Methyl syringate alleviates DSS-induced colitis in mice by suppressing intestinal epithelial cell apoptosis via inhibiting the MAPK signaling pathway

doi:10.12122/j.issn.1673-4254.2026.07.21

Abstract

Abstract:

Objective To investigate the protective effect of methyl syringate (MS) against dextran sodium sulfate (DSS)‑induced colitis in mice and the underlying mechanism. Methods Twenty-four C57BL/6 mice were random and equally into control group, DSS model group, and MS (100 mg/kg) treatment group. The therapeutic effect of MS on colitis was assessed by measuring changes in body weight, disease activity index (DAI) score and colon length and histopathological examinations with HE and AB-PAS staining. ELISA and RT-qPCR were used to detect the expressions of IL-6, TNF-α, and IL-10 in the colon tissue, and immunohistochemistry, immunofluorescence staining, Western blotting and TUNEL staining were used to detect the expressions of myeloperoxidase (MPO), tight junction proteins ZO-1 and claudin-1, and MAPK pathway proteins as well as cell apoptosis in the colon. In cultured NCM460 cells treated with 1% DSS, the effects of MS (50 μmol/L) treatment on cell apoptosis and expressions of poptosis-related proteins and MAPK pathway proteins were evaluated using flow cytometry and Western blotting. Results MS treatment significantly ameliorated DSS-induced body weight loss, colon shortening, increased DAI score and histological inflammation score, and intestinal pathologies in mice. MS downregulated IL-6, TNF-α, and MPO, upregulated IL-10, and restored the expression and distribution of ZO-1 and claudin-1 in the colon tissue of the mice. In the mouse and cell models, MS treatment significantly reduced apoptosis rate of intestinal epithelial cells, upregulated Bcl-2 and XIAP, and downregulated cleaved caspase-3 expressions. KEGG enrichment analysis suggested a possible association of MAPK pathway with the therapeutic effect of MS, which was confirmed by lowered phosphorylation levels of p-JNK, p-ERK, and p-p38 in both the MS-treated mouse and cell models. Conclusion MS alleviates DSS-induced colitis in mice by reducing intestinal epithelial cell apoptosis and improving intestinal barrier damage possibly by inhibiting the MAPK signaling pathway.

Key words: inflammatory bowel disease, methyl syringate, apoptosis, intestinal barrier, MAPK signaling pathway

Longtao ZHANG, Yu ZHANG, Tong QIAO, Keni ZHANG, Lin YIN, Ju HUANG, Jing LI, Zhijun GENG, Jianguo HU. Methyl syringate alleviates DSS-induced colitis in mice by suppressing intestinal epithelial cell apoptosis via inhibiting the MAPK signaling pathway[J]. Journal of Southern Medical University, 2026, 46(7): 1685-1695.

Figures/Tables 9

Fig.1 Effect of methyl syringate (MS) treatment on disease status in dextran sodium sulfate (DSS)-induced colitis in mice. A, B: Changes in body weight and DAI scores of the mice. C, D: Comparison of colon lengths among the groups. Data are presented as Mean±SD (n=8). *P<0.05 vs Con group; #P<0.05 vs DSS group.

Fig.2 Effect of MS treatment on colonic pathology in mice with DSS-induced colitis. A: HE staining of colon tissue in different groups. B: Changes in histological scores (Mean±SD, n=8). C: AB-PAS staining of colon tissue in different groups. D: Goblet cell count (Mean±SD, n=3). *P<0.05 vs Con group; #P<0.05 vs DSS group.

Fig.3 Effect of MS treatment on intestinal inflammatory cytokines in the colon tissues of mice with DSS-induced colitis. A: ELISA results of IL-6, TNF-α and IL-10 in the intestinal mucosa of the mice. B: RT-qPCR results of IL-6, TNF-α and IL-10 in the intestinal mucosa of the mice. C: MPO immunohistochemical staining results. D: Relative integrated optical density value of MPO. Data are presented as Mean±SD (n=3). *P<0.05 vs Con group; #P<0.05 vs DSS group.

