别旁茶苷治疗溃疡性结肠炎小鼠的疗效及机制探讨

Investigation of the efficacy and the mechanism of Jasminoside in ulcerative colitis mice

目的:探讨别旁茶苷对葡聚糖硫酸钠(DSS)诱导的溃疡性结肠炎(UC)小鼠的治疗作用及其相关的作用机制。方法:18只C57BL/6小鼠随机分为对照组、UC组和UC+别旁茶苷组,每组6只。UC组和UC+别旁茶苷组小鼠自由饮用3%葡聚糖硫酸钠(DSS)溶液7 d,建立UC小鼠模型。对照组小鼠自由饮用不加DSS的水。造模期间,UC+别旁茶苷组小鼠连续7 d给予别旁茶苷灌胃,剂量20 mg/(kg·d);对照组和UC组小鼠给予等体积蒸馏水灌胃。每日观察小鼠体质量和疾病活动指数(DAI)变化情况。给药7 d后处死小鼠,测量结肠长度,HE染色观察结肠炎症情况,Western blot检测各组小鼠结肠组织抗凋亡蛋白Bcl-2和Bcl-xl、小窝蛋白-1(CAV-1)、诱导型一氧化氮合酶(iNOS)、紧密连接蛋白Occludin和Claudin-1的表达情况。统计分析3组小鼠上述指标的差异。结果:所有小鼠均存活。与对照组比较,UC组小鼠体质量更低,DAI评分更高,结肠更短,差异均具有统计学意义(均P<0.05),结肠组织炎性浸润严重。与UC组小鼠相比,UC+别旁茶苷组小鼠体质量更高,DAI评分更低,结肠更长,差异均具有统计学意义(均P<0.05),结肠组织炎性浸润得到缓解。Western blot结果显示,与对照组比较,UC组小鼠结肠组织Bcl-2、Bcl-xl、CAV-1、Occludin和Claudin-1的表达明显更低,iNOS表达明显更高,差异均具有统计学意义(均P<0.05)。UC+别旁茶苷组小鼠结肠组织中Bcl-2和Bcl-xl、CAV-1、Occludin和Claudin-1的表达明显高于UC组,而iNOS表达低于UC组,差异均具有统计学意义(均P<0.05)。结论:别旁茶苷能缓解UC模型小鼠的症状,其作用机制可能与上调抗凋亡蛋白表达、通过CAV-1/iNOS途径保护肠黏膜屏障相关。

Objective To investigate the efficacy and mechanism of Jasminoside in dextran sodium sulfate(DSS)⁃induced ulcerative colitis(UC)mice.Methods Eighteen C57BL/6 mice were randomly divided into control group,UC group and UC+Jasminoside group,with six mice in each group.The mice in UC group and UC+Jasminoside group freely drank 3%DSS solution for 7 days to induce UC mouse model.The mice in control group freely drank the water without DSS.During the modeling period,the mice in the UC+Jasminoside group were given Jasminoside at a dose of 20 mg/(kg·d)by gavage for 7 consecutive days,meanwhile the mice in control group and UC group were given equal volumes of distilled water by gavage.The change of body weight and disease activity index(DAI)of the mice were observed daily,and the length of the colon was measured 7 days after the intervention.HE staining was used to observe the inflammatory changes of the colon,and Western blot was used to measure the expression of anti⁃apoptotic proteins(Bcl⁃2 and Bcl⁃xl),caveolin⁃1(CAV⁃1),inducible nitric oxide synthase(iNOS),tight junction proteins(Occludin and Claudin⁃1).The differences in the above indicators among the mice in three groups were analyzed statistically.Results All the mice survived.Compared with the control group,the body weight was lower,DAI score was higher,colon was shorter,whose differences were all statistically significant(all P<0.05),and inflammatory infiltration of colon tissue was more severe in mice of UC group.Compared with the UC group,body weight was higher,DAI score was lower,colon was longer,whose differences were all statistically significant(all P<0.05),and inflammatory infiltration of colon tissue was alleviated in mice of UC+Jasminoside group.Western blot results showed that compared with control group,the expression of Bcl⁃2,Bcl⁃xl,CAV⁃1,Occludin and Claudin⁃1 was significantly lower and the expression of iNOS was significantly higher in the colon tissues of mice in UC group,and the differences were statistically significant(all P<0.05).The expression of Bcl⁃2,Bcl⁃xl,CAV⁃1,Occludin and Claudin⁃1 in the colon tissues of mice in UC+Jasminoside group was significantly higher than those in UC group,while the expression of iNOS was lower,and the differences were statistically significant(all P<0.05).Conclusion Jasminoside can alleviate the symptoms of UC model mice,and its mechanism of action may be related to upregulating the expression of anti⁃apoptotic proteins and protecting the intestinal mucosal barrier through CAV⁃1/iNOS pathway.