Inhibition of hepatic apolipoprotein A-I gene expression by histamine

Structural, Spectroscopic, and Docking Analysis of N,O-Donor Ligand Metal Complex Nanoparticles With Hypolipidemic Effects via Lipoprotein Lipase Activation in High-Fat Diet Mice

New Cd(II), Zn(II), and Cu(II) chelates with cetirizine.2HCl (CETZ.2HCl) in incidence of 1,10 phenanthroline monohydrate (Phen.H2O) were synthesized in search of new biologically active compounds. The ligands and their chelates were described by 1H NMR, FT-IR, elemental analysis, UV-vis spectrophotometry, thermal analyses, molar conductance, x-ray diffraction (XRD), and magnetic-susceptibility measurements. FT-IR demonstrated that CETZ.2HCl is bonded with metal ions, as a monodentate via carboxylate oxygen atom and Phen.H2O chelated via two nitrogen atoms. The molar conductivity data showed that the complexes were nonelectrolytes, whereas XRD data supported that the compounds were crystalline. Density functional theory (DFT) was utilized to gain insight into the compounds' optimized design. The effects of CETZ.2HCl and the complexes on the activity of lipoprotein-(L)-lipase in mice were investigated. Unlike Cd(II) complex, all the other compounds exhibited significant increase in lipase activity, with reduction in triglycerides. Cu(II) and Zn(II) complexes showed robust hypolipidemic efficacy evidenced by lower levels of total cholesterol and low-density lipoprotein (LDL), concomitant with higher levels of high-density lipoprotein (HDL). Furthermore, Zn(II) complex was a safe alternative as it has a lower liver toxicity. Molecular docking demonstrated that Cu(II) and Zn(II) chelates exhibited greater affinities to lipase than the parent ligand. Finally, Cu(II) complex showed the highest antibacterial activity.

Hypolipemic effects of histamine is due to inhibition of VLDL secretion from the liver: involvement of both H1 and H2-receptors

The research was performed to study the mechanism whereby histamine affects the profile of plasma lipids. Six groups of ten male rats were received two injections with histamine or its H1- and H2-agonists and antagonists. Histamine caused a significant decrease in the concentrations of triglyceride, total cholesterol, and LDLc, while HDLc had no significant change. The rate of VLDL secretion was 263.6 ± 25.8 mg/h dL in control rats and was inhibited by about 68% in histamine injected rats. These changes have been mimicked by either histamine H1- or H2-agonists. The effects of H1- and H2-agonists were abolished in the presence of cetirizine and famotidine respectively. Histamine causes a significant decrease in serum triglyceride, total, and LDL-cholesterol by both H1 and H2-receptors. The decrease in serum lipids is due to the inhibitory effect of histamine or its agonists on VLDL secretion from the liver.

Azelastine a potent antihistamine agent, as hypolipidemic and modulator for aortic calcification in diabetic hyperlipidemic rats model

AIM

Our study aimed to illustrate the effect of the antihistaminic drug azelastine on aortic calcification in diabetic hyperlipidemic (DH) rats along with the underlying molecular mechanism.

METHODS

Twenty-four male albino Wistar rats were categorised into four groups. One group received normal rodent chow (normal group), while the other groups were rendered diabetic and hyperlipidemic; one received no drugs and served as a positive control while the other two groups received either azelastine (4 mg/kg) or 10-dehydrogingerdione (10 mg/kg) orally and daily for 8 weeks.

RESULTS

Azelastine significantly reduced blood glucose, HbA1c and serum ALP, OCN, downregulated apo B, improved the lipid profile (LDL-c decrease and HDL-c increase), attenuated calcium deposition and aortic calcification as compared to control group. 10-DHGD showed comparatively lower effect.

CONCLUSION

Anti-calcifying effect of azelastine might be related to upregulation of apo A (HDL-c) and downregulation of apo B mRNA expression indeed good modulator of aortic calcification.

IMPACT STATEMENT

Many studies have indicated that high-density lipoprotein-cholesterol (HDL-c) is inversely correlated with atherosclerotic plaque progression and could reduce cardiovascular disease risk. An anti-calcifying effect of HDL-c has been reported and targeting this lipoprotein may therefore be a valuable approach to vascular calcification control. Azelastine is a selective H1 antagonist that was identified to increase mRNA expression of apolipoprotein A. This encouraged us to investigate the effect of azelastine on lipid profile and markers of aortic calcification in DH rats. Our findings showed that azelastine ameliorated aortic calcification and increased apoA expression along with a decline in apo B. This may represent the underlying mechanism while the histopathological findings offered a significant support to the collected biochemical data.

