Production of gymnemic acid from hairy root cultures of Gymnema sylvestre R. Br. as influenced by polyunsaturated fatty acids (PUFAs) and their antioxidant activity

Elicitation is one of the few strategies that find commercial application in the improvement of secondary metabolite production from plants as well as cell and organ culture systems. Gymnema sylvestre is an important medicinal plant which bears bioactive compound namely gymnemic acid that finds application in the treatment of diabetes. The present study relates to different polyunsaturated fatty acids (PUFAs) as elicitors to enhance biomass accumulation and gymnemic acid production in hairy root cultures of G. sylvestre. Hairy root cultures of G. sylvestre were elicited with oleic and linolenic acid at 0, 1, 5, 10 and 50 μM concentrations respectively. Elicitors were added to the hairy root cultures on 15th day of culture and the roots were harvested on day 20. Cultures supplemented with 1 and 5 μM linolenic acid enhanced the gymnemic acid content significantly (45.10 ± 0.11 mg g−1 DW) and (87.99 ± 0.53 mg g−1 DW) compared to that of control (11.30 ± 0.20 mg g−1 DW) respectively without the decrease of hairy root biomass. An increase of 7.78 fold increment of gymnemic acid content was evident with 5 μM linolenic acid compared to that of the control. Supplementation of oleic acid also increased the production of gymnemic acid content in hairy root cultures but not in considerable amounts compared with the linolenic acid treatments. Changes in the total phenolics, flavonoids and antioxidant activity were evident upon elicitation with PUFAs. This is the first report on linolenic acid as an elicitor for gymnemic acid production in G. sylvestre hairy root cultures.