Sini San

Current treatment options for cholestatic liver diseases are limited, and addressing impaired intestinal barrier has emerged as a promising therapeutic approach. Si-Ni-San (SNS) is a Traditional Chinese Medicine (TCM) formula commonly utilized in the management of chronic liver diseases. Our previous studies have indicated that SNS effectively enhanced intestinal barrier function through the modulation of gut microbiota.

This study aims to verify the therapeutic effects of SNS on cholestatic liver injury, focusing on elucidating the underlying mechanism involving the gut-liver axis.

The 16s RNA gene sequencing, non-targeted metabolomics were used to investigate the effects of SNS on the gut microbiota dysbiosis. Fecal microbiota transplantation (FMT) was conducted to identify potential beneficial probiotics underlying the therapeutic effects of SNS.

Our results demonstrated that SNS significantly ameliorated cholestatic liver injury induced by partial bile duct ligation (pBDL). Additionally, SNS effectively suppressed cholestasis-induced inflammation and barrier dysfunction in both the small intestine and colon. While SNS did not impact the intestinal FXR-FGF15-hepatic CYP7A1 axis, it notably improved gut microbiota dysbiosis and modulated the profile of microbial metabolites, including beneficial secondary bile acids and tryptophan derivatives. Furthermore, gut microbiota depletion experiments and FMT confirmed that the therapeutic benefits of SNS in cholestatic liver disease are dependent on gut microbiota modulation, particularly through the promotion of the growth of potential probiotic P. goldsteinii. Moreover, a synergistic improvement in cholestatic liver injury was observed with the co-administration of P. goldsteinii and SNS.

Our study underscores that SNS effectively alleviates cholestatic liver injury by addressing gut microbiota dysbiosis and enhancing intestinal barrier function, supporting its rational clinical utilization. Furthermore, we highlight P. goldsteinii as a promising probiotic candidate for the management of cholestatic liver diseases.

Autoimmune thyroid diseases (AITD), a group of prevalent and persistent immune-mediated disorders affecting the endocrine system, can progressively result in total thyroid failure, thereby drastically impacting metabolic processes. Given the inadequacies of current clinical approaches to managing AITD, The exigency to investigate novel therapeutic strategies demands immediate attention, given the limitations and potential resistances associated with conventional approaches. Si-Ni-San (SNS), first chronicled in the esteemed Eastern Han Dynasty medical text " Treatise on Cold Damage and Miscellaneous Diseases" circa 200-210 AD, is a time-honored remedy known for its harmonizing effects on the liver and invigorating properties for the spleen. Research indicates that saikosaponins and peony glycosides, two primary constituents of SNS, possess anti-inflammatory properties and can ameliorate immune dysfunction in the treatment of AITD. Despite initial insights, a comprehensive exploration of the underlying mechanisms by which SNS alleviates AITD symptoms requires further in-depth investigation to decipher their intricate interplay.

This study aimed to identify the key therapeutic components of SNS for the treatment of AITD and to elucidate the underlying molecular mechanisms, revealing potential targets.

We initially screened prospective components of SNS for AITD therapy through comprehensive database exploration, followed by an evaluation of the results via PPI networks. To illuminate the therapeutic mechanisms of SNS in AITD, we employed GO enrichment analysis and surveyed the KEGG pathways. Employing UHPLC-QE-MS, we conducted an in-depth analysis of SNS's principal elements, complemented by molecular docking studies to unravel their interaction dynamics. Finally, we substantiated the central therapeutic pathway of SNS in the treatment of AITD using an experimental autoimmune thyroiditis (EAT) mouse model, validated meticulously through in vivo experimentation.

Network pharmacology analysis revealed 32 common targets from the overlap between SNS and AITD-related targets. Based on subsequent PPI network and KEGG analysis, we focused on the IL-6/JAK2/STAT3/IL-17 pathway, which drives the differentiation of Th17 cells, as a central therapeutic target of SNS in AITD. Crucially, our in vivo findings, substantiated through immunohistochemical, western blot, RT-qPCR analyses and Flow cytometry analysis, reveal SNS's therapeutic potential in AITD. It effectively dampens IL-6 production, inhibits IL-6/JAK2/STAT3/IL-17 pathway activation, and rebalances the Th17/Treg cell ratio, thus elucidating its anti-inflammatory mechanism.

The protective effect of SNS against AITD is likely mediated through the modulation of the IL-6/JAK2/STAT3/IL-17 pathway and the restoration of balance within the Th17/Treg ratio. This suggests that SNS may exert its therapeutic effects on AITD by targeting these key molecular mechanisms, thereby providing a novel perspective for the treatment of AITD.