Antiprotozoal Activity of Turkish Essential Oil and Its Components.

Essential oil of species is well known for antimicrobial activity, but only a few have been evaluated in narrow spectrum antiprotozoal assays. Herein, we assessed the antiprotozoal potential of Turkish L. oil and its major constituents against a panel of parasitic protozoa. The essential oil was obtained by hydrodistillation from the dried herbal parts of and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). The in vitro activity of the oil and its major components were evaluated against , , , and . The main component of the oil was identified as carvacrol (70.6%), followed by linalool (9.7%), -cymene (7%), γ-terpinene (2.1%), and thymol (1.8%). The oil showed significant in vitro activity against (IC 180 ng/mL), and moderate antileishmanial and antiplasmodial effects, without toxicity to mammalian cells. Carvacrol, thymol, and 10 additional abundant oil constituents were tested against the same panel; carvacrol and thymol retained the oil's in vitro antiparasitic potency. In the mouse model, thymol, but not carvacrol, extended the mean survival of animals. This study indicates the potential of the essential oil of and its constituents in the treatment of protozoal infections.