Effect of ezetimibe on insulin secretion in db/db diabetic mice

The therapeutic effect of NRF2 activator, ezetimibe, in cardiac cachexia

INTRODUCTION

Heart failure (HF) is caused by functional and structural irregularity leading to impaired ejection or filling capacity of the heart. HF leads to chronic inflammatory conditions in the heart leads to weight loss, anorexia, and muscle atrophy known as cachexia. The present study was carried out to investigate the role of Ezetimibe, an NRF2 activator, in cardiac cachexia and to develop a treatment strategy for cardiac cachexia.

METHOD

Balb/c mice of either sex at 6-8 weeks of age were given 2 mg/kg of doxorubicin in 0.9% sodium chloride solution intraperitoneally (i.p.) for the alternate days for the first week and then once a week for the next 4 weeks. After induction of cardiac atrophy, treatment with Ezetimibe (1.5 mg/kg, p.o) was given for the next 4 weeks.

RESULT

In the cardiac cachectic animals, a significant decrease in body weight, food, and water intake was observed. Cardiac cachectic animals showed a significant increase in serum glucose, total cholesterol, LDL, triglyceride, VLDL, CK-MB, LDH, and CRP levels. Cardiac atrophic index, heart weight to body weight ratios (HW/BW), right ventricular weight to heart weight ratios (RV/HW), and left ventricular weight to heart weight ratios (LV/HW), were significantly decreased in cardiac cachectic animals. The weights of the skeletal muscles such as EDL, gastrocnemius, soleus, tibialis anterior, and quadriceps muscles, and the weight of adipose tissue such as subcutaneous, visceral, perirenal, and brown adipose tissue were significantly decreased in the cardiac cachectic group relative to the normal group. Treatment with ezetimibe improves body weight, food intake, and water intake. Ezetimibe decreases serum glucose, total cholesterol, LDL, triglyceride, VLDL, CK-MB, LDH and CRP levels. Cardiac atrophic markers such as HW/BW, RV/HW, and LV/HW were improved. The weight of skeletal muscles and adipose tissue was increased after treatment with ezetimibe.

CONCLUSION

Our data showed that the NRF2 activator, Ezetimibe produces a beneficial effect on cardiac cachexia in the doxorubicin-induced cardiac cachexia model. Ezetimibe was successful to reduce the levels of inflammatory cytokines, ameliorate the effects on cardiac muscle wasting, lipid levels, fat tissues, and skeletal muscles.

Fructose overconsumption accelerates renal dysfunction with aberrant glomerular endothelial-mesangial cell interactions in db/db mice

For the advancement of DKD treatment, identifying unrecognized residual risk factors is essential. We explored the impact of obesity diversity derived from different carbohydrate qualities, with an emphasis on the increasing trend of excessive fructose consumption and its effect on DKD progression. In this study, we utilized db/db mice to establish a novel diabetic model characterized by fructose overconsumption, aiming to uncover the underlying mechanisms of renal damage. Compared to the control diet group, the fructose-fed db/db mice exhibited more pronounced obesity yet demonstrated milder glucose intolerance. Plasma cystatin C levels were elevated in the fructose model compared to the control, and this elevation was accompanied by enhanced glomerular sclerosis, even though albuminuria levels and tubular lesions were comparable. Single-cell RNA sequencing of the whole kidney highlighted an increase in Lrg1 in glomerular endothelial cells (GECs) in the fructose model, which appeared to drive mesangial fibrosis through enhanced TGF-β1 signaling. Our findings suggest that excessive fructose intake exacerbates diabetic kidney disease progression, mediated by aberrant Lrg1-driven crosstalk between GECs and mesangial cells.

Expanding the therapeutic landscape: ezetimibe as non-statin therapy for dyslipidemia

Dyslipidemia is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD), and statins are the primary therapeutic options for reducing low-density lipoprotein cholesterol (LDL-C) levels. However, it can be challenging to achieve optimal LDL-C goals with statin monotherapy. Ezetimibe, a cholesterol absorption inhibitor, offers a potential non-statin therapy to optimize LDL-C management. Key clinical trials, such as IMPROVE-IT and RACING, have demonstrated that the addition of ezetimibe to statin therapy leads to further decreases in LDL-C or significant decreases in major adverse cardiovascular events (MACEs), particularly in patients with high ASCVD risk. Subsequent meta-analyses and clinical trials have further supported the beneficial effect of ezetimibe, suggesting additive decreases in LDL-C and MACEs, as well as pleiotropic effects. This review provides a comprehensive analysis of the clinical implications of ezetimibe for managing dyslipidemia; it also evaluates the available evidence that supports the role of ezetimibe as an adjunct non-statin therapy for long-term use. However, the long-term pleiotropic effects of ezetimibe remain controversial because of limited clinical data. Therefore, additional research is needed to clarify its potential benefits beyond LDL-C reduction. Nonetheless, an understanding of the role of ezetimibe in dyslipidemia management will help clinicians to develop effective treatment strategies.

