The statement in the above-referenced editorial that "DNCB depletes the activity of glutathione S-transferase in rat skin, thus blocking an important detoxification system of mammalian cells" was indeed incorrect. In fact, "activity of glutathione S-transferase" should read "content of glutathione."Undoubtedly, the Ames test is a relatively quick and inexpensive test, which is preferentially designed to sensitively detect point mutations in Salmonella typhimurium. The correlation between carcinogenic potency and mutagenic potency in the Ames test is promising; the overlap between the detections of mutagenicity and carcinogenicity of more than 1,000 compounds was 70% to 80%.1-3 However, the routinely performed assay is suitable neither for direct extrapolation to humans nor for quantitative risk assessment.4Also, if one considers the positive results of DCNB in the Ames test and the mammalian cell transformation assay as "just a first step," these findings cannot to ignored.
Happle R, Summer K. Potential Hazards of Dinitrochlorobenzene (DNCB) Disputed-Reply. Arch Dermatol. 1986;122(1):12-13. doi:10.1001/archderm.1986.01660130013002