Extraction, identification, mechanism of action, and application of Hu Zhang (Polygonumcuspidatum) extracts against non-O1/O139 Vibriocholerae in prawn storage

Plant-derived alternatives to antibiotics are of great concern. The goal of this work was to enhance the Hu Zhang (Polygonumcuspidatum) extraction procedure against non-O1/O139 V.cholerae (HZE), identify the antibacterial components, analyze the mechanism of action, and investigate its potential in prawn storage. The extraction process of HZE optimized by one-factor-at-a-time experiment combined with response surface methodology was as follows: 95% methanol of extraction solvent, 28 mL/g of the ratio of liquid to solid, 88 °C of extraction temperature, and 150 min of extraction time. The MIC and MBC values of HZE were 1.5 and 3.0 mg/mL. The anti-V.cholera activity of HZE was attributed to the synergistic effects of various active chemical components such as rhein, aloe-emodin, chrysophanol, etc. HZE could significantly damage the integrity and permeability of the cell membrane and change bacterial morphology. Further practical potential in prawn storage indicated HZE could significantly decrease total V.cholera count in prawns at 4 °C. In this paper, the inhibitory activity of HZE against V.cholerae was investigated and its cellular damage mechanism was revealed for the first time. The results demonstrate the potential of HZE as a natural and effective antimicrobial agent to control V.cholera in fishery products. •It is the first extraction report of HZE against non-O1/O139 Vibriocholerae.•The anti-V.cholerae activity of HZE was attributed to the synergistic effects.•HZE have strong impairing effects on the cell membrane of V.cholerae.•HZE could effectively inhibit TVC in shrimps at 4 °C.