Persicaria amphibia, an old traditional remedy and wild edible herb: in vitro evaluation of cytotoxicity and antimicrobial properties

Abstract

Persicaria amphibia (subfam. Polygonoideae), an aquatic macrophyte rich in dietary polyphenolics, is used as a traditional remedy and culinary herb. Nevertheless, P. amphibia from the Balkan region has been insufficiently studied and underutilized. Here, the cytotoxicity and antimicrobial properties of the previously chemically characterised ethanol extract of P. amphibia aerial parts were tested. The following methods were carried out: the MTT assay, qRT-PCR, microdilution assay, Chromobacterium violaceum screening assay (monitoring of quorum sensing, QS) and the agar plating method (antifungal activity). The study was conducted to determine the cytotoxic effects of P. amphibia against lung cancer cells (A549) and its combination with cytostatic doxorubicin (Dox). A dose-dependent decrease in cell viability (up to 82% reduction) and additive interactions of the tested agents were noted. Both alone and combined with Dox, P. amphibia reduced the expression of Nrf2 (p < 0.05). In terms of antimicrobial effects, P. amphibia exhibited an antipathogenic effect since it disrupted QS communication, which was evident through the inhibition of violacein production of C. violaceum CV025. The antifungal screening revealed that P. amphibia induced significant growth inhibition of Aspergillus spp. (28.23%). Based on the obtained results, further examination of the potential use of P. amphibia in modern phytotherapy and diet-derived cancer chemoprevention is encouraged.