ABSTRACT
Abstract Catharanthus roseus (L.) G. Don, Apocynaceae, is an immensely important medicinal plant, produces a variety of anticancerous compounds. The yield of two most investigated alkaloids vinblastine and vincristine is unfortunately very low. A vast array of technologies including elicitation have recently been used to enrich Catharanthus alkaloid in culture. Yeast extract is a biotic elicitor, the polysaccharide and the peptide moiety have been recognized as a signalling element in enriching secondary metabolites. In this study, the yeast extract elicitation on vinblastine and vincristine was studied in various protoplast derived tissues and plantlets. Four different yeast extract treatments (T1 = 0.5 g/l, T2 = 1.0 g/l, T3 = 1.5 g/l and T4 = 2.0 g/l) were prepared and used. The alkaloid was quantified and a comparative account of yield were presented by the use of High performance thin layer chromatography. The yeast extract amendment in medium improved vinblastine and vincristine yield in cultivating tissues, maximum being in germinating embryos and in in vitro raised leaf. The highest yield was in T3 (1.5 mg/l) in which 22.74% vinblastine and 48.49% vincristine enrichment was noted in germinating embryos; the enhancement was however, treatment-specific. Antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase activities were investigated as addition of yeast extract caused cellular stress and had enriched level of alkaloids.