Risk Element Interaction with an Emerging Contaminant in Mammals: The Case of Arsenic and Carbamazepine Orally Taken up by Microtus arvalis L. as a Model Organism

Arsenic (As), a well-known ‘traditional’ environmental contaminant, and carbamazepine (CBZ), an emerging contaminant of a pharmaceutical category, are both frequently detected in the environment and have been shown to exhibit toxicity at exposure concentrations present in the environment. This study aimed to assess the single and combined exposure effects of these pollutants on the adult common vole (Microtus arvalis L.), a model mammalian organism. This study assessed As and CBZ accumulation, their biotransformation processes, and antioxidant enzyme defence responses after sole and combined exposure. The animals were fed a diet containing either a low (1.25 mg/kg) or high level (166 mg/kg) of As. Moreover, half of the animals were exposed to CBZ via drinking water infused with 10 ng/L of CBZ, and the second half had the use of drinking water devoid of CBZ. The results showed enhanced total As and As species contents in the organs of the As + CBZ exposure group compared to the As exposure group. High As exposure in the As + CBZ group did not cause an enhanced uptake of CBZ in the liver compared to the CBZ exposure group. There was a potential accumulation of CBZ in the liver of the CBZ exposed groups (CBZ and As + CBZ), raising concerns about potential toxic effects in mammals from long-term exposure. Glutathione peroxidase (GPx) activity, reflecting the antioxidant enzyme defence responses against single and co-exposure of the two pollutants, showed that the CBZ group exhibited comparable activity to the control group, while the As group had down-regulation and the As + CBZ group had up-regulation. These findings suggest that the CBZ group experienced minimal oxidative stress conditions, similar to the control group. The As group showed a rapid adaptation response to curtail or offset potential oxidative stress tissue damage conditions, compared to the slow adaptation/response in the As + CBZ group. The findings of this experiment indicate that the possible interactions of various environmental pollutants could alter the potential effects of the individual pollutants after a sole exposure. These findings indicate the necessity of investigating these interactions for better understanding of the potential risk of these pollutants in real environmental conditions.