In vitro antimicrobial activity, phytochemical analysis and total phenolic content of essential oil from Mentha spicata and Mentha piperita

To find the efficacy of Mentha spicata and Mentha piperita essential oils against selected clinical isolates. The oil from both common herbs has been evaluated for phytochemical constituents, TLC bioautography assay and total phenolic content. The antimicrobial potential of mint species essential oils was evaluated by agar well diffusion method against selected clinical isolates. Preliminary phytochemical analysis and total phenolic content was analyzed. The antibacterial effect was investigated using the TLC-bioautographic method. Antimicrobial activity of mint species essential oils was assessed on 11 bacterial and 4 fungal clinical isolates. Both the essential oils showed maximum activity against S. aureus 1, producing the maximum zone of inhibition 21 +/- 0.09 mm in Mentha spicata and 19.2 +/- 0.07 mm in Mentha piperita. Preliminary phytochemical analysis demonstrated the presence of most of the phytochemicals including flavonoids, saponins, cardiac glycosides, reducing sugars and steroids in both the essential oils tested. Thin layer chromatography and bioautography assay in Mentha spicata essential oil demonstrated well defined growth inhibition zones against Acinetobacter spp. in correspondence with alkaloids observed at Rf value ranging from 0.76 to 0.90. Total phenolic content shows that Mentha piperita had the highest contents of total phenolic (12.63 +/- 0.878 mu g GAE) followed by Mentha spicata (9.41 +/- 0.594 mu g GAE). Based on the present study, the essential oils from mint species possess antimicrobial activity against several clinical isolates tested and thus can be a good source of natural antimicrobial agent. (C) All Rights Reserved