Effect of Extraction Methodologies on Antioxidant Potential and Synergistic Anticancer Behavior of Leaf Extract of Polygonum amplexicaule Against HCT-116 Cells

Medicinal plants have been used as a source of medicine in almost all societies in the history of mankind. Polygonum amplexicaule is reported as a folkloric medicine and rich in antioxidants. The main objective of the study was to establish a suitable extraction method (maceration, Soxhlet method, microwave-assisted extraction method (MAE), extraction at room temperature (ERT) and sonication) for extraction of antioxidants from P. amplexicaule and to evaluate the anticancer properties of the plant against HCT-116 cancer cell line. Different extraction solvents were used such as n-hexane, ethyl acetate, chloroform and methanol. All the extracts were tested for their antioxidant potential using DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay. The ethanolic and methanolic extracts of leaf, shoot and rhizome were screened against HCT-116 cancer cell line. The maximum extracted yield was obtained in methanol extract, i.e., 14% prepared by maceration method. The highest antioxidant activity was found in ethyl acetate extract using ERT method having IC50 value 3.35g/mL followed by MAE IC50 3.59g/mL and Soxhlet method IC50 3.87g/mL. Among ethanolic extracts of shoot, rhizome and leaf, it was found that leaf extract was most active against HCT-116 colon cancer cell line with IC50 of 569 g/mL, in comparison with gallic acid, whose IC50 was shown to be 806g/mL. Whereas, among all methanolic extracts, leaf extract was found highly potent with IC50 of 1282g/mL as compared to gallic acid, with IC50 of 1120g/mL.