Ethoxyresorufin- O -deethylase (EROD) Activity Modulation of 2,3,7,8-Tetrachlorodibenzo- p -dioxin and 3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126) in the Presence of Aqueous Suspensions of Nano-C 60

Abstract

The increase in commercial production and inevitable release of fullerenes into the environment accelerates concerns about their potential toxicity. Furthermore, the concomitant release of xenobiotics poses a health hazard to humans, and might present potential long-term risks to human health. In the present study, we found that an aqueous suspension of buckminsterfullerene (aqu-nC₆₀) does not result in the induction of ethoxyresorufin-O-deethylase (EROD) activity in H4IIE rat liver cells in vitro. The simultaneous and sequential exposure of aqu-nC₆₀ and the dioxin TCDD induces EROD activity to the same extent as TCDD alone (i.e. in the absence of fullerene), in spite of the high affinity of C₆₀ for TCDD. However, the co-exposure of aqu-nC₆₀ and PCB 126 induces elevated EROD activity, and sequential exposure increases responses 2-fold compared to the control samples. Our in vitro observations suggest a potential source of drug–drug type interaction of fullerene with xenobiotics, particularly after a sequential exposure.