Statins for treatment of chronic liver disease

Nrf2/HO-1, NF-κB and PI3K/Akt signalling pathways decipher the therapeutic mechanism of pitavastatin in early phase liver fibrosis in rats

Liver fibrosis is a common chronic hepatic disease. This study aimed to investigate the effect of pitavastatin (Pit) against thioacetamide (TAA)-induced liver fibrosis. Rats were divided into four groups: (1) control group; (2) TAA group (100 mg/kg, i.p.) three times weekly for 2 weeks; (3 and 4) TAA/Pit-treated group, in which Pit was administered orally (0.4 and 0.8 mg/kg/day) for 2 weeks following TAA injections. TAA caused liver damage manifested by elevated serum transaminases, reduced albumin and histological alterations. Hepatic malondialdehyde (MDA) was increased, and glutathione (GSH) and superoxide dismutase (SOD) were decreased in TAA-administered rats. TAA upregulated the inflammatory markers NF-κB, NF-κB p65, TNF-α and IL-6. Treatment with Pit ameliorated serum transaminases, elevated serum albumin and prevented histopathological changes in TAA-intoxicated rats. Pit suppressed MDA, NF-κB, NF-κB p65, the inflammatory cytokines and PI3K mRNA in TAA-intoxicated rats. In addition, Pit enhanced hepatic antioxidants and boosted the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) mRNA. Moreover, immunohistological studies supported the ability of Pit to reduce liver fibrosis via suppressing p-AKT expression. In conclusion, Pit effectively prevents TAA-induced liver fibrosis by attenuating oxidative stress and the inflammatory response. The hepatoprotective efficacy of Pit was associated with the upregulation of Nrf2/HO-1 and downregulation of NF-κB and PI3K/Akt signalling pathways.

Low-dose atorvastatin therapy induced rhabdomyolysis in a liver cirrhosis patient - a case report

Introduction

Rhabdomyolysis may arise due to traumatic or non-traumatic causes leading to muscle injury. However, increased statin use has raised drug-related side effects like statin-related muscle damage.

Case report

A 74-year-old male with liver cirrhosis secondary to alcohol was prescribed atorvastatin for hyperlipidemia. He developed muscle tenderness and decreased muscle power 2 weeks following statin therapy, evident with a creatine phosphokinase level of more than 22 000 IU/l. The urinalysis also revealed positive for blood. Hence, atorvastatin was ceased. The patient's laboratory parameters improved significantly, implying atorvastatin is the causative agent for rhabdomyolysis.

Discussion

Statins are usually safe and well-tolerated drugs; however, skeletal muscle symptoms occur in ~5-10% of patients. The risk factor for statin-induced muscle injury includes advanced age, drug-altering statin plasma level, liver disease, or chronic kidney disease. Moreover, the hepatic level of CYP450 and its CYP3A4 isoform are altered in chronic liver diseases. CYP3A4 isoenzyme and its activity declines in hepatic cirrhosis patients.

Conclusion

Statins are generally prescribed for hyperlipidemia and primary and secondary prevention in high-risk cardiovascular diseases. However, several risk factors alter statin metabolism, causing statin-induced muscle injury. Thus, despite several studies suggesting otherwise, special precautions should be taken in patients with chronic liver disease.

Advancements in MAFLD Modeling with Human Cell and Organoid Models

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is one of the most prevalent liver diseases and has no approved therapeutics. The high failure rates witnessed in late-phase MAFLD drug trials reflect the complexity of the disease, and how the disease develops and progresses remains to be fully understood. In vitro, human disease models play a pivotal role in mechanistic studies to unravel novel disease drivers and in drug testing studies to evaluate human-specific responses. This review focuses on MAFLD disease modeling using human cell and organoid models. The spectrum of patient-derived primary cells and immortalized cell lines employed to model various liver parenchymal and non-parenchymal cell types essential for MAFLD development and progression is discussed. Diverse forms of cell culture platforms utilized to recapitulate tissue-level pathophysiology in different stages of the disease are also reviewed.

Hepatic macrophage mediated immune response in liver steatosis driven carcinogenesis

Obesity confers an independent risk for carcinogenesis. Classically viewed as a genetic disease, owing to the discovery of tumor suppressors and oncogenes, genetic events alone are not sufficient to explain the progression and development of cancers. Tumor development is often associated with metabolic and immunological changes. In particular, obesity is found to significantly increase the mortality rate of liver cancer. As its role is not defined, a fundamental question is whether and how metabolic changes drive the development of cancer. In this review, we will dissect the current literature demonstrating that liver lipid dysfunction is a critical component driving the progression of cancer. We will discuss the involvement of inflammation in lipid dysfunction driven liver cancer development with a focus on the involvement of liver macrophages. We will first discuss the association of steatosis with liver cancer. This will be followed with a literature summary demonstrating the importance of inflammation and particularly macrophages in the progression of liver steatosis and highlighting the evidence that macrophages and macrophage produced inflammatory mediators are critical for liver cancer development. We will then discuss the specific inflammatory mediators and their roles in steatosis driven liver cancer development. Finally, we will summarize the molecular pattern (PAMP and DAMP) as well as lipid particle signals that are involved in the activation, infiltration and reprogramming of liver macrophages. We will also discuss some of the therapies that may interfere with lipid metabolism and also affect liver cancer development.

Simvastatin ameliorates oxidative stress levels in HepG2 cells and hyperlipidemic rats

Simvastatin is an established anti-hyperlipidemic drug and few studies have indicated its role in the mitigation of oxidative stress. However, a systematic study considering molecular binding/interaction of simvastatin with anti-oxidant enzymes followed by confirmational in vitro and in vivo studies have never been done. We investigated the molecular binding of simvastatin with multiple anti-oxidant enzymes and assessed their levels after the treatment of simvastatin in vitro and in vivo. This study is the first to show the molecular binding of simvastatin to catalase through molecular docking analysis. Moreover, the anti-oxidative properties of simvastatin have not been studied in Lipopolysaccharide (LPS) induced oxidative stress in HepG2 cells. We found that simvastatin effectively attenuated oxidative stress in LPS induced HepG2 cells and high-fat diet (HFD) fed hyperlipidemic rats by increasing the levels of antioxidant enzymes. The activity of catalase and superoxide dismutase (SOD) both increased significantly in oxidatively stressed HepG2 cells after the treatment with simvastatin (10 ​μM, 24 ​h). In addition to this, he original cell morphology of oxidatively stressed cells was restored by simvastatin, and an increase in antioxidant enzymes, catalase (0.08 U/cells to 0.12 U/cells), and SOD (0.57 U/cells to 0.74 U/cells) was also noted in HepG2 cells. Furthermore, a significant increase in the antioxidant enzymes such as Catalase, SOD, and reduced glutathione (GSH) was noted after simvastatin treatment in the HFD model. Moreover, we also observed degradation of by-products of lipid peroxidation thiobarbituric acid reactive substances (TBARs), nitric oxide (NO), and protein carbonyl levels. This indicates that simvastatin enhances anti-oxidant enzyme activities and can be repurposed for the treatment of oxidative stress in liver diseases in humans after extensive clinical trials.

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In silico, molecular docking analysis shows that simvastatin binds to the active site of the catalase enzyme.

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Simvastatin attenuates LPS induced oxidative stress in HepG2 cells by increasing the amount of antioxidant enzymes catalase and SOD.

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Simvastatin significantly reduces triglycerides, cholesterol, LDL, VLDL, and increases HDL level in HFD induced oxidative stress in Wistar rats.

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Simvastatin can be repurposed for the treatment of oxidative stress in liver diseases.