The effectiveness and safety of Chinese herbal formulas on skin photoaging: A protocol for systematic review and meta-analysis.

Background: Skin photoaging (SP) is a complex and complicated process of skin characteristic changes caused by excessive sunlight. Wrinkles, looseness, coarseness, and increase or loss of pigment are the main clinical manifestations of the disease. The pathogenesis of SP mainly involving oxidative stress, inflammatory reaction, immune dysregulation and DNA damage, and so on. In recent years, traditional Chinese medicine, as an significant form of complementary and alternative medicine, has attracted the more and more attention within the field of health care and indicated a desirable effect on SP. Chinese herbal formula (CHF) is an essential part of traditional Chinese medicine interventions, and the number of clinical trails on SP treated by CHFs have shown a growing trend. Therefore, we developed this systematic review and meta-analysis protocol to assess the effectiveness and safety of CHFs in the therapy of SP, so as to provide reliable evidence-based evidence for clinical decision-making.

Methods: A overall literature retrieval will be carried out in 9 electronic journal database. We will include randomized controlled trials (RCTs) on CHFs alone or combined with routine western medicine measures in the treatment of SP. The outcomes we focused on are consists of symptom score (skin relaxation, telangiectasia, pore coarseness, pigmentation, etc), total effective rate, and adverse reactions. Meta-analysis will be performed using Stata 13.0 software. Literature retrieval and screening, data extraction, risk of bias assessment of RCTs, evidence confidence rating by grading of recommendations assessment, development, and evaluation method and methodological quality assessment of systematic review by assessment of multiple systematic reviews-2 will be conducted independently by 2 reviewers, and disagreements will be resolved through discussion or judged by a third senior reviewer.

Results: This systematic review and meta-analysis will pool the proof of RCTs on SP treated by CHFs alone or combined with conventional western medicine treatments. The findings of this study will be presented at relevant conferences and submitted to peer-reviewed journals for publication.

Conclusion: We expect that the results of this systematic review will provide comprehensive and reliable evidence for clinicians and policy makers.

Registration Number: INPLASY 2020120005.