Atividades in vitro dos óleos essenciais de Cuminum cyminum, Anethum graveolens e Thymus vulgaris sobre Haemonchus contortus

Abstract

Gastrointestinal nematodes are the major cause of losses in sheep production, among them Haemonchus contortus. The control of these nematodes is basically due to the use of commercial anthelmintics, but these have shown a considerable decrease in their efficiency over the decades. Therefore, the need to search for new control alternatives to these parasites is of paramount importance. In view of this, the present study aimed to evaluate the in vitro action of the essential oils of the aromatic plants Anethum graveolens (dill), Cuminun cyminum (cumin) and Thymus vulgaris (thyme), in H. contortus eggs and larvae (L1 and L3), determine their main constituents and determine the 50% inhibitory concentration (IC50). For this, the essential oils (OEs) of the plants were extracted from seeds, through the clevenger apparatus and to determine the main constituents was carried out the gas chromatography coupled to mass spectrometry. Eggs and larvae were obtained by collecting naturally infected sheep feces. The eggs hatch inhibition test (IE), larval migration inhibition test (IML) and larval development inhibition test (IDL) were performed. The concentrations used were: 9.4; 4.7; 2.35; 1.17; 0.58; 0.29 mg / mL, all tests followed by commercial anthelmintic positive control, negative control distilled water and control with tween. The results obtained in the highest concentration of the different OEs (9.4 mg / mL) for IE were 100%, 98.62% and 100%, for IDL were 98.58%, 69.12%, 100% and for IML were of 63.7%, 23.45% and 95.30% for A. graveolens, C. cyminum and T. vulgaris, respectively. The major constituents present in OE A. graveolens were Dihydrocarvone (39.1%), OE C. cyminum, Cumaldehyde (27.39%) and OE T. vulgaris and endoBorneol (30.48), respectively. The IC50 was 0.7642 mg / mL, 0.0012 mg / mL and 0.1373 mg / mL (IE), 0.8297 mg / mL, 3.70 mg / mL and 0.8056 mg / mL (IDL) and 2.234 mg / mL, 104.34 mg / mL and 0.7253 mg / mL (IML), for A. graveolens, C. cyminum and T. vulgaris, respectively. Based on the results presented here, it can be concluded that the evaluated OEs have an action on the different stages of development of H. contortus, therefore with potential to obtain biomolecules with anthelmintic activity.