Plant growth regulators induced changes in antioxidant potential and andrographolide content in Andrographis paniculata Wall.ex Nees

In this study, 5 μM ABA and GA₃ concentration were used to study the effect of these growth regulators on the andrographolide content and antioxidant potentials of Andrographis paniculata. The growth regulators were applied by means of foliar spray during morning hours. A significant enhancement in non-enzymatic antioxidant contents was observed in all sampling days in A.paniculata plants under ABA and GA₃ treatments. Ascorbic acid and α-tocopherol content was increased significantly under the growth regulator treatments in leaves, stem and roots of A. paniculata. The activities of antioxidant enzymes such as ascorbate peroxidase, superoxide dismutase and catalase were increased by ABA and GA₃ treatments in the leaves, stem and roots of A. paniculata plants. The HPLC analysis was used to quantify the andrographolide content in control and growth regulator treated plants. The growth regulators ABA and GA₃ treated plants showed increased contents of andrographolide when compared to control.