Assessment of Adverse Effects of Lead, Nickel and Cadmium on Biochemical Parameters, Antioxidants Status and Metallothionein Expression in Buffaloes Slaughtered at Local Abattoir

Abstract

Background: With the pace of industrialization, heavy metal level has been increasing in animals thereby causing deleterious effects, which emanate as public health concern, associated with their accumulation in food chain. The present study was undertaken to assess the systemic damage caused by heavy metals in buffaloes. Methods: The assessment of adverse effects of the lead (Pb), nickel (Ni) and cadmium (Cd), in blood was determined by monitoring the levels of biochemical parameters, antioxidants and expression of metallothionein in buffaloes. Blood and tissue (liver, kidney, pancreas and ovary) samples (n=50) were collected from local abattoir to estimate the levels of lead, nickel and cadmium using atomic absorption spectrophotometry. Antioxidants and biochemical parameters were estimated using standard procedures and while the expression of metallothionein-2 was analyzed using real-time PCR.Result: After determining the concentration of heavy metals in samples the buffaloes were classified as heavy metal exposed and non-exposed groups. The plasma level of heavy metals were found to be significantly (p less than 0.05) higher than the permissible limit in exposed buffaloes. In tissues, heavy metals levels were within the permissible limits. Malondialdehyde level in each of lead, nickel and cadmium exposed groups was significantly (p less than 0.05) higher than the non-exposed, control group. The antioxidant activity of superoxide dismutase, catalase and glutathione was found to be increased significantly (p less than 0.05) in exposed groups. Also, plasma glucose, cholesterol, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), creatine kinase (CK), urea and creatinine levels were found to be significantly higher (p less than 0.05) in the blood of the animal model used for the study. The fold change expression of MT-2 in blood was found to be at maximum level in cadmium and minimum in nickel exposed buffaloes. It can be concluded from the results of the experiment that heavy metals affect major organs (liver, kidney and muscle etc.) as evident by altered intracellular expression of MT-2, antioxidants and biochemical parameters.