Compound glycyrrhizin plus conventional therapy for psoriasis vulgaris: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background: Psoriasis vulgaris is a chronic skin condition affecting patients’ quality of life. Long-term use of conventional therapy increases risk of unwanted side effects. Compound glycyrrhizin in conjunction with conventional therapy has been used in clinical practice, but the evidence for such practice has not been evaluated systematically.

Objective: This review aims to evaluate the efficacy and safety of compound glycyrrhizin in combination with conventional therapy for psoriasis vulgaris.

Methods: PubMed, Excerpta Medica dataBASE (Embase), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials, Allied and Complementary Medicine Database (AMED), CiNii, Chinese Biomedical Literature, China National Knowledge Infrastructure, Chinese Scientific Journals Full Text Database and Wanfang Data were searched from their respective inceptions to July 2015. Randomized controlled trials comparing compound glycyrrhizin plus conventional therapy to conventional therapy alone for psoriasis vulgaris were included. Data analysis was performed using Review Manager 5.3.

Results: Eleven randomized controlled trials were included in this review. Meta-analysis of the 11 randomized controlled trials indicated that the addition of compound glycyrrhizin increased the number of patients achieving Psoriasis Area and Severity Index (PASI) 60 (RR: 1.30 [1.21, 1.40], I² = 6%), when compared with conventional therapy alone. Comparable numbers of patients experienced adverse events in the two groups.

Conclusions: Compound glycyrrhizin in conjunction with conventional therapy enhances clinical response, and compound glycyrrhizin as add-on therapy does not appear to pose any additional risk in the treatment of psoriasis vulgaris. However, the findings should be interpreted with caution of methodological flaws in the included studies.

PROSPERO registration number: CRD42015027763.

Keywords:

• Evidence-based medicine
• glycyrrhizin
• meta-analysis
• psoriasis
• review, systematic

Transparency

Declaration of funding

The project is jointly supported by the China–Australia International Research Centre for Chinese Medicine (CAIRCCM) – a joint initiative of RMIT University, Australia and the Guangdong Provincial Academy of Chinese Medical Sciences, China with additional funding support from the Ministry of Science & Technology of China, under Grant Number 02012DFA31760, and State Administration of Traditional Chinese Medicine in China, under Grant Number 1601500000027(11).

Author contributions: J.J.Y. conceived and drafted the manuscript. J.J.Y., Y.D. and C.S.Z. screened and analyzed the studies. J.J.Y., C.S.Z., M.E.C., X.G. and A.L.Z. interpreted the evidence from methodological and clinical perspective. C.C.X. and C.L. oversaw the conduct of the study and contributed to the overall design, analysis and write-up. All authors read, critically reviewed and approved the final manuscript.

Declaration of financial/other relationships

J.J.Y., C.S.Z., M.E.C., Y.D., A.L.Z., X.G., C.C.X., and C.L. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewer 1 has disclosed that she is the owner of Zamia Life Nutrition and has received grants from the National Center for Complementary and Integrative Health. CMRO peer reviewer 2 has no relevant financial or other relationships to disclose.

Acknowledgments

We acknowledge Dr Amy Tan and Songpei Li’s help in the search of the Japanese database.