The effect of chitosan on the concentration of 17β-estradiol and free triiodothyronine in mice exposed to polychlorinated biphenyls (PCBs)

Abstract

The aim of this work was to examine (i) how the applied PCB mixture influences the level of 17β-estradiol (E2) and free triiodothyronine (FT3) in the blood plasma of mice (C57/BL/6J) and (ii) whether supplementation with chitosan would protect against the observed changes in the examined plasma hormone concentrations. In the study we used a mixture of indicator PCBs (CB no. 28, 52, 101, 118, 138, 153, 180) and our results showed their anti-estrogenic effects. Exposure to the mixture resulted in a significant decrease (P < 0.05) in plasma concentration of E2 relative to the control, and chitosan administration did not prevent the decrease. To the contrary, E2 concentration in the blood plasma of the mice which received both the PCB mixture and chitosan was lower compared to those which did not receive chitosan. Exposure to the PCBs also resulted in a decrease in FT3 concentration in the treatedgroup, although it was not as pronounced as for E2 and was prevented with dietary supplementation with chitosan, with the observed FT3 level in the chitosan-treated group similar to the control. In summary, supplementation with chitosan can only to a certain extent minimize the negative effects of exposure to PCBs.