In vitro callus culture studies of Gymnema sylvestre R. Br. leaves for production and identification of Gymnemic acid (as Gymnemagenin) using HPTLC

Gymnema sylvestre R. Br. (Family: Asclepiadaceae) commonly called as Gudmar or Madhunashini is an endangered medicinal woody climber. Due to immense pharmaceutical potential of Gymnemic acid found in its leaves, the plant is widely used against various harmful ailments. Owing to its increased demand and continued over exploitation, the species is declining rapidly and is on the verge of extinction. Hence, in the present study, an attempt has been made to explore in vitro callus culture study for production of Gymnemic acid which may lead to conservation of Gymnema sylvestre R. Br., an important medicinal plant. Callus studies were carried out on MS and WPM media fortified with plant growth regulators (PGRs) including Auxins - 2, 4-dichlorophenoxyacetic acid (2,4-D) and Cytokinins - benzylaminopurine(BAP) from four different segments of leaf lamina (apical, middle, basal and petiole) for production of Gymnemic acid. Amongst all the tested combinations, apical segment of leaf on MS medium fortified with 2 mg l(-1) 2, 4-D + lmg l(-1) BAP combination produced maximum amount of green friable callus within 25 days of incubation. It was observed that MS medium fortified with 2, 4-D or BAP alone was less effective while 2, 4-D in combination with BAP was very effective in inducing and proliferating the callus. Further, Gymnemic acid was identified in these callus extracts and leaf extracts by developing a comparative fingerprint profile along with the standard Gymnemic acid (Gymnemagenin) using HPTLC.