Abstract: Objective To evaluate the efficacy of Yinxing Shiliu Jian in the treatment of psoriasis vulgaris(PV)and its effects on the level of PAF in sera,and the expression of PAFR in lesions of patients with PV.Methods Forty-six patients with PV enrolled into this study.The patients received oral Yinxing Shiliu Jian thrice a day for 1 to 3 months(1 month as a treatment session);changes in the clinical signs of the disease were evaluated at the end of every treatment session using the psoriasis area severity index (PASI)score.ELISA was used to measure the serum levels of PAF in all patients before treatment,15 patients after treatment,and 10 normal human controls.The expression of PAFR was detected by immuno-histochemical method in typical active lesions of 20 patients before the start of the medication,in subsiding lesions of 8 patients after medication,and in 5 foreskin specimens to serve as control.Results The PASI scores of these patients significantly decreased after treatment with the Chinese medicine(2.858±1.813 vs 32.814±14.768,P<0.01).The serum level of PAF in patients before treatment was significantly higher than that in normal human controls(15.407±4.277 pg/mL vs 5.769±1.469 pg/mL,P<0.01),and in patients after treatment(15.407±4.277 pg/mL vs 8.251±2.432 pg/mL,P<0.05).Furthermore,the level of PAF was positively correlated with PASI score in PV patients(r=0.46,P<0.05).The numbers of PAFR-positive cells were significantly lower in angio-endotbelial cells and inflammatory cells in lesional epidermis and dermis after treatment compared to the corresponding numbers before treatment(P<0.05).Conclusions There is a high expression of PAF in sera,and PAFR in lesions of progressive PV patients.The level of PAF and the number of PAFR-positive ceils closely correlated with the disease severity;the Yinxing Shiliu Jian could clearly downregulate the high level of PAF,and the high expression of PAFR.

Key words: Psoriasis, Drugs, Chinese herbal, Platelet activating factor, Receptor, platelet activating factor