In vitro ethno-toxicology of Hunteria umbellata methanol seed and stem extracts against Vibrio parahaemolyticus and its molecular implication on swarming and adhesion genes

摘要

Abstract Background Hunteria umbellatta (HU) is a predominant plant with a share of therapeutic properties against various human diseases with no scientific report of its in vitro ethno-toxicology coupled with molecular implication in the literature. This study, therefore, evaluated in vitro toxicological activity and quantification of expression of specific swarming gene, lateral flagellar (Laf A) and adhesion gene (ExsE) of Vibrio parahaemolyticus (VP) treated with methanol seed and stem extracts of HU at 500, 250, 125, 62.5, 31.25, 15.625, 7.8125, 3.90625 µg/µL concentrations.Results The toxicological results of all the eight tested concentrations from as low as 3.90625 µg/µL to as high as 500 µg/µL of HU seed and stem extracts revealed significantly (p ˂ 0.05) uninhibited bacterial growth in a dose-dependent manner compared to controls (positive and negative). The quantity of Laf A and ExsE genes’ expressions in VP was significantly higher (p ˂ 0.05) at 500 µg/µL of HU seed and stem compared to control while at 125 µg/µL of the same extract (seed and stem) showed significantly lowered (p ˂ 0.05) expression of swarming and adhesion genes in VP relative to control. Comparative to control, adhesion gene (ExsE) expression in VP significantly increased (p ˂ 0.05) at 250 µg/µL of HU seed and stem extracts. Conclusions The results obtained suggest toxicity at varying concentrations and higher concentration dosing of HU seed and stem is harmful as it could lead to increased expression of the gene colonization factor of VP as a major contributory agent of gastroenteritis.