小檗碱通过促进巨噬细胞M2极化缓解溃疡性结肠炎

Berberine alleviates ulcerative colitis by promoting M2 polarization of macrophages

目的探究小檗碱缓解小鼠溃疡性结肠炎(UC)的机制。方法将30只小鼠随机均分为对照组、模型组和小檗碱组,每组10只,使用质量浓度为50 g·L^(-1)的葡聚糖硫酸钠(DSS)诱导UC模型。造模成功后,分别灌胃相应药物进行治疗,每日给药1次。给药期间,每日监测小鼠排便、体质量及生理活性。给药结束后,将小鼠处死,取出结肠组织,进行病理组织学指数(HI)评分检测,对小鼠UC的炎症反应进行评估。同时,使用Elisa法检测结肠组织中促炎因子肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和抗炎因子白细胞介素-10(IL-10)、肿瘤生长因子-β(TGF-β)的水平,使用qRT-PCR法检测核因子-κB(NF-κB)p50和p65、M1型巨噬细胞标记物诱导型一氧化氮合酶(iNOS)、M2型巨噬细胞标记物精氨酸酶1(Arg1)的mRNA表达,采用Western Blot法检测Arg1、iNOS和p65的蛋白表达,最后使用流式细胞术检测结肠M2/M1巨噬细胞比值。结果与对照组相比,DSS诱导后的UC模型组小鼠腹泻、黏液脓血便、体质量减轻,HI评分升高(P<0.05)。与模型组相比,小檗碱组的体质量下降趋势减缓,HI评分下降(P<0.05),促炎因子TNF-α、IL-6水平下降(P<0.05),抗炎因子IL-10、TGF-β水平升高(P<0.05);iNOS mRNA表达下降、Arg1 mRNA表达升高(P<0.05),M2/M1巨噬细胞比值升高,小檗碱组结肠组织中NF-κB亚基p50、p65 mRNA表达下降。结论小檗碱可通过抑制NF-κB信号通路,抑制巨噬细胞M1极化,促进巨噬细胞M2极化,改善肠道炎症环境,缓解UC。

Objective To explore the mechanism of berberine in alleviating ulcerative colitis(UC).Methods 30 mice were randomly divided into control group,model group and berberine group,10 in each group.The UC mice were induced by 50 g·L^(-1) dextran sodium sulfate(DSS).Then,the mice were treated with corresponding drugs by intragastric gavage once a day.During the treatment,the defecation,body weight,and physiological activity of mice were measured every day.At the end of the experiment,the mice were sacrificed,and the histological index(HI)scores of colon tissue test were performed to evaluate the inflammatory response of colitis in mice.Meanwhile,Elisa was used to detect the secretion of pro-inflammatory factors tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and anti-inflammatory factors interleukin-10(IL-10)and transforming growth factor-β(TGF-β)in colon tissues,and qRT-PCR was used to detect the expression of nuclear factor kappa-B(NF-κB)p50,p65,M1 macrophage marker inducible nitric oxide synthase(iNOS),and M2 macrophage marker arginase-1(Arg1)mRNA expression.Then,the protein expression of Arg1,iNOS and p65 was detected by Western Blot.The colonic M2/M1 macrophage ratios were detected by using flow cytometry.Results Compared with the control group,UC model mice induced by DSS had diarrhea,bloody mucopurulent stool,and weight loss.And the colon HI score increased(P<0.05)in model group.Compared with the model group,after administered by intragastric injection of berberine,the weight loss trend in berberine group was slowed down,the colonic HI score(P<0.05),and the levels of proinflammatory factors TNF-αand IL-6 were decreased(P<0.05),while the levels of anti-inflammatory factors IL-10 and TGF-βwere increased(P<0.05).At the same time,the inhibition of M1 macrophage marker iNOS mRNA,upregulation of M2 macrophage marker Arg1 mRNA,and the increase of M2/M1 ratio were observed in berberine group(P<0.05).Moreover,the expression of NF-κB subunits p50 and p65 mRNA were decreased in colon tissue of berberine group.Conclusion Berberine may inhibit M1 polarization of macrophages,promote M2 polarization of macrophages,improve the intestinal inflammatory environment,and relieve colitis by inhibiting NF-κB signaling pathway.