Introduction: The balance between T helper 17 (Th17) and regulatory T cells (Treg) is a new paradigm in the pathogenesis of systemic lupus erythematosus (SLE). Currently, there are no drugs that able to modulate Th17/Treg balance specifically in SLE. Curcumin is a bioactive agent that has a specific action against hyperproliferative cells. However, its role in modulating Th17/Treg balance in SLE is still unknown. This research aimed to investigate the role of curcumin in modulating Th17/Treg balance on CD4+ T cell cultures of SLE patients.
Material and methods: CD4+ T cells from SLE 6 untreated patients and 6 healthy subjects were collected, stimulated with Th17 differentiating factors, and curcumin 0.1 and 1 µg/ml was added on cultures. After 72 hours incubation, cells were harvested and measured for Th17 and Treg percentages using flow cytometry and interleukin-17A (IL-17A) and transforming growth factor-β1 (TGF-β1) levels using ELISA.
Results: Administration of low doses of curcumin (0.1 and 1 µg/ml) could decrease Th17 percentages (p = 0.000 and p = 0.000 compared to control), reduce IL-17A productions (p = 0.000 and p = 0.000 compared to control), increase Treg percentages (p = 0.001 and p = 0.000 compared to control), and increase TGF-β1 productions (p = 0.001 and p = 0.000 compared to control) on CD4+ T cells of SLE patients. Interestingly, these effects were not reproduced on CD4+ T cells cultures of healthy subjects.
Conclusions: These data suggest that curcumin can modulate Th17/Treg balance specifically on CD4+ T cells of SLE patients without affecting healthy subjects.
Keywords: Th17/Treg balance; curcumin; systemic lupus erythematosus.