Fisetin Attenuates Metabolic Dysfunction in Mice Challenged with a High-Fructose Diet

The protective effects of fisetin in metabolic disorders: a focus on oxidative stress and associated events

Abstract

Metabolic syndrome is increasingly recognized as a significant precursor to various chronic diseases, contributing to a growing public health concern. Its complex pathogenesis involves multiple interrelated mechanisms, with oxidative stress identified as a cornerstone that exacerbates other pathogenic pathways. This study elucidates the molecular mechanisms by which oxidative stress intensifies metabolic disturbances, particularly insulin resistance. Some recent research has focused on fisetin, a natural product known for its potential benefits in diabetes and its associated microvascular and macrovascular complications. This paper compiles a comprehensive collection of findings by reviewing studies conducted over the past decade, detailing dosages, investigated markers, and their respective outcomes. Notably, a recurrent finding was fisetin's ability to enhance Nrf2, a principal regulator of antioxidant defense, in both metabolic and non-metabolic diseases. Furthermore, intriguing results suggest that the effects of Nrf2 extend beyond oxidative stress modulation, demonstrating favorable impacts on tissue-specific functions in metabolic regulation. This highlights fisetin not only as an antioxidant but also as a potential therapeutic agent for improving metabolic health and mitigating the effects of metabolic syndrome. In conclusion, fisetin can enhance the body's antioxidant defenses by modulating the Nrf2 pathway while also improving metabolic health through its effects on inflammation, cell survival, and energy metabolism, offering a comprehensive approach to managing metabolic disorders.

Graphical Abstract

Polysaccharide-mediated modulation of gut microbiota in the treatment of liver diseases: Promising approach with significant challenges

Liver disease represents a significant global health burden, with an increasing prevalence and a lack of efficient treatment options. The microbiota-gut-liver axis involves bidirectional communication between liver function and intestinal microorganisms. A balanced gut flora protects intestinal homeostasis, while imbalances contribute to the development of liver diseases. Distinct alterations in the structure of gut flora during illness are crucial in the management of various liver diseases. Polysaccharides derived from herbal products, fungi, and other sources have been identified to possess diverse biological activities and are well-tolerated in the treatment of liver diseases. This review provides updates on the therapeutic effects of polysaccharides on liver diseases, including fatty liver diseases, acute liver injuries and liver cancers. It also summarizes advancements in understanding the mechanisms involved, particularly from the perspective of gut microbiota and metabolites, by highlighting the changes in the composition of potentially beneficial and harmful bacteria and their correlation with the therapeutic effects of polysaccharides. Additionally, by exploring the structure-activity relationship, our review provides valuable insights for the structural modification of polysaccharides and expanding their applications. In conclusion, this review offers theoretical support and novel perspectives on developing polysaccharides-based therapeutic approaches for the treatment of liver diseases.

The flavonoid fisetin reduces multiple physiological risk factors for dementia

Dementia is a growing problem around the globe as the world's population continues to age. Multiple studies have identified potentially modifiable risk factors for the development of dementia suggesting that addressing some or all of these risk factors might have a significant impact on the aging population worldwide. However, this is not always as straightforward as it seems since many of these risk factors are currently treated with drugs specific to the risk factor. Moreover, since people can have multiple risk factors, addressing each of them individually could be highly problematic as it would likely lead to negative outcomes associated with polypharmacy and, in the long term, could do significant harm. A potential alternative is to identify compounds that have shown efficacy against a number of these different risk factors. As discussed in this review, there is strong evidence that the flavonol fisetin is one such compound. In animal studies it has shown efficacy against many of the risk factors that have been associated with an increased risk of developing dementia and also exhibits direct neuroprotective effects. Thus, further human research on fisetin in the context of dementia risk factors is clearly warranted.

