The Effect of Plantago major on Wound Healing in Preclinical Studies: A Systematic Review

BACKGROUND: Plantago major is a medicinal plant that has been used for centuries to treat various health conditions including wounds. PURPOSE: To investigate the effectiveness of the topical use of P major in healing skin wounds in animal models. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted. Seven (7) electronic databases (Virtual Health Library, Public/Publisher MEDLINE, Scopus, Web of Science, Embase, Cumulative Index of Nursing and Allied Health Literature, and CAB Direct) were searched for controlled studies published in English from January 2006 to March 2020. The Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies tools guided the evaluation of the studies and determined their quality. The Systematic Review Center for Laboratory Animal Experimentation was used to assess the risk of bias. RESULTS: Of the 176 publications identified, 4 met the inclusion criteria. Studies included 20 to 100 animals and varying concentrations of P major. There were no reports of losses during research. Wound healing was assessed between 17 and 21 days following wounding. The best response in terms of wound contraction rate occurred with 10%, 20%, and 50% concentrations when compared with control groups. One (1) study did not have an animal ethics committee review. All studies had a high risk of bias and a lack of methodological rigor. CONCLUSION: The results of this review did not find evidence about the in vivo effectiveness of P major for wound healing. More rigorous preclinical studies with adequate sample sizes are required to identify the best concentrations and formulations as well as increase understanding about the mechanisms of action of P major in wound healing.