In vitro propagation and cell cultures of memory tonic herb Evolvulus alsinoides: a best source for elicited production of scopoletin

摘要

Evolvulus alsinoides L. is used for preparation of 'Shankhapushpi', an important popular ayurvedic drug that contributes considerably to the improvement of memory power. The improvement is attributed to the presence of furanocoumarin scopoletin, a metabolite with a wide range of biological activities. This report describes, for the first time, an in vitro culture system for propagation and enhanced production of scopoletin. Different concentrations of auxins and cytokinins individually and in combination were used in Murashige and Skoog (MS) medium to induce shoot regeneration in cotyledonary nodal explants and callus formation in leaf explants. The best response was achieved in MS medium fortified with 5.0 mu M 6-benzyladenine (BA) in which 96 % of cultures produced 7.6 +/- 0.6 shoots per explant. Regenerated shoots were rooted on MS medium with 5.0 mu M indole-3-acetic acid (IAA). Plantlets were successfully acclimatized and established in soil. MS medium fortified with 10 mu M BA + 5.0 mu M IAA showed maximum growth and accumulation of scopoletin in cell cultures. Cell cultures could be maintained over 24 months. The influences of auxins, cytokinins, organic acids, amino acids, and fungal-derived elicitors on production of scopoletin were studied. Presence of either L-arginine, sodium pyruvate, or yeast extract highly promoted scopoletin production as compared with control and achieved 75.02-, 72.13-, and 57.98-fold higher accumulation, respectively. The results presented herein have laid solid foundation for large-scale production of scopoletin and further investigation of its purification and utilization as a novel pharmaceutical drug.