In vitro interaction of the pesticides flupyradifurone, bupirimate and its metabolite ethirimol with the ATP-binding cassette transporter G2 (ABCG2).

ABCG2 is an ATP-binding cassette efflux transporter that is expressed in absorptive and excretory organs such as liver, intestine, kidney, brain and testis where it plays a crucial physiological and toxicological role in protecting cells against xenobiotics, affecting pharmacokinetics of its substrates. In addition, the induction of ABCG2 expression in mammary gland during lactation is related to active secretion of many toxicants into milk. In this study, the in vitro interactions between ABCG2 and three pesticides flupyradifurone, bupirimate and its metabolite ethirimol were investigated to check whether these compounds are substrates and/or inhibitors of this transporter. Using in vitro transepithelial assays with cells transduced with murine, ovine and human ABCG2, we showed that ethirimol and flupyradifurone were transported efficiently by murine Abcg2 and ovine ABCG2 but not by human ABCG2. Bupirimate was not found to be an in vitro substrate of ABCG2 transporter. Accumulation assays using mitoxantrone in transduced MDCK-II cells suggest that none of the tested pesticides were efficient ABCG2 inhibitors, at least in our experimental conditions. Our studies disclose that ethirimol and flupyradifurone are in vitro substrates of murine and ovine ABCG2, opening the possibility of a potential relevance of ABCG2 in the toxicokinetics of these pesticides.