ABSTRACT
Objective:
To evaluate the effect of
melatonin preconditioning on hepatic
ischemia-
reperfusion (I/R)
injury in
rats with
non-alcoholic fatty liver disease (
NAFLD).
Methods:
Forty-eight SPF
male Sprague-Dawley rats,
aged 10-12 weeks, weighing 200-230 g, were divided into 4 groups ( n=12 each) using a random number table
method:
control group (Con group),
NAFLD group,
NAFLD + hepatic I/R group (
NAFLD+ HIR group), and
NAFLD + hepatic I/R +
melatonin treatment group (
NAFLD+ HIR+ MT group). The
NAFLD model was developed by a high-fat and high-
glucose diet (10%
glucose, 10% fat) for 8 consecutive weeks in
NAFLD,
NAFLD+ HIR and
NAFLD+ HIR+ M groups, and
rats were fed with common chow and freely drank
water in the other groups.
Melatonin 10 mg/kg was given intragastrically daily for 2 consecutive weeks before developing the model in group
NAFLD+ HIR+ MT.The model of
liver I/R
injury was developed by clipping the
hepatic artery and
portal vein for 20 min, opening for 5 min, and re-
clamping for 20 min followed by restoration of
perfusion.
Blood samples from
inferior vena cava were collected and
liver tissues were obtained at 6 h of
reperfusion to detect
serum levels of
insulin,
blood glucose,
free fatty acid (FFA),
triglyceride (TG),
alanine aminotransferase (ALT), aspartate amino transferase (AST) and
ferritin, and
insulin resistance index was calculated.The levels of
superoxide dismutase (SOD),
glutathione peroxidase (GSH-Px),
reactive oxygen species (ROS) and Fe 2+ in
liver tissues were detected by
enzyme-linked immunosorbent assay, the pathological changes of
liver tissues were examined with a
light microscope after
hematoxylin-
eosin staining.The expression of
nuclear factor E2-related factor 2 (Nrf2),
lysophosphatidylcholine acyltransferase 3 (LPCAT3), long-chain fatty acyl-CoA synthase 4 (ACSL4) and
glutathione peptide peroxidase 4 (GPX4) was detected by
Western blot.
Results:
Compared with Con group, the levels of
serum FFA, TG, ALT, AST and
ferritin and
insulin resistance index were significantly increased, the levels of ROS and Fe 2+ in
liver tissues were increased, the levels of GSH-Px and SOD were decreased, the expression of ACSL4 and LPCAT3 was up-regulated, and the expression of Nrf2 and GPX4 was down-regulated in
NAFLD group ( P<0.05). Compared with
NAFLD group, the
serum levels of FFA, TG, ALT, AST and
ferritin and
insulin resistance index were significantly increased, the levels of ROS and Fe 2+ were decreased, the levels of GSH-Px and SOD were increased, the expression of ACSL4 and LPCAT3 was up-regulated, and the expression of Nrf2 and GPX4 was down-regulated in
NAFLD+ HIR group ( P<0.05). Compared with
NAFLD+ HIR group, the
serum levels of FFA, TG, ALT, AST and
ferritin and
insulin resistance index were significantly increased, the levels of ROS and Fe 2+ were decreased, the levels of GSH-Px and SOD were increased, the expression of ACSL4 and LPCAT3 was down-regulated, and the expression of Nrf2 and GPX4 was up-regulated in
NAFLD+ HIR+ MT group ( P<0.05).
Conclusions:
Melatonin preconditioning can alleviate hepatic I/R
injury in
rats with
NAFLD, and the mechanism may be related to activation of Nrf2 signaling pathway, reduction of
lipid peroxidation and inhibition of
ferroptosis.