Regulation of Fructose Metabolism in Nonalcoholic Fatty Liver Disease

Elevations in fructose consumption have been reported to contribute significantly to an increased incidence of obesity and metabolic diseases in industrial countries. Mechanistically, a high fructose intake leads to the dysregulation of glucose, triglyceride, and cholesterol metabolism in the liver, and causes elevations in inflammation and drives the progression of nonalcoholic fatty liver disease (NAFLD). A high fructose consumption is considered to be toxic to the body, and there are ongoing measures to develop pharmaceutical therapies targeting fructose metabolism. Although a large amount of work has summarized the effects fructose exposure within the intestine, liver, and kidney, there remains a gap in our knowledge regarding how fructose both indirectly and directly influences immune cell recruitment, activation, and function in metabolic tissues, which are essential to tissue and systemic inflammation. The most recent literature demonstrates that direct fructose exposure regulates oxidative metabolism in macrophages, leading to inflammation. The present review highlights (1) the mechanisms by which fructose metabolism impacts crosstalk between tissues, nonparenchymal cells, microbes, and immune cells; (2) the direct impact of fructose on immune cell metabolism and function; and (3) therapeutic targets of fructose metabolism to treat NAFLD. In addition, the review highlights how fructose disrupts liver tissue homeostasis and identifies new therapeutic targets for treating NAFLD and obesity.

Exploring the underlying mechanisms of fisetin in the treatment of hepatic insulin resistance via network pharmacology and in vitro validation

OBJECTIVE

To characterize potential mechanisms of fisetin on hepatic insulin resistance (IR) using network pharmacology and in vitro validation.

METHODS

Putative targets of fisetin were retrieved from the Traditional Chinese Medicine Systems Pharmacology database, whereas the potential genes of hepatic IR were obtained from GeneCards database. A protein-protein interaction (PPI) network was constructed according to the intersection targets of fisetin and hepatic IR using the Venn diagram. The biological functions and potential pathways related to genes were determined using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Cell experiments were also conducted to further verify the mechanism of fisetin on hepatic IR.

RESULTS

A total of 118 potential targets from fisetin were associated with hepatic IR. The areas of nodes and corresponding degree values of TP53, AKT1, TNF, IL6, CASP3, CTNNB1, JUN, SRC, epidermal growth factor receptor (EGFR), and HSP90AA1 were larger and could be easily found in the PPI network. Furthermore, GO analysis revealed that these key targets were significantly involved in multiple biological processes that participated in oxidative stress and serine/threonine kinase activity. KEGG enrichment analysis showed that the PI3K/AKT signaling pathway was a significant pathway involved in hepatic IR. Our in vitro results demonstrated that fisetin treatment increased the expressions of EGFR and IRS in HepG2 and L02 cells under normal or IR conditions. Western blot results revealed that p-AKT/AKT levels were significantly up-regulated, suggesting that fisetin was involved in the PI3K/AKT signaling pathway to regulate insulin signaling.

CONCLUSION

We explored the pharmacological actions and the potential molecular mechanism of fisetin in treating hepatic IR from a holistic perspective. Our study lays a theoretical foundation for the development of fisetin for type 2 diabetes.

Biological effects and mechanisms of fisetin in cancer: a promising anti-cancer agent

Fisetin, a natural flavonoid, possesses numerous biological activities that have been extensively studied in various diseases. When it comes to cancer, fisetin exhibits a range of biological effects, such as suppressing cell growth, triggering programmed cell death, reducing the formation of new blood vessels, protecting against oxidative stress, and inhibiting cell migration. Moreover, fisetin has the ability to enhance the effectiveness of chemotherapy. The anticancer properties of fisetin can be attributed to a diverse array of molecules and signaling pathways, including vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), PI3K/Akt/mTOR, and Nrf2/HO-1. Consequently, fisetin holds promise as a therapeutic agent for anticancer treatment. In this review, we place emphasis on the biological functions and various molecular targets of fisetin in anticancer therapy.

Fisetin, a Natural Polyphenol, Ameliorates Endometriosis Modulating Mast Cells Derived NLRP-3 Inflammasome Pathway and Oxidative Stress

A chronic, painful, and inflammatory condition known as endometriosis is defined by the extra-uterine development of endometrial tissue. The aim of this study was to evaluate the beneficial effects of fisetin, a naturally occurring polyphenol that is frequently present in a variety of fruits and vegetables. Uterine fragments were injected intraperitoneally to cause endometriosis, and fisetin was given orally every day. At 14 days of treatment, laparotomy was performed, and the endometrial implants and peritoneal fluids were collected for histological, biochemical, and molecular analyses. Rats subjected to endometriosis presented important macroscopic and microscopic changes, increased mast cell (MC) infiltration, and fibrosis. Fisetin treatment reduced endometriotic implant area, diameter, and volumes, as well as histological alterations, neutrophil infiltration, cytokines release, the number of MCs together with the expression of chymase and tryptase, and diminished α smooth muscle actin (α-sma) and transforming growth factor beta (TGF β) expressions. In addition, fisetin was able to reduce markers of oxidative stress as well as nitrotyrosine and Poly ADP ribose expressions and increase apoptosis in endometrial lesions. In conclusion, fisetin could represent a new therapeutic strategy to control endometriosis perhaps by targeting the MC-derived NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathway and oxidative stress.