Fig.4 Effect of MS treatment on intestinal barrier function of the mice with DSS-induced colitis. A-C: 3D immunofluorescence staining and the mean fluorescence intensities for ZO-1 and claudin-1. D: Protein levels of ZO-1 and claudin-1 detected by Western blotting. E: Relative protein expression levels of ZO-1 and claudin-1. Data are presented as Mean±SD (n=3). *P<0.05 vs Con group. #P<0.05 vs DSS group.

Fig.5 Results of network pharmacology analysis. A: Venn diagram of MS and IBD. B: PPI network of intersecting targets between MS and IBD. C: Bar chart of GO enrichment analysis for MS and IBD. D: Bubble plot of KEGG pathway enrichment analysis for MS and IBD.

Fig.6 Effect of treatments with different concentrations of MS for 24 h on viability of NCM460 cells (Mean±SD, n=5).

Fig.7 Effect of MS treatment on apoptosis of colon epithelial cells in DSS-treated mice. A: TUNEL staining for detecting apoptosis in intestinal epithelial cells. B: Apoptosis cell ratio of intestinal epithelial cells. C: Protein expression levels of XIAP, Bcl-2, and cleaved caspase-3 in mouse colon tissues detected by Western blotting. D: Relative protein expression levels of XIAP, Bcl-2, and cleaved caspase-3 in mouse colon tissue. Data are presented as Mean±SD (n=3). *P<0.05 vs Con group; #P<0.05 vs DSS group.

Fig.8 Effect of MS treatment on DSS-induced apoptosis in NCM460 cells. A: Apoptosis of NCM460 cells detected by flow cytometry. B: Apoptosis cell ratio of NCM460 cells. C: Protein expression levels of XIAP, Bcl-2, and cleaved caspase-3 in NCM460 cells detected by Western blotting. D: Relative protein expression levels of XIAP, Bcl-2, and cleaved caspase-3 in NCM460 cells. Data are presented as Mean±SD (n=3). *P<0.05 vs Con group; #P<0.05 vs DSS group.

Fig.9 Effect of MS treatment on MAPK pathway activation. A: Protein expression levels of p-ERK, ERK, p-JNK, JNK, p-p38, and p38 in mouse colon mucosal tissues detected by Western blotting. B: Relative protein expression levels of p-ERK, p-JNK, and p-p38 in mouse colon mucosal tissues. C: Protein expression levels of p-ERK, ERK, p-JNK, JNK, p-p38, and p38 in NCM460 cells detected by Western blotting. D: Relative protein expression levels of p-ERK, p-JNK, and p-p38 in NCM460 cells. Data are presented as Mean±SD (n=3). *P<0.05 vs Con group; #P<0.05 vs DSS group.

