Metabolic syndrome (MetS) is a cluster of risk factors that increase the likelihood of developing cardiovascular, metabolic and other diseases. The pharmacological management of MetS often involves polypharmacy, making it essential to understand how drug-metabolising enzymes, transporters, transcription factors and other proteins involved are affected under different metabolic conditions. This study investigated the relative mRNA expression of key hepatic and intestinal genes involved in drug metabolism, including Cyp1a2, Cyp3a23, Cyp2d1, Cyp2c11, Cyp2c6, Cyp2e1, Cyp7a1, Cyp2b1, Cyp2a1, Abcg5, Abcg8, Abcb1, Nr1i3, Nr1i2, Ahr, Gsta1 and Comt, in four nonobese rat models of MetS: hereditary hypertriglyceridaemic (HHTg), spontaneously hypertensive rat (SHR), SHR expressing transgenic human C-reactive protein (SHR-CRP), and bilaterally ovariectomised Wistar (W-OVX), compared to Wistar controls. Gene expression was quantified by RT-PCR with data normalised using the ΔΔCt method. Between the models studied, measurements showed significant differences in the liver. The upregulation of Cyp2c6 and Cyp3a23 was observed only in SHR; upregulated Cyp2d1 was found in SHR as well as in HHTg rats. The downregulated Cyp1a2 was measured in a condition of hypertriglyceridemia, postmenopause or hypertension. These findings highlight model-specific alterations in gene expression that may affect drug metabolism and interactions. The HHTg may be, in particular, a suitable model for preclinical studies focusing on intestinal drug-drug interactions in MetS-related conditions.

• Keywords
• drug metabolism, metabolic syndrome, rat model,
• MeSH
• Liver metabolism   enzymology   MeSH
• Rats MeSH
• Humans MeSH
• Membrane Transport Proteins * genetics   metabolism   MeSH
• RNA, Messenger * metabolism   genetics   MeSH
• Metabolic Syndrome * genetics   metabolism   MeSH
• Disease Models, Animal MeSH
• Rats, Inbred SHR MeSH
• Rats, Wistar MeSH
• Receptors, Cytoplasmic and Nuclear * genetics   metabolism   MeSH
• Cytochrome P-450 Enzyme System * genetics   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Membrane Transport Proteins * MeSH
• RNA, Messenger * MeSH
• Receptors, Cytoplasmic and Nuclear * MeSH
• Cytochrome P-450 Enzyme System * MeSH

Background: Hypertriglyceridemia has serious health risks such as cardiovascular disease, type 2 diabetes mellitus, nephropathy, and others. Fenofibrate is an effective hypolipidemic drug, but its benefits for ameliorating disorders associated with hypertriglyceridemia failed to be proven in clinical trials. Methods: To search for possible causes of this situation and possibilities of their favorable influence, we tested the effect of FF monotherapy and the combination of fenofibrate with silymarin on metabolic disorders in a unique model of hereditary hypertriglyceridemic rats (HHTg). Results: Fenofibrate treatment (100 mg/kg BW/day for four weeks) significantly decreased serum levels of triglyceride, (-77%) and free fatty acids (-29%), the hepatic accumulation of triglycerides, and the expression of genes encoding transcription factors involved in lipid metabolism (Srebf2, Nr1h4. Rxrα, and Slco1a1). In contrast, the hypertriglyceridemia-induced ectopic storage of lipids in muscles, the heart, and kidneys reduced glucose utilization in muscles and was not affected. In addition, fenofibrate reduced the activity of the antioxidant system, including Nrf2 expression (-35%) and increased lipoperoxidation in the liver and, to a lesser extent, in the kidneys and heart. Adding silymarin (micronized form, 600 mg/kg BW/day) to fenofibrate therapy increased the synthesis of glycogen in muscles, (+36%) and reduced hyperinsulinemia (-34%). In the liver, it increased the activity of the antioxidant system, including PON-1 activity and Nrf2 expression, and reduced the formation of lipoperoxides. The beneficial effect of combination therapy on the parameters of oxidative stress and lipoperoxidation was also observed, to a lesser extent, in the heart and kidneys. Conclusions: Our results suggest the potential beneficial use of the combination of FF with SLM in the treatment of hypertriglyceridemia-induced metabolic disorders.

