In vitro antibacterial and antifungal potentials of Ocimum tenuiflorum and Ocimum gratissimum essential oil

Abstract

Introduction

Ocimum known as Tulsi has various health benefits mentioned in Ayurveda. Ocimum polysaccharides are used in pharmacology as the capacity to prevent ageing, boost immunity, suppress tumor growth, reduce diabetes mellitus and function as an antioxidant. Therefore, the goal of the current investigation was to examine the antibacterial and antifungal activities of Ocimum tenuiflorum and Ocimum gratissimum essential oils.

Method

Essential oils of Ocimum tenuiflorum and Ocimum gratissimum were extracted by hydrodistillation method and antibacterial and antifungal activities were done by agar well diffusion and broth micro dilution method. Furthermore, In silico toxicity analysis was done by the SwissADME server.

Result

Ocimum gratissimum essential oil was found to have an extraction yield of 2.75 ± 0.5 % and 3.90 ± 0.5 % for O. tenuiflorum. α-thujene (15.33 %), eugenol (16.11 %) and β-terpineol (7.75 %) were the major phytocompounds of O. tenuiflorum whereas chavibetol (17.70), α-pinene (15.16 %) and bicyclosesquiphellandrene (9.07 %) were the major phytocompounds of O. gratissimum essential oil. Forging ahead, essential oil of O. tenuiflorum showed MIC of 0.078 % against E. coli ATCC29213, 0.3125 % against K. pneumoniae MTCC39, 0.078 % against S. aureus ATCC25922, 0.625 % against both C. albicans, MTCC277 and ATCC90028, however, essential oil of O. gratissimum showed MIC of 1.25 % against E. coli ATCC29213, followed by K. pneumonia MTCC39 (2.5 %) and S. aureus ATCC25922 (2.5 %) and 5.0 % against both C. albicans MTCC277 and ATCC90028. Certainly, phytocompounds of both the Ocimum spp. also fulfilled the Lipinski rule and showed characteristics similar to drugs. β-terpinole demonstrated the best antibacterial activity with a P_a value of 0610 and β-caryophyllene and caryophyllene oxide had the best antifungal activity with a P_a value of 0647.

Conclusion

To conclude, the current study showed that O. tenuiflorum and O. gratissimum have good antibacterial and antifungal activity and on the basis of further experimentation, can be used as a source of natural antimicrobials.