Vol. 12, Issue 5 (2023)

Author(s):
Hariharan T and Vasan P

Abstract:
The aim of the present investigation was to evaluate the antioxidant activities of whole plant extracts of Andrographis paniculata (APWP) by in vitro model DPPH free radical scavenging assay. Gallic acid, at a concentration of 0.5, 1.5, 2.0 and 2.5 µg/ml was used as reference inhibitor in DPPH assay which showed 6.55, 23.24, 44.32 and 78.72 percent inhibition of DPPH free radicals, respectively with IC₅₀ value of 2.65 µg/ml (2.31- to 3.08 µg/ml). Both ethanolic and aqueous extracts of APWP at a concentration of 10, 25, 50, 100 and 200 µg/ml showed 0, 0, 2.38, 15.10 and 38.75 percent inhibition and 9.39, 13.80, 15.57, 24.96 and 39.07 percent inhibition of DPPH free radicals, respectively. The IC₅₀ value of the ethanolic and aqueous extract samples in DPPH radical scavenging assay was 292.96 µg/ml (224.74 - 448.95 µg/ml) and 681.66 µg/ml (320.35 - 3518.99 µg/ml) respectively. So, the in vitro studies clearly showed that the whole plant extracts of A. paniculata has a significant antioxidant activity and the aqueous extract was found to be more effective in the hydroxyl radical scavenging activity with better IC₅₀ value than the ethanolic extract of APWP. It could therefore be concluded that the free radical scavenging activity of the whole plant extract of Andrographis paniculata might be responsible for the therapeutic properties.