Efficacy and Safety of Tripterygium Wilfordii Hook F on Psoriasis Vulgaris: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND: Psoriasis is a chronic autoimmune-mediated skin disease that is characterized by persistent localized erythematous scaly plaque. Tripterygium wilfordii Hook F (TwHF), a well-known Chinese medicine that has been used for centuries in China to treat immune diseases, inflammation, and tumor, is accompanied by a degree of toxic effects. Its clinical efficacy and safety on psoriasis are incompletely understood. AIM: To summarize evidence concerning the efficacy and safety of TwHF in treating psoriasis. Methods. EMBASE, Ovid MEDLINE, PubMed, Web of Science, Springer, Cochrane Library, CNKI, CBM, Wanfang, and VIP database were searched up to October 2017. The included literature was assessed and extracted by two independent reviewers. To enhance the available evidence, a systematic review was performed to examine all relevant published literature relating to randomized controlled trials (RCTs) of TwHF. Relative ratios (RRs) and 95% confidence intervals (CIs) were calculated, and a meta-analysis was conducted with RevMan 5.3 software. RESULTS: Twenty eligible RCTs with 1872 participants were included for systematic review and meta-analysis. Studies were assessed using the Cochrane risk of bias tool. The meta-analysis of add-on effect of TwHF conferred benefit for psoriasis: combination treatment with compound glycyrrhizin (four studies, OR = 0.34, 95% CI 0.22–0.52, P < 0.00001, I(2) = 0%), combination treatment with acitretin (three studies, OR = 0.25, 95% CI 0.10–0.63, P = 0.003, I(2) = 50%), and combination treatment with compound amino-polypeptide tablet (three studies, OR = 0.37, 95% CI 0.22–0.63, P = 0.0002, I(2) = 0%). CONCLUSIONS: Despite several mild side effects of TwHF, there is evidence that TwHF is an effective therapy for psoriasis. However, the conclusions are limited by the small number of included trials. More well-designed RCTs with extensive follow-up periods are warranted to clarify the effects and safety of TwHF in treating psoriasis. TRIAL REGISTRATION: This review was registered in the International Prospective Register of Systematic Reviews (CRD42016041363).