Nanocurcumin supplementation ameliorates Behcet’s disease by modulating regulatory T cells: A randomized, double‐blind, placebo‐controlled trial

•Nanocurcumin supplementation increased Treg cells frequency significantly compared with baseline and placebo group.•Nanocurcumin supplementation increased FoxP3, TGF-β, IL‐10, miRNA-25, and miRNA-106b mRNA expression significantly compared to baseline and placebo group.•Nanocurcumin supplementation increased serum TGF-β and IL-10 significantly compared to baseline and placebo group.•Nanocurcumin supplementation decreased disease activity significantly compared to placebo group. Current research was designed to assess the effects of nanocurcumin supplementation on regulatory T (Treg) cells frequency and function in Behçet's disease (BD). In this randomized double-masked, placebo-controlled trial, 36 BD subjects were randomly put into two groups to take one 80 mg nanocurcumin capsule or placebo daily for 8 weeks. Before and after trial, disease activity, Treg cells frequency and expression of related immunologic parameters including forkhead box protein P3 (Foxp3) transcription factor messenger RNA (mRNA) and microRNAs (miRNAs) such as miRNA-25 and miRNA-106b as well as cytokines including transforming growth factor (TGF)-β and interleukin (IL)-10 were studied. Thirty-two patients (17 in the nanocurcumin and 15 in the placebo groups) completed the trial. Treg cells frequency increased significantly in the nanocurcumin group compared with baseline (P