Evaluation of antimicrobial and phytochemical screening of Fennel, Juniper and Kalonji essential oils against multi drug resistant clinical isolates

ABSTRACT

Objective: The inhibitory effects of essential oils including fennel, juniper and kalonji from Foeniculum Vulgare, Juniperus Osteosperma and Nigella Sativa on multi drug resistant clinical isolates were investigated. All the oils have been evaluated for phytochemical constituents, antibacterial activity and TLC bioautography assay. Methods: Preliminary phytochemical analysis was performed. The antibacterial potential of essential oils from fennel, juniper and kalonji fennel, juniper and kalonji was evaluated by agar well diffusion method against multi drug resistant clinical isolates. The antibacterial effect was investigated using the TLC-bioautographic method. Results: Preliminary phytochemical analysis demonstrated the presence of most of the phytochemicals including saponins, cardiac glycosides, steroids, terpenoids, flavonoids and tannins. Antibacterial activity of essential oils was assessed on eight multi-drug resistant (MDR) clinical isolates from both Gram-positive and Gram-negative bacteria and two standard strains. All the oils tested showed significant to moderate antibacterial activity toward all tested strains except Acinetobacter sp and Staphylococcus aureus MRSA. The maximum zone of inhibition was found to be 25依0.12 mm for juniper oil followed by 21依0.085 mm for kalonji oil againstStaphylococcus aureus 2. Thin layer chromatography and bioautography assay demonstrated well-defined growth inhibition zones against Staphylococcus aureus 2 and E. coli for juniper essential oil in correspondence with tannins observed at Rf values of 0.07 and 0.57. Conclusions: Based on the present study, the essential oils from juniper and kalonji possess antibacterial activity against several multi drug resistant pathogenic bacteria and thus can be used as a base for the development of new potent drugs and phytomedicine.