黄芪总苷对应激大鼠胃黏膜氧自由基及褪黑素受体的影响

Levels of MDA and SOD in acute gastric mucosal injury in rats exposed to positive acceleration

AIM: To determine the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in acute gastric mucosal injury in rats exposed to positive acceleration (+Gz), observe the impact of +Gz exposure on gastric mucosal injury, and clarify the role of oxygen free radicals in this process.

METHODS: Thirty male SD rats were randomly divided into three groups: A (ethanol), B (ethanol with +5Gz exposure), and C (ethanol with +10Gz exposure). All rats were intragastrically given ethanol (0.4 mL/100 mg) after 24 h of fasting and water deprivation for 12 h. One hour after ethanol administration, group A did not undergo +Gz, while groups B and C were continuously exposed to +5Gz and +10Gz for 3 minutes, respectively. Immediately after +Gz exposure, gastric tissue samples were taken to observe gastric mucosal injury by light microscopy. The indexes of gastric mucosal injury were calculated, and the contents of MDA and SOD in the gastric mucosa were determined by ELISA.

RESULTS: Gastric mucosal injury was observed in all the groups, and gastric mucosal injury was most severe in group C, followed by groups B and A. Group A had mildest gastric mucosal injury. Group B showed visible gastric mucosal congestion, edema and scattered bleeding spots, and light microscopy revealed acute inflammatory cell infiltration. The indexes of gastric mucosal injury were significantly higher in group B than in group A (naked eye: 23.654 ± 9.678 vs 11.410 ± 3.742; light microscopy: 5.000 ± 1.054 vs 3.800 ± 1.399; both P < 0.05). Group C had heaviest gastric mucosal injury. Diffuse gastric mucosal congestion, edema, erosion and many bleeding spots were visible, and light microscopy revealed disorderly arranged gland structure, interstitial congestion, erosion, and acute inflammatory cell infiltration. The indexes of gastric mucosal injury were significantly higher in group C than in groups A and B (naked eye: 49.080 ± 10.254, light microscopy: 9.400 ± 2.011; all P < 0.05). Compared with group A, the content of MDA in the gastric mucosa did not rise significantly in group B (0.255 ± 0.074 vs 0.235 ± 0.044, P > 0.05); however, MDA content in group C (0.376 ± 0.084) was significantly higher than those in groups A and B (both P < 0.05). The content of SOD in the gastric mucosa was significantly lower in group C than in groups A and B (8.852 ± 1.001 vs 10.000 ± 1.067, 10.694 ± 0.965, P < 0.05), although no significant difference was observed between the latter two groups (P > 0.05).

CONCLUSION: +Gz exposure aggravates acute gastric mucosal injury in rats possibly by altering the contents of MDA and SOD in gastric tissue.

Effect of Shenqi Fuzheng Injection on serum levels of ROS, SOD, LPO, NF-κB and CTGF mRNA expression in rats with alcoholic hepatic fibrosis

AIM: To explore the effect of Shenqi Fuzheng Injection on serum levels of ROS, SOD, LPO, NF-κB and CTGF mRNA expression in rats with alcoholic hepatic fibrosis.

METHODS: One hundred male SD rats were divided into normal group, model group, low [(2.0 mL/(100 g•d)], medium [(2.5 mL/(100 g•d)] and high-dose [(3.0 mL/(100 g•d)] Shenqi Fuzheng Injection groups. Rats were intragastrically administered with alcohol for 16 wk to induce hepatic fibrosis. Shenqi Fuzheng Injection was injected into the tail vein of rats in the three treatment groups. The rats were killed after 16 wk. The histological structure of the liver tissue was observed under an optical microscope, the levels of ROS, SOD, LPO and NF-κB in serum were determined by radioimmunoassay, and the expression of connective tissue growth factor (CTGF) mRNA was measured by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS: Compared to the normal group, the level of serum SOD decreased significantly and the fibrosis score and the levels of ROS, LPO, NF-κB and CTGF mRNA increased significantly in the model group (all P < 0.01). Compared to the model group, the level of serum SOD increased significantly and the fibrosis score and the levels of ROS, LPO, NF-κB and CTGF mRNA decreased significantly in the treatment groups (all P < 0.01). The levels of ROS, LPO and CTGF mRNA were positively correlated with the fibrosis score (r = 0.463, 0.425, 0.412, all P < 0.05).

