[Protective effect and mechanism of hyperbaric oxygen therapy on non-alcoholic fatty liver disease in mice].

Objective

To investigate the curative effect and mechanism of hyperbaric oxygen therapy on nonalcoholic fatty liver disease in mice.

Methods

Twenty-one 8-week-old male C57BL/6J mice were divided into three groups: control group (normal diet), model group (high-fat and high-cholesterol diet), and hyperbaric oxygen group (high-fat and high-cholesterol diet + hyperbaric oxygen therapy), with seven mice in each group. The changes in body weight, serum liver enzymes, and blood lipids were compared after treatment between the three groups. Hematoxylin-eosin staining, Oil Red O staining, Sirius red staining, and F4/80 immunohistochemical staining were used to observe the pathological changes in liver tissues. RT-qPCR and Western blot methods were used to detect the expression levels of oxidative stress and inflammatory factors. One-way analysis of variance was used for comparison among the groups.

Results

Mice in the hyperbaric oxygen group had significantly improved liver histopathology. The serological levels of alanine aminotransferase, aspartate aminotransferase, and cholesterol were (77.50±13.59) U/L, (156.06±23.68) U/L, and (4.80±0.53) mmol/L, which were significantly lower than those in the model group [(109.43±16.88) U/L, (216.62±18.79) U/L, and (5.86±0.53) mmol/L, P<0.05], and accompanied by lower levels of lipid deposition, macrophage infiltration, and fibrosis. In addition, compared with the model group, the expression of antioxidant stress protein nuclear transcription factor erythroid 2-related factor 2 [(0.30±0.06) and (2.16±1.21), P<0.05] and heme oxygenase-1 [(0.48±0.19) and (1.01±0.18), P<0.05] in liver tissue showed an upward trend following hyperbaric oxygen treatment, which was also validated at the transcriptional level (P<0.05). Simultaneously, compared with the model group, the mRNA expressions of tumor necrosis factor-α [(2.60±0.71) and (0.66±0.15), P<0.05], interleukin-1β [(2.41±1.01) and (0.78±0.23), P<0.05], and interleukin-6 [(3.61±2.17) and (0.94±0.25), P<0.05] in the liver tissue of mice in the hyperbaric oxygen group were decreased. The tumor necrosis factor-α protein level [(7.50±4.73) and (1.05±0.58), P<0.05] and interleukin-1β [(1.65±0.35) and (1.02±0.02), P<0.05] was reduced following hyperbaric oxygen treatment compared with those in the model group.

Conclusion

Hyperbaric oxygen therapy can slow down the progression of nonalcoholic fatty liver disease by regulating the levels of oxidative stress and inflammation in the mice.