Cytotoxic effects of tris(2,3-dibromopropyl)phosphate and 2,4-diaminoanisole

The flame retardant tris(2,3-dibromopropyl)phosphate (Tris-BP) and the hair-dye component 2,4-diaminoanisole (2,4-DAA) were studied by possible cytotoxic effects in rat hepatoma cells grown in culture and in suspensions of isolated rat hepatocytes. Cell growth of Reuber cells was inhibited by 50% at 50 microgram/ml Tris-BP and 20 microgram/ml 2,4-DAA, respectively. At 200 microgram/ml Tris-BP protein synthesis in Reuber cells was reduced by 40%, whereas 50% inhibition of protein synthesis in isolated hepatocytes was seen at 100 microgram/ml. IC50 of 2,4-DAA with respect to protein synthesis was found at 400 microgram/ml in Reuber cells and at 3600 microgram/ml in MH1C1 cells, whereas in the isolated hepatocytes IC50 was 650 microgram/ml. DNA synthesis was inhibited by 50% at 225 microgram/ml Tris-BP in Reuber cells. At 500 microgram/ml 2,4-DAA DNA synthesis in Reuber and MH1C1 cells was inhibited by more than 80%.