References 34

[1]	杨翠萍, 陈平. 全球炎症性肠病的流行趋势分析及诊治现状[J]. 诊断学理论与实践, 2025, 24(4): 373-82. doi：10.16150/j.1671-2870.2025.04.003
[2]	Hracs L, Windsor JW, Gorospe J, et al. Global evolution of inflammatory bowel disease across epidemiologic stages[J]. Nature, 2025, 642(8067): 458-66.
[3]	Kaplan GG. The global burden of inflammatory bowel disease: from 2025 to 2045[J]. Nat Rev Gastroenterol Hepatol, 2025, 22(10): 708-20. doi：10.1038/s41575-025-01097-1
[4]	Kaplan GG, Windsor JW. The four epidemiological stages in the global evolution of inflammatory bowel disease[J]. Nat Rev Gastroenterol Hepatol, 2021, 18(1): 56-66. doi：10.1038/s41575-020-00360-x
[5]	Wan J, Zhou JM, Wang Z, et al. Epidemiology, pathogenesis, diagnosis, and treatment of inflammatory bowel disease: Insights from the past two years[J]. Chin Med J, 2025, 138(7): 763-76. doi：10.1097/cm9.0000000000003542
[6]	Nicolò S, Faggiani I, Errico C, et al. Translational characterization of immune pathways in inflammatory bowel disease: insights for targeted treatments[J]. Expert Rev Clin Immunol, 2025, 21(1): 55-72. doi：10.1080/1744666x.2024.2400300
[7]	Lamb CA, Kennedy NA, Raine T, et al. British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults[J]. Gut, 2019, 68(): s1-s106. doi：10.1136/gutjnl-2019-318484
[8]	Greuter T, Rieder F, Kucharzik T, et al. Emerging treatment options for extraintestinal manifestations in IBD[J]. Gut, 2021, 70(4): 796-802. doi：10.1136/gutjnl-2020-322129
[9]	Di Rienzo A, Marinelli L, Dimmito MP, et al. Advancements in inflammatory bowel disease management: from traditional treatments to monoclonal antibodies and future drug delivery systems[J]. Pharmaceutics, 2024, 16(9): 1185. doi：10.3390/pharmaceutics16091185
[10]	Zhao CX, Lin S. PANoptosis in intestinal epithelium: its significance in inflammatory bowel disease and a potential novel therapeutic target for natural products[J]. Front Immunol, 2025, 15: 1507065. doi：10.3389/fimmu.2024.1507065
[11]	Abraham C, Abreu MT, Turner JR. Pattern recognition receptor signaling and cytokine networks in microbial defenses and regulation of intestinal barriers: implications for inflammatory bowel disease[J]. Gastroenterology, 2022, 162(6): 1602-16.e6. doi：10.1053/j.gastro.2021.12.288
[12]	Xu JQ, Li SH, Jin W, et al. Epithelial Gab1 calibrates RIPK3-dependent necroptosis to prevent intestinal inflammation[J]. JCI Insight, 2023, 8(6): e162701. doi：10.1172/jci.insight.162701
[13]	Broom OJ, Widjaya B, Troelsen J, et al. Mitogen activated protein kinases: a role in inflammatory bowel disease[J]? Clin Exp Immunol, 2009, 158(3): 272-80. doi：10.1111/j.1365-2249.2009.04033.x
[14]	Meng TT, Liu CM, Chen YL, et al. Dietary Chito-oligosaccharide attenuates LPS-challenged intestinal inflammation via regulating mitochondrial apoptotic and MAPK signaling pathway[J]. Int Immunopharmacol, 2024, 126: 111153. doi：10.1016/j.intimp.2023.111153
[15]	Jiang KX, Bai YN, Hou RY, et al. Advances in dietary polyphenols: Regulation of inflammatory bowel disease (IBD) via bile acid metabolism and the gut-brain axis[J]. Food Chem, 2025, 472: 142932. doi：10.1016/j.foodchem.2025.142932
[16]	Tian YW, Jian T, Li J, et al. Phenolic acids from Chicory roots ameliorate dextran sulfate sodium-induced colitis in mice by targeting TRP signaling pathways and the gut microbiota[J]. Phytomedicine, 2024, 128: 155378. doi：10.1016/j.phymed.2024.155378
