Background

Inflammatory bowel disease (IBD) is a significant global health concern that can lead to depression in affected patients. Liquiritin apioside (LA) possesses anti-oxidative and anti-inflammatory properties. However, its anti-inflammatory mechanism in IBD has not been extensively studied.

Purpose

This study elucidates the pivotal role of LA in alleviating inflammation by regulating gut metabiota-derived metabolites and evaluating its regulative effects on promoting a balance of Th17/Treg cells in colitis mice.

Methods

To evaluate the effect of LA on IBD,16S rRNA gene sequencing and UPLC-QTOF-MS analysis were used to identify the changes of intestinal bacteria and their metabolites. Cytokines levels were determined by ELISA and qPCR, while immune cell ratios were evaluated via flow cytometry.

Results

Our findings revealed that LA treatment ameliorated general states of DSS-induced colitis mice and their accompanying depressive behaviors. Moreover, LA restricted the expression of pro-inflammatory cytokines and revised the imbalanced Treg/Th17 differentiation, while promoting SCFAs production in inflamed colon tissues. Fecal microbiota transplantation from LA-fed mice also corrected the imbalanced Treg/Th17 differentiation, indicating that LA-mediated restoration of the colonic Treg/Th17 balance mainly depends on the changes in gut metabolites.

Conclusion

These results provide scientific evidence explaining the apparent paradox of low bioavailability and high bioactivity in polyphenols, and suggesting that LA could be used as a potential dietary supplement for the prevention and improvement of IBD.

中文翻译：

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甘草苷芹菜苷通过肠道代谢物和 Th17/Treg 平衡减轻结肠炎症和伴随的结肠炎抑郁样症状

背景

炎症性肠病（IBD）是一个重大的全球健康问题，可能导致受影响患者抑郁。甘草苷 (LA) 具有抗氧化和抗炎特性。然而，其在IBD中的抗炎机制尚未得到广泛研究。

目的

本研究阐明了 LA 通过调节肠道代谢物衍生的代谢物来减轻炎症的关键作用，并评估其对促进结肠炎小鼠 Th17/Treg 细胞平衡的调节作用。

方法

为了评估LA对IBD的影响，采用16S rRNA基因测序和UPLC-QTOF-MS分析来鉴定肠道细菌及其代谢物的变化。通过 ELISA 和 qPCR 测定细胞因子水平，通过流式细胞术评估免疫细胞比例。

结果

我们的研究结果表明，LA 治疗改善了 DSS 诱导的结肠炎小鼠的一般状态及其伴随的抑郁行为。此外，LA 限制促炎细胞因子的表达并纠正不平衡的 Treg/Th17 分化，同时促进发炎结肠组织中 SCFA 的产生。LA喂养小鼠的粪便微生物群移植也纠正了不平衡的Treg/Th17分化，表明LA介导的结肠Treg/Th17平衡的恢复主要取决于肠道代谢物的变化。

结论

这些结果提供了科学证据，解释了多酚的低生物利用度和高生物活性的明显矛盾，并表明 LA 可作为预防和改善 IBD 的潜在膳食补充剂。