Atividades anti-nematoides dos óleos essenciais de Petroselinum crispum, Ruta graveolens e Thymus vulgaris no modelo nematoide Caenorhabditis elegans

Abstract

The nematode parasites represent a major public health problem and several economic loss in the agricultural sector. The study of essential oils in the model organism Caenorhabditis elegans allows to identify the nematicidal potential of these phytotherapics for control of parasites. The objective of this study was to evaluate the anti-nematode activities of commercial essential oils of Petroselinum crispum (parsley), Ruta graveolens (rue) and Thymus vulgaris (white thyme) in C. elegans model. The essential oils were tested at concentrations of 0.25%, 0.5%, 1%, 2%, 3% and 4%. The solvent DMSO 8% was used as negative control. The percentage of nematodes that remained alive, motility and the presence of eggs and live larvae in the time periods of 0h, 6h, 24h and 48h were evaluated for the test with adult nematodes. The Levamisole 25 mM was used in this test as reference antiparasitic drug. Then, the egg hatchability inhibition test was performed to evaluate the ovicidal/ovistact potential of each oil after 24h. All essential oils showed significant nematicidal activity in the adult nematode (p<0.05), with P. crispum activity being the most pronounced, showing a significant effect beginning at 0.5% concentration in all evaluated periods, corresponding to the effect with 1% or 2% of T. vulgaris oil, and 2% of R. graveolens oil. Similar effect occurred to the Levamisole group at the highest concentrations. The essential oils decreased nematode motility and did not allow the survival of young larvae, with 2% T. vulgaris oil, 2% or 3% of the oil of P. crispum and 3% of R. graveolens oil. The essential oil with more ovicidal/ovistact activity in lower concentration was T. vulgaris at 2% (p<0.05). The analysis of chemical characterization of the essential oils identified myristicin (52.5%), apiole (18.6%) and α-pinene (10.4%) in the oil of P. crispum, 2-undecanone (96%) in oil of R. graveolens and p-cymene (73.6%) and camphene (13.8%) in oil of T. vulgaris. This study concluded that the essential oils of P. crispum, R. graveolens and T. vulgaris present higer potential for use as anthelmintics, and may be an alternative to help in the control of diseases caused by nematode parasites.