Protective effects of simvastatin administered in the experimental hepatic ischemia-reperfusion injury rat model

Drug-Induced Liver Injury from Statins

The hydroxymethyglutaryl-coenzyme A reductase inhibitors (statins) are a commonly prescribed class of medication for the treatment of hyperlipidemia and coronary artery disease. This class of medication has several proven benefits, including reduction of mortality related to coronary artery disease. A major consideration when prescribing these drugs are the potential for adverse effects, mainly myalgias, myopathy, and hepatotoxicity. In this article, we summarize current data on statin-associated hepatotoxicity and highlight that the risk of clinically significant idiosyncratic drug-induced liver injury is actually quite small. We also review preclinical data suggesting potential hepatoprotective effects of statin therapy.

The effects of simvastatin preconditioning on the expression of caspase-3 after myocardial ischemia reperfusion injury in rats

Effect of simvastatin on the expression of caspase-3 in myocardial ischemia reperfusion injury in rats was observed to explore the protective effect of caspase-3 through anti-apoptosis mechanism. A total of 48 healthy male SD rats weighing 160–240 g were selected and divided into 4 groups randomly, namely, the blank group, the sham operation group, the ischemia-reperfusion group and the simvastatin group, with 12 rats in each group. The model of SD rats was made by ligation. The loosen ligature made the reperfusion animal model, the occurrence of arrhythmia in the electrocardiogram of lead II in the experimental animal model was observed, and the area of myocardial infarction in the experimental animal models was detected. The number of apoptotic cells was detected by immunohistochemistry, and the expression of caspase-3 was detected by western blotting. The infarct area in the simvastatin group was significantly lower than the ischemia reperfusion group (P<0.05). The positive rate of the expression of caspase-3 and the positive rate of the expression of apoptotic cells in the ischemic reperfusion and simvastatin groups were significantly higher than that of the blank and sham operation groups, and the positive rate of the expression of caspase-3 and apoptotic cells in the simvastatin group was significantly lower than that of the ischemia-reperfusion group (P<0.05). The arrhythmia score of the simvastatin group was significantly lower than that of the ischemia-reperfusion group (P<0.05). Compared with the blank and sham operation groups, the expression of caspase-3 protein in the ischemia-reperfusion and simvastatin groups was significantly increased, and the expression of caspase-3 protein in the simvastatin group was significantly lower than that of the ischemia reperfusion group (P<0.05). Simvastatin has a protective effect on myocardial ischemia-reperfusion injury, which may be related to the reduction of caspase-3 expression and inhibition of apoptosis.

Simvastatin protects against acetaminophen-induced liver injury in mice

The present study aimed to investigate the effect of simvastatin on acetaminophen (APAP) hepatotoxicity in a mouse model. Male C57BL/6 mice were allocated into the following groups: control, APAP, APAP+SIM10, APAP+SIM20, APAP+SIM100 and APAP+SIM200 groups. The mice in the APAP group were treated with saline intraperitoneally (i.p.) 72 h before and 24 h or 72 h after APAP challenge (i.p., 400 mg/kg of APAP). The simvastatin-treated groups were treated with different doses of simvastatin i.p. (10, 20, 100 and 200 mg/kg/day) as in the APAP group. After 24 h or 72 h of APAP challenge, blood and liver samples were collected to detect hepatic injury and liver regeneration. The results showed that low doses of simvastatin (10 and 20 mg/kg) could significantly reverse the histological change and decrease hepatic injury. Simvastatin also reduced the serum cytokine levels and transcriptional levels of tumor necrosis factor-α and interleukin-6 in the liver. The malonyldialdehyde and myeloperoxidase levels significantly decreased in the simvastatin treatment groups compared with the APAP group. Simvastatin restored the decrease in superoxide dismutase, catalase, glutathione and glutathione peroxidase activities induced by APAP hepatotoxicity. In addition, simvastatin inhibited hepatic C/EBP-homologous protein expression and hepatocyte apoptosis. However, simvastatin had no effect on liver regeneration after APAP hepatotoxicity. Moreover, high doses could aggravate APAP-induced liver injury. In conclusion, low doses of simvastatin had a significant therapeutic effect in APAP-induced liver injury by inhibiting oxidative stress, inflammation and apoptosis. However, high doses of simvastatin had adverse hepatotoxicity.

ATORVASTATIN CAN PREVENT HEPATIC REMOTE REPERFUSION INJURY

Background:

Some studies have shown that statins have a promising effect on protection against reperfusion injury.