Endoplasmic reticulum as a target in cardiovascular diseases: Is there a role for flavonoids?

Flavonoids are found in natural health products and plant-based foods. The flavonoid molecules contain a 15-carbon skeleton with the particular structural construction of subclasses. The most flavonoid's critical subclasses with improved health properties are the catechins or flavonols (e.g., epigallocatechin 3-gallate from green tea), the flavones (e.g., apigenin from celery), the flavanones (e.g., naringenin from citrus), the flavanols (e.g., quercetin glycosides from berries, onion, and apples), the isoflavones (e.g., genistein from soya beans) and the anthocyanins (e.g., cyanidin-3-O-glucoside from berries). Scientific data conclusively demonstrates that frequent intake of efficient amounts of dietary flavonoids decreases chronic inflammation and the chance of oxidative stress expressing the pathogenesis of human diseases like cardiovascular diseases (CVDs). The endoplasmic reticulum (ER) is a critical organelle that plays a role in protein folding, post-transcriptional conversion, and transportation, which plays a critical part in maintaining cell homeostasis. Various stimuli can lead to the creation of unfolded or misfolded proteins in the endoplasmic reticulum and then arise in endoplasmic reticulum stress. Constant endoplasmic reticulum stress triggers unfolded protein response (UPR), which ultimately causes apoptosis. Research has shown that endoplasmic reticulum stress plays a critical part in the pathogenesis of several cardiovascular diseases, including diabetic cardiomyopathy, ischemic heart disease, heart failure, aortic aneurysm, and hypertension. Endoplasmic reticulum stress could be one of the crucial points in treating multiple cardiovascular diseases. In this review, we summarized findings on flavonoids' effects on the endoplasmic reticulum and their role in the prevention and treatment of cardiovascular diseases.

Recent advances in potential of Fisetin in the management of myocardial ischemia-reperfusion injury-A systematic review

BACKGROUND

The primary therapeutic strategy in managing ischemic heart diseases is to restore the perfusion of the myocardial ischemic area by surgical methods that often result in an unavoidable injury called ischemia-reperfusion injury (IR). Fisetin is an effective flavonoid with antioxidant and anti-inflammatory properties, proven to be cardioprotective against IR injury in both in-vitro and invivo models, apart from its promising health benefits against cancer, diabetes, and neurodegenerative ailments.

PURPOSE

The potential of fisetin in attenuating myocardial IR is inconclusive as the effectiveness of fisetin needs more understanding in terms of its possible target sites and underlying different mechanisms. Considering the surge in recent scientific interests in fisetin as a pharmacological agent, this review not only updates the existing preclinical and clinical studies with fisetin and its underlying mechanisms but also summarizes its possible targets during IR protection.

METHODS

We performed a literature survey using search engines Pubmed, PMC, Science direct, Google, and research gate published across the years 2006-2021. The relevant studies were extracted from the databases with the combinations of the following keywords and summarized: myocardial ischemia-reperfusion injury, natural products, flavonoid, fisetin, PI3K, JAK-STAT, Nrf2, PKC, JNK, autophagy.

RESULTS

Fisetin is reported to be effective in attenuating IR injury by delaying the clotting time, preserving the mitochondrial function, reducing oxidative stress, and inhibiting GSK 3β. But it failed to protect diseased cardiomyocytes challenged to IR. As discussed in the current review, fisetin not only acts as a conventional antioxidant and anti-inflammatory agent to exert its biological effect but may also exert modulatory action on the cellular metabolism and adaptation via direct action on various signalling pathways that comprise PI3K, JAK-STAT, Nrf2, PKC, JNK, and autophagy. Moreover, the dosage of fisetin and co-morbidities like diabetes and obesity are found to be detrimental factors for cardioprotection.

CONCLUSION

For further evaluation and smooth clinical translation of the fisetin molecule in IR treatment, researchers should pay close attention to the potential of fisetin to possibly alter the key cardioprotective pathways and dosage, as the efficacy of fisetin is tissue and cell type-specific and varies with different doses.

