In vitro antimicrobial activity of phytomedicine against acidogenic oral bacteria
BEUKES, S.* Department of Orthodontics, School of Dentistry, University of Pretoria,
Patients receiving orthodontic treatment have a higher risk of accumulating plaque as fixed appliances make plaque removal more difficult. Bacteria causing decalcification, such as Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei and Actinomyces naeslundii flourish in an environment with poor oral hygiene. Objectives: To test the in vitro antimicrobial activity of ethanol, acetone and hexane extracts from eight medicinal plants (Hydrastis Canadensis, Cyclopia Intermedia, Hypericum perforatum, Ginkgoaceae, Passiflora incarnata, Achillea Millefolium, Arciosiaphylos uva-ursi and Artemisia absinthium) against S. mutans, S. sobrinus, L. casei and A. naeslundii involved in dental demineralisation. Thin layer chromatography (TLC) was used for analysing the plant extracts. Materials & Methods: The chromatograms were also tested for antimicrobial activity and the minimum inhibitory concentration [MIC] of the extracts was determined using serial dilution of the extracts in a microplate method. Results: Acetone extracts had the highest activity followed by hexane and ethanol, indicating that non-polar and intermediate polarity compounds were the most efficient, particularly against S. mutans, and slightly less against S. sobrinus, L. casei and A. naeslundii. The herbs with activity ranges of 0,04-0,3 mg/ml included Ginkgoaceae, Achillea Millefolium, Passiflora incarnata, Arciosiaphylos uva-ursi and Hypericum perforatum. The acetone extracts showed inhibition zones for five and the hexane extracts for six of the selected herbs. The MIC values of the herbal extracts compared well with the fluoride and chlorhexidine control treatments. Conclusion: Certain plant extracts can prevent demineralisation and might even outperform some of the currently used products. Funding: NRF