Quercetin improves myocardial redox status in rats with type 2 diabetes

Role of Quercetin in Diabetic Cardiomyopathy

Diabetic cardiomyopathy is a significant and severe complication of diabetes that affects a large portion of the global population, with its prevalence continuing to rise. Secondary metabolites, including quercetin, have shown promising effects in mitigating the progression of diabetic cardiomyopathy by targeting multiple pathological mechanisms, including impaired insulin signaling, glucotoxicity, lipotoxicity, oxidative stress, inflammation, fibrosis, apoptosis, autophagy, mitochondrial dysfunction, cardiac stiffness, and disrupted calcium handling. Addressing these mechanisms is crucial to prevent left ventricular diastolic and systolic dysfunction in advanced stages of diabetic heart disease. Scientific evidence has highlighted the cardioprotective properties of quercetin at both the myocardial and cellular/molecular levels in diabetic models. Therefore, this review aims to present a comprehensive overview of the proposed mechanisms underlying quercetin's beneficial effects, providing valuable insights that could inform future drug discovery efforts specific to diabetic cardiomyopathy.

Identification of key pathways and mRNAs in interstitial cystitis/bladder pain syndrome treatment with quercetin through bioinformatics analysis of mRNA-sequence data

BACKGROUND

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition with painful bladder. At present, the pathogenesis of IC/BPS is still unknown. Quercetin (QCT) is a kind of natural flavonoid with wide sources and multiple biological activities. The purpose of this study was to explore the effects of QCT on mRNA expression and related regulatory signal pathways in IC model rats.

METHODS

LL-37 was used to induce the IC/BPS model rats. 20 mg/kg QCT was injected intraperitoneally into IC/BPS rats. ELISA, HE, Masson and TB staining were used to evaluate the level of inflammation and pathology. The concentration of QCT in rats was detected by HPLC. The mRNA sequencing was used to detect the differentially expressed (DE) mRNA in each group. The over-expression experiment of Lpl was carried out in IC/BPS model rats.

RESULTS

QCT treatment significantly decreased the level of MPO, IL-1β, IL-6 and TNF-α induced by LL-37 in rats, and alleviated bladder injury and mast cell degranulation. There were significant differences in mRNA sequencing data between groups, and the hub gene Lpl were screened by Cytohubba. The expression of Lpl was downregulated in IC/BPS rats. QCT intervention promoted Lpl expression. Overexpression of Lpl reduced the bladder injury induced by LL-37, increased GAG level and decreased the expression of MPO, IL-1β, IL-6 and TNF-α.

CONCLUSION

In this study, we provided the DE mRNA in IC/BPS rats treated with QCT, the signaling pathways for DE enrichment, screened out the hub genes, and revealed that Lpl overexpression alleviated IC/BPS model rats.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatment of diabetes and its complications: An update since 2010

Diabetes, characterized as a well-known chronic metabolic syndrome, with its associated complications pose a substantial and escalating health and healthcare challenge on a global scale. Current strategies addressing diabetes are mainly symptomatic and there are fewer available curative pharmaceuticals for diabetic complications. Thus, there is an urgent need to identify novel pharmacological targets and agents. The impaired mitochondria have been associated with the etiology of diabetes and its complications, and the intervention of mitochondrial dysfunction represents an attractive breakthrough point for the treatments of diabetes and its complications. Natural products (NPs), with multicenter characteristics, multi-pharmacological activities and lower toxicity, have been caught attentions as the modulators of mitochondrial functions in the therapeutical filed of diabetes and its complications. This review mainly summarizes the recent progresses on the potential of 39 NPs and 2 plant-extracted mixtures to improve mitochondrial dysfunction against diabetes and its complications. It is expected that this work may be useful to accelerate the development of innovative drugs originated from NPs and improve upcoming therapeutics in diabetes and its complications.

Molecular targets and mechanisms of Jiawei Jiaotai Pill on diabetic cardiomyopathy based on network pharmacology

BACKGROUND

Jiawei Jiaotai Pill is commonly used in clinical practice to reduce apoptosis, increase insulin secretion, and improve blood glucose tolerance. However, its mechanism of action in the treatment of diabetic cardiomyopathy (DCM) remains unclear, hindering research efforts aimed at developing drugs specifically for the treatment of DCM.

AIM

To explore the pharmacodynamic basis and molecular mechanism of Jiawei Jiaotai Pill in DCM treatment.

METHODS

We explored various databases and software, including the Traditional Chinese Medicine Systems Pharmacology Database, Uniport, PubChem, GenCards, String, and Cytoscape, to identify the active components and targets of Jiawei Jiaotai Pill, and the disease targets in DCM. Protein-protein interaction network, gene ontology, and Kyoto Encyclopedia of Genes and Genomes analyses were used to determine the mechanism of action of Jiawei Jiaotai Pill in treating DCM. Molecular docking of key active components and core targets was verified using AutoDock software.