Malus toringoides (Rehd.) Hughes improves glucose and lipid metabolism and liver injury in high fructose-induced mice

Malus toringoides (Rehd.) Hughes, as a traditional medicinal and edible plant used in Tibet, China, is used to treat hypertension, hyperlipidemia, and liver diseases. In recent decades, excessive fructose intake with diet has greatly increased the occurrence of a series of metabolic diseases including obesity, insulin resistance, hypertension, and hyperlipidemia. The present study was designed to investigate the effects of an ethanol extract of M. toringoides (EMT) on glucose and lipid metabolism and liver injury in high fructose-induced mice. The C57BL/6J male mice were orally administrated with 30% fructose solution for 8 weeks, and EMT was given orally for another 8 weeks. The level of liver lipids related parameters, hepatic oxidative stress, and inflammatory mediators was detected by the kits. The improving effects of EMT on liver injury and lipid accumulation of mice were observed by hematoxylin and eosin staining and Oil Red O staining. In vitro, the hypolipidemic effect of EMT on palmitic acid-induced HepG2 cells was detected by the kits and Oil Red O staining. Our results showed that EMT has the hypolipidemic effect in vivo and in vitro, and can improve liver injury caused by fructose intake though ameliorating oxidative stress and inflammatory responses. Thus, we suggested that EMT may be a candidate therapeutic agent to improve a series of metabolic diseases including obesity, insulin resistance, and hyperlipidemia. PRACTICAL APPLICATIONS: Our study was aimed to find a novel candidate drug for liver diseases using natural products. We assessed the protective effects of Malus toringoides (Rehd.) Hughes in the pathogenesis of glucose and lipid metabolism. In vivo, the plant significantly improved the disorder of blood lipid and blood glucose, and liver injury in mice induced by fructose, and in vitro, this plant significantly improved the lipid accumulation of HepG2 cells induced by palmitic acid. To sum up, our studies suggested that the plant may be beneficial in the prevention and management of diet-induced abnormal glucose and lipid metabolism and liver diseases. Therefore, it will be a candidate therapeutic agent to improve liver diseases.

Dietary Phytochemicals that Can Extend Longevity by Regulation of Metabolism

Diet provides energy and nutrition for human survival, and also provides various joy of taste. Extensive studies have shown that the major components of diet, such as protein, carbohydrate and fat, play important roles in regulating aging and longevity. Whether other dietary ingredients can help prevent aging and extend longevity is a very interesting question. Here based on recent findings, we discussed dietary plant ingredients that can extend longevity by regulation of metabolism, targeting TRP channels, mitophagy, senescence pathways and circadian rhythms. Better understanding of the detailed effects and mechanisms of dietary ingredients on longevity regulation, would be helpful for developing new intervention tools for preventing aging and aging related diseases.

Ameliorative effects of fisetin in letrozole-induced rat model of polycystic ovary syndrome

BACKGROUND

The present study was conducted to investigate the therapeutic effects of a potent polyphenol, fisetin, on the letrozole-induced rat model of polycystic ovary syndrome (PCOS).

METHODOLOGY

Twenty-four female Wistar rats (42 days old) were divided into four groups: control group (received carboxy methylcellulose (CMC 0.5 %)), PCOS group treated with letrozole (1 mg/kg), fisetin group received same dose of letrozole + fisetin (10 mg/kg), and metformin group received same dose of letrozole + metformin (300 mg/kg). At the end of the experiment, biochemical (glucose, lipid profile) and hormonal (insulin, testosterone, estradiol, and progesterone) parameters were analyzed. Histological examinations of ovaries were also conducted by hematoxylin and eosin (H&E) staining. Real-time polymerase chain reaction (PCR) and western blotting were carried out for cytochrome P450 17A1 (CYP17A1), sirtuin-1 (SIRT1), and 5' AMP-activated protein kinase (AMPK) gene expression in the ovaries. Furthermore, enzymatic activities of antioxidants including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the ovaries were analyzed by colorimetric method.

RESULTS

Letrozole administration resulted in a remarkable abnormality in biochemical and hormonal parameters. Fisetin normalized levels of glucose, lipid profile, homeostatic model assessment for insulin resistance (HOMA-IR), testosterone, estradiol, and progesterone. Moreover, fisetin increased expression levels of SIRT1 and AMPK, and decreased expression level of CYP17A1 in the ovaries. Additionally, fisetin showed protective effect by enhancing antioxidant activities of CAT, SOD, and GPx depleted secondary to induction of PCOS. Fisetin effects were comparable to metformin, as the standard drug used for treatment of PCOS.

