The search to elucidate the potential therapeutic effects of medicinal plants has been expanding worldwide. Data from the Global Report on Complementary and Traditional Medicine showed that 88% of World Health Organization member states recognize the use of complementary and traditional medicine as essential and are developing guidelines for the creation of policies, laws, regulations, and programs that involve the use of medicinal plants in health systems.1 Due to their great potential to treat and prevent diseases, medicinal plants have been used traditionally in wound management.2,3 In Brazil, medicinal plants are mainly used in primary health care because of a considerable lack of availability of new technologies to treat wounds.4 Because of this, in 2009, the Brazilian Ministry of Health created the National List of Medicinal Plants of Interest to the Unified Health System (Relação Nacional de Plantas Medicinais de Interesse ao Sistema Único de Saúde or RENISUS), seeking alternatives for the treatment of common diseases that affect the population.2 Plantago major belongs to the Plantaginaceae family and has 185 accepted species.4 It plays an essential role in complementary and traditional medicine in different cultures of the world, and it is used to treat diseases related to the skin, digestive system, circulatory system, urinary system, and skin lesions.5
The benefits of P major are related to the use of its leaves and seeds, which have been shown to have analgesic, anti-inflammatory, antioxidant, immunomodulatory, antifungal, anticancer, and wound healing effects in in vivo and in vitro studies.5,6 These outcomes are believed to be related to the various bioactive compounds, such as flavonoids, alkaloids, terpenoids, phenolic compounds, iridoid glycosides, fatty acids, polysaccharides, and vitamins.6,7 P major has been recommended for human use in various forms such as roasted seeds, decoction, syrup, liniment, gargle, rectal enema, vaginal suppository, and eye and nasal drops.5
Human skin is the main barrier against the environment, and acute and chronic problems can occur because of exposure to damaging factors. Tissue repair is physiological but can be compromised8,9; therefore, there have been many efforts to investigate the possible therapeutic effect of medicinal plants in the treatment of wounds.8,9
In their study utilizing a scratch assay, Zubair et al10 researched 5 populations of P major collected in different regions of Sweden and identified plantamajoside among the most expressive phenolic compounds, followed by 4 new compounds identified as PLMA 1 to PLMA 4. Compounds such as plantamajoside and iridoid glycosides have an anti-inflammatory and antioxidant action, which may contribute to the healing of skin wounds.11,12 Results of other in vitro, in vivo, and ex vivo studies have supported the medicinal effects of various Plantago species via their ability to decrease the inflammatory cascade induced by nuclear factor-kappa B, nitric oxide, cyclooxygenase-2, and B4 leukotrienes as well as to improve wound healing.10,13–15
Despite the use of P major to treat diseases related to skin, respiratory organs, digestive organs, and reproduction as well as its use against infections, Plantago’s ability to heal wounds has only been evaluated in preclinical studies.10 Research on the topical use of P major in skin wounds has been limited in clinical practice, although it has been used in folk medicine. However, a recent clinical trial testing a P major solution versus a bicarbonate and chlorhexidine solution in the treatment of oral mucositis demonstrated that there were no differences in outcomes between the groups, and the authors suggested that the use of P major extract in the management of oral mucositis could be considered for clinical practice.16 In this context, the present systematic review aimed to evaluate the effectiveness of the topical use of P major in the healing of skin wounds in animal models.