Medical Hemorrhoid Gel Ameliorates Croton Oil-Induced Hemorrhoids by Suppressing the NLRP3 Inflammasome Activation via NF-κB Signaling Pathway

Zhongzhu Ai,1,2,* Dongfeng Yuan,3,* Yun Li,3 Jingyi Cai,3 Daonian Zhou,2 Wei Liu2 1Department of Pharmaceutics, School of Pharmaceutical Science, Peking University, Beijing, 100191, People’s Republic of China; 2Post-Doctoral Research Center, Mayinglong Pharmaceutical Group Co., Ltd, Wuhan, 430070, People’s Republic of China; 3School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wei Liu, Email [email protected] Daonian Zhou, Email [email protected]: Hemorrhoidal disease (HD) is characterized by the pathological dilation of anal vascular cushions, causing pain, itching and bleeding. Recent evidence links HD onset and progression to rectal inflammation. Medical Hemorrhoid Gel (MHG), a multi-component botanical preparation, has gained empirical validation for HD management. This study aims to systematically evaluate the safety, efficacy, and mechanism of action of MHG in treating HD.Methods: The phytochemical composition of MHG was characterized using UPLC-QTOF-MS/MS and GC-MS/MS analyses. In vivo, the efficacy was assessed in a croton oil preparation (COP)‑induced HD rat model (n=10 per group) via anorectal coefficient (ARC) measurement, macroscopic severity score, Evans blue extravasation quantification, and H&E/PAS staining. Transcriptomic sequencing of anorectal tissues was integrated with experimental validation using ELISA, immunohistochemistry (IHC), and Western blotting to delineate molecular mechanism. Data were analyzed by one-way analysis of variance (ANOVA) followed by Dunnett’s multiple comparison post hoc test (significance at p< 0.05).Results: MHG significantly reduced ARC, macroscopic severity score, and Evans blue extravasation, restored intestinal villus structure and goblet cell numbers, and alleviated inflammation. Acute toxicity tests showed that MHG did not cause anorectal abnormalities or systemic toxicity in rats. Transcriptomic analysis integrated with experimental validation suggested the therapeutic mechanism of MHG involves inflammation response and NF-κB pathway. Specifically, MHG suppressed the levels of the pro-inflammatory mediator TNF-α, while it enhanced the levels of the anti-inflammatory mediator IL-10. Mechanistic studies revealed that MHG inhibited NLRP3 inflammasome activation, reduced the phosphorylation level of p65 and enhanced IκBα expression. Phytochemical analysis identified 20 constituents that contribute to the bioactivity of MHG.Conclusion: Our study substantiated that MHG exerts anti-hemorrhoidal effects through NLRP3 inflammasome suppression via NF-κB pathway regulation. This mechanistic insight provides scientific validation for clinical application of MHG in HD management.Keywords: medical hemorrhoid gel, hemorrhoidal disease, inflammation, NLRP3 inflammasomes, NK-κB signaling pathway