Curcumin shows excellent therapeutic effect on psoriasis in mouse model.

Curcumin is an active herbal ingredient possessing surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. Recently, it has been reported to exhibit inhibitory activity on potassium channel subtype Kv1.3. As Kv1.3 channels are mainly expressed in T cells and play a key role in psoriasis, the effects of curcumin were investigated on inflammatory factors secretion in T cells and psoriasis developed in keratin (K) 14-vascular endothelial growth factor (VEGF) transgenic mouse model. Results showed that, 10 μM of curcumin significantly inhibited secretion of inflammatory factors including interleukin (IL)-17,IL-22, IFN-γ, IL-2, IL-8 and TNF-α in T cells by 30-60% in vitro. Notably, more than 50% of T cells proliferation was inhibited by application of 100 μM curcumin. Compared with severe psoriatic symptoms observed in the negative control mice, all psoriasis indexes including ear redness, weight, thickness and lymph node weight were significantly improved by oral application of curcumin in treatment mouse group. Histological examination indicated that curcumin had anti-inflammatory function in the experimental animals. More than 50% level of inflammatory factors including TNF-α, IFN-γ, IL-2, IL-12, IL-22 and IL-23 in mouse serum was decreased by curcumin treatment as well as cyclosporine. Compared with renal fibrosis observed in the mouse group treated by cyclosporine, no obvious side effect in mouse kidney was found after treated by curcumin. Taken together, curcumin, with high efficacy and safety, has a great potential to treat psoriasis.