The peculiarities of the structural organization of the tongue quite often become the object of research by domestic and foreign researchers. At the same time, most of the contemporary scientific works are devoted to the study of the structural features of the lingual mucosa. Changes in the muscles of the tongue under the influence of certain unfavorable factors, in most cases, are insufficiently described. Aim: experimental study of the morphometric parameters of muscles of the tongue of the albino rats in introduction of complex food additives (monosodium glutamate, sodium nitrite, Ponceau 4R) into the ration over a period of 16 weeks. 60 outbred albino rats were involved into the study. The ration of experimental animals was supplemented with complex food additives, namely, monosodium glutamate, Ponceau 4R, sodium nitrite for 1 and 4 weeks. Animals of the experimental groups, in addition to the standard diet, received a combination of food additives monosodium glutamate, ponceau 4R, sodium nitrate for 1, 4, 8, 12 and 16 weeks. The animals were sacrificed under thiopentone anesthesia overdose. Conventional histological microspecimens were made from tongue preparations, stained with hematoxylin and eosin. On the microspecimens, the ratio between the muscle and connective tissues, the diameter of the muscle fibers of the tongue on the tip, body and base were measured. The findings of the studies have shown that introduction of complex food additives (monosodium glutamate, sodium nitrite, Ponceau 4R) into the ration of laboratory animals for one week leads to an increase in the relative amount of muscle tissue in the tongue and to a heterogeneous change in the diameter of muscle fibers on the tip, body and base. The described parameters resulted from the changes in the nature of the movement of the tongue in the process of food mixing, when adapting to changes in the ration. Starting from week 4 of consumption of complex food additives supplemented into the ration of the laboratory animals, progressive atrophic changes were observed in the muscle fibers of all parts of the tongue, manifested by a gradual decrease in the diameter. At the same time, gradual decrease in the relative amount of muscle fibers and an increase in the relative amount of connective tissue were noted in the tongue of experimental animals.

Food additives are quite widely used in different countries worldwide. They include emulsifiers, antioxidants, dyes, and corrective substances. In Ukraine, about 500 substances are allowed to be use in the food industry; they are labelled with the letter "E" and the corresponding number and even are approved by the European Community. Food additives are divided into additives of natural origin and chemically synthesized. For safe use, each substance must undergo experimental or clinical studies and have an evidence base for the absence of carcinogenicity, acute and chronic toxicity, teratogenicity, mutagenicity and gonadotropic properties. To date, not all food additives or their compounds have been studied sufficiently in relation to their impact on the human body. According to the analysis of modern foreign and domestic sources, those substances used in the wide field of food technologies and not having clear indicators on permissible dosage were selected: monosodium glutamate, ponso-4R and sodium nitrite. Data on the effects of long-term consumption of monosodium glutamate, which has a toxic effect on salivary glands, dental tissues, liver, pancreas, colon, female and male reproductive systems, were analyzed. A separate analysis of studies on the combined effect of monosodium glutamate, ponso-4R and sodium nitrite on the liver and organs of the oral cavity was carried out. The results of the study indicate the occurrence of fatty and hydropic dystrophy of hepatocytes, the appearance of "dark hepatocytes" and an increase in the relative amount of the stromal component. Changes are also seen in the salivary and protein mucous glands of the oral cavity. Thus, having analyzed the experimental studies of modern scientists, we have found out that not all food additives allowed to be used in Ukraine are completely safe. Both individual substances and their combinations lead to significant morphological changes in various organs and systems. The impact of dietary supplements on the female and male reproductive systems is remaining one of the least studied areas. Therefore, there is a need for further research in order to minimize disorders of the functions of the reproductive system and infertility.