Phytochemical profile and antioxidant activity of water pepper (Polygonum hydropiper L.)

Abstract

Polygonum hydropiper L. (water pepper), an important medicinal plant from the Polygonaceae family, is traditionally used in folk medicine as an anti-cancer and anti-rheumatic agent, against diarrhea, positively influencing cerebral ischemia, Parkinson's disease, and with neuroprotective effects. The aim of the current study was to evaluate and compare the total polyphenol content and antioxidant activity of water (infusion, decoction and microwave) and alcohol (tincture) extracts of Polygonum hydropiper. The total flavonoid content, total monomeric anthocyanin content and detailed phenolic acids profile were additionally assessed. The polyphenol content was established to be in range from 5.02 ± 0.07 to 17.44 ± 0.24 mg GAE/g dw, the total flavonoids from 3766.27 ± 118.25 to 6909.66 ± 66.03 μM QE/g dw and total monomeric anthocyanins from 0.26 ± 0.14 to 3.17 ± 0.44 mg/l. The in vitro antioxidant activity was evaluated by four common procedures, the highest results were established for the decoction, and tincture extracts. The phenolic acids profile revealed the highest yield, in respect of total phenolic acids, in the water pepper tincture - 3243.74 μg/g dw. As a result, the consumption of P. hydropiper extracts could be recommended as a good source of biologically active substances with potential benefit effects.