HDL-Based Therapy: Vascular Protection at All Stages

It is known that lipid metabolism disorders are involved in a wide range of pathologies. These pathologies include cardiovascular, metabolic, neurodegenerative diseases, and even cancer. All these diseases lead to serious health consequences, which makes it impossible to ignore them. Unfortunately, these diseases most often have a complex pathogenesis, which makes it difficult to study them and, in particular, diagnose and treat them. HDL is an important part of lipid metabolism, performing many functions under normal conditions. One of such functions is the maintaining of the reverse cholesterol transport. These functions are also implicated in pathology development. Thus, HDL contributes to vascular protection, which has been demonstrated in various conditions: Alzheimer’s disease, atherosclerosis, etc. Many studies have shown that serum levels of HDL cholesterol correlate negatively with CV risk. With these data, HDL-C is a promising therapeutic target. In this manuscript, we reviewed HDL-based therapeutic strategies that are currently being used or may be developed soon.

Cholesterol-induced toxicity: An integrated view of the role of cholesterol in multiple diseases

High levels of cholesterol are generally considered to be associated with atherosclerosis. In the past two decades, however, a number of studies have shown that excess cholesterol accumulation in various tissues and organs plays a critical role in the pathogenesis of multiple diseases. Here, we summarize the effects of excess cholesterol on disease pathogenesis, including liver diseases, diabetes, chronic kidney disease, Alzheimer's disease, osteoporosis, osteoarthritis, pituitary-thyroid axis dysfunction, immune disorders, and COVID-19, while proposing that excess cholesterol-induced toxicity is ubiquitous. We believe this concept will help broaden the appreciation of the toxic effect of excess cholesterol, and thus potentially expand the therapeutic use of cholesterol-lowering medications.

Oral delivery of exenatide-loaded hybrid zein nanoparticles for stable blood glucose control and β-cell repair of type 2 diabetes mice

BACKGROUND

Exenatide is an insulinotropic peptide drug for type 2 diabetes treatment with low risk of hypoglycemia, and is administrated by subcutaneous injection. Oral administration is the most preferred route for lifelong treatment of diabetes, but oral delivery of peptide drug remains a significant challenge due to the absorption obstacles in gastrointestinal tract. We aimed to produce exenatide-loaded nanoparticles containing absorption enhancer, protectant and stabilizer using FDA approved inactive ingredients and easy to scale-up method, and to evaluate their long-term oral therapeutic effect in type 2 diabetes db/db mice.

RESULTS

Two types of nanoparticles, named COM NPs and DIS NPs, were fabricated using anti-solvent precipitation method. In COM NPs, the exenatide was complexed with cholic acid and phosphatidylcholine to increase the exenatide loading efficiency. In both nanoparticles, zein acted as the cement and the other ingredients were embedded in zein nanoparticles by hydrophobic interaction. Casein acted as the stabilizer. The nanoparticles had excellent lyophilization, storage and re-dispersion stability. Hypromellose phthalate protected the loaded exenatide from degradation in simulated gastric fluid. Cholic acid promoted the intestinal absorption of the loaded exenatide via bile acid transporters. The exenatide loading efficiencies of COM NPs and DIS NPs were 79.7% and 53.6%, respectively. The exenatide oral pharmacological availability of COM NPs was 18.6% and DIS NPs was 13.1%. COM NPs controlled the blood glucose level of the db/db mice well and the HbA_1c concentration significantly decreased to 6.8% during and after 7 weeks of once daily oral administration consecutively. Both DIS NPs and COM NPs oral groups substantially increased the insulin secretion by more than 60% and promoted the β-cell proliferation by more than 120% after the 7-week administration.

CONCLUSIONS

Both COM NPs and DIS NPs are promising systems for oral delivery of exenatide, and COM NPs are better in blood glucose level control than DIS NPs. Using prolamin to produce multifunctional nanoparticles for oral delivery of peptide drug by hydrophobic interaction is a simple and effective strategy.

