Seasonal variation in oxidative stress markers of Murrah buffaloes in heavy metal exposed areas of Ludhiana

The parameters related to oxidative stress and heavy metal levels were assessed during summer and winter seasons in buffaloes from environmentally exposed areas (n=60) of Ludhiana district of Punjab (India) and control area (n=40). Buffaloes of heavy metal exposed areas exhibited significantly (p<0.05) increased blood levels of Cr, Ni, As and Pb along with significantly (p<0.05) higher erythrocytic malondialdehyde (MDA) levels; whereas significant (p<0.05) decrease was observed in superoxide dismutase activity and the levels of reduced glutathione (GSH), vitamins C and E as compared to buffaloes from control area. The level of oxidative stress was higher in all buffaloes during summer as compared to winter as indicated by significantly (p<0.05) higher MDA level, and lower concentrations of GSH, vitamins C and E irrespective of the area. Blood Cr, Ni, As and Pb levels showed highly significant positive correlation (p<0.01) with MDA level but negative correlation with SOD activity and the concentrations of GSH, vitamins C and E. Thus, it may be concluded that buffaloes exposed to heavy metals encounter significant oxidative stress and potential to quench free radicals is compromised during summer.