Antiprotozoal Activity of Turkish Origanum onites Essential Oil and Its Components

Abstract

Essential oil of Origanum 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 Origanum onites 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 O. onites 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 Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. The main component of the oil was identified as carvacrol (70.6%), followed by linalool (9.7%), p-cymene (7%), γ-terpinene (2.1%), and thymol (1.8%). The oil showed significant in vitro activity against T. b. rhodesiense (IC50 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 T. b. brucei mouse model, thymol, but not carvacrol, extended the mean survival of animals. This study indicates the potential of the essential oil of O. onites and its constituents in the treatment of protozoal infections.

Pharmacological Assessment of the Carvacrol Chemotype Essential Oil FromPlectranthus amboinicusGrowing in Cuba

“…In addition, it is notable that carvacrol showed same activity of EO-Pa against P. falciparum (Figure 3), which could suggest that antiplasmodial activity is caused by the main active compound. Similar results were shown by Tasdemir et al, 59 who previously reported an IC 50 value for carvacrol of 6.4 ± 0.9 µg/mL against P. falciparum K1 strain (chloroquine-and pyrimethamine-resistant).…”

An overview of the treatment of cutaneous leishmaniasis

“…Tasdemir et al . assessed the antiprotozoal activity of Origanum onites against some protozoa 61 . The main components of the oil were carvacrol (70.6%), linalool (9.7%), p -cymene (7%), γ -terpinene (2.1%), and thymol (1.8%).…”

“…It did not show toxicity to mammalian cells. Some of these compounds were assessed individually with a decrease in their activity, suggesting that they have an additive action 61 .…”

Trypanocidal Essential Oils: A Review

“…Tasdemir et al (2019) [ 42 ] evaluated the in vitro activity of the essential oil of Turkish Origanum onites L. and its main constituents against T. cruzi . The main components found in the essential oil were carvacrol (70.6%), followed by linalool (9.7%), p -cymene (7%), γ-terpinene (2.1%), and thymol (1.8%).…”

“…Tasdemir et al (2019) [ 42 ] also evaluated the in vitro activity of the essential oil of Origanum onites L. turco and its main constituents against T. brucei rhodesiense . The oil showed significant in vitro activity against T. brucei rhodesiense (IC 50 180 ng/mL) without causing toxicity in mammalian cells.…”