If we say that one of the active components of the cato, one of the two isothiazalone derivatives, methyl isothiazolinone, may be dangerous for pregnant women, it is unlikely that anyone will panic. And what happens if you say that the health of a future child is threatened by a normal shampoo? Let's see.

American neuroscientist Elias Aizenman and his colleagues at the University of Pittsburgh Department of Neurobiology have suggested that they say that the methylisothiazolinone (MIT) preservative in shampoos and moisturizers can adversely affect development Nerve cells.

Meanwhile, the chemical, whose abbreviation coincides with the name of the Massachusetts Institute of Technology, is widely used by manufacturers of cosmetics and detergents, as it kills bacteria, prolongs the shelf life of products and, probably, does something else.

Preliminary tests have shown that this chemical can cause slight irritation on the skin of particularly susceptible people, but its effect on nerve cells, if anything has been known so far, then a little.

To try to understand this issue, Elias Eisenman's group took rat neurons and subjected them in vitro to the effect of the "horse" dose of MIT. As a result, most nerve cells died within 10 minutes.

Then the scientists decided to check what the effect of smaller doses received by neurons over a long period of time. That is, in the example of rats, they wanted to know what could happen to the cells of people who work with MIT every day, for example, in cosmetics factories.

Researchers for 18 hours subjected developing rat neurons to a concentration of MIT equivalent to 1 gram of a chemical dissolved in 8,000 liters of water.

Growing nerve cells usually have shoots - axons - conductive nerve impulses from the body of the cell to innervated organs or other nerve cells. But after exposure to MIT, the number of axons decreased almost twice.

From this, Eisenman makes the assumption that products containing MIT can be potentially dangerous for pregnant women and their future children.

"I think the US Environmental Protection Agency (EPA) should be interested in our study," said Aizenman. "I would not advise a pregnant woman to work in a factory where this chemical is used, because this could lead to some anomaly in the development of the fetal nervous system".

Neuroscientists presented the results of their study on December 5, 2004 in Washington at the annual meeting of the American Society for Cell Biology, in which their findings aroused the anger, irritation and concern of some other toxicologists.

"Extrapolating from tissue grown in vitro to humans, scientifically, is dangerous," said former toxicologist at the University of London, and now a consultant to pharmaceutical companies, Tony Dayan,. "Cells cultured in vitro are in completely different conditions - they are defenseless, so changes in the growth of neurons are not particularly surprising - compared to the cells that develop cells in the human body".

"In artificial conditions, it's very difficult to prove the danger of something for humans by research, because we are much more difficult than test-tube cultures," another British toxicologist Wilson Steele agrees with Dayan, who, however, recognizes the importance of further experiments with MIT.

Eisenman, in turn, argues that his work does show a potential risk, because in detergents the concentration of a chemical exceeds that used in experiments 100-200 times.

Although the risk here is, rather, factory workers, not people who shampoo their hair with shampoo. "I can not say for sure, because there is too little information on the effect of this chemical," the neurobiologist shares, "so I'm interested in conducting the appropriate tests".

Now Eisenman, who has already discovered that MIT affects a specific enzyme responsible for the growth of axons, intends to continue experiments on nerve cells not in test tubes, but already in the bodies of animals.

It seems that for experiments with the same compositions of shampoos, there is an untilled field. Thus, following methyl isothiazolinone, for example, another isothiazalone derivative, methyl chloroisothiazolinone. You look, and it affects the rats, and we, terribly to say, pour it on our heads.

Medicus. En.