Gallium-68: methodology and novel radiotracers for positron emission tomography (2012–2017)

Commercial 68Ge/68Ga generators provide a means to produce positron emission tomography agents on site without use of a cyclotron. This development has led to a rapid growth of academic literature and patents ongallium-68 (68Ga). As 68Ga positron emission tomography agents usually involve a targeting moiety attached to a metal chelator, the development lends itself to the investigation of theragnostic applications; the 68Ga-based diagnostic is utilized to determine if the biological target is present and, if so, a therapeutic isotope (e.g., 177Lu, 225Ac) can be complexed with the same scaffold to generate a corresponding radiotherapeutic. This review considers patents issued between 2012 and 2017 that contain a 68Ga-labeled molecule indexed by Chemical Abstract Services (a division of the American Chemical Society).

Effect of ezetimibe on glycemic control: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Given the increased risk of incident diabetes and the side effects on glycemic control with statin treatment, statin and ezetimibe combination therapy has been widely used. However, whether the same concern exists in ezetimibe remains uncertain. This meta-analysis aimed to investigate the influence of ezetimibe treatment on glycemic control.

METHODS

Articles were searched from PubMed, EMBASE, and Cochrane Library. Randomized controlled trials (RCTs) were included if they compared the effects of ezetimibe with placebo, ezetimibe plus statin with the same statin, or low-dose stain plus ezetimibe with high-dose statin on FBG and glycosylated hemoglobin A1c (HbA1c).

RESULTS

Of the 2440 articles retrieved, 16 RCTs were included. Ezetimibe did not cause side effects on FBG (WMD -0.62, 95% CI: -3.13 to 1.90) and HbA1c (WMD 0.07, 95% CI: -0.07 to 0.20%). No significant changes in FBG (WMD -1.78, 95% CI: -6.33 to 2.77%) and HbA1c (WMD -0.05, 95% CI: -0.14 to 0.05%) were observed in ezetimibe plus low-dose statin treatment compared with high-dose statin. According to subgroup analysis, in comparison with high-dose statin, ezetimibe plus low-dose statin taken for more than 3 months showed a significant decrease in FBG (WMD -7.12, 95% CI: -13.86 to -0.38%) compared with that taken for less than 3 months (WMD 0.90, 95% CI: -2.91 to 4.71%). Nevertheless, this difference was invalid when the study conducted by Dagli et al. was removed.

CONCLUSIONS

Compared with high-dose statin therapy, ezetimibe with low-dose statin for more than 3 months may have a beneficial tendency of effects on glycemic control.

Anti-diabetic Effect of Punica granatum Flower Polyphenols Extract in Type 2 Diabetic Rats: Activation of Akt/GSK-3β and Inhibition of IRE1α-XBP1 Pathways

Type 2 diabetes mellitus (T2DM) is the most common type of diabetes with more than hundreds of millions of patients worldwide. However, the medicines for treatment of T2DM are very limited. In China, Punica granatum L. flower (PGF) has been used as an anti-diabetic herb in the herbal medicine. The activity involves in improvement of insulin sensitivity. However, the underlying mechanism of action is elusive. The current study was designed to address this issue by investigating the effect of polyphenols extract of PGF in diabetic rats. A rat model was orally administrated with PGF polyphenols extract at doses of 50 and 100 mg/kg for 4 weeks. Insulin sensitivity was improved as indicated by oral glucose tolerance test (OGTT), insulin tolerance test (ITT) and homeostasis model assessment of insulin resistance (HOMA-IR). At the molecular level, insulin signaling activity was improved with an elevation in insulin-stimulated phosphorylation of insulin receptor substrate (IRS-1), Akt and GSK-3β. Endoplasmic reticulum (ER) stress signals including phosphorylation of inositol-requiring kinase1 (IRE1) and activation of X box binding protein (XBP-1) splicing were decreased by the PGF treatment. Expressions of IRE1α, XBPs, and CHOP were all decreased by PGF. Blood lipid profile, liver glycogen content and antioxidant status were improved by PGF in the rats. The observations suggest that PGF is able to lower glucose levels in T2DM rats by improving the insulin resistance. The mechanism is likely related to the activation of Akt-GSK3β signaling pathway and inhibition of ER stress.

