Prolonged liver fluke infection combined with alcoholization: An experimental mouse model

Abstract

Liver fluke infections disrupt the bile-excreting function of the human liver. Worldwide, excessive alcohol consumption also leads primarily to liver diseases. Our aim was to comprehensively assess the liver state in mice in parallel with the characterization of inflammation when the two adverse factors were combined. C57BL/6 mice were used for the experimental modeling; half of them beforehand were gradually accustomed to consumption of increasing doses of ethanol (from 5% to 20%). Then, half of the animals in each subgroup was infected with Opisthorchis felineus helminths. Finally, the infected (OF), 20% ethanol-consuming (Eth), and subjected to both factors (Eth + OF) mice were compared with no-treatment control. In OF and especially Eth + OF mice, relative liver weight was greater, activities of alanine aminotransferase and aspartate aminotransferase were higher, and bile ducts were considerably enlarged. Eth + OF mice contained noticeably more helminths in the liver than OF mice did. Massive cholangiofibrosis and periductal fibrosis were noted in the liver of the infected mice, especially Eth + OF ones. The liver fluke infection caused inflammatory infiltration and bile duct proliferation. Splenomegaly due to structural changes in the spleen as well as increased levels of interleukin 6 and leukocyte and monocyte counts in the blood reflected substantial inflammation in Eth + OF mice. Thus, in the proposed experimental model, it is shown that a double hit to the liver, i.e., the combination of O. felineus infection with prolonged alcoholization, can be detrimental to both the liver and whole body.

Keywords: Blood; C57BL/6 mice; Chronic ethanol; Liver; Opisthorchis felineus; Spleen.