Estrogenic and anti-estrogenic activities of two types of diesel exhaust particles

In an earlier study using a recombinant yeast screen we found that a suspension of diesel exhaust particles (DEP) and some extracts of DEP are not estrogenic but possess anti-estrogenic activity. In the present study, estrogenic and anti-estrogenic activities of two types of DEP, type-1 (old type) and type-2 (new type) were compared. Whole DEP of both types were found to possess estrogenic and anti-estrogenic activities. The DEP were serially extracted with organic solvents and then with 1 M ammonia and 1 M HCl. In type-2 DEP, the ratio of dry weight of a hexane extract was higher than those of methanol and ammonia extracts, which were lower than those in type-1 DEP. In the hexane extract, estrogenic activity was found in both types of DEP. In the benzene and dichloromethane extracts, estrogenic and anti-estrogenic activities were found in both types of DEP. In the methanol extract, estrogenic activity was found in type-2 DEP, and extracts of both types decreased the activity of estrogen. Anti-estrogenic activity was found in extracts of ammonia and HCl from both types of DEP. It was found that both type-1 and type-2 DEP possess estrogenic and anti-estrogenic activities.