Changes in Serum Thiol-Disulphide Homeostasis in Sheep with Gastrointestinal Nematodes

Abstract

This work aimed to evaluate the thiol-disulphide homeostasis in serum of lambs naturally infected by gastrointestinal nematodes presenting different levels of parasite load indirectly indicated by faecal worm egg counts (EPG). Furthermore, the possible changes in the thiol-disulphide dynamic after different procedures to reduce the parasitic charge, such as the integrated crop-livestock system or anthelmintic treatment, were assessed. The results were compared with a panel of various oxidative stress and inflammatory biomarkers. The lambs were divided into three groups: animals highly infected (EPG higher than 5000) and packed cell volume (PCV) lower than 24% (G1); animals highly infected (EPG higher than 5000) and normal PCV (>24%) (G2); and animals presenting EPG lower than 5000 and normal PCV (>24%) (G3). The highly infected lambs (G1 and G2) showed lower total thiol (TT) and native thiol (SH) (p ≤ 0.01) than those from G3. After treatment, TT and SH increased significantly in all groups (p ≤ 0.01), and the disulphide (SS)/TT and SS/SH ratios decreased significantly (p < 0.01) in G1 and G2. These results show that the thiol-disulphide balance was impaired in lambs infected by gastrointestinal nematodes and that it could be potentially used as a biomarker to monitor this disease.

Effect of Supplementation of Lambs with Whole Cottonseed: Impact on Serum Biomarkers and Infection by Gastrointestinal Parasites under Field Conditions

“…and GIN co-infection. There could be changes in serum proteins in animals with parasitic infections caused by GIN [ 2 , 39 , 40 ] and by Eimeria spp. in sheep [ 41 , 42 ].…”

“…Biomarkers of oxidative stress provide data regarding the monitoring of different procedures to reduce the parasite load and GIN in sheep [ 40 , 47 , 48 , 49 ], stress monitoring [ 50 ], and evaluation of diets fed to lambs [ 51 ] as well as the intake of cottonseed [ 52 ] in the oxidative status of sheep.…”

“…Although FRAP and CUPRAC concentrations did not change, the higher TEAC concentration in lambs supplemented with WCS could reflect an increase in the antioxidants related to a decrease in GI parasites [ 50 ]. Increases in TEAC and CUPRAC concentrations were reported in lambs naturally infected by GIN after 70 days of an anthelmintic treatment and under the influence of the ICLS; there was a negative correlation of these biomarkers with EPG [ 40 ]. Cottonseed oil is rich in tocopherol and has an antioxidant activity by reacting against free radicals [ 36 , 53 ].…”

“…There are literature reports demonstrating increased oxidants concentrations in sheep infected with GIN [ 47 , 48 , 49 ], which induce local intestinal oxidative stress associated with an inflammatory infiltrate in the mucosa of the abomasum. These effects could cause systemic changes depending on the intensity of infection and changes in the redox status with the purpose of cellular protection [ 40 ]. Thus, the inclusion of WCS in the diet reduced the production of oxidants by decreasing the parasite burden at the end of the trial.…”