A review of southern African medicinal plants used traditionally to treat wounds, and studies into their wound healing properties

Wounds are a common medical condition and numerous plants are used across southern Africa to promote their healing. This review summarises the traditional use of southern African plants to treat wounds and to promote healing. Our study used expanded search parameters and a wider geographical focus than in previous reviews to identify further plant species, resulting in the identification of 292 plants species that are used to treat wounds in the southern African region. This inventory included 96 species that were not recorded in previous reviews. Notably, existing ethnobotanical records are incomplete, and details of the plant part used, the preparation and the biological target(s) of many of the identified plants are lacking. Of the plants whose use has been more completely reported, the main part used to promote wound healing is the leaves (∼40%), and nearly 40% of all plant parts are applied directly to the wound, either as the whole part, or as a powder or paste. Notably, only 152 plants (52% of the identified species) have been scientifically evaluated for bioactivities related to one or more phases of wound healing. Of the screening studies, a relatively low proportion have examined the therapeutic mechanism(s) in detail. Additionally, many of the previous screening studies (particularly the older studies) have used less quantitative and/or outdated methods to evaluate the wound healing properties of these plants. Substantially more research is required to better evaluate those plants, and to screen plants that have previously been neglected. This review establishes a structured framework that highlights current knowledge gaps in the literature, thereby guiding researchers in the informed selection of plants and assays.