As a ligand-dependent transcription factor,retinoid-associated orphan receptor γt(RORyt)that controls T helper(Th)17 cell differentiation and interleukin(IL)-17 expression plays a critical role in the pro-gression of several inflammatory and autoimmune conditions.An emerging novel approach to the therapy of these diseases thus involves controlling the transcriptional capacity of RORyt to decrease Th17 cell development and IL-17 production.Several RORyt inhibitors including both antagonists and inverse agonists have been discovered to regulate the transcriptional activity of RORyt by binding to orthosteric-or allosteric-binding sites in the ligand-binding domain.Some of small-molecule inhibitors have entered clinical evaluations.Therefore,in current review,the role of RORyt in Th17 regulation and Th17-related inflammatory and autoimmune diseases was highlighted.Notably,the recently developed RORyt inhibitors were summarized,with an emphasis on their optimization from lead compounds,ef-ficacy,toxicity,mechanisms of action,and clinical trials.The limitations of current development in this area were also discussed to facilitate future research.

Ulcerative colitis (UC) is one of types of inflammatory bowel disease with high recurrence. Recent studies have highlighted that microbial dysbiosis as well as abnormal gut immunity are crucial factors that initiate a series of inflammatory responses in the UC. Modulating the gut microbiota-intestinal immunity loop has been suggested as one of key strategies for relieving UC. Many Chinese herbal medicines including some of single herb, herbal formulas and the derived constituents have been reported with protective effect against UC through modulating gut microbiome and intestinal immunity. Some clinical trials have shown promising results. This review thus focused on the current knowledge on using Chinese herbal medicines for treating UC from the mechanism aspects of regulating intestinal homeostasis involving microbiota and gut immunity. The existing clinical trials are also summarized.