RESULTS

Total 42 active ingredients and 142 potential targets of Jiawei Jiaotai Pill were identified. There were 100 common targets between the DCM and Jiawei Jiaotai Pills. Through this screening process, TNF, IL6, TP53, EGFR, INS, and other important targets were identified. These targets are mainly involved in the positive regulation of the mitogen-activated protein kinase (MAPK) MAPK cascade, response to xenobiotic stimuli, response to hypoxia, positive regulation of gene expression, positive regulation of cell proliferation, negative regulation of the apoptotic process, and other biological processes. It was mainly enriched in the AGE-RAGE signaling pathway in diabetic complications, DCM, PI3K-Akt, interleukin-17, and MAPK signaling pathways. Molecular docking results showed that Jiawei Jiaotai Pill's active ingredients had good docking activity with DCM's core target.

CONCLUSION

The active components of Jiawei Jiaotai Pill may play a role in the treatment of DCM by reducing oxidative stress, cardiomyocyte apoptosis and fibrosis, and maintaining metabolic homeostasis.

A Descriptive Review of the Action Mechanisms of Berberine, Quercetin and Silymarin on Insulin Resistance/Hyperinsulinemia and Cardiovascular Prevention

Insulin resistance (IR) and the associated hyperinsulinemia are early pathophysiological changes which, if not well treated, can lead to type 2 diabetes, endothelial dysfunction and cardiovascular disease. While diabetes care is fairly well standardized, the prevention and treatment of IR lacks a single pharmaceutical approach and many lifestyle and dietary interventions have been proposed, including a wide range of food supplements. Among the most interesting and well-known natural remedies, alkaloid berberine and the flavonol quercetin have particular relevance in the literature, while silymarin-the active principle of the Silybum marianum thistle-was traditionally used for lipid metabolism disorders and to sustain liver function. This review describes the major defects of insulin signaling leading to IR and the main properties of the three mentioned natural substances, their molecular targets and synergistic action mechanisms. The actions of berberine, quercetin and silymarin are partially superimposable as remedies against reactive oxygen intermediates generated by a high-lipid diet and by NADPH oxidase, which is triggered by phagocyte activation. Furthermore, these compounds inhibit the secretion of a battery of pro-inflammatory cytokines, modulate intestinal microbiota and are especially able to control the various disorders of the insulin receptor and post-receptor signaling systems. Although most of the evidence on the effects of berberine, quercetin and silymarin in modulating insulin resistance and preventing cardiovascular disease derive from experimental studies on animals, the amount of pre-clinical knowledge strongly suggests the need to investigate the therapeutic potential of these substances in human pathology.

Flavonoids improve type 2 diabetes mellitus and its complications: a review

The prevalence of type 2 diabetes mellitus (T2DM) is increasing every year. Medications are currently the most common therapy for T2DM. However, these medications have certain adverse effects. In order to find safe and effective ways to improve this disease, researchers have discovered that some natural products can decrease blood sugar. Flavonoids are one of the most essential low molecular weight phenolic chemicals in the plant world, which widely exist in plant roots, stems, leaves, flowers, and fruits. They possess a variety of biological activities, including organ protection, hypoglycemic, lipid-lowering, anti-oxidative and anti-inflammatory effects. Some natural flavonoids ameliorate T2DM and its complications through anti-oxidation, anti-inflammatory action, glucose and lipid metabolism regulation, insulin resistance management, etc. Hence, this review aims at demonstrating the potential benefits of flavonoids in T2DM and its complications. This laid the foundation for the development of novel hypoglycemic medications from flavonoids.

Quercetin ameliorates oxidative stress‑induced cell apoptosis of seminal vesicles via activating Nrf2 in type 1 diabetic rats

It was known that diabetes may affect the male reproductive function by inhibiting the secretion of male accessory glands including seminal vesicles. Increased cell apoptosis induced by oxidative stress is thought to be an important pathological change in the seminal vesicles in diabetic patients. Quercetin is a potent anti-oxidative bioflavonoid. In this study, we explore the effect of quercetin on cell apoptosis of seminal vesicles and its underlying mechanism. The STZ-induced type 1 diabetic rat model was established. Three doses (low, medium and high) of quercetin were administrated to the STZ-induced type 1 diabetic rats for 4 months. Fasting blood glucose, the fructose in seminal plasma, total antioxidant capacity (T-AOC) and malondialdehyde (MDA) in seminal vesicles were determined by colorimetric method. Nuclear transcription factor- Nrf2 was observed by immunofluorescent staining. Biomarkers related to cell apoptosis, such as Bcl-2, Bax and cleaved -Caspase3 were measured by Western blotting and immumohistochemical staining. The body weight and seminal vesicle weight indexes were also determined. The results showed that T-AOC and Nrf2 were decreased, the levels of MDA were increased, the cleaved Caspase-3 was increased and the ratio of Bax to BCL-2 was decreased in seminal vesicles of diabetic rats, along with the severe hyperglycemia. When diabetic rats were treated by quercetin for 4 months, all the indexes were reversed at different degree except the fasting blood glucose. Our results suggested that quercetin could ameliorate oxidative stress‑induced cell apoptosis of seminal vesicles via inhibiting Nrf2 in type 1 diabetic rats, which indicated that quercetin could be used for preventing lesions of seminal vesicles in type 1 diabetes.