Nanocurcumin: A novel strategy in treating ankylosing spondylitis by modulating Th17 cells frequency and function.

Ankylosing spondylitis (AS) is a chronic rheumatic disease which mainly affects the axial skeleton and sacroiliac joints. T-helper 17 (Th17) cells have been reportedly involved in AS pathogenesis. Nanocurcumin is considered to be beneficial, as an anti-inflammatory compound, in AS patients treatment. In this study, Th17-related immunological parameters were evaluated in AS patients. Transcription factors messenger RNA (mRNA) expression level, cytokines, and related microRNAs (miRNAs) were measured by real-time polymerase chain reaction. Additionally, Th17 frequency and cytokines secretion were evaluated by flow cytometry and enzyme-linked immunosorbent assay tests, respectively. The frequency of Th17 was higher in AS patients. Gained data from nanocurcumin group also demonstrated that retinoic acid-related orphan receptor γ (RORγt) and interleukin-17 (IL-17) mRNA expression levels were significantly decreased (P = 0.0001 and 0.0006, respectively), as the decrease also happened in Th17-associated miRNAs including miR-141, miR-155, and miR-200 ( P = 0.04, P = 0.02, and P < 0.0001, respectively). Posttreatment data of miR-155 and miR-200 in the nanocurcumin and placebo groups also showed a higher expression level in the placebo group compared with nanocurcumin-treated patients. Some clinical symptoms of AS patients were also improved at the end of the treatment process. The results of this study showed the potential ability of nanocurcumin to regulate Th17 cells activity in AS patients. This study provided further evidence on the function and underlying mechanism of nanocurcumin helping better treatment of AS.