Background: Emerging evidence suggests that gut microbiota plays a vital role in the occurrence of multiple endocrine disorders including polycystic ovary syndrome (PCOS). Shaoyao-Gancao Decoction (SGD), a classical Chinese prescription, has been widely used in the treatment of PCOS for decades. In previous studies, we found that SGD treatment could effectively reduce ovarian inflammation in PCOS rats. However, whether the anti-inflammation effect of SGD involves the regulation of the gut microbiota remains elusive.Methods: Letrozole-induced PCOS rat models were established, and the therapeutic effects of SGD were evaluated. Specifically, body weight, serum hormone concentrations, estrus phase and ovary histopathology were assessed. Then the structure of gut microbiota was determined by 16s rRNA sequencing. Additionally, the serum levels of pro-inflammatory cytokines and LPS were measured by ELISA kits. The key gene and protein expressions of TLR4/NF-κB signaling pathway were detected by quantitative real-time PCR and western blot.Results: SGD could effectively reduce body weight, regulate estrous cycles and ameliorate hyperandrogenism in PCOS rats. In addition, SGD treatment decreased releases of pro-inflammatory cytokines, enhanced the expressions of tight junction (occludin and claudin1), and then prevented a translocation of LPS into bloodstream. SGD could significantly reduce the ratio of Firmicutes to Bacteroidetes, decrease the abundance of LPS-producing pathogens Proteobateria and enrich the abundance of Butyricicoccus, Coprococcus, Akkermansia Blautia and Bacteroides in PCOS rats. Furthermore, SGD blunted the key gene and protein expressions of TLR4/NF-κB signaling pathway both in vivo and in LPS-induced RAW264.7 cells.Conclusion: SGD administration could ameliorate the inflammatory response in PCOS rats by remodeling gut microbiome structure, protecting gut barrier, and suppressing TLR4/NF-κB signaling pathway.

Shaoyao-Gancao Decoction (SGD) has been widely used for the treatment of gynopathy. The present study aimed to evaluate the therapeutic effect and potential mechanism of SGD on hyperandrogenism in polycystic ovary syndrome (PCOS) rats. In the present work, SGD was orally administrated to the PCOS rats at the dose of 12.5, 25, and 50 g/kg/d for 14 consecutive days. UPLC–MS/MS was performed to identify the main chemical components of SGD. Body weight, ovarian weight, cystic dilating follicles, and serum levels of steroid hormones were tested to evaluate the therapeutic effect of SGD. In order to further clarify the underlying mechanism, we also measured mRNA and the protein levels of NF-κB, NF-κB p65, P-NF-κB p65, and IκB by RT-qPCR and Western blotting techniques. Our results showed that SGD treatment significantly alleviated hyperandrogenism in PCOS rats as evidenced by reduced serum levels of T and increased E₂ and FSH levels. In addition, SGD effectively reduced the phosphorylation of NF-κB p65 and increased the expression of IκB. Results of the present study demonstrated that SGD could ameliorate hyperandrogenism in PCOS rats, and the potential mechanism may relate to the NF-κB pathway.

The enterohepatic circulation of bile acids (BAs) critically depends on BA transporters and enzymes, which can be affected by inflammatory bowel disease. Diarrhea in colitis is believed to result in part from BA malabsorption. The work aimed to investigate whether diarrhea in colitis was associated with the expression of BA transporters, enzymes, and nuclear receptors. RT-qPCR and Western blot techniques were used to evaluate the gene and protein levels of Cyp7a1, Asbt, SHP, FXR, Ostβ in a 2,4,6-trinitrobenzenesulfonic-acid-induced rat model of colitis. The total BAs (TBAs) levels were assayed using ELISA kits, and the individual BAs were measured by LC–MS/MS. Results showed that the fecal excretions of TBAs were significantly increased by 1.6-fold in acute stage of colitis. In ileum, Asbt was significantly decreased; however, there was a compensatory increase in Cyp7a1 level in liver. Moreover, FXR has a decreased tendency and the downstream target gene SHP was downregulated. Contrary to acute stage, molecular changes were completely reversible during the remission phase. Our results indicated that the expression of Asbt and Cyp7a1 were altered in acute colitis, which performed vital roles in maintaining BA homeostasis. Early medical manipulation of BA transporters and enzymes may help prevent diarrhea.

Postinflammatory irritable bowel syndrome (PI‐IBS) is a common functional gastrointestinal disorder, which is characterized by abdominal pain, low‐grade inflammation, and visceral hypersensitivity. Shaoyao‐Gancao decoction (SGD) has been used to improve the clinical symptoms of abdominal spasmodic pain accompanying acute gastroenteritis, but the underlying therapeutic mechanism has not been fully elucidated. In the present study, a rat model of PI‐IBS was established via rectal administration of TNBS. Rats were scored daily for 28 days using disease activity index (DAI). Abdominal withdrawal reflex (AWR) was used to measure the pain threshold. After SGD (6.25, 12.5, and 25 g/kg/d) treatment for 14 days, rat colonic tissue was collected for histopathological grading, enterochromaffin (EC) cell count, and 5‐HT content measurement. RT‐qPCR and western blot analyses were employed to detect the gene and protein level of tryptophan hydroxylase (TPH), serotonin reuptake transporter (SERT), and transient receptor potential vanilloid 1 (TRPV1). To further validate the effect of SGD on TRPV1, another experiment was performed in cells. The results revealed that visceral hyperalgesia, reflected by increased DAI, AWR, pathological injury score, 5‐HT content, and EC cell count in PI‐IBS rats, was significantly ameliorated by SGD. In cells, SGD markedly inhibited the expression and function of TRPV1. Moreover, the expression levels of TPH were also repressed by SGD. The findings of the present study indicated that the therapeutic effect of SGD on visceral hyperalgesia may be closely associated with the regulatory role of TRPV1 and 5‐HT signaling pathways.