Antibacterial efficacy of essential oil of two different varieties of ocimum (tulsi) on oral microbiota-an invitro study

Introduction: Ocimum (Tulsi) is an Indian sacred plant which has immense medicinal values. There are various varieties of Tulsi grown in India most common being Ocimum sanctum and Ocimum basilicum. Objectives: To test in-vitro the antibacterial efficacy of commercially available essential oil extracts of different varieties of Ocimum (Tulsi) on common oral pathogens. Methodology: Commercially available essential oil of two varieties of Ocimum i.e. Ocimum sanctum and Ocimum basilicum were procured and checked for their antibacterial activity in-vitro. Five common oral pathogens were selected (two aerobic and three anaerobic). The organisms were incubated on respective culture media. Agar well diffusion method was used to check their activity. The oils were tested undiluted form and 1 in 10 dilutions. The activity of oils was compared with chlorhexidine. Results: Both the oils showed antimicrobial activity against all the test strains. The zone of inhibition produced by Ocimum sanctum oil was maximum for Porphyromonas gingivalis (55 mm) followed by Prevotella intermedia (48 mm). The zone produced was much wider than that of chlorhexidine. For Fusobacterium nucleatum, the zone was equivalent to control. For aerobic bacteria, Ocimum sanctum, showed almost equal efficacy as of chlorhexidine but the effect produced by Ocimum basilicum oil was lesser than control. Conclusion: The essential oil of two varieties of Tulsi showed good antimicrobial activity against the common anaerobic and aerobic organisms of the oral cavity. The activity was more pronounced against anaerobes and was found to be better than chlorhexidine. Ocimum sanctum oil produced a wider zone of inhibition as compared to Ocimum basilicum for all the test strains.