Anti-proliferative, in vitro antioxidant, and cellular antioxidant activities of the leaf extracts from Polygonum minus Huds: Effects of solvent polarity

Abstract

ABSTRACTThe present study reports the antioxidant and anti-proliferative activities of Polygonum minus leaf extracts obtained through sequential extraction using four solvents of varying polarities (i.e. hexane (HX), ethyl acetate (EA), methanol, and water). The antioxidant potential was evaluated by measuring the total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical-scavenging, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical-scavenging, superoxide anion and nitric oxide scavenging, ferrous ion-chelating (FIC), and cellular antioxidant activity (CAA) assays. The highest antioxidant potential was generally shown by the methanol extract (PM-MeOH). PM-MeOH exhibited the highest values for TPC (174.00 ± 0.18 mg GAE/g), TFC (53.19 ± 0.71 mg GAE/g), FRAP (1728.33 ± 0.96 µmol Fe2+/g), ABTS (226.25 ± 4.25 µmol TE/g), DPPH (1276.81 ± 7.08 µmol TE/g), and nitric oxide scavenging assays (IC50, 675 ± 32.33 µg/mL). In the CAA assay, PM-MeOH dose-dependently inhibited the peroxyl radical-induced oxidation of 2ʹ,7ʹ-dichlorodihydrofluorescein (DCFH2) to 2ʹ,7ʹ-dichlorofluorescein (DCF) in HCT116 cells, with an EC50 value of 263.92 ± 21.60 µg/mL. Liquid chromatography and mass spectrometry analyses of PM-MeOH suggested the presence of tannins and flavonoids including apigetrin, hyperoside, isoquercetin, astragalin, miquelianin, quercetin, and quercitrin. P. minus hexane (PM-HX) and ethyl acetate (PM-EA) extracts showed selective cytotoxicity towards HCT116 with IC50 values of 40.00 ± 0.83 µg/mL and 43.18 ± 0.67 µg/mL, respectively. Taken together, these results highlight the potential of P. minus as a source of bioactive phytochemicals that may be useful in cancer therapeutics and nutraceutical industry.