EFFECTS OF MELATONIN AND PHYSICAL EXERCISE ON SECONDARY BILIARY CIRRHOSIS

Introduction and Objectives

Cirrhosis is characterized by the formation of septa and fibrotic nodules in the liver parenchyma, and it is a relevant public health problem. Bile duct ligation (BDL) is an effective experimental model for inducing secondary biliary cirrhosis. Melatonin (MLT) has antioxidant, antifibrotic, and cytoprotective properties. Physical exercise (EX) has shown beneficial effects in different diseases.

To investigate the effects of MLT and EX on BDL-induced biliary cirrhosis in rats.

Materials and Methods

The study, was approved by CEUA/HCPA (2021-0642). We used 26 male Wistar rats (60 days, ±350g), distributed into four groups: CO, BDL, BDL+MLT, and BDL+EX. BDL was performed on day 1 in the experimental groups. From the 15th day onwards, MLT (20 mg/kg/day) was administered and the swimming protocol was started. On the 29th day, blood (for analysis of AST, ALT and FA) and liver were collected. Data were analyzed by One-Way ANOVA with Student-Newman-Keuls post-test (mean±SE; p<0.05).

Results

AST, ALT and FA were increased significantly in the LDB group vs. CO (p<0.05), with reduction in the LDB+MLT and LDB+EX groups (p<0.05). The Picrosirius staining indicated intense fibrosis in the LDB group, this effect was attenuated by treatments. GPx activity was reduced in the LDB group (p<0.01), but increased with MLT and EX. CAT increased in the LDB group and decreased with treatments (p<0.05). Nitric oxide levels increased in the LDB group and decreased with MLT.

Conclusions

MLT and EX promoted protective effects in the liver of rats with biliary cirrhosis, attenuating biochemical, oxidative and fibrotic changes.

Conflict of interest: None

Histological analysis of the liver (Picrosirius)