Evaluation of Antioxidant Enzyme Activities in Withania somnifera L. in vitro and in vivo Grown Explants

Background: Withania somnifera L. Dunal, (Ashwagandha) belongs to the family Solanaceae and is known as ‘Indian ginseng’ in the traditional system of medicine. Objectives: In the present investigation, comparative analysis was carried out between two different ecotypes of W. somnifera related to total soluble protein and antioxidant enzyme activity [catalase (CAT), superoxide dismutase (SOD) and guaiacol peroxidase (GPX)] to find out the expression of isozyme in response to climatic variation. Materials and Methods: Viable and healthy seeds were germinated under the optimal condition to develop the in vitro and in vivo plants. The plant materials were taken for the analysis of total soluble protein and evaluated for antioxidant enzyme activity in both ecotypes. Results: Maximum protein (15.54 mg/gm fresh weight) was quantified from the in vitro grown plants of W1 ecotype. The CAT and SOD activity was found to be the maximum in W1 plants whereas, GPX activity was more in W2 plants. Specific activity staining of isozyme pattern exhibited only one band of CAT in all types of plants. In case of SOD, four isoforms (SOD 1, SOD 2, SOD 3 and SOD 4) were observed in W1 ecotype whereas one band (SOD 1) was missing in W2. Conclusions: The supplementation of required nutrients under in vitro condition enhanced the yield of antioxidant enzymes. The geographical distribution of plants contributes to the variation in the expression of the isozyme in the same species, and that may be due to the climatic variation.