Non-alcoholic fatty liver disease is associated with a number of disorders (diabetes, obesity, cardiovascular diseases), and can also be induced by drugs or toxic compounds. Recently the important branch of medicine is the search for effective means of prevention and treatment of fatty hepatosis. Our work was aimed to study the effect of some biologically active natural polyphenols (resveratrol and pinosylvin stilbenes as well as dihydromyricetin dihydroflavonol) on the function and histologic features of the liver. In the experimental model of thioacetamide-induced toxic hepaptitis, the male rats of the Wistar line daily received the effective doses of polyphenols intragastically by gavage together with 0.05% thioacetamide added to drinking water. All studied polyphenols contributed to stabilization of rat weight and a two-fold significant (p < 0.05) decrease in the level of direct bilirubin in the blood serum of animals treated with thioacetamide. Histological analysis of the liver confirmed a decrease in inflammation and hemorrhage in animals treated with polyphenols amid continued administration of thioacetamide for 30 days. Based on the data obtained, it can be concluded that the natural polyphenols which belong to the classes of dihydroflavonols (dihydromyricetin) and stilbenes (resveratrol and pinosylvin) have a positive effect on liver function in the experimental model of toxic hepatosis. The studied polyphenols can be considered as potential hepatoprotective drugs used as a part of the liver diseases complex therapy.