The Glucotoxicity Protecting Effect of Ezetimibe in Pancreatic Beta Cells via Inhibition of CD36

Inhibition of CD36, a fatty acid transporter, has been reported to prevent glucotoxicity and ameliorate high glucose induced beta cell dysfunction. Ezetimibe is a selective cholesterol absorption inhibitor that blocks Niemann Pick C1-like 1 protein, but may exert its effect through suppression of CD36. We attempted to clarify the beneficial effect of ezetimibe on insulin secreting cells and to determine whether this effect is related to change of CD36 expression. mRNA expression of insulin and CD36, intracellular peroxide level and glucose stimulated insulin secretion (GSIS) under normal (5.6 mM) or high glucose (30 mM) condition in INS-1 cells and primary rat islet cells were compared. Changes of the aforementioned factors with treatment with ezetimibe (20 μM) under normal or high glucose condition were also assessed. mRNA expression of insulin was decreased with high glucose, which was reversed by ezetimibe in both INS-1 cells and primary rat islets. CD36 mRNA expression was increased with high glucose, but decreased by ezetimibe in INS-1 cells and primary rat islets. Three-day treatment with high glucose resulted in an increase in intracellular peroxide level; however, it was decreased by treatment with ezetimibe. Decrease in GSIS by three-day treatment with high glucose was reversed by ezetimibe. Palmitate uptake following exposure to high glucose conditions for three days was significantly elevated, which was reversed by ezetimibe in INS-1 cells. Ezetimibe may prevent glucotoxicity in pancreatic β-cells through a decrease in fatty acid influx via inhibition of CD36.

Ezetimibe/statin combination therapy to treat patients with type 2 diabetes

Patients with diabetes represent a population at higher risk for cardiovascular disease. Diabetic dyslipidemia is characterized by the so-called atherogenic lipid triad, consisting of an increase in small dense low density lipoprotein particles and in triglyceride-rich lipoproteins, and a decrease in high-density lipoprotein cholesterol, with an increase in non-HDL cholesterol. Numerous trials have investigated the efficacy of add-on ezetimibe therapy for patients with type 2 diabetes and not controlled by statin therapy. The published data highly suggest that patients with type 2 diabetes may be more likely to benefit from ezetimibe/statin combination therapy. However, evidence specifically addressing hard clinical endpoints and prospective trials addressing differences in response between patients with or without diabetes are still needed.

A randomized, double-blind, placebo-controlled study of the effect of ezetimibe on glucose metabolism in subjects with type 2 diabetes mellitus and hypercholesterolemia

Background

Recent evidence points to an increased incidence of new-onset diabetes and a negative impact on glucose parameters with statin use. This study examined the safety of ezetimibe vs placebo for change from baseline to week 24 in HbA1c (primary endpoint), glycoalbumin, and fasting plasma glucose (secondary endpoints) in Japanese subjects with type 2 diabetes and hypercholesterolemia.

Methods

This was a randomized, double-blind, placebo-controlled, parallel-group, multi-site trial. Adults with type 2 diabetes and hypercholesterolemia whose LDL-C measured <140 mg/dl (subjects receiving lipid-lowering drugs) or <160 mg/dl (subjects not receiving lipid-lowering drugs) at the start of the screening phase, were randomized after a 5-week wash-out period to ezetimibe 10 mg or placebo (1:1) for 24 weeks. Changes in HbA1c, glycoalbumin and fasting plasma glucose from baseline to week 24 were evaluated. The non-inferiority margin was set at 0.5% for HbA1c.

Results

Overall, 152 subjects were randomized (75 to ezetimibe and 77 to placebo). From baseline to 24 weeks, HbA1c significantly increased in both the ezetimibe and placebo groups (between-treatment difference 0.08 [95% CI: −0.07 to 0.23]). Ezetimibe was statistically non-inferior to placebo. At 24 weeks, the mean change from baseline in glycoalbumin levels (between-treatment differences 0.00 [95% CI: −0.47, 0.47]) and fasting plasma glucose (between-treatment differences −4.8 [95% CI: −12.1, 2.1]) were similar in both treatment groups.

Conclusions

These results suggest that ezetimibe 10 mg does not result in dysregulation of glucose metabolism in Japanese patients with type 2 diabetes and hypercholesterolemia over 24 weeks of treatment.

Trial registration

ClinicalTrials.gov identifier NCT01611883.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0036-z) contains supplementary material, which is available to authorized users.