Eficácia in vitro do óleo da semente de Carapa guianensis Aubl. (Meliaceae) sobre Damalinia (Bovicola) ovis Schrank (1781)

Abstract

One of the main ectoparasitoses diagnosed in sheep is pediculosis, which causes economic losses in production. It may be caused by chewing lice, such as Damalinia (Bovicola) ovis Schrank (1781). Among the pediculosis control measures, the application of chemicals with insecticidal activity has been widely used, although there are reports of resistance to different drugs. Considering that the lice infestation in sheep of Mossoró-RN, represents a factor that compromises the production of these animals, and that there is on the part of the owners the indiscriminate use of ectoparasiticides that leads to the emergence of resistance, it is necessary to search for methods. alternatives for pediculosis control. This study aimed to evaluate the in vitro efficacy of Carapa guianensis (andiroba) seed oil on D. (Bovicola) ovis. To carry out the experiment, 900 specimens of D. (Bovicola) ovis collected from naturally infested sheep belonging to the NUTESA-UFERSA Animal Production Technology Transfer and Production Nucleus were used. The parasites were sent to the Animal Parasitology Laboratory (LPA) of the Rural Federal University of Semi-arid (UFERSA) for identification and divided into groups with the following treatments: (G1), C. guianensis oil at a concentration of 1000 mg/mL 500 mg/mL, 250 mg/mL, 125 mg/mL, 62,5 mg/mL, 31,2 mg/mL and 15,6 mg/mL diluted in a Tween 80 solution (3%); (G2), Tween 80 Solution (3%) (negative control) and Amitraz 1.25 g/mL (G3), (positive control). For each experimental group four replicates were made, consisting of 25 lice each. The lice were immersed in oil with different concentrations and after immersion, were transferred to Petri dishes. Mortality was observed after 1, 3, 6, 24, 48 and 72 hours of the start of the test. There was a difference in the mortality of ectoparasites between and within some treatments studied and over the analyzed times. In relation to Amitraz, the oil in the highest concentration analyzed (1000 mg/mL) caused the death of a larger number of lice at times 1, 3, 6 and 24 hours after immersion. After 48 hours, the oil in the highest concentration had action equal to Amitraz. Compared to Tween 80, the oil in the highest concentration caused the death of a larger number of lice in all studied times, except 72 hours. Considering the action of the oil and the sex factor of the lice, the oil acted regardless of whether the specimen was male, female or nymph. Inhibitory concentrations IC50 and IC90 of andiroba oil on lice were 439, 21 mg/mL and 807.09 mg/mL, respectively. C. guianensis seed oil showed in vitro activity against D. (Bovicola) ovis. It is suggested that andiroba oil adopted under the conditions of the present study can be used in in vivo experimental research to produce a herbal medicine to be used as an alternative control in sheep pediculosis caused by D. (Bovicola) ovis.