The feasibility of southern African traditional plant therapies for ophthalmic use

Abstract

Ophthalmic infections are common and can cause substantial loss of eyesight. It is estimated that nearly 45% of the South African population has suffered from partial or total loss of eyesight with a substantial portion of this being due to infections. However, in approximately 80% of cases, this loss of eyesight could have been easily prevented or even treated. Multiple plant species are used in traditional South African medicine to treat eye infections, yet the therapeutic properties of most of these plants have been poorly studied. An extensive literature review of the ethnobotanical literature was undertaken to document the plant species used in southern African traditional medicine to treat eye disorders. A search was subsequently undertaken to identify and summarise studies that have provided some scientific evidence to support traditional use against these eye disorders. A total of 137 plant species belonging to 53 plant families are recorded to treat eye disorders in traditional southern African medicine. The use of many plants was credited with vague indications such as “eye problems” and “eye conditions”. Only 42 of the identified species have been evaluated for inhibitory activity against any eye-related pathogens. Whilst bacterial Staphylococcal pathogens were the most extensively tested, many other pathogens associated with eye infections have been neglected. Additionally, several fungal and most viral pathogens have been completely neglected to date. Furthermore, few studies have tested the toxicity of the plant extracts and mechanistic studies are lacking. Whilst this review identifies and highlights plant species used in traditional southern African medicine to treat eye infections, substantially more research is required to completely validate their traditional use and to evaluate the potential of the plant preparations as drug leads.