Curcumin against imiquimod-induced psoriasis of mice through IL-6/STAT3 signaling pathway

To explore the possible mechanism of Curcumin (Cur) for protecting imiquimod-induced psoriasis in mice.

Sixty BALB/c mice were removal the back hair about 2 cm × 3 cm and divided into five groups. The control group was used Vaseline, the model and the drug group used 5% imiquimod in the back skin for 7 days, once time a day (62.5 mg/day/mice). At the same time, control and model mice were intragastric administration of normal saline, while the drug group were orally administrated with 50, 100 and 200 mg/kg Cur, respectively. The morphology, histopathological changes were observed. The serum levels of tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6) were analyzed by ELISA. The protein expression levels of phosphorylation STAT 3 and its down-stream protein expression in lesion skin were detected by western blot. The protein expression of TNF-α and IL-6 in lesion skin were analyzed by immunohistochemistry. The result showed that Cur could improve the lesion skin pathological, decrease the levels of TNF-α and IL-6 in serum and in lesion skin of psoriasis mice. In addition, Cur also reduced the protein levels of phosphorylation STAT 3 and its down-stream protein levels of Cyclin D1, Bcl-2 and Pim 1 in lesion skin of psoriasis mice.

Cur could effectivly improve the pathological characteristics of psoriasis mice, which may be through the regulation of IL-6/STAT3 signaling pathway.