Medicinal plants are rich sources of phytochemicals and have been recognized to possess a wide range of properties including, antibacterial, anti-inflammatory, and anti-carcinogenic actions. Acmella oleracea
commonly referred to as Spilanthes
or “toothache herb”. It is flowers and leaves are traditionally chewed or used in the form of a tincture or paste and applied at site of toothache, gum and throat infection hence need to test their antimicrobial activity on root canal cell lines. Twigs of Acmella oleracea
were collected, air dried and ground into coarse powder. The maceration method of extraction using aqueous and 80 % ethanol was done. The mixtures were gravity filtered and the filtrates pooled and sterile filtered through a Nalgene ®
disposable filter unit with 0.45µm pore size filter. The aqueous filtrates were freeze dried while the ethanol filtrates were reduced under vacuum and the yields determined. The tenfold liquid microdilution method using sterile Microtiter plates 96 U-well with lids was undertaken to determine the Minimum Inhibitory Concentrations and Minimum Bactericidal concentrations of the extracts on pure strains of Enterococcus faecalis (ATCC 29212), Streptococcus mutans (ATCC 25175), Staphylococcus aureus (ATCC 25923), Fusobacterium nucleatum (ATCC 25586)
, Lactobacillus acidophilus (ATCC 4356) and Candida albicans (ATCC 24433).
Growth was determined as optical density at 630 nm after incubation for 24, and 48hrs at 37O
C. Bacterial growth increased especially at 50 mg/ml and 25mg/ml extract concentrations at 24 hours, and 48hours incubation. The mean bacterial inhibition was 25.74% at 95% CI [28.81, 22.67]. Most of tested microorganism showed resistance to these extracts while 2% CHX showed higher growth inhibition. Conclusion: Acmella oleracea
L aqueous and ethanal extracts generally potentiated growth of the tested root canal microorganisms. Although, 50mg/ml ethanol extracts showed bacteriostatic growth inhibition against S. mutans
ATCC® 25175™, L. acidophilus
ATCC® 4356™ and with S. aureus
ATCC® 25923™ showing complete resistance.