Antibacterial Efficacy of Lemongrass (Cymbopogon citratus) Oil against Enterococcus faecalis

Abstract Background: Sodium hypochlorite (NaOCl) is a commonly used irrigant in endodontic procedures, but one of its drawbacks is tissue toxicity. Cymbopogon citratus , an herbal remedy with antibacterial properties, presents a potential alternative. Enterococcus faecalis , an anaerobic bacterium known for its resilience in harsh environments, can contribute to post-endodontic treatment failure. Aims: To determine the effect of C. citratus extract on the elimination of E. faecalis . Materials and Methods: This is an in vitro study, with C. citratus oil stored at −20°C. E. faecalis was cultured, achieving a turbidity reading of 0.5 on the McFarland scale (equivalent to 1.5 × 10 8 bacteria/mL). The culture was then inoculated onto Mueller–Hinton agar plates with three uniformly-sized wells. The negative control used distilled water, while the positive control employed 2.5% NaOCl. Inhibition zones around each well were measured, indicating bacterial sensitivity. Data were analysed using one-way analysis of variance followed by Tukey’s post hoc test, with significance set at P < 0.05. Results: C. citratus extract was effective in eliminating E. faecalis , producing a mean inhibition zone of 22.86 ± 5.98 mm, which was comparable to 2.5% NaOCl (22.09 ± 2.59 mm; P < 0.05), while no inhibition was observed for saline. Conclusion: C. citratus extract demonstrates significant antibacterial activity against E. faecalis in vitro . Additional in vitro studies are required to optimize its concentration, formulation and determine its mechanism of action.