银杏叶提取物的胃粘膜保护作用

Protective Effect of Ginkgo Biloba Extract on Gastric Mucosa

采用大鼠束缚－冷冻应激模型和小鼠无水乙醇损伤模型观察银杏叶提取物（ＧｂＥ）对胃粘膜损伤指数的影响；采用幽门结扎法收集胃液，观察ＧｂＥ对胃液分泌量，胃液酸度和胃蛋白酶活性的影响；采用硫代巴比妥酸（ＴＢＡ）法测定胃粘膜及血清中丙二醛（ＭＤＡ）含量。结果表明，ＧｂＥ（２５，５０，１００ｍｇ／ｋｇ，ｂｉｄ×５ｄ，ｉｇ）可剂量依赖性地抑制束缚－冷冻应激（ＲＣＳ）和无水乙醇引起的胃粘膜损伤。用药组应激后的胃粘膜损伤指数分别为对照组的５８．１１％，４２．９９％和３１．２３％；用药组乙醇诱发的胃粘膜损伤指数降至对照组的６１．５４％，３６．０６％和２５．６４％；ＧｂＥ尚能增强西米替丁对胃粘膜的保护作用。但对大鼠胃液分泌量、胃液酸度及胃蛋白酶活性ＧｂＥ并无明显影响。小鼠经无水乙醇ｉｇ后１ｈ，胃粘膜和血清中的ＭＤＡ含量显著升高（Ｐ＜０．０１），而ＧｂＥ（２５，５０，１００ｍｇ／ｋｇｉｇ）预处理则可以明显抑制ＭＤＡ的升高。因此认为ＧｂＥ具有胃粘膜保护作用，并且与西米替丁在治疗胃溃疡方面具有协同作用，这些作用可能与其抗氧化作用相关。

AIM:To study the protective effect of Ginkgo Biloba extract (GBE) on gastric mucosa.METHODS:By means of restraint cold stress (RCS) in rats and absolute ethanol gavage in mice,the index of gastric mucosa injury was evaluated.After the gastric juice was collected with the method of pyloric ligation the volume and acidity of this juice,and activity of pepsin were determined.And the content of malondialdydehyde (MDA) in gastic mucosa and serum was measured by thiobarbituric acid (TBA) method.RESULTS:GBE (25,50 and 100mg/kg×2/d×5d ig) inhibited dose dependently the gastric mucosa injury induced by RCS and absolute ethanol gavage.The indexes of gastric mucosa injury after RCS in groups pretreated with GBE were 58.1%,43.0% and 31.2% of control group respectively.The indexes of gastric mucosa injury induced by ethanol in groups pretreated with GBE decreased to 61.5%,36.1% and 25.6% of control group respectively.And GBE enchanced the protective effects of Cimetidine (Cim) on gastric mucosa.But it didn't obviously influence the volume and acidity of gastric juice as well as activity of pepsin.After ig (absolute ethanol) for 1 hr,the contents of MDA in gastric mucosa and serum of mice significantly increased vs control group ( P< 0.01).But pretreatment with GBE (25,50 and 100mg/kg ig) could significantly inhibited the increase of MDA formation induced by absolute ethanol both in gastric mucosa and serum.CONCLUSION:GBE has protective effect on gastric mucosa and GBE plus Cim possess the synergism in the treatment of gastric ulcer.These effects may be related to its antioxidant action.