Effect of chicoric acid on oxidative stress during myocardial injury in sepsis rats and relationship with Nrf2 signaling pathway / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of chicoric acid on oxidative stress during myocardial injury in sepsis rats and the relationship with nuclear factor E2-related factor 2 (Nrf2) signaling pathway.Methods:Forty healthy male Sprague-Dawley rats, aged 8-12 weeks, weighing 220-250 g, were divided into 5 groups ( n=8 each) using a random number table method: control group (group C), lipopolysaccharide (LPS) group (group LPS), LPS+ chicoric acid group (group LPS+ CA), LPS+ Nrf2 inhibitor ML385 group (group LPS+ ML) and LPS+ chicoric acid+ ML385 group (group LPS+ CA+ ML). LPS 15 mg/kg was intraperitoneally injected to induce sepsis.Immediately after intraperitoneal injection of LPS, chicoric acid 10 mg/kg or ML385 15 mg/kg (in dimethyl sulfoxide) was intraperitoneally injected in group LPS+ CA and group LPS+ ML, respectively, and ML385 15 mg/kg and chicoric acid 10 mg/kg were intraperitoneally injected in LPS+ CA+ ML group.The equal volume of dimethyl sulfoxide was given instead in group C. At 48 h after establishment of the model, blood samples were collected from the aorta for measurement of concentration of serum interleukin-6 (IL-6) and the activities of lactate dehydrogenase (LDH) and creatine kinase isoenzyme (CK-MB) (by enzyme-linked immunosorbent assay). The animals were then sacrificed, and myocardial tissues were obtained for microscopic examination of pathological changes (by HE staining), for determination of activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and contents of reactive oxygen species(ROS) and iron (by colorimetry), for calculation of the ratio of oxidized nicotinamide adenine 2 nucleotides to reduced nicotinamide adenine 2 nucleotides (NAD + /NADH), and for detection of the expression of Nrf2, NADPH quinone oxidoreductase 1 (NQO1), glutathione peroxidase 4 (GPX4) and nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1) (by Western blot). Results:Compared with C group, the activities of serum LDH and CK-MB and concentration of IL-6 were significantly increased, the contents of ROS and iron and the ratio of NAD + /NADH were increased, activities of GSH-Px and SOD were decreased, expression of Nrf2, NQO1 and GPX4 was down-regulated, and NOX1 expression was up-regulated in the other four groups ( P<0.05). Compared with group LPS, the activities of serum LDH and CK-MB and concentration of IL-6 were significantly decreased, the contents of ROS and iron and the ratio of NAD + /NADH were decreased, activities of GSH-Px and SOD were increased, expression of Nrf2, NQO1 and GPX4 was up-regulated, NOX1 expression was down-regulated ( P<0.05), and the pathological changes of cardiomyocytes were significantly reduced in group LPS+ CA, and the activities of serum LDH and CK-MB and concentration of IL-6 were significantly increased, the ratio of NAD + /NADH were increased, activities of GSH-Px and SOD were decreased, expression of Nrf2, NQO1 and GPX4 was down-regulated, NOX1 expression was up-regulated ( P<0.05), and the pathological changes of cardiomyocytes were accentuated in group LPS+ ML.Compared with group LPS+ CA, the activities of serum LDH and CK-MB and concentration of IL-6 were significantly increased, the contents of ROS and iron and the ratio of NAD + /NADH were increased, activities of GSH-Px and SOD were decreased, expression of Nrf2, NQO1 and GPX4 was down-regulated, NOX1 expression was up-regulated ( P<0.05), and the pathological changes of cardiomyocytes were accentuated in group LPS+ CA+ ML. Conclusion:The mechanism by which chicoric acid reduces myocardial injury in sepsis rats may be related to activating Nrf2 signaling pathway and inhibiting oxidative stress.