The plasma lipid peroxidation intensity (MDA) and chain-breaking antioxidant concentrations in the cows with clinic or subclinic mastitis

Abstract

SUMMARY The aim of this study was to determine lipid peroxidation intensity by measurement of plasma malonedialdehyde (MDA) concentrations and plasma chain-breaking antioxidant concentrations such as reduced glutathione (GSH), vitamin A, E, C and β-carotene in the cows with and without mastitis. The study was conducted on 30 Holstein cows which were divided into 3 equal groups on the basis of clinical examination and California Mastitis Test (CMT): in the group CM, clinical mastitis was evidenced; in the group SCM, mastitis was subclinical, and the group C served as a control. The plasma lipid peroxidation index was measured according to the concentration of thiobarbituric acid reactive species (MDA), and GSH activity was measured spectrophotometrically using Ellman’s reagent. Vitamin A, β-carotene and vitamin E values were spectrophotometrically determined, and vitamin C value was colorimetrically determined using a phosphotungstic acid method. The mean plasma GSH (p<0.01) and β-carotene (p<0.001) concentrations were showed significant differences between the 3 groups, whereas mean plasma MDA and serum vitamin C concentrations significantly differed only between the C and CM groups (p<0.05). The decreased chain-breaking antioxidant concentrations and the enhanced concentrations of GSH and MDA suggest that an inflammatory-related oxidative stress occurs in the cows with clinical and subclinical mastitis.