Toxicological characteristics of raw milk with different contents of 17β-estradiol

Despite the benefits and biological value of dairy products, they can also be a source of dangerous substances of natural and artificial origin. Such substances include the estrogen hormone 17β-estradiol, an excessive amount of which causes oncological diseases and reproductive system dysfunction. A study was conducted to determine the toxicological evaluation of raw milk with different 17β-estradiol content on the culture of the ciliate Tetrachymena pyriformis. The content of 17β-estradiol was determined by enzyme immunoassay using the RIDASCREEN®17β-őstradiol test system (Art-Biopharm/R-Biopharm, Darmstadt, Germany). During the determination of acute toxicity, under the condition of the content of 17ß-estradiol in the raw milk in the amount from 20.0 to 2500 pg/ml, no changes in motor activity, body shape and inhibition of reproduction of ciliates were observed. At the content of 17ß-estradiol in milk in the range of 5000.0−5500.0 pg/ml, a slowdown in the motor activity of ciliates was observed without changing the nature of the movement. Thus, the amount of 17ß-estradiol in milk greater than 5000.0 pg/ml causes a minor effect on the vital activity and motor activity of Tetrachymena pyriformis ciliates. During 96 hours of the existence of ciliates in milk, chronic toxic effects on cells were not observed for the content of 17ß-estradiol from 20.0 to 2500.0 pg/ml. Addition of 17ß-estradiol to raw milk in the amount of 5000.0 to 5500.0 pg/ml caused a chronic toxic effect on ciliates, as a result of which the total score in all determined indicators increased to 2 points. Thus, raw milk with an amount of 17ß-estradiol from 5000.0 to 5500.0 pg/ml may exhibit some chronic toxic effect on the cells of the ciliated infusoria. It was established that the relative biological value of raw milk with a content of 17ß-estradiol up to 2500.0 pg/ml was from 98.6 to 97.7 %, and in samples of raw milk with the maximum amount of the hormone (5000.0−5500.0 pg/ml) decreased by an average of 10 % to 89.22 %. Therefore, if the amount of 17ß-estradiol in milk is more than 5000.0 mg/ml, a chronic toxic effect on Tetrachymena pyriformis cells is possible.