Perfil oxidativo de cordeiros infectados por Haemonchus contortus e tratados com edetato de zinco

Abstract

The emergence of parasite resistance to most classes of anthelmintics, as well as the difficulty of controlling Haemonchus contortus infection, are among the main problems faced in the sheep farming industry. Alternative and/or auxiliary control methods are essential to minimize the losses caused by H. contortus infection. The inflammatory process caused by parasitic infection increases the production of reactive species, when produced in excess exacerbate the damage caused by such infections. Given the importance of alternative control methods and the role that zinc plays in the activity of enzymes associated with the oxidative profile, the aim of the present study was to assess the action of a source of parenteral zinc (edetate zinc) in oxidative profile of lambs infected by H. contortus. For this, 24 lambs were divided into four groups: Group I - uninfected animals; Group II - uninfected animals and treated with 3 mg of edetate zinc kg-1 body weight; Group III - animals infected with 12000 larvae in the third stage of H. contortus; and Group IV - animals infected with 12000 larvae in the third stage of H. contortus and treated with 3 mg of edetate zinc kg-1 body weight. The lambs were monitored for 38 days, during which time feces and blood samples were collected on day zero and at seven days intervals. Serum samples from animals with an oxidative profile were analyzed by quantifying the total antioxidant capacity (TAC) and the total oxidation status (TOS). The eggs per gram (EPG) in feces were also counted. On the last experimental day, three animals from each group were euthanized and the quantity of H. contortus adults in the abomasums was determined. The results showed that oxidative stress in the animals from group IV was lower than in Group I 17 days after treatment with edetate zinc. Furthermore, 24 days after treatment, group IV showed a reduction in oxidative stress in relation to group III. No interference in the parasite load was recorded. These results show that treatment with edetate zinc could assist in reducing the damage caused by oxidative stress, but does not reduce infection with H. contortus.