Anti-Helicobacter pylori activity and essential oil composition of Thymus caramanicus from Iran.

The essential oil of the dried aerial parts of Thymus caramanicus at full flowering stage was prepared by hydrodistillation with a yield of 2.5% oil. The oil analysis by a combination of capillary GC and GC-MS revealed 26 components of which carvacrol (68.9%) was the main component, followed by p-cymene (6.0%), thymol (5.3%), gamma-terpinene (4.6%) and borneol (4.0%) representing 98.9% of the total oil. The in vitro antibacterial activity of the essential oil was determined against ten clinical isolates of Helicobacter pylori using disc diffusion, as well as measurement of minimum inhibitory concentrations. The results showed high inhibitory activity against all test bacteria by the disc diffusion method (zones of inhibition of 50.0 - 65.0 mm). Minimum inhibitory concentration values were within the range 14.5 - 58.0 microg/mL for the clinical isolates.