Methods: Sixteen plants were collected from various regions of Uganda based on literature information. Fresh plant parts were then cut into pieces and ground in fruit juicer to obtain fresh crude extracts. The extracts were tested against caries associated Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, and periodontitis associated Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia using agar diffusion assay. The extracts were tested without dilution and at 50% and 25% concentration after dilution in Brain Heart Infusion (BHI) broth. Doxycyline (30µg) and BHI served as positive and negative control, respectively.
Result: Extracts from four plants, namely Zanthoxylum chalybeum, Euclea latidens, Ocimum gratissimum, and Clematis hirsuta, had activity against at least one bacterial species. Extract from Zanthoxylum chalybeum and Euclea latidens showed activity against all the bacterial species tested. The most active extract was from Zanthoxylum chalybeum. It exhibited the best activity against L.acidophiluswith the undiluted and 25% extract concentration producing 62% and 54% zones of inhibition respectively compared to doxycycline control.
Conclusion: The antibacterial activities of Z.chalybeum and E.latidens shows they could be possible alternatives for combating tooth decay and periodontal diseases.