熊果酸对H22荷瘤小鼠抗肿瘤及肠道细菌群落结构多样性的影响

Effect of Ursolic Acid on Anti-tumor and Intestinal Bacterial Community Structure and Diversity in H22 Tumor-bearing Mice

研究熊果酸对H22荷瘤小鼠抗肿瘤及肠道细菌的影响。皮下接种H22肝癌细胞构建移植瘤小鼠模型,设正常组、模型组、阳性对照组(环磷酰胺)和熊果酸组(低、中、高剂量),连续给药3周后,计算抑瘤率和肝脾指数,检测血清T淋巴细胞亚群、白细胞介素-2(IL-2)和肿瘤坏死因子α(TNF-α)浓度,采用高通量测序技术分析熊果酸对H22荷瘤肠道细菌群落结构多样性的影响。结果显示,与模型组相比,熊果酸各剂量组均能显著减少移植瘤质量(P<0.05),其中熊果酸中、高剂量组能显著提高荷瘤小鼠血清中T细胞亚群、IL-2和TNF-α的含量(P<0.05)。主成分分析(Principal Component Analysis,PCA)显示,与正常组比较,模型组和熊果酸低剂量组小鼠肠道细菌相似性差异显著(P<0.05),而熊果酸中剂量组和高剂量组小鼠肠道细菌相似性差异不显著(P>0.05)。熊果酸各剂量组肠道细菌在门水平和科水平的比例和分布均比模型组更接近正常组。与模型组比较,熊果酸小鼠肠道Akkermansia和Lactobacillus丰度显著增加(P<0.05),而Muribaculum显著减少(P<0.05)。表明熊果酸可抑制肿瘤生长,增强H22荷瘤小鼠免疫力,对肿瘤小鼠肠道细菌菌群紊乱具有一定恢复作用。

The purpose of this study was to investigate the effect of ursolic acid(UA)on anti-tumor and intestinal bacteria in H22 tumor-bearing mice.In this experiment,the models of tumor-bearing mice were established by injection of colonic cancer cells H22.Then,the mice were randomly divided into normal group,model group,positive control group(cytoxan group)and the groups treated with low,middle and high dose of UA,respectively.After 3 weeks,the tumor inhibition rate,index of liver and spleen were calculated.The concentrations of T-cell subsets,interleukin-2(IL-2)and tumor necrosis factorα(TNF-α)in serum were detected.The effect of ursolic acid on intestinal bacterial community structure and diversity in H22 tumor-bearing mice were analyzed using high-throughput sequencing platform.The results showed that UA could significantly reduce the xenograft tumor weight compared with the model group(P<0.05).The level of T-cell subsets,IL-2 and TNF-αin mice treated with middle and high dose of UA significantly increased by comparing with the model group(P<0.05).Compared with normal group,PCA analysis indicated that there were significantly differences in intestinal bacteria of model group and group treated with low dose of UA.However,there were no significant difference in intestinal bacteria of groups treated with middle and high dose of UA by comparing with normal group(P>0.05).At phylum and family level,the proportion and distribution of intestinal bacteria in mice treated with UA were closer to the normal group than model group.Compared with model group,the relative abundance of Akkermansia and Lactobacillus significantly increased in mice treated with UA(P<0.05),and the relative abundance of Muribaculum significantly decreased(P<0.05).It indicated that UA could inhibit the growth of tumor and increase immunity of mice,accelerate the recovery of intestinal bacteria imbalance associated with tumor.