• Keywords
• fenofibrate, glycogen synthesis, insulin resistance, metabolic syndrome, oxidative stress, reesterification of fatty acids, silymarin, triglycerides,
• Publication type
• Journal Article MeSH

The efficacy of fenofibrate in the treatment of hepatic steatosis has not been clearly demonstrated. In this study, we investigated the effects of fenofibrate and silymarin, administered as monotherapy and in combination to existing hepatic steatosis in a unique strain of hereditary hypertriglyceridemic rats (HHTg), a non-obese model of metabolic syndrome. HHTg rats were fed a standard diet without or with fenofibrate (100 mg/kg b.wt./day) or with silymarin (1%) or with a combination of fenofibrate with silymarin for four weeks. Fenofibrate alone and in combination with silymarin decreased serum and liver triglycerides and cholesterol and increased HDL cholesterol. These effects were associated with the decreased gene expression of enzymes involved in lipid synthesis and transport, while enzymes of lipid conversion were upregulated. The combination treatment had a beneficial effect on the gene expression of hepatic cytochrome P450 (CYP) enzymes. The expression of the CYP2E1 enzyme, which is source of hepatic reactive oxygen species, was reduced. In addition, fenofibrate-induced increased CYP4A1 expression was decreased, suggesting a reduction in the pro-inflammatory effects of fenofibrate. These results show high efficacy and mechanisms of action of the combination of fenofibrate with silymarin in treating hepatic steatosis and indicate the possibility of protection against disorders in which oxidative stress and inflammation are involved.

• Keywords
• CYP 2E1, CYP 4A1, NAFLD, fenofibrate, lipoperoxidation, liver, silymarin, triglycerides,
• Publication type
• Journal Article MeSH

Chronic low-grade inflammation plays an important role in the pathogenesis of insulin resistance. In the current study, we tested the effects of salsalate, a non-steroidal anti-inflammatory drug, in an animal model of inflammation and metabolic syndrome using spontaneously hypertensive rats (SHR) that transgenically express human C-reactive protein (SHR-CRP rats). We treated 15-month-old male transgenic SHR-CRP rats and nontransgenic SHR with salsalate (200 mg/kg/day) mixed as part of a standard diet for 4 weeks. A corresponding untreated control group of male transgenic SHR-CRP and SHR rats were fed a standard diet without salsalate. In the SHR-CRP transgenic strain, salsalate treatment decreased circulating concentrations of the inflammatory markers TNF-α and MCP-1, reduced oxidative stress in the liver and kidney, increased sensitivity of skeletal muscles to insulin action and improved tolerance to glucose. In SHR controls with no CRP-induced inflammation, salsalate treatment reduced body weight, decreased concentrations of serum free fatty acids and total and HDL cholesterol and increased palmitate oxidation and incorporation in brown adipose tissue. Salsalate regulated inflammation by affecting the expression of genes from MAPK signalling and NOD-like receptor signalling pathways and lipid metabolism by affecting hepatic expression of genes that favour lipid oxidation from PPAR-α signalling pathways. These findings suggest that salsalate has metabolic effects beyond suppressing inflammation.

• MeSH
• C-Reactive Protein biosynthesis   genetics   MeSH
• Animals, Genetically Modified genetics   MeSH
• Adipose Tissue, Brown metabolism   MeSH
• Hypertension drug therapy   genetics   pathology   MeSH
• Insulin Resistance genetics   MeSH
• Liver metabolism   MeSH
• Rats MeSH
• Fatty Acids, Nonesterified metabolism   MeSH
• Humans MeSH
• Metabolic Syndrome drug therapy   genetics   pathology   MeSH
• Lipid Metabolism drug effects   MeSH
• NLR Proteins biosynthesis   MeSH
• Oxidative Stress drug effects   MeSH
• PPAR alpha biosynthesis   MeSH
• Salicylates administration & dosage   MeSH
• Tumor Necrosis Factor-alpha biosynthesis   MeSH
• Inflammation drug therapy   genetics   pathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• C-Reactive Protein MeSH
• Fatty Acids, Nonesterified MeSH
• NLR Proteins MeSH
• PPAR alpha MeSH
• Salicylates MeSH
• salicylsalicylic acid MeSH Browser
• Tumor Necrosis Factor-alpha MeSH