Chlorophyllin-enhanced excretion of urinary and fecal mutagens in rats given 2-amino-3-methylimidazo[4,5-f]quinoline.

Sodium/copper chlorophyllin (CHL) is a water-soluble derivative of chlorophyll that exhibits antimutagenic activity in several short-term genotoxicity assays and inhibits carcinogen-DNA binding in vivo. The effect of CHL pretreatment on the excretion of mutagens in the urine and feces of male Sprague-Dawley rats has been studied using the Salmonella mutagenicity assay. Animals were given 1 percent CHL in the drinking water for 2 days before administering a single dose of 2-amino-3-methylimidazo-[4,5-f]quinoline (IQ) by oral gavage. Rats pretreated with CHL had higher levels of mutagens in the urine and feces compared with animals given IQ alone; 48 hr after IQ administration, the total mutagenic dose excreted was < 4% in controls vs. 18% in rats given CHL. Mutagenicity required the presence of an activation system, was unaffected by treatment with beta-glucuronidase or arylsulfatase, and in both the urine and feces was accounted for by increased elimination of unmetabolized parent compound. The results support the view that CHL may operate in vivo as a "desmutagen" or interceptor molecule, interacting with IQ in the gut and tissues, and reducing carcinogen bioavailability.