The estrogenic and androgenic potential of pyrethroids in vitro. Review

Synthetic pyrethroids are used worldwide as insecticides. Their metabolites are regularly detected in the urine of adults and children from the general population. There is increasing concern that they may induce sex-hormone disrupting effects. The present work reviews available published information on the (anti)estrogenic and (anti)androgenic activity of pyrethroids in in vitro screening tests. In recent years, a large number of pyrethroids have been evaluated using various common testing methods. In tests using recombinant yeast or mammalian cells, the pyrethroids were found to be essentially negative or weakly estrogenic. More inconsistent results were found regarding their estrogenic action in proliferation tests. Conflicting findings were also reported across studies and/or assays which evaluated their anti-estrogenic or anti-androgenic potential. Some studies have suggested that certain pyrethroids may have potential antagonist activity. However, no strong interaction with the estrogenic or androgenic pathway was reported. The present review confirms the interest in performing a screening battery and in adopting an integrative approach for identifying the potential of different compounds from a chemical family to interfere with the endocrine system.