Aim:

To evaluate the ability of ischemic postconditioning, statins and both associated to prevent or minimize reperfusion injury in the liver of rats subjected to ischemia and reperfusion by abdominal aorta clamping.

Method:

Were used 41 Wistar rats, which were distributed into five groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + statin (IPC+S), statin (S) and Sham. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; excepting Sham group, all the others were submitted to the aorta clamping for 70 min (ischemia) and posterior clamping removing (reperfusion, 70 min). In the IPC and IPC+S groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 s each. In IPC+S and S groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. The left hepatic lobe was removed for histological study and euthanasia was performed.

Results:

The mean hepatic injury was 3 in the I/R group, 1.5 in the IPC group, 1.2 in the IPC+S group, 1.2 in the S group, and 0 in the SHAM group. The I/R group had a higher degree of tissue injury compared to the others in the statistical analysis and there was no difference between the others (p<0.01).

Conclusion:

Ischemic postconditioning and atorvastatin were able to minimize hepatic reperfusion injury, either alone or in combination.

Effect of Ischemic Postconditioning and Atorvastatin in the Prevention of Remote Lung Reperfusion Injury

Objective

The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping.

Methods

We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion).

Results

The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01).

Conclusion

Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.

Atorvastatin mitigates cyclophosphamide-induced hepatotoxicity via suppression of oxidative stress and apoptosis in rat model

Cyclophosphamide (CP), as a chemotherapy drug, induces hepatotoxicity through causing oxidative stress. Atorvastatin (ATV) at a low dose has antioxidant and anti-inflammatory properties. The present study was designed to investigate the protective effects of ATV against CP-induced hepatotoxicity in rat. In this experimental study, 32 rats were treated with ATV orally at a dose of 10 mg/kg for 10 consecutive days, 5 days before and 5 days after the administration of a single intraperitoneal injection of CP (150 mg/kg). The hepatoprotective effect of ATV was evaluated by measuring liver function markers, oxidative markers, histological and immunohistochemical assays. The biochemical results showed that administration of CP increased hepatic biomarkers enzymes as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels. CP increased malondialdehyde (MDA), protein carbonyl (PC) and decreased glutathione (GSH) content in rats. Moreover, administration of CP was associated with periportal leucocyte infiltration, dilation sinusoids, hepatocyte vacuolation, congestion and hemorrhage in livers of rats. CP significantly increased immunoreactivity of caspase-3 as a marker of apoptosis in liver tissue. ATV markedly mitigated liver injury through reduction in oxidative stress biomarkers, histopathological findings and apoptosis. The antioxidant and anti-apoptotic activities of ATV are main proposed mechanisms involved in its hepatoprotective effects against CP-induced hepatic injury.

Biochemical targets of drugs mitigating oxidative stress via redox-independent mechanisms

Acute or chronic oxidative stress plays an important role in many pathologies. Two opposite approaches are typically used to prevent the damage induced by reactive oxygen and nitrogen species (RONS), namely treatment either with antioxidants or with weak oxidants that up-regulate endogenous antioxidant mechanisms. This review discusses options for the third pharmacological approach, namely amelioration of oxidative stress by 'redox-inert' compounds, which do not inactivate RONS but either inhibit the basic mechanisms leading to their formation (i.e. inflammation) or help cells to cope with their toxic action. The present study describes biochemical targets of many drugs mitigating acute oxidative stress in animal models of ischemia-reperfusion injury or N-acetyl-p-aminophenol overdose. In addition to the pro-inflammatory molecules, the targets of mitigating drugs include protein kinases and transcription factors involved in regulation of energy metabolism and cell life/death balance, proteins regulating mitochondrial permeability transition, proteins involved in the endoplasmic reticulum stress and unfolded protein response, nuclear receptors such as peroxisome proliferator-activated receptors, and isoprenoid synthesis. The data may help in identification of oxidative stress mitigators that will be effective in human disease on top of the current standard of care.

Atorvastatin does not protect against ischemia-reperfusion damage in cholestatic rat livers

BACKGROUND

Extrahepatic cholestasis sensitizes the liver to ischemia/reperfusion (I/R) injury during surgery for perihilar cholangiocarcinoma. It is associated with pre-existent sterile inflammation, microvascular perfusion defects, and impaired energy status. Statins have been shown to protect against I/R injury in normal and steatotic mouse livers. Therefore, the hepatoprotective properties of atorvastatin were evaluated in a rat model of cholestatic I/R injury.

