Planta Med 2011; 77 - SL35
DOI: 10.1055/s-0031-1282158

Antimicrobial investigations with impact – what can researchers do to ensure continuity?

SF Van Vuuren 1, H De Wet 2, AM Viljoen 3, RL Van Zyl 1
  • 1Department of Pharmacy and Pharmacology, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa.
  • 2Department of Botany, University of Zululand, KwaDlangezwa, 3886, South Africa.
  • 3Department of Pharmaceutical Sciences, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.

When reflecting on past antimicrobial studies undertaken on medicinal plants, it is clear that those having the most impact have been when a targeted disciplinary approach has been adopted. In order to elaborate on this, past and present studies will be presented with different approaches (pathogen specific, ethnopharmacological correlations, combination studies, structure activity relationships, formulations etc) in order to achieve outcomes that address recommendations made from previous antimicrobial reviews [1,2,3,4]. Medicinal plant use by inhabitants from Maputaland, Zululand (Southern Africa) were undertaken, whereby the in vitro antimicrobial investigations against diseases associated with diarrhoea, respiratory and sexually transmitted infections were validated. The outcomes of these studies address the need to investigate specific pathogens, interactive efficacies between different plant species and toxicity profiles. When popular essential oils (Melaleuca alternifolia Cheel, Thymus vulgaris L., Mentha piperita L. and Rosmarinus officinalis L.) were combined with conventional antimicrobials (ciprofloxacin and amphotericin B), a predominantly antagonistic interaction was noted, highlighting the need to not only focus on synergistic interactions. Structure activity relationships are important when reporting both the chemistry and antimicrobial activity and pharmacokinetic profiles of Leptospermum petersonii F.M.Bailey and the major compounds demonstrate the cidal effect of citral within 1 hr exposure to Staphylococcus aureus. Future formulation studies look promising, as demonstrated by the enhanced antimicrobial efficacy of Melaleuca alternifolia when encapsulated into polymeric liposomes. With analysis of past shortfalls and future recommendations, researchers should be encouraged to continue producing as much information as possible to allow for a better understanding of plant-based antimicrobial research.

Keywords: antimicrobial, pathogen specific, ethnopharmacological correlations, combination studies, structure activity relationships, formulations

References: 1. Rios JL, Recio MC (2005)J Ethnopharmacol 100: 80–84.

2. Cos P et al. (2006)J Ethnopharmacol 106: 290–302.

3. Van Vuuren SF (2008)J Ethnopharmacol 119: 462–472.

4. Van Vuuren SF, Viljoen AM (2011) Plant Med DOI http://dx.doi.org/10.1055/s-0030–1250736.