Antimicrobial activity of South African medicinal plants.

This paper reviews the antimicrobial research undertaken on South African medicinal plants during the period 1997-2008. Antimicrobial methods (disc diffusion, minimum inhibitory concentration (MIC), bio-autography) are briefly discussed and an analysis of the publications reviewed indicates that the majority of papers use MIC assays for antimicrobial determination. Antimicrobial investigations on extracts are presented where the most active plants are identified from screening publications. A summary of some bioactive compounds are given with data restricted to papers reporting quantitative antimicrobial activity equivalent to or below 200 microg/ml. Antimicrobial activities on the essential oils of indigenous medicinal aromatic plants are also reviewed. An overview is given on what activities (extracts, compounds and oils) should be considered noteworthy for publication. Studies focusing on geographical ethnobotany, specific pathogenesis, formulation aspects and in vivo investigations are examined. Future recommendations to consider include pathogen selection, interactive studies and dosage administrations.