Cyto toxicity of hair colorant constituents chromosome damage induced by 2 nitro phenylenediamines in cultured chinese hamster cells
Kirkland, D.J.; Venitt, S.
Mutation Research 40(1): 47-56
ISSN/ISBN: 1386-1964 Accession: 005083475
Two aromatic amines, 2-nitro-p-phenylenediamine (2NPPD) and 4-nitro-o-phenylenediamine (4NOPD) are constituent dyes of many widely used proprietary hair colorants. Both compounds were cytotoxic (in the dose-range 500-100 .mu.g/ml) to cultured Chinese hamster CHMP/E cells (a recently-derived near-diploid (2n = 24) clone of prostate cells) following 5 days continuous exposure. 2NPPD was more toxic than 4 NOPD at equivalent doses. These cytotoxic effects were paralleled by a time-dependent increase in the yield of chromosome aberrations following exposure of CHMP/E cells to 25 .mu.g/ml 2NPPD or 4NOPD, compared with control cultures. The increase in the incidence of breaks and exchanges was particularly marked after 4 and 7 days exposure, and 2NPPD caused more chromosome damage than 4NOPD at equivalent doses. The use of 2NPPD and 4NOPD as hair-colorant constituents may be associated with a long-term health hazard in humans, having regard to the present results and to the earlier reports of the mutagenicity in bacteria of 4NOPD and 2NPPD, and the chromosome-damaging effects of 2NPPD in cultured lymphocytes. Attention is drawn to well established correlations between these biological effects and carcinogenicity, and to epidemiological studies which suggest that the elevated incidence of certain tumors in hairdressers and in those engaged in cosmetics manufacture might be due to exposure to chemical carcinogens.