Cell metabolic changes of porphyrins and superoxide anions by anthracene and benzo(a)pyrene

The aim of this work was to evaluate the induction of protoporphyrins IX (PpIX) activity and superoxide anions (SO) in human leukocytes exposed to anthracene (ANT) and benzo(a)pyrene (B(a)P). The leukocyte LC50s for both hydrocarbons and the PpIX accumulation and SO overproduction were measured. The LC50s were 0.35 and 3.23 μM for ANT and B(a)P, respectively. A linear relationship (r = 0.97, p < 0.01) between PpIX and ANT concentration was obtained. The induced accumulation of PpIX was proportional (r = 0.63, p < 0.01) to B(a)P concentration. SO overproduction showed a linear relationship (r = 0.83, p < 0.05) with ANT concentrations. The linear regression analysis of the effect of B(a)P on the superoxide anion overproduction showed a good coefficient (r = 0.97, p < 0.01), showed that ANT and B(a)P exposure induces PpIX accumulation, probably by disruption of the haem biosynthesis. ANT and B(a)P induce SO overproduction, perhaps through a process of redox cycling.