Background: The prevalence of inflammatory bowel disease is rapidly increasing around the world. Quercetin is a flavonoid commonly found in vegetables and fruits and has been reported to exert numerous pharmacological activities such as enhancing antioxidant capacity or suppressing inflammation.

Objective: We aimed to explore whether quercetin was effective for IBD and the underlying mechanism of quercetin for the ameliorative effects on the DSS-induced colitis in mice.

Methods: Thirty-six mice were randomly assigned to three treatments, including the control group (Ctr), DSS-induced colitis group (DSS) and DSS-induced colitis supplemented with 500 ppm quercetin (DQ500). Colitis was induced by DSS intake, and body weight was recorded every day. After six days administration of DSS, intestinal permeability was measured, and the liver was taken for antioxidant enzyme tests. Colonic tissue was taken for the histopathlogical score and RNA-sequencing analysis.

Results: In this experiment, dietary quercetin for 500ppm alleviated the DSS-induced colitis, possibly by strengthening intestinal integrity, liver antioxidant capacity. Based on the results of the transcriptome of colon tissue, several key genes were modulated by quercetin. ERK1/2-FKBP pathway and RXR-STAT3 pathway were involved in the development of IBD, furthermore, in the down-regulation of S100a8/9, FBN2 contributed to lowering the risk of colongenesis.

Conclusion: We demonstrated that dietary quercetin alleviated the DSS-induced colitis in mice. This is most likely due to its beneficial effects on intestinal integrity and modulation of several key pathways. Based on our research, quercetin was a promising candidate for IBD and its pharmaceutical effects on both IBD and colongenesis need further research.

背景：全球炎症性肠病的发病率正在迅速上升。槲皮素是一种常见于蔬菜和水果中的类黄酮，据报道其具有多种药理活性，例如增强抗氧化能力或抑制炎症。

目的：我们旨在探讨槲皮素是否对IBD有效，以及槲皮素对小鼠DSS引起的结肠炎的缓解作用的潜在机制。

方法：36只小鼠随机分为三组，分别为对照组（Ctr），DSS诱导的结肠炎组（DSS）和DSS诱导的结肠炎，并补充500 ppm槲皮素（DQ500）。摄入DSS会诱发结肠炎，并每天记录体重。服用DSS六天后，测量肠道通透性，并取肝脏进行抗氧化酶测试。取结肠组织用于组织病理学评分和RNA测序分析。

结果：在该实验中，饮食中的槲皮素含量为500ppm时，可能通过增强肠的完整性，肝脏抗氧化能力来缓解DSS诱导的结肠炎。根据结肠组织转录组的结果，槲皮素调节了几个关键基因。ERK1 / 2-FKBP途径和RXR-STAT3途径参与了IBD的发展，此外，在S100a8 / 9的下调中，FBN2有助于降低结肠发生的风险。

结论：我们证明饮食中的槲皮素可以减轻DSS诱发的小鼠结肠炎。这很可能是由于其对肠道完整性和几种关键途径的调节具有有益作用。根据我们的研究，槲皮素是IBD的有希望的候选者，其对IBD和结肠癌的药理作用还需要进一步研究。