IN VITRO ASSESSMENT OF ANTIOXIDANT AND ANTIPROLIFERATIVE EFFICACY OF ANDROGRAPHIS PANICULATAAbstract
The present study investigated the antioxidant and antiproliferative efficacy of Andrographis paniculata, a well-known medicinal plant, using in-vitro systems. The dried leaves of A. paniculata were powdered and subjected to successive solvent extraction taking from polar to non-polar solvents (descending polarity) and simultaneously from non-polar to polar solvents (ascending polarity). Solvents used for extraction were hexane, chloroform, ethyl acetate, acetone, methanol, and water. All the extracts were screened for the presence or absence of various secondary metabolites. The antioxidant activity of all extracts at 100 μg/ml was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Further DPPH assay and reducing power assay were used to check the free radical scavenging capacity of methanolic and water extracts at their lower concentrations. The methanolic and water extracts of A. paniculata exhibited maximum DPPH inhibition of 20.75% and 17.71% respectively, at 100 μg/ml. A positive correlation between reducing power and concentration was found. Thin Layer Chromatography (TLC) of methanolic and water extracts of A. paniculata was performed. The antiproliferative effect of different concentrations of methanolic and water extracts on C6 glioma cells was investigated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The methanolic extract exhibited 50% inhibition of proliferation of C6 glioma cells at much lower concentration (12.5 μg/ml) than did the water extract (200 μg/ml). This study is a novel approach towards the antioxidant and antiproliferative role of methanolic and water extracts of A. paniculata which suggests its anticancer potential.