Plants used to treat skin diseases in northern Maputaland, South Africa: antimicrobial activity and in vitro permeability studies.

CONTEXT: Ethnobotanical claims of medicinal plants used in northern Maputaland are limited. Objectives To establish scientific validity for a selection of the plants used in Maputaland to treat skin diseases. MATERIALS AND METHODS: Aqueous and dichloromethane-methanol extracts were prepared from 37 plant species which were collected from four rural communities in Maputaland. Antimicrobial screening was performed on extracts against 12 dermatological relevant pathogens using the micro-titre plate dilution assay. Their combined effect was evaluated by determining the sum of the fractional inhibitory concentrations (ΣFICs). Chemical analysis was undertaken using reverse-phase high-performance liquid chromatography (RP-HPLC) and investigated in vitro across excised intact porcine skin using the ILC07 automated system. RESULTS: The organic extract of Garcinia livingstonei T. Anderson (Clusiaceae) was found to be the most antimicrobially active displaying an average broad-spectrum MIC value of 270 µg/mL. The combination of Sclerocarya birrea (A. Rich.) Hotsch. (Anacardaceae) with Syzygium cordatum Hochst. ex C. Krauss (Myrtaceae) displayed synergistic effects. The four antimicrobially active organic extracts were found to possess mainly anthraquinones, flavonoids, tannins and saponins. The organic extracts of Kigelia africana (Lam.) Benth. (Bignoniaceae) and S. cordatum were found to have more compounds capable of permeating intact skin after 10 min of exposure. CONCLUSION: More than 80% of the organic extracts tested displayed a correlation between the antimicrobial efficacy and the reported traditional uses of the plants. Furthermore, the traditional use of topically applied plant preparations is validated as some compounds from the active plants are capable of permeating the skin in vitro.

Medicinal plants used for the treatment of various skin disorders by a rural community in northern Maputaland, South Africa.

BACKGROUND: Skin diseases have been of major concern recently due to their association with the Human Immunodeficiency Virus and Acquired Immunity Deficiency Syndrome (HIV/AIDS). The study area (northern Maputaland) has the highest HIV infection rate in South Africa, which made them more prone to a wide range of skin conditions. Fungal infections due to the hot climate and overcrowding households are common in this area, as well as burn accidents due to the use of wood as the major fuel for cooking. It is known that the lay people in this area depend on medicinal plants for their primary health care. However no survey has been done in northern Maputaland to document the medicinal plants used to treat various skin disorder. METHODS: Interviews were undertaken at 80 homesteads, using structured questionnaires. The focus was on plants used for dermatological conditions and information regarding vernacular plant names, plant parts used, preparation (independently and in various combinations) and application was collected. RESULTS: A total of 87 lay people, both male (22%) and female (78%) were interviewed on their knowledge of medicinal plants used to treat disorders of the skin. Forty-seven plant species from 35 families were recorded in the present survey for the treatment of 11 different skin disorders including abscesses, acne, burns, boils, incisions, ringworm, rashes, shingles, sores, wounds and warts. When searching the most frequently used scientific databases (ScienceDirect, Scopus and Pubmed), nine plant species (Acacia burkei, Brachylaena discolor, Ozoroa engleri, Parinari capensis, subsp. capensis, Portulacaria afra, Sida pseudocordifolia, Solanum rigescens, Strychnos madagascariensis and Drimia delagoensis) were found to be recorded for the first time globally as a treatment for skin disorders. Fourteen plant combinations were used. Surprisingly, the application of enema's was frequently mentioned. CONCLUSIONS: The preference of traditional medicine over allopathic medicine by most of the interviewees strengthens previous studies on the importance that traditional medicine can have in the primary health care system in this rural community. Studies to validate the potential of these plants independently and in their various combinations is underway to provide insight into the anti-infective role of each plant.