Posted on Feb 16, 2017, 6 a.m.
The antimicrobial triclosan, found in soaps and shampoos, causes liver fibrosis and cancer in laboratory mice through molecular mechanisms that are also relevant in humans.
Triclosan is an antimicrobial agent commonly added to soaps and shampoos. Robert H. Tukey, from the University of California/San Diego (California, USA), and colleagues found that triclosan disrupted liver integrity and compromised liver function in mouse models. Mice exposed to triclosan for six months (roughly equivalent to 18 human years) were more susceptible to chemical-induced liver tumors. Their tumors were also larger and more frequent than in mice not exposed to triclosan. The team posits that the mechanism of action may be that triclosan interferes with the constitutive androstane receptor, a protein responsible for detoxifying foreign chemicals in the body. To compensate for this stress, liver cells proliferate and turn fibrotic over time. Repeated triclosan exposure and continued liver fibrosis eventually promote tumor formation. The study authors urge that: “These findings strongly suggest there are adverse health effects in mice with long-term [triclosan] exposure, especially on enhancing liver fibrogenesis and tumorigenesis, and the relevance of [triclosan] liver toxicity to humans should be evaluated.”
Yueh MF, Taniguchi K, Chen S, Evans RM, Hammock BD, Karin M, Tukey RH. “The commonly used antimicrobial additive triclosan is a liver tumor promoter.” Proc Natl Acad Sci U S A. 2014 Dec 2;111(48):17200-5.