[17]	Zhou P, Lai J, Li YY, et al. Methyl gallate alleviates acute ulcerative colitis by modulating gut microbiota and inhibiting TLR4/NF-κB pathway[J]. Int J Mol Sci, 2022, 23(22): 14024. doi：10.3390/ijms232214024
[18]	胡疆, 张卫东, 柳润辉, 等. 两面针的化学成分研究[J]. 中国中药杂志, 2006, 31(20): 1689-91.
[19]	Gargiulo E, Roscetto E, Galdiero U, et al. Antibacterial metabolites produced by Limonium lopadusanum, an endemic plant of Lampedusa Island[J]. Biomolecules, 2024, 14(1): 134. doi：10.3390/biom14010134
[20]	Elamine Y, Lyoussi B, Miguel MG, et al. Physicochemical characteristics and antiproliferative and antioxidant activities of Moroccan Zantaz honey rich in methyl syringate[J]. Food Chem, 2021, 339: 128098. doi：10.1016/j.foodchem.2020.128098
[21]	Zhang HH, Gu HJ, Jia QH, et al. Syringin protects against colitis by ameliorating inflammation[J]. Arch Biochem Biophys, 2020, 680: 108242. doi：10.1016/j.abb.2019.108242
[22]	Bai J, Deng SW, Zhang XY, et al. Cinnamaldehyde alleviates Zearalenone-induced LS174T cell apoptosis, barrier dysfunction and mucin reduction through JNK/NF-κB signaling pathway[J]. Ecotoxicol Environ Saf, 2023, 263: 115276. doi：10.1016/j.ecoenv.2023.115276
[23]	Hu QC, Chen J, Zhang YH, et al. Natural molecule paeoniflorin acts as a gastric mucosal repair agent by targeting PTEN[J]. Phytomedicine, 2025, 148: 157443. doi：10.1016/j.phymed.2025.157443
[24]	Dai YX, Lu QL, Li PY, et al. Xianglian Pill attenuates ulcerative colitis through TLR4/MyD88/NF‑κB signaling pathway[J]. J Ethnopharmacol, 2023, 300: 115690. doi：10.1016/j.jep.2022.115690
[25]	Cooper HS, Murthy SN, Shah RS, et al. Clinicopathologic study of dextran sulfate sodium experimental murine colitis[J]. Lab Invest, 1993, 69(2): 238-49.
[26]	Araruna ME, Serafim C, Alves Júnior E, et al. Intestinal anti-inflammatory activity of terpenes in experimental models (2010-2020): a review[J]. Molecules, 2020, 25(22): 5430. doi：10.3390/molecules25225430
[27]	赫俊杰, 吴晓燕, 阎星旭, 等. 基于功效的两面针药理作用研究进展及临床应用分析[J]. 辽宁中医药大学学报, 2023, 25(5): 93-7.
[28]	Qin X, Xin YZ, Zou JH, et al. Efficient degradation of aflatoxin B(1) and Zearalenone by laccase-like multicopper oxidase from Streptomyces thermocarboxydus in the presence of mediators[J]. Toxins, 2021, 13(11): 754. doi：10.3390/toxins13110754
[29]	Liu J, Niu DY, Tang Y, et al. Beta-hydroxy-beta-methylbutyrate (HMB) ameliorates DSS-induced colitis by inhibiting ERK/NF-κB activation in macrophages[J]. Phytomedicine, 2025, 139: 156492. doi：10.1016/j.phymed.2025.156492
[30]	Liu YH, Wu JZ, Tan LY, et al. (-)‑Syringaresinol attenuates ulcerative colitis by improving intestinal epithelial barrier function and inhibiting inflammatory responses[J]. Phytomedicine, 2024, 124: 155292. doi：10.1016/j.phymed.2023.155292
[31]	Huang J, Li J, Geng ZJ, et al. Cynaroside ameliorates TNBS-induced colitis by inhibiting intestinal epithelial cell apoptosis via the PI3K/AKT signalling pathway[J]. Front Pharmacol, 2025, 15: 1496068. doi：10.3389/fphar.2024.1496068
[32]	Peng SY, Zhao Y, Jiang W, et al. MAPK signaling mediated intestinal inflammation induced by endoplasmic reticulum stress and NOD2[J]. Mol Cell Biochem, 2025, 480(6): 3709-17. doi：10.1007/s11010-025-05212-3
[33]	Coskun M, Olsen J, Seidelin JB, et al. MAP kinases in inflammatory bowel disease[J]. Clin Chim Acta, 2011, 412(7/8): 513-20. doi：10.1016/j.cca.2010.12.020
[34]	Waetzig GH, Seegert D, Rosenstiel P, et al. p38 mitogen-activated protein kinase is activated and linked to TNF-alpha signaling in inflammatory bowel disease[J]. J Immunol, 2002, 168(10): 5342-51. doi：10.4049/jimmunol.168.10.5342