Luo Lei, Yan Jing, Chen Bingyu, Luo Yi, Liu Lina, Sun Zhiguang, Lu Yin
Institute of First Clinical Medicine, Nanjing University of Chinese Medicine Nanjing 210023, Jiangsu, China.
Department of Gastroenterology, Jiangsu Provincial Second Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine Nanjing 210017, Jiangsu, China.
Am J Transl Res. 2021 Jan 15;13(1):38-56. eCollection 2021.
Natural phytochemicals are extensively considered to potentially ameliorate or reverse the pathological progression of colitis-associated colon cancer (CAC). The present study aimed to evaluate the therapeutic effect of menthol on CAC and the promoting effect on the gut microbiome and metabolites. In this study, azoxymethane (AOM) combined with dextran sulfate sodium (DSS) was adopted to build CAC mouse models. H&E staining was performed to identify the pathological damage of colon tissue. By immunohistochemistry and immunofluorescence, the expression levels of β-catenin and Ki67 were measured. The mRNA expression of inflammatory cytokines and myeloperoxidase (MPO) was evaluated through RT-PCR. The infiltration of immune cells was measured by flow cytometry analysis. With 16SrDNA sequencing technology, the composition of gut microbiome were detected. To determine the concentration of short-chain fatty acids (SCFAs) in the feces, gas chromatography coupled to mass spectrometry (GC-MS) was performed. A significant inhibiting effect of menthol on AOM/DSS-induced tumorigenesis was observed, as indicated by the significantly fewer small adenomas, lower disease activity index (DAI) scores and histopathological scores, lower expression of proliferation biomarkers (β-catenin and Ki67) and pro-inflammatory cytokines (IL-6, TNF-α and MPO), and decreased immune cells infiltration. As suggested from the results of 16SrDNA sequencing, compared with AOM/DSS (AD) group, MSD exhibited higher α-diversity and shared more similar β-diversity with the control (Ctrl). Moreover, a higher abundance of butyrate-producing bacteria (Allobaculum, Roseburia and Intestinimonas) and the higher fecal butyrate concentrations were measured in the MSD compared with the AD group. MSD effectively ameliorated AOM/DSS-induced tumorigenesis and facilitated the predominant growth of butyrate-producing bacteria.
天然植物化学物质被广泛认为可能改善或逆转结肠炎相关结肠癌（CAC）的病理进程。本研究旨在评估薄荷醇对CAC的治疗效果以及对肠道微生物群和代谢产物的促进作用。在本研究中，采用氧化偶氮甲烷（AOM）联合葡聚糖硫酸钠（DSS）构建CAC小鼠模型。进行苏木精-伊红（H&E）染色以鉴定结肠组织的病理损伤。通过免疫组织化学和免疫荧光法检测β-连环蛋白和Ki67的表达水平。通过逆转录聚合酶链反应（RT-PCR）评估炎性细胞因子和髓过氧化物酶（MPO）的mRNA表达。通过流式细胞术分析测量免疫细胞的浸润情况。采用16S核糖体DNA（rDNA）测序技术检测肠道微生物群的组成。为了测定粪便中短链脂肪酸（SCFAs）的浓度，进行了气相色谱-质谱联用（GC-MS）分析。观察到薄荷醇对AOM/DSS诱导的肿瘤发生具有显著的抑制作用，表现为小腺瘤显著减少、疾病活动指数（DAI）评分和组织病理学评分降低、增殖生物标志物（β-连环蛋白和Ki67）和促炎细胞因子（白细胞介素-6、肿瘤坏死因子-α和MPO）的表达降低以及免疫细胞浸润减少。根据16S rDNA测序结果，与AOM/DSS（AD）组相比，薄荷醇+DSS+AOM（MSD）组表现出更高的α多样性，并且与对照组（Ctrl）共享更相似的β多样性。此外，与AD组相比，MSD组中产生丁酸盐的细菌（Allobaculum、Roseburia和Intestinimonas）丰度更高，粪便丁酸盐浓度也更高。MSD有效地改善了AOM/DSS诱导的肿瘤发生，并促进了产生丁酸盐细菌的优势生长。
