Silybin (SIL) is a versatile bioactive compound used for improving liver damage and lipid disorders and is also thought to be beneficial for atherosclerosis (AS). The goal of this study was to investigate the efficacy of SIL in the treatment of AS in ApoE^-/-mice fed a high-fat diet and explore the mechanism underlying treatment outcomes. We found that SIL significantly alleviated AS-related parameters, including the extent of aortic plaque formation, hyperlipidemia, and adhesion molecule secretion in the vascular endothelium. 16 S rRNA gene sequencing analysis, together with the application of antibiotics, showed that intestinal butyrate-producing bacteria mediated the ameliorative effect of SIL on AS. Further analysis revealed that SIL facilitated butyrate production by increasing the level of butyryl-CoA: acetate CoA-transferase (BUT). The increased expression of monocarboxylic acid transporter-1 (MCT1) induced by butyrate and MCT4 induced by SIL in the apical and basolateral membranes of colonocytes, respectively, resulted in enhanced absorption of intestinal butyrate into the circulation, leading to the alleviation of arterial endothelium dysfunction. Moreover, the SIL-mediated increase in intestinal butyrate levels restored gut integrity by upregulating the expression of tight junction proteins and promoting gut immunity, thus inhibiting the AS-induced inflammatory response. This is the first study to show that SIL can alleviate AS by modulating the production of bacterial butyrate and its subsequent absorption.

Saussurea involucrata has been reported to have potential therapeutic effects against myocardial ischemia. The pharmacological effects of oral natural medicines may be influenced by the participation of gut microbiota. In this study, we aimed to investigate the bidirectional regulation of gut microbiota and the main components of Saussurea involucrata. We first established a quantitative method for the four main components (chlorogenic acid, syringin, acanthoside B, rutin) which were chosen by fingerprint using liquid chromatography tandem mass spectrometry (LC-MS/MS), and found that gut microbiota has a strong metabolic effect on them. Meanwhile, we identified five major rat gut microbiota metabolites (M1–M5) using liquid chromatography tandem time-of-flight mass spectrometry (LC/MSⁿ-IT-TOF). The metabolic properties of metabolites in vitro were preliminarily elucidated by LC-MS/MS for the first time. These five metabolites of Saussurea involucrata may all have potential contributions to the treatment of myocardial ischemia. Furthermore, the four main components (10 μg/mL) can significantly stimulate intestinal bacteria to produce short chain fatty acids in vitro, respectively, which can further contribute to the effect in myocardial ischemia. In this study, the therapeutic effect against myocardial ischemia of Saussurea involucrata was first reported to be related to the intestinal flora, which can be useful in understanding the effective substances of Saussurea involucrata.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with a rising global incidence in recent years. Dengzhan shengmai (DZSM), a plant-based formulation clinically used in the management of cerebrovascular diseases, possesses documented anti-inflammatory and antioxidant properties; however, its effects on UC are unclear. In this study, we investigated the therapeutic potential and underlying mechanism of DZSM in a dextran sulfate sodium (DSS)-induced murine colitis model. Our results showed that DZSM significantly alleviated UC-related parameters. Mechanistically, DZSM remodeled gut microbiota dysbiosis, specifically enriching the abundance of short-chain fatty acid (SCFA)-producing bacteria and elevating colonic levels of SCFAs. Notably, butyrate upregulated the expression of the sodium-dependent vitamin C transporter 1 (SVCT1) in colonic epithelial cells, thereby enhancing cellular vitamin C (VitC) uptake. The accumulated VitC synergized with butyrate to exert potent antioxidant and anti-inflammatory effects, further reinforcing epithelial barrier function. Importantly, fecal microbiota transplantation (FMT) confirmed that the protective effects of DZSM on UC were achieved by modulating gut microbiota, at least partially. Collectively, our findings demonstrate for the first time that DZSM alleviates DSS-induced colitis in mice through a novel butyrate-SVCT1-VitC axis driven by gut microbiota remodeling, providing new mechanistic insights into the microbiota-dependent efficacy of plant-based medicine.

Glycyrrhizic acid (GL), a natural triterpenoid glycoside extracted from the “medicine food homology” herb Glycyrrhiza glabra L., exhibits potent anti-atherosclerotic effects; yet its underlying mechanisms remain unclear due to its poor oral bioavailability. The gut microbiota plays a pivotal role in the development of atherosclerosis (AS). In this study, the microbiota-dependent anti-AS effects of GL were evaluated in high-fat diet (HFD)-fed ApoE^−/− mice using antibiotic depletion and fecal microbiota transplantation (FMT). Integrated metagenomic and metabolomic analyses were performed to identify the key bioactive microbial metabolite. Further in vivo and in vitro experiments, including co-immunoprecipitation and dual-luciferase reporter assays, were utilized to elucidate the underlying molecular mechanisms. It was demonstrated that oral administration of GL alleviated AS in a microbiota-dependent manner by reversing gut dysbiosis, improving intestinal barrier function, and reducing pro-inflammatory lipopolysaccharide (LPS) levels. GL shifted intestinal tryptophan metabolism toward bacterial-derived indole-3-lactic acid (ILA) production, suppressing LPS-induced vascular endothelial adhesion dysfunction by activating the aryl hydrocarbon receptor (AhR). Mechanistically, ILA-activated AhR interacted with the NF-κB subunit p65 in the cytoplasm, effectively preventing the nuclear translocation of p65 and suppressing the promoter activities of adhesion molecules (VCAM1 and ICAM1), resulting in the amelioration of HFD-induced AS. These findings elucidate the microbiota-dependent mechanism of orally administered GL against AS, and highlight the therapeutic potential of targeting the ILA-AhR-p65 axis in the vascular endothelium as a strategy for AS.