extracts of C. asiatica (whole plant) gave well resolved twin spots of both madecassoside and asiaticoside in the mobile phase (4:1:5, v/v) butanol:ethyl acetate:water, at R_f values 0.34+or-0.02 and 0.47+or-0.02, respectively. Both triterpene glycosides were evaluated densitometrically at 570 nm. Of the sixty accessions, highest detected madecassoside and asiaticoside contents were 5.67+or-0.08% (dry wt. of whole plant) and 1.70+or-0.02%, respectively. Three C. asiatica accessions showed only non-detectable (near zero) levels of both triterpene glycosides. Elite chemotypes/genotypes with high madecassoside/asiaticoside contents were discovered in this study, recommending their conservation and cultivation for large-scale applications of C. asiatica. Since the vegetatively propagated progenies of these sixty C. asiatica accessions were grown under identical environmental conditions, the variations in madecassoside/asiaticoside content(s) between them are only due to variations in their genetic make-up, expression levels and other biosynthetic steps. No correlation with the sea level heights of their original collection locations and madecassoside/asiaticoside content(s) was found in this study.