Inhibitory Effects of Acidic Xylooligosaccharide on Stress-induced Gastric Inflammation in Mice

摘要

トウモロコシのキシランから精製した酸性キンロオリゴ糖を，100または200mg/kg体重の投与量でマウスに経口投与したところ，寒冷拘束ストレスによる胃粘膜の出血痕数が有意に低下した．また，酸性キシロオリゴ糖には，3.3～4.3mg/mLの濃度範囲で濃度依存的なスーパーオキシドアニオンラジカル消去作用が認められ，そのIC_(50)値は3.5mg/mLであった．酸性キシロオリゴ糖の示した抗酸化作用は，その抗胃炎作用に一部寄与しているものと考えられる．酸性キシロオリゴ糖の関連糖であるキシロース，キシロビオース，キシランおよびグルクロン酸には，100mg/kg体重の投与量ではマウスの胃炎抑制作用は認められなかった．これらの結果から，少なくとも3量体以上の酸性キシロオリゴ糖には，マウスのストレス性胃炎を抑制する効果のある可能性が示唆された．%The preventive effects of acidic Xylooligosaccharide prepared from xylan of corncobs and related sugars on stress-induced gastric inflammation in mice were investigated. Oral administration of acidic Xylooligosaccharide and hydrocortisone at doses of 100 and 200 mg/kg body weight significantly reduced the number of bleeding points in the gastric mucosa of mice loaded with cold-restraint stress. Acidic Xylooligosaccharide showed concentration-dependent superoxide anion radical-scavenging activity at concentrations of 3.3-4.3 mg/mL and its IC_(50) was 3.5 mg/mL, although this value is approximately six times that of quercetin. The antioxidant activity of acidic Xylooligosaccharide could contribute, in part, to its suppressive activities on stress-induced mouse gastritis. Xylose, xylobiose, xylan, and glucuronic acid showed no significant suppressive activities on mouse gastric inflammation at a dose of 100 mg/kg body weight. These results suggest that an appropriate degree of polymerization of xylan (larger than trimer) is necessary for the activities of acidic Xylooligosaccharide.