Amino acids tyrosine (Tyr) and tryptophan (Trp) play a significant role in the regulation of energy metabolism, locomotor activity, and eating behavior. We studied the possibility of modulating these processes in obesity by increasing the pool of Tyr and Trp in the experimental diet. As a model of obesity, we used Wistar rats fed a diet with an excess specific energy value (HFCD) for 64 days. Trp led to a normalization of the rats’ body weight almost to the control level, but increased anxiety-like behavior and decreased long-term memory. The consumption of amino acids resulted in increased grip strength and impairment of short-term memory. The locomotor activity of animals decreased with age as a result of Tyr consumption, while Trp, on the contrary, prevented this. The Tyr supplementation led to the normalization of triglycerides and LDL. In the spleen cell lysates, amino acids suppressed the production of proinflammatory cytokines. The liver tissue morphology showed that the consumption of Tyr noticeably weakened the signs of fatty degeneration. The addition of Trp, on the contrary, led to an unfavorable effect, consisting of the appearance of a high number of large rounded fatty vacuoles. The data obtained indicate a more pronounced anti-inflammatory effect of Tyr as compared to Trp.

The experimental data on the oral toxicity of nanostructured amorphous silica (SiO₂), widely used in food supplements, pharmaceuticals, and cosmetics, in terms of its in vivo effect on the immune system, are contradictory. Therefore, this study aimed to assess the rat’s immune function after SiO₂ oral administration. In the first experiment, SiO₂ was daily orally administered to Wistar rats for 92 days in doses of 0.1, 1.0, 10, and 100 mg/kg of body weight (bw). In the second 28-day experiment, SiO₂ in a dose of 100 mg/kg bw was daily orally administered to rats parenterally immunized with the food allergen ovalbumin (OVA) for the reproduction of systemic anaphylaxis reaction. Together with integral indices, we assessed intestinal permeability to protein macromolecules; hematology; CD45RA+, CD3+, CD4+, CD8+, and CD161a+ cells; cytokines TNF-α, IL-6, and IL-10; and IgG to OVA. The results obtained showed that SiO₂ has no effect on the severity of the anaphylactic reaction, but is capable inducing a toxic effect on the T-cell immune systems of rats. Estimated no observed adverse effect level NOAEL for SiO₂ ranges up to 100 mg/kg bw in terms of its daily consumption for 1–3 months. Using SiO₂ as a food additive should be the subject of regulation.

We studied the effects of the addition of large neutral amino acids, such as tyrosine (Tyr) and tryptophan (Trp), in mice DBA/2J and tetrahybrid mice DBCB receiving a high-fat, high-carbohydrate diet (HFCD) for 65 days. The locomotor activity, anxiety, muscle tone, mass of internal organs, liver morphology, adipokines, cytokines, and biochemical indices of animals were assessed. The Tyr supplementation potentiated increased anxiety in EPM and contributed to a muscle tone increase, a decrease in the AST/ALT ratio, and an increase in protein anabolism in both mice strains. Tyr contributed to a decrease in liver fatty degeneration and ALT reduction only in DBCB that were sensitive to the development of obesity. The addition of Trp caused an increase in muscle tone and potentiated an increase in anxiety with age in animals of both genotypes. Trp had toxic effects on the livers of mice, which was manifested in increased fatty degeneration in DBCB, edema, and the appearance of micronuclei in DBA/2J. The main identified effects of Tyr on mice are considered in the light of its modulating effect on the dopamine neurotransmitter metabolism, while for the Trp supplement, effects were presumably associated with the synthesis of its toxic metabolites by representatives of the intestinal microflora.

Recent years a worldwide interest in the use of alternative sources of protein, in particular, protein from insects, has increased. Edible insects for thousands of years have been a part of the human diet in Asian-Pacific region and South America, while in the European Union, the USA and Canada the use of insects for food purposes is a modern trend that is determined by the care of the environment, global warming combating, etc. Thus, the legal rules governing the food use of insects have significant differences among countries. In the Eurasian Economic Union requirements to food are regulated by the Customs Union Technical Regulations. Since none of the Technical Regulations contains the name of such food as "products obtained with the use of insects", these products may be classified as "food products of novel type" which are subjected to state registration. Fundamental and applied research should be conducted as a part of this novel food safety assessment system, that include the determination of nutritional and biological value of food raw materials derived from insects, and toxicological, reprotoxicological, allergological experiments in vivo on several generations of laboratory animals. The aim of the research was studying and comparing the nutritional and biological values of Hermetia illucens larvae dry biomass and basic foodstuffs of animal and plant origin. Material and methods. Nutritional and biological value analysis of H. illucens minced dry larvae biomass, dried at 110-120 °C, was carried out on 83 indicators, which included determination of protein content and amino acid composition, determination of fat level and fatty acid composition, determination of the content of carbohydrates, vitamins, minerals and trace elements, ash and moisture. Results. A study of the nutritional value of dry larvae biomass showed high levels of protein and fat (39 and 38%, respectively), while ash, dietary fiber and carbohydrate accounted for less than 20%. The amino acid profile had a balanced content of essential amino acids and was comparable to the protein of a hen's egg, as well as other animal products. The fatty acid composition of the biomass was characterized by a relatively high content of lauric acid (39.9% of the total fatty acid content), also found in some fruits and seeds of tropical plants; the ratio of other acids was more consistent with the fatty acid profile of fish oil. The dry larvae biomass contained carotenoids (0.23 mg/100 g), tocopherol (3.1 mg/100 g) and thiamine (53 μg/100 g) in amounts significantly lower to those of foods, which traditionally are sources of these vitamins. Based on the analysis of the mineral composition, the H. illucens biomass can be attributed to the sources of calcium, iron, copper and chromium. In terms of the content of the above elements, as well as magnesium and zinc, dry biomass significantly exceed the main food products of animal origin (beef, eggs, fish and seafood), and in terms of the content of potassium and phosphorus, it was comparable to them. Conclusion. The results of dry larvae biomass comparative evaluation with the basic foodstuffs of animal and plant origin evidence to its high nutritional and biological value, allowing to consider H. illucens as a promising source of complete protein, lauric acid, minerals and trace elements.