Effect of Tung Oil Combined with Acitretin on Psoriasis Vulgaris and Its Effect on IL-23/Th17 Signaling Pathway

OBJECTIVE To observe the effect of Tung oil combined with acitretin on mild to moderate psoriasis vulgaris and its effect on IL-23/Th17 signaling pathway. METHODS One hundred and ninety six patients with psoriasis vulgaris were randomly divided into tung oil group(n=98) and control group(n=98). The control group were treated with acitretin combined with narrow-band UVB (NB-UVB) treatment. The patients of tung oil group were given a topical application of Tung oil on the basis of the control group. The efficacy of the tung oil group and the control group was evaluated by the psoriasis area and severity index(PASI). The levels of IL-17, IL-22, TNF-α and IL-23 in the lesions of the two groups before and after treatment were detected by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry was used to analyze the changes of Th17 cell in the lesions of the two groups before and after treatment. RESULTS The total effective rate of the tung oil group (94.90%) was significantly higher than that of the control group (76.53%), and the difference was statistically significant (P<0.05). Compared with before treatment, the PASI scores of the two groups were significantly lower after treatment(P<0.01). And the PASI score of the tung oil group was significantly lower than that of the control group (P<0.05). Compared with before treatment, the levels of IL-23, IL-17, IL-22 and TNF-α in the lesions of the two groups were significantly lower after treatment(P<0.05), and the tung oil group were significantly lower than those in the control group after treatment(P<0.05). The percentage of Th17 cells in the lesions of the two groups was significantly lower than that before treatment, and the tung oil group was significantly lower than that in the control group (P<0.05). The incidence of adverse reactions in the tung oil group (14.29%) was slightly higher than that in the control group (10.20%), but the difference was not statistically significant. CONCLUSION Tung oil external application combined with acitretin has a good curative effect on mild to moderate psoriasis vulgaris. The mechanism may be related to the inhibition of IL-23/Th17 signaling pathway activity in skin lesions.