Manda suppresses emotional stress-induced stomach ulcers in rats

Manda, a natural product made by yeast fermentation of many fruits and black sugar, has antioxidant activity. In the present study, manda prevented stomach ulcers caused by immobilization-induced emotional stress. Manda [5% manda solution (w/v)] and saline as control, were administered by a canula into the stomach of each experimental animal subsequently after 1, 2, 3, 4, and 5 hours from the start of the emotional stress. We classified the severity of gastric lesion formation induced by immobilization with each rat lying on its back for 6 hours at room temperature on a five-grade scale. The control rats all showed congestion and some degree of bleeding in the mucosa of the stomach. However, of the experimental rats, one showed no hemorrhagic lesions only congestion in four cases, and slight or moderate bleeding in eight cases with no massive bleeding cases. The distribution of these data significantly differ from that of the control rats, which suffered the greater damage (X 2 =10.589, p <0.05). In light microscopic examinations, the control rats showed necrosis in the gastric mucous membranes, desquamation, and bleeding of gastric mucosa. However, the rats treated with manda showed only congestion and did not show erosion or hemorrhage. These results suggest that manda or manda metabolite(s) was absorbed from the stomach and may have produced these action. In the meantime, we are analyzing manda components to try to isolate the active ingredient(s)