Cyto- and genotoxic potential of the photosensitizer Photosan 3 in the absence of light

In the present investigation, cultures of rat hepatocytes were treated with Photosan 3 (PS 3) and examined for possible mutagenic effects in the absence of light. Hepatocytes are particularly useful in genotoxicity studies because of their capacity to metabolize a large variety of promutagenic/procarcinogenic compounds. The cytogenetic endpoints determined were chromosomal aberrations and the induction of micronuclei. Three hours of incubation with PS 3 (at concentrations of 0.1, 1, 10, and 100 micrograms ml-1) induced significantly elevated levels of chromosomal aberrations and micronuclei already at the lowest concentration of 0.1 micrograms ml-1 compared with the controls. A concentration of 100 micrograms ml-1 PS 3 appeared to be cytotoxic: no mitotic figures could be detected.