Studying the anti-inflammatory activity of <i>Bifidobacterium bifidum</i> supernatants and chicken embryo cells on a model of opisthochic invasion

Morphological changes in the liver during infection with Opisthorchis felineus are characterized by significant structural changes. It has been proven that O. felineus modifies immune reactivity by increasing the synthesis of IL-10 and TGF-β and decreasing the levels of IL-4 and IL-5. The experiment was carried out on 15 Mesocricetus auratus aged from 4 to 6 weeks. The animals were divided into 3 equal groups. The duration of observation was 24 days. Live metacercariae of O. felineus were isolated from infected cyprinid fish. Infection was carried out by oral administration of 50 metacercariae. Animals in the experimental groups were injected intraperitoneally with 1 ml of the test supernatants. Histological preparations were examined by video microscopy with morphometry. It has been established that in the acute phase of opisthorchiasis, general infiltration of the portal tract area predominates. The cellular composition of infiltrates is characterized by the presence of lymphocytes, macrophages, fibroblasts, epithelioid cells and foreign body cells. The described cell changes are associated with a local decrease in oxygen access to hepatocytes in the peripheral zone of the lobule due to their compression by fibrous tissue. In the liver of the experimental groups, only tissue-specific changes were noted, and the damage to hepatocytes was the least pronounced in the group with the introduction of B. bifidum supernatant. The cytokine profile in the control group corresponded to the Th1 variant. In experimental group 1, when using the supernatant of B. bifidum, in comparison with the control, the ability of lymphocytes to produce the main pro-inflammatory cytokine, TNFα, decreased 4 times; a suppressive effect was also observed in relation to IL-1β, IL-2, IL-6, IL-8, and IFNγ. Inhibition of IL-10 production was observed, while the level of IL-4 and IL-5 increased in comparison with the control. When using the supernatant of chicken embryo cells, we observed similar results to group 1: a suppressive effect on pro-inflammatory and activation of the production of anti-inflammatory cytokines. IL-17 levels decreased in both experimental groups. Activation of the production of anti-inflammatory cytokines in experimental groups modulates the immune response towards Th2, which helps block inflammatory effects.