Catharanthus roseus extract attenuates E. coli toxin-induced short circuit current in isolated jejunal epithelium of goat and buffalo

Enterotoxigenic E. coli-derived heat-stable enterotoxin not only alters intestinal barrier functions and produces secretory diarrhea but also causes production losses in livestock. This study aimed to elucidate the ameliorative effect of Catharanthus roseus extract on Cl- secretion in an in vitro model. Isolated jejunal epithelia from goats (N=10) and buffaloes (N=4) were divided into four groups: A) control; B) 1.5% C. roseus extract; C) 10% E. coli toxin, and D) 10% E. coli toxin and 1.5% C. roseus extract. The jejunal epithelia were mounted on Ussing chambers with an exposed surface area of 0.95 cm2 and treated with E. coli toxin on the mucosal side to invoke Cl- channels. Transepithelial potential difference (Pdt), tissue conductance (Gt), and short circuit current (Isc) were determined under voltage-clamped conditions. E. coli toxin produced a significant increase in the Pdt, Gt, and Isc for both goat and buffalo jejunal epithelia, whereas C. roseus extract on the mucosal side alone or followed by the E. coli toxin decreased these parameters, which were comparable with the control. The change in Isc was more pronounced in goats than buffaloes (ΔIscgoat > ΔIscbuff). In experiments with the goat jejunal epithelia, replacement of Cl- from the mucosal buffer decreased Isc, similar to a decrease observed for the C. roseus extract groups. In conclusion, the results of this study suggest that C. roseus extract has a potential to attenuate E. coli-induced Cl- secretion in isolated jejunal epithelia of goats and buffaloes.
Keywords: Catharanthus roseus extract; Electrophysiology; Secretory diarrhea; Small intestine, Ruminants