IPCS INCHEM Home

International Agency for Research on Cancer (IARC) - Summaries & Evaluations

PYRIDO[3,4-c]PSORALEN AND 7-METHYLPYRIDO[3,4-c]PSORALEN

VOL.: 40 (1986) (p. 349)

Pyrido[3,4-c]psoralen
CAS No.: 85878-62-2
Chem. Abstr. Name: 5H-Furo[3',2':6,7][1]benzopyrano[3,4-c]pyridin-5-one

7-Methylpyrido[3,4-c]psoralen
CAS No.: 85878-63-3
Chem. Abstr. Name: 7-Methyl-5H-furo[3',2':6,7][1]benzopyrano[3,4-c]pyridin-5-one

5. Summary of Data Reported and Evaluation

5.1 Exposure

There is no known human exposure to pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]-psoralen, other than in limited clinical trials for the treatment of psoriasis.

5.2 Experimental data

In one incompletely reported study of pyrido[3,4-c]psoralen and 7-methylpyrido[3,4-c]-psoralen in combination with ultraviolet A radiation in mice, skin tumours were observed. No data were available to evaluate the carcinogenicity to experimental animals of pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen in the absence of ultraviolet A radiation.

No data were available to evaluate the reproductive effects or prenatal toxicity of pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen to experimental animals.

In the presence of ultraviolet A radiation, pyrido[3,4-c]psoralen and 7-methylpyrido[3,4-c]-psoralen bound covalently to isolated DNA. In combination with ultraviolet A radiation, 7-methylpyrido[3,4-c]psoralen induced DNA damage in yeast and human fibroblasts in vitro. Both compounds were mutagenic to Salmonella typhimurium in the dark. In the presence of ultraviolet A radiation, pyrido[3,4-c]psoralen and 7-methylpyrido[3,4-c]-psoralen induced mutations and mitotic recombination in yeast. In the dark, 7-methylpyrido[3,4-c]psoralen, but not pyrido[3,4-d]psoralen, induced sister chromatid exchanges in mammalian cells in vitro; and, in combination with ultraviolet A irradiation, both compounds induced sister chromatid exchanges in cultured mammalian cells.

5.3 Human data

No case report or epidemiological study of the carcinogenicity of pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen was available to the Working Group.

5.4 Evaluation

There is inadequate evidence that pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]-psoralen in combination with ultraviolet A radiation is carcinogenic to experimental animals. No data were available to evaluate the carcinogenicity of pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen to experimental animals in the absence of ultraviolet A radiation.

No evaluation could be made of the carcinogenicity of pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen to humans.

For definition of the italicized terms, see Preamble Evaluation.

Subsequent evaluation: Suppl. 7 (1987) (p. 71: Group 3)

Synonym for Pyrido[3,4-c]psoralen

Synonym for 7-Methylpyrido[3,4-c]psoralen


Last updated: 21 April 1998






















    See Also:
       Toxicological Abbreviations