OBJECTIVE: To assess the ability of bovine whey protein hydrolysate and its low molecular weight fraction (molecular weight <1kDa) to protect the gastric mucosa of rats against ulcerative process induced by three different agents. METHODS: Adult Wistar rats were subjected to the indomethacin-induced ulcer (30mg/kg body weigh), absolute ethanol (1ml/animal) and immobilization and cold stress (4(0)C/2h), models. RESULTS: Whey protein hydrolysate was obtained by treatment with pancreatin to a degree of hydrolysis of 20% and fractionated using a tangential flow membrane with a molecular weight cut-off of 1kDa to obtain the fraction containing low molecular weight peptides (<1kDa). In the ethanol-induced acute ulcer model (single dose), whey protein hydrolysate inhibited the gastric lesion index by 65.5% and the double dose resulted in a 77.4% inhibition. CONCLUSION: For the anti-inflammatory model, the cytoprotective effect of low molecular weight peptides was stronger than that of total hydrolysate (53.1 and 71.6%, ulcerative lesion index) for single and double dose, respectively. No mucosa cytoprotective activity was found for whey protein concentrate, whey protein hydrolysate or WPHP in the immobilization and cold stress model.
protein hydrolysates; peptides; rats; stomach ulcer