Insulin mimetic effect of D-allulose on apolipoprotein A-I gene

Several nutrients modulate the transcriptional activity of the apolipoprotein A-I (apo A-I) gene. To determine the influence of rare sugars on apo A-I expression in hepatic (HepG2) and intestinal derived (Caco-2) cell lines, apo A-I, albumin, and SP1 were quantified with enzyme immunoassay and Western blots while mRNA levels were quantified with real-time polymerase chain reaction. The promoter activity was measured using transient transfection assays with plasmids containing various segments and mutations in the promoter. D-allulose and D-tagatose, increased apo A-I concentration in culture media while D-sorbose and D-allose did not have any measurable effects. D-allulose did not increase apo A-I levels in Caco-2 cells. These changes paralleled the increased mRNA levels and promoter activity. D-allulose-response was mapped at the insulin response core element (IRCE). Mutation of the IRCE decreased the ability of D-allulose and insulin to activate the promoter. Treatment of HepG2 cells, but not Caco-2 cells, with D-alluose and insulin increased SP1 expression relative to control cells. D-allulose augmented the expression and IRCE binding of SP1, an essential transcription factor for the insulin on apo A-I promoter activity. D-allulose can modulate some insulin-responsive genes and may have anti-atherogenic properties, in part due to increasing apo A-I production. PRACTICAL APPLICATIONS: Coronary artery disease (CAD) is the number one cause of mortality in industrialized countries. A risk factor associated with CAD is low high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apo A-I) concentrations in plasma. Thus, novel therapeutic agents or nutrients that upregulate apo A-I production should be identified. D-allulose and D-tagatose are used as sweeteners and may have favorable effects on insulin resistance and diabetes. This study shows that D-allulose and D-tagatose increases apo A-I production through increased transcription factor SP1-binding to insulin response element of the promoter. These sweeteners modulate some insulin responsive genes, increase the production of apo-A-I, and therefore may have anti-atherogenic properties.

Apolipoprotein-AI and AIBP synergetic anti-inflammation as vascular diseases therapy: the new perspective

Vascular diseases (VDs) including pulmonary arterial hypertension (PAH), atherosclerosis (AS) and coronary arterial diseases (CADs) contribute to the higher morbidity and mortality worldwide. Apolipoprotein A-I (Apo A-I) binding protein (AIBP) and Apo-AI negatively correlate with VDs. However, the mechanism by which AIBP and apo-AI regulate VDs still remains unexplained. Here, we provide an overview of the role of AIBP and apo-AI regulation of vascular diseases molecular mechanisms such as vascular energy homeostasis imbalance, oxidative and endoplasmic reticulum stress and inflammation in VDs. In addition, the role of AIBP and apo-AI in endothelial cells (ECs), vascular smooth muscle (VSMCs) and immune cells activation in the pathogenesis of VDs are explained. The in-depth understanding of AIBP and apo-AI function in the vascular system may lead to the discovery of VDs therapy.

The Rise and Fall "ing" of the HDL Hypothesis

Earlier epidemiological studies have shown an inverse correlation between high-density lipoprotein cholesterol (HDLc) and coronary heart disease (CHD). This observation along with the finding that reverse cholesterol transport is mediated by HDL, supported the hypothesis that the HDL molecule has a cardioprotective role. More recently, epidemiological data suggest a U-shaped curve correlating HDLc and CHD. In addition, randomized clinical trials of drugs that significantly increase plasma HDLc levels, such as nicotinic acid and cholesterol ester transfer protein (CETP) inhibitors failed to show a reduction in major adverse cardiovascular events. These observations challenge the hypothesis that HDL has a cardioprotective role. It is possible that HDL quality and function is optimal only when de novo synthesis of apo A-I occurs. Inhibition of turnover of HDL with currently available agents yields HDL molecules that are ineffective in reverse cholesterol transport. To test this hypothesis, newer therapeutic drugs that increase de novo production of HDL and apo A-I should be tested in clinical trials.

Losartan and azelastine either alone or in combination as modulators for endothelial dysfunction and platelets activation in diabetic hyperlipidemic rats

AIM

The present study aimed mainly to demonstrate the effect of the antihistamine azelastine (AZ) and Angiotensin receptor blocker ( ARB), represented by losartan (LOS) either alone or in combined form on certain metabolic aspects, endothelial dysfunction and platelets activation markers in diabetic hyperlipidemic rat model.

METHODS

Rats were randomly classified to five groups: One group fed normal chow diet (NC). Four groups received alloxan and CCT-diet. One group received no treatment (DHC while the other three groups received AZ, LOS and their combination form, respectively for 8 weeks. Serum and tissue samples were collected for biochemical and histological evaluations.

RESULTS

DHC rats demonstrated significant hyperglycaemia, dyslipidemia, disturbances in endothelial and platelet activation markers. AZ or LOS administration demonstrated hypoglycaemic and hypolipidemic effects. VCAM-1 and sE-selectin (Endothelial function markers) along with CD63 (Platelet activation marker) showed significant decrease as compared to control group. AZ administration exerted little prominent effects than that of LOS, while their combination demonstrated remarkable changes compared to monotherapy. Histopathological findings were in agreement to certain extent with the biomarkers results.

CONCLUSIONS

Both drug categories may be expressed as suitable therapeutic tools for atherosclerotic complications either alone or along with other hypolipidemic drugs.