ESTIMATION OF PHYTOSTEROLS USING GAS CHROMATOGRAPHY AND SYNTHESIS OF SILVER NANOPARTICLES IN CENTELLA ASIATICA

Abstract

In the Ayurvedic system of medicine, Centella asiatica (gotu kola) is one of the important rejuvenating herbs for nerve and brain cells and is believed to be capable of increasing intelligence, longevity, and memory. It contains several active constituents and the most important bioactive compounds are triterpenoid saponins, including asiaticoside, centelloside, madecassoside, and asiatic acid. It possesses anti-leprotic, anti-viral, anti-bacterial, anti-tumor activities. Due to its medicinal importance, this plant is being overexploited and to conserve this plant it is necessary to micropropagate this plant in laboratory with high biomass yeild. In the present investigation, estimation of phytosterols was done in five accessions of Centella asiatica and a comparative study for shoot multiplication was performed. For shoot culture, explants of different accessions of C. asiatica were inoculated in different media i.e. MS, Gamborg’s B5 and Nitsch which were supplemented with 1 mg/l BAP. The cultures were incubated at 25 ± 2 °C with photoperiod of 16 hours. After eight week of incubation period it was found that MS media showed highest growth in all the accessions. Estimation of stigmasterol was done and it was found the accession no.342109 showed highest amount of stigmasterol content i.e. 4.55±0.70μg/200mg of leaves. It was also found that all the accession contains β-sitosterol and tocopherol. In qualitative analysis of phytochemicals ethanolic, methanolic and aqueous extract of Centella asiatica (whole plant) were used. In case of ethanolic and methanolic extract it showed positive results for terpenoid, steroid, flavonoid and coumarins whereas in case of aqueous extract it showed positive results for terpenoid, steroid, flavonoid, coumarins and tannin. Further synthesis of silver nanoparticles was done and characterization of synthesized nanoparticles was done by using UV-VIS spectroscopy, FT-IR and SEM.