Abstract
This research intends to clarify the protective effect of barley and its hydrolysates with respect to a water immersion stress-induced ulcer in the rat model. The β-(1→3)-glucan content of barley, and specifically β-(1→4),(1→3)-glucan content was determined and then gastric stress ulcerogenesis induced by water immersion was conducted using five-week-old male Sprague-Dawley rats (7 rats in one group). The barley diet group was fed 10% barley flour that was substituted with sucrose in the control diet. For the 3 groups fed on soluble dietary fiber (SDF), the diets were supplemented with 0.46 g of SDF, equivalent to 100 g of the control diet; 0.46 g of SDF is equivalent to 10 g of barley flour. The rats were housed in a stress-cage and immersed in a water bath (23°C) up to their necks for 21 h. The content of SDF and β-(1→3)-glucan content in barley flour were 4.6% and 3.4%, respectively. Although strongly anti-ulcer activities were observed in the barley (10%), SDF isolated and β-(1→3)-glucan fraction (Hydrolysate I) prepared from barley flour after treatment with lichenase, in other words, β-(1→4),(1→3)-glucan itself, its hydrolysate (Hydrolysate II) with β-(1→3)-glucosidase did not display any anti-ulcer activity. This finding suggests that the β-(1→3)-glucosyl-linkage on β-(1→3)-glucan is an important part of the active principle for anti-ulcerogenesis.
