Chemical analyses and evaluation of anthelmintic effects of Origanum majorana essential oil, in vitro and in vivo studies
A Abidi, E Sebai, M Dhibi, MA Darghouth, H Akkari
Because of the development of resistance in helminths against major anthelmintic drugs, the search for alternatives is necessary. Medicinal plants are being studied as an alternative source of anthelmintics against gastrointestinal nematodes. The objective of this study is to analyse the chemical composition and evaluate the anthelmintic efficacy of Origanum majorana essential oil. Determination of chemical composition by gas chromatography/mass chromatography (GC/MS) revealed that essential oil was dominated by terpenoids, particularly carvacrol (35.65 %) and terpenic hydrocarbons p-cymene (15.82 %). In vitro anthelmintic effects against Haemonchus contortus were assessed by egg hatch assay (EHA) and adult worm motility assay (AWMA) compared with a reference drug albendazole. Essential oil showed ovicidal activity at all tested concentrations (1, 2, 4 and 8 mg/ml) and more than 80% egg hatching inhibition was observed at the highest dose (8 mg/ml). Eight hours exposure at 0.5 mg/ml essential oil induced a 50% inhibition worm motility. The in vivo study was performed on H. polygyrus by measuring the egg count reduction (ECR) and adult worm count reduction (AWCR) following treatment of animals with different doses (2000, 4000 and 5000 mg/kg) of plant essential oil, and 22 mg/kg for albendazole as positive control. The results showed that 5 000 mg/kg of essential oil inhibited egg count and adult worm count by 76.3 and 74.0 % respectively, seven days post treatment. These findings support the possible use of O. majorana essential oil to control gastrointestinal nematodes.
Origanum majorana; fresh herb; Haemonchus contortus; Heligmosomoides polygyrus; anthelmintic activity; faecal egg count; GC-MS analysis