Effect of Diosgenin on T‑Helper 17 Cells in Mice with Collagen‑Induced Arthritis

Objective: The objective of this study is to explore the therapeutic effects of diosgenin against collagen‑induced arthritis (CIA) in DBA/1J mice. Materials and Methods: The CIA model was established using chicken type II collagen‑immunized DBA1/J mice (0.1 mL/mouse), with the same stimulus repeated on day 21. Next, the CIA mouse model was selected, and inguinal lymph nodes were excised to obtain a single‑cell suspension. Using CCK‑8, control group, model group, and high‑/medium‑/low‑dose diosgenin group were set based on drug toxicity. Next, the ratio of T‑helper 17 cells (Th17) to CD3+ T cells was analyzed using flow cytometer. The levels of interleukin 17 (IL)‑17 and IL‑6 were determined by the enzyme‑linked immunosorbent assay. The expression of RORγt was determined using the reverse‑transcription quantitative real‑time polymerase chain reaction and Western blot analysis. Results: An in vitro inhibitory rate of ≥ 70% was set as the cutoff value to select the high (25 µmol/L), medium (12.5 µmol/L), and low (6.25 µmol/L) doses of diosgenin. The Th17 cell ratio in CD3+ T cells, the levels of IL‑17 and IL‑6, and mRNA and protein expression of RORγt showed significantly increased tendency in the model group compared with the control group (P < 0.01 and/or P < 0.05). Diosgenin significantly decreased the Th17 cell ratio in CD3+ T cells, IL‑17 and IL‑6 levels, and RORγt expression when compared with the model group (P < 0.01 and/ or P < 0.05). Conclusion: Diosgenin exhibited an antiarthritic effect in CIA mice by downregulating the differentiation of Th17 cells.