METHODS

Male Wistar rats were subjected to 70% hepatic ischemia (during 30 min) at 7 days after bile duct ligation. Rats were randomized to atorvastatin treatment or vehicle-control in three test arms: (1) oral treatment with 5 mg/kg during 7 days after bile duct ligation; (2) intravenous treatment with 2.5, 5, or 7.5 mg/kg at 24 h before ischemia; and (3) intravenous treatment with 5 mg/kg at 30 min before ischemia. Hepatocellular damage was assessed by plasma alanine aminotransferase (ALT) and histological necrosis.

RESULTS

I/R induced severe hepatocellular injury in the cholestatic rat livers (~10-fold increase in ALT at 6 h after I/R and ~30% necrotic areas at 24 h after I/R). Both oral and intravenous atorvastatin treatment decreased ALT levels before ischemia. Intravenous atorvastatin treatment at 5 mg/kg at 24 h before ischemia was the only regimen that reduced ALT levels at 6 h after reperfusion, but not at 24 h after reperfusion. None of the tested regimens were able to reduce histological necrosis at 24 h after reperfusion.

CONCLUSION

Pre-treatment with atorvastatin did not protect cholestatic livers from hepatocellular damage after I/R. Clinical studies investigating the role of statins in the protection against hepatic I/R injury should not include cholestatic patients with perihilar cholangiocarcinoma. These patients require (pharmacological) interventions that specifically target the cholestasis-associated hepatopathology.

Grape seed protects cholestatic rats liver from ischemia/reperfusion injury

PURPOSE

To determine the effect of grape-seed extract against ischemia/reperfusion injury in cholestatic liver.

METHODS

Eighteen Wistar albino rats were divided into three groups. In control and study groups, cholestasis was provided by bile duct ligation. Seven days later, the rats were subjected to 30 min hepatic ischemia, followed by 60 min of reperfusion. Oral administration of 50 mg/kg/day grape-seed extract was started 15 days before bile duct ligation and continued to the second operation in the study group. Serum, plasma and liver samples were taken. Laboratory analysis, tissue gluthation, malondialdehyde, myeloperoxidase levels and histopathological examination were performed.

RESULTS

Significant decrease in liver gluthation level and significant increase in malondialdehyde level and myeloperoxidase activity were observed after ischemia/reperfusion in cholestatic rats. Serum and plasma levels for laboratory analysis were also significantly higher in cholestatic I/R group. Hepatic necrosis and fibrosis were detected in histopathological examination. Oral grape-seed extract administiration reversed all these parameters and histopathological findings except serum bilirubin levels.

CONCLUSION

Oral grape-seed extract treatment can improve liver functions and attenuate the inflammation and oxidative stress in cholestatic ischemia/reperfusion injury.

Antioxidant Effect of Ukrain Versus N-Acetylcysteine Against Acute Biliary Pancreatitis in An Experimental Rat Model

Purpose/Aim: Oxidative stress plays an important role in the pathogenesis of acute pancreatitis (AP). We compared the therapeutic effects of Ukrain (NSC 631570) and N-acetylcysteine (NAC) in rats with AP.

MATERIALS AND METHODS

Forty male Sprague Dawley rats were divided into four groups: controls; AP; AP with NAC; and AP with Ukrain. AP was induced via the ligation of the bile-pancreatic duct; drugs were administered intraperitoneally (i.p.) 30 min and 12 h after AP induction. Twenty-four hours after AP induction, animals were sacrificed and the pancreas was excised. Levels of malondialdehyde (MDA) and nitric oxide (NO), and activity levels of tumor necrosis factor (TNF)-α, and myeloperoxidase (MPO) were measured in tissue samples. Total oxidant status (TOS), total antioxidant status (TAS), and total bilirubin, as well as activity levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase and lipase were measured in serum samples. Pancreatic tissue histopathology was also evaluated.

RESULTS

Test drugs reduced levels of MDA, NO, TNF-α, total bilirubin, AST, ALT, TOS and MPO, amylase and lipase activities (P < 0.001), and increased TAS (P < 0.001). Rats treated with test drugs attenuated AP-induced morphologic changes and decreased pancreatic damage scores compared with the AP group (P < 0.05). Both test drugs attenuated pancreatic damage, but the therapeutic effect was more pronounced in rats that received Ukrain than in those receiving NAC.

CONCLUSIONS

These results suggest that treatment with Ukrain or NAC can reduce pancreatic damage via anti-inflammatory and antioxidant effects.