Assessment of blood mercury, immune response, heat shock and oxidative stress marker in free-ranging chicken (Gallus Gallus domesticus) from gold mining areas in Zamfara State, Nigeria

Abstract

We investigated serum mercury, immune response, heat shock and oxidative stress marker in free-ranging chicken (Gallus Gallus domesticus) from Artisanal and small-scale gold mining (ASGM) areas. Six groups were created from sixty free-ranging chickens (Gallus Gallus domesticus), three each from ASGM and non-ASGM areas. Immune response, heat shock and oxidative stress markers were analysed, and multivariate and univariate data analysis were used to discriminate the difference in the study group. Results revealed a significant increase in serum mercury (Hg) from chicken in ASGM areas. Superoxide dismutase, glutathione peroxidase (GPx), glutathione (GSH), catalase and total antioxidant capacity significantly decreased, while lactic acid dehydrogenase and malondialdehyde (MDA) content significantly increased in animals from ASGM areas. A unit increase in GPx and GSH significantly corresponds to a decrease in serum Hg by 0.001 μg/mL and 0.206 μg/mL, respectively. While a unit increase in MDA significantly corresponds to an increase in serum Hg level by 0.003 μg/mL. The activities of HSP-70, TNF-α, IL-1β and IL-6 were significantly higher in the serum of chicken from ASGM areas. All significance at p < 0.05. ASGM activities result in mercury bioaccumulation with potential health effects caused by dysregulated immunity, heat shock and oxidative stress.