Traditional Chinese Medicine Treatment for Androgenetic Alopecia Based on Animal Experiments: A Systematic Review and Meta-Analysis

BACKGROUND: In the present study, we systematically evaluated the effects of Traditional Chinese Medicine (TCM) on androgenetic alopecia (AGA) in rodent models (rats and mice) to provide potential evidence for the treatment of AGA by TCM. METHODS: Previous research papers focusing on the treatment of AGA by TCM were retrieved from various electronic databases (PubMed, Embase, The Cochrane Library, CNKI, Vip, Wanfang data, and CBM) up to October 30, 2021. Screening of the literature was performed independently, and data were extracted and assessed. A meta-analysis was performed using RevMan 5.3 software. RESULTS: When compared with the model groups, a group of C57BL/6 mice treated with TCM showed an increase in the total number of hair follicles (mean difference [MD] = 11.99, 95% confidence interval [CI] [5.94,18.03], P=0.0001), as well as a decrease in serum testosterone (T) level (MD = −1.10, 95% CI [−1.43, −0.78], P < 0.00001), skin discoloration time (MD = −2.93, 95% CI [−4.03, −1.84], P < 0.00001), and skin hair growth time (MD = −3.16, 95% CI [−4.16, −2.16], P < 0.00001). Terminal hair/vellus hair also increased in TCM-treated AGA animals (MD = 3.02, 95% CI [2.05, 3.98], P < 0.00001). No significant difference was found in serum estradiol (E(2)) level, skin tissue E(2) level, or skin tissue T level between the TCM-treated group and the model group. CONCLUSION: TCM can increase the total number of hair follicles and terminal hair/vellus hair ratio, and reduce skin discoloration time and skin hair growth time in AGA animal models. These effects may be related to the reduction of the serum T level in AGA animals. These conclusions need to be verified by high-quality studies as the current analysis may be affected by the number and quality of the studies identified.