小叶苦丁茶多酚提取物对盐酸/乙醇诱导小鼠胃损伤的预防效果

Preventive Effect of Small-leaf Kudingcha Polyphenol Extract on Hydrochloric Acid/Ethanol Gastric Injury in Mice

本研究以小叶苦丁茶多酚提取物为研究对象,测定其在体外清除DPPH自由基、ABTS自由基、羟自由基的能力,并以60%酒精和40%150 mmol/L盐酸混合液为诱导剂构建盐酸/乙醇诱导胃损伤小鼠模型,通过检测小鼠血清和胃组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,观察组织病理切片的变化,测定内皮型一氧化氮合酶(eNOS)、神经型一氧化氮合酶(nNOS)、环氧合酶-2(COX-2)的mRNA表达,从而对小叶苦丁茶多酚对小鼠盐酸/乙醇性胃损伤的预防效果进行综合评价。结果表明,小叶苦丁茶多酚类物质具有较强的还原能力,能够有效清除DPPH自由基、ABTS自由基、羟自由基,随着浓度的增加,清除能力逐渐增强。动物试验结果表明,小叶苦丁茶多酚提取物在一定浓度下可降低小鼠的胃损伤程度,提高胃损伤抑制率,减少胃液分泌量,增加胃液pH;与模型组相比,小叶苦丁茶多酚提取物能显著(p<0.05)提高超氧化物歧化酶(SOD)活性和谷胱甘肽(GSH)含量,降低丙二醛(MDA)的生成,缓解胃组织病理症状,能显著(p<0.05)上调铜/锌-超氧化物歧化酶(Cu/Zn-SOD)、锰-超氧化物歧化酶(Mn-SOD)、过氧化氢酶(CAT)、内皮型一氧化氮合酶(eNOS)、神经型一氧化氮合酶(nNOS)的mRNA相对表达量,降低诱导型一氧化氮合酶(iNOS)、环氧合酶-2(COX-2)的mRNA相对表达量,且高浓度(200 mg/kg)的小叶苦丁茶多酚提取物效果比低浓度(100 mg/kg)的小叶苦丁茶多酚提取物更明显。由此可见,小叶苦丁茶多酚提取物能有效缓解盐酸/乙醇诱导的小鼠胃损伤程度,是一类具有胃损伤改善作用的活性成分,具有较好的应用前景。

In this study,the small-leaf kudingcha polyphenol extract was studied,and its ability to remove DPPH(1,1-diphenyl-2-picryhydrazl)free radicals,ABTS(2,2-azino-bis(3-ethylbenzothiazoline 6-sulfonic acid))free radicals and hydroxyl radicals were measured in vitro. A mouse model of gastric injury induced by hydrochloric acid/ethanol was established using 60% alcohol and 40% 150 mmol/L hydrochloric acid mixture as inducers,and the activities of related enzymes in mouse serum and gastric tissues,the changes of histopathological sections were detected. The mRNA expression of endothelial nitric oxide synthase(eNOS),neural nitric oxide synthase(nNOS)and cyclooxygenase-2(cox-2)was determined,and the preventive effects of small-leaf kudingcha polyphenol extract on alcoholic gastric injury in mice were comprehensively evaluated. Small-leaf kudingcha polyphenol extract had strong reducing ability and could effectively remove DPPH(1,1-diphenyl-2-picryhydrazl)free radicals and ABTS(2,2-azino-bis(3-ethylbenzothiazoline-)6-sulfonic acid))free radicals and hydroxyl radicals,with the increase of concentration,the scavenging ability was gradually enhanced. The results of animal experiments showed that the small-leaf kudingcha polyphenol extract could reduce the degree of gastric injury in mice,increase the gastric injuryinhibition rate,reduce the secretion of gastric juice and increase the pH value of gastric juice. Compared with the model group,the small-leaf kudingcha polyphenol extract significantly increased superoxide dismutase(SOD)activity and glutathione(GSH)content,decreased malondialdehyde(MDA)production(p<0.05),and relieved gastric histopathology,significantly up-regulate Cu/Zn-superoxide dismutase(Cu/Zn-SOD),Mn-superoxide dismutase(Mn-SOD),catalase(CAT),endothelial nitric oxide synthase(eNOS),neuronal nitric oxide synthase(nNOS)mRNA expressions(p<0.05),decreased inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2)mRNA expressions,and the effect of high concentration(200 mg/kg)of the polyphenol extract of the tea was more obvious than that of low concentration(100 mg/kg). It can be seen that small-leaf kudingcha polyphenol extract(SKCPE)can effectively alleviate the degree of gastric injury induced by hydrochloric acid/ethanol in mice,SKCPE is a kind of active component with improving gastric injury,therefore it has a good application prospect.