Histological changes in the liver of rats exposed to food preservatives under chronic stress

The effects of the combined exposure to food preservatives and chronic stress on the liver remain poorly understood, although both factors are widespread in the modern world. Objective. The aim of the study is to determine the nature and degree of morphological changes in rat liver after 28-day exposure to sorbic and benzoic acids and to find out whether chronic psychological stress enhances the toxic effect of the above-mentioned food preservatives. Materials and Methods. The authors conducted a 28-day in vivo experiment. Male rats (n=24) were divided into 4 equal groups: control, chronic stress, food preservatives, and combined effect of the above-mentioned factors. After euthanasia, histological examination and morphometry were performed. We assessed the area of hepatocyte nucleus and cytoplasm, the nuclear-cytoplasmic ratio (NCR), and the number of binucleated and anucleate cells. Statistical analysis was performed using the bootstrap method with Holm-Bonferroni correction (p<0.05). Results. Chronic stress decreased the nuclear area (-20 %, p<0.0001) and the cytoplasm area (-16 %, p<0.0001), but increased the number of binucleated hepatocytes (+71 %, p=0.006). Necrotic changes were not recorded. Preservatives caused moderate hepatocyte hypertrophy (nuclear area +11 %, p=0.0004) without increase in NCR and cytolysis. Under the collective effect of factors, the cytoplasm area decreased (-10 %, p=0.0060), and NCR increased (+18 %, p=0.0005) with preserved architecture and an unchanged number of binucleated cells. Conclusion. Chronic stress modifies early hepatotoxic effects of sorbic and benzoic acids. The process is accompanied by an increase in the nuclear-cytoplasmic ratio. Final conclusions on the problem under consideration require further development of mathematical approaches to the analysis of the toxic effect of a chemical agent under chronic psycho-emotional stress.