CONCLUSION: Lipid peroxidation, NF-κB activation and CTGF are closely related to the severity of alcoholic hepatic fibrosis, and there may be a synergetic interaction among lipid peroxidation, NF-κB and CTGF in the pathogenesis of alcoholic hepatic fibrosis. Shenqi Fuzheng Injection can inhibit lipid peroxidation, decrease NF-κB activity and CTGF mRNA expression and thereby alleviate the severity of hepatic fibrosis in rats with alcoholic hepatic fibrosis.

Role of ghrelin and NF-κB in the pathogenesis of acute necrotizing pancreatitis-associated liver injury

AIM: To investigate the expression of ghrelin in the liver of rats with acute necrotizing pancreatitis (ANP) with liver injury and to explore the role of ghrelin and NF-κB in the pathogenesis of ANP-associated liver injury and the mechanism underlying the therapeutic effects of melatonin against ANP.

METHODS: Seventy-two male Sprague-Dawley rats were randomly and equally divided into control group, ANP group, and melatonin intervention group. Rats of the ANP group and melatonin intervention group were injected with 6% L-Arg (1.5 g/kg) intraperitoneally three times to induce ANP. Rats of the control group were injected with same volume of normal saline. The melatonin intervention group was given 1% melatonin (50 μg/kg) intraperitoneally 0.5 h before the first injection of L-Arg. Rats were sacrificed at 6, 12, and 24 h after the injection of melatonin. Pathological changes in the pancreatic and hepatic tissue were observed and graded under a microscope. The expression of ghrelin and NF-κB mRNAs was evaluated by RT-PCR, while the protein expression of NF-κB was detected by Western blot.

RESULTS: Pancreatic and hepatic pathological scores, serum amylase, and expression of NF-κB mRNA (6 h: 0.74 ± 0.04 vs 0.40 ± 0.05; 12 h: 0.77 ± 0.03 vs 0.40 ± 0.02; 24 h: 0.82 ± 0.04 vs 0.40 ± 0.03, all P = 0.001) and protein in the liver at all time points were significantly higher (24 h: 0.48 ± 0.07 vs 0.6 ± 0.04, P < 0.05), and ghrelin mRNA expression was significantly lower in the ANP group than in the control group (6 h: 0.39 ± 0.04 vs 0.66 ± 0.03; 12 h: 0.14 ± 0.37 vs 0.30 ± 0.05; 24 h: 0.22 ± 0.02 vs 0.59 ± 0.05, all P < 0.05). Pancreatic pathological scores, hepatic pathological scores, serum amylase, and expression of NF-κB mRNA(6 h: 0.50 ± 0.05 vs 0.74 ± 0.04, 12 h: 0.54 ± 0.04 vs 0.77 ± 0.03, 24 h: 0.57 ± 0.03 vs 0.82 ± 0.04, all P < 0.05) and protein were decreased (24 h: 0.32 ± 0.04 vs 0.48 ± 0.07, P < 0.05), and ghrelin mRNA expression was elevated (6 h: 0.54 ± 0.03 vs 0.39 ± 0.04, 12 h: 0.40 ± 0.09 vs 0.30 ± 0.05, 24 h: 0.39 ± 0.04 vs 0.22 ± 0.02, all P < 0.05) in the melatonin intervention group compared with in the ANP group.

CONCLUSION: The expression of ghrelin may be related to the severity of ANP with liver injury. NF-κB may also be involved in the pathogenesis of ANP with liver injury. Exogenous melatonin can reduce ANP possibly by up-regulating ghrelin expression and down-regulating NF-κB expression.