A COMPARATIVE STUDY ON ONTOGENIC EXPRESSION OF ANTIOXIDANTS AND SECONDARY METABOLITES IN WITHANIA SOMNIFERA

Abstract

Withania somnifera (WS), also known as Ashwagandha, Indian ginseng and winter cherry, has been an important herb in the ayruvedic and indigenous medical system for over 3000 years. Antioxidant activity and phytochemical analysis of both in vitro and in vivo grown leaves were studied in W. somnifera at different time period. Antioxidants are an important group of medicinal preventive compounds as well as being food additives inhibiting detrimental changes of easily oxidizable nutrients. The estimated antioxidant enzymes were superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase. The analyses were carried out in the leaves of in vitro and in vivo plants. It was found that in vitro leaves contained a significant quantity of enzymatic antioxidants than in the leaves of in vivo plants. Plants are able to produce and accumulate many medicinally valuable secondary metabolites. Search for the concerned active compounds has led to the identification of several withanolides, alkaloids, steroids, phenolics, tannins, saponins and quinones from leaves of

1. somnifera. The fresh leaves were extracted with increasing and decreasing polarity of solvents and it was found that ethyl acetate extract contains all the metabolites present in the leaves, analyzed by thin layer chromatography using chloroform: methanol in the ratio of 9:1 as solvent system. The chromatogram was developed using 10% sulphuric acid followed by heating and the spots were visualized. These findings have high significance in the pharmacological industry; however, a detailed investigation is needed to confirm this conclusion, which is underway in our laboratory.