Antibacterial activities of extracts from Ugandan medicinal plants used for oral care

Ethnopharmacological relevance: Medicinal plants are widely used for treatment of oral/dental diseases in Uganda. Aim of the study: To investigate antibacterial activities of 16 commonly used medicinal plants on microorganisms associated with periodontal diseases (PD) and dental caries (DC). Materials and methods: Pulp juice and solvent extracts (hexane, methanol and water) from the plants were tested against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia associated with PD and Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus associated with DC. Tests were done using agar well-diffusion (pulp juice) and agar-dilution (Solvent extracts) assays. Results: Pulp juice from Zanthoxylum chalybeum and Euclea latidens showed activity against all the bacteria, Zanthoxylum chalybeum being most active. Hexane extract from aerial part of Helichrysum odoratissimum was most active (MIC: 0.125-0.5 mg/ml). Methanol extract from leaves of Lantana trifolia showed activity against all bacteria (MIC: 0.25-1 mg/ml). Conclusion: Several of the tested plants showed antibacterial activities against bacteria associated with PD and DC, meriting further investigations. (C) 2014 Elsevier Ireland Ltd. All rights reserved.