CONCLUSION

Our results showed that, fisetin treatment caused significant alleviating effects by restoring PCOS-induced alterations in the key genes involved in energy homeostasis and antioxidant enzymes, suggesting that it may have a key role in combating with PCOS.

Nanoformulation Development to Improve the Biopharmaceutical Properties of Fisetin Using Design of Experiment Approach

This study aimed to design an effective nanoparticle-based carrier for the oral delivery of fisetin (FST) with improved biopharmaceutical properties. FST-loaded nanoparticles were prepared with polyvinyl alcohol (PVA) and poly(lactic-co-glycolic acid) (PLGA) by the interfacial deposition method. A central composite design of two independent variables, the concentration of PVA and the amount of PLGA, was applied for the optimization of the preparative parameter. The responses, including average particle size, polydispersity index, encapsulation efficiency, and zeta potential, were assessed. The optimized formulation possessed a mean particle size of 187.9 nm, the polydispersity index of 0.121, encapsulation efficiency of 79.3%, and zeta potential of −29.2 mV. The morphological observation demonstrated a globular shape for particles. Differential scanning calorimetry and powder X-ray diffraction studies confirmed that the encapsulated FST was presented as the amorphous state. The dissolution test indicated a 3.06-fold increase for the accumulating concentrations, and the everted gut sac test showed a 4.9-fold gain for permeability at the duodenum region. In conclusion, the optimized FST-loaded nanoparticle formulation in this work can be developed as an efficient oral delivery system of FST to improve its biopharmaceutic properties.

Fisetin inhibits lipopolysaccharide-induced inflammatory response by activating β-catenin, leading to a decrease in endotoxic shock

Fisetin is a naturally occurring flavonoid that possesses several pharmacological benefits including anti-inflammatory activity. However, its precise anti-inflammatory mechanism is not clear. In the present study, we found that fisetin significantly inhibited the expression of proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2), and cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Additionally, fisetin attenuated LPS-induced mortality and abnormalities in zebrafish larvae and normalized the heart rate. Fisetin decreased the recruitment of macrophages and neutrophils to the LPS-microinjected inflammatory site in zebrafish larvae, concomitant with a significant downregulation of proinflammatory genes, such as inducible NO synthase (iNOS), cyclooxygenase-2a (COX-2a), IL-6, and TNF-α. Fisetin inhibited the nuclear localization of nuclear factor-kappa B (NF-κB), which reduced the expression of pro-inflammatory genes. Further, fisetin inactivated glycogen synthase kinase 3β (GSK-3β) via phosphorylation at Ser9, and inhibited the degradation of β-catenin, which consequently promoted the localization of β-catenin into the nucleus. The pharmacological inhibition of β-catenin with FH535 reversed the fisetin-induced anti-inflammatory activity and restored NF-κB activity, which indicated that fisetin-mediated activation of β-catenin results in the inhibition of LPS-induced NF-κB activity. In LPS-microinjected zebrafish larvae, FH535 promoted the migration of macrophages to the yolk sac and decreased resident neutrophil counts in the posterior blood island and induced high expression of iNOS and COX-2a, which was accompanied by the inhibition of fisetin-induced anti-inflammatory activity. Altogether, the current study confirmed that the dietary flavonoid, fisetin, inhibited LPS-induced inflammation and endotoxic shock through crosstalk between GSK-3β/β-catenin and the NF-κB signaling pathways.

Natural Aldose Reductase Inhibitor: A Potential Therapeutic Agent for Non-alcoholic Fatty Liver Disease

Aldose reductase (AR) has been reported to be involved in the development of nonalcoholic fatty liver disease (NAFLD). Hepatic AR is induced under hyperglycemia condition and converts excess glucose to lipogenic fructose, which contributes in part to the accumulation of fat in the liver cells of diabetes rodents. In addition, the hyperglycemia-induced AR or nutrition-induced AR causes suppression of the transcriptional activity of peroxisome proliferator-activated receptor (PPAR) α and reduced lipolysis in the liver, which also contribute to the development of NAFLD. Moreover, AR induction in non-alcoholic steatohepatitis (NASH) may aggravate oxidative stress and the expression of inflammatory cytokines in the liver. Here, we summarize the knowledge on AR inhibitors of plant origin and review the effect of some plant-derived AR inhibitors on NAFLD/NASH in rodents. Natural AR inhibitors may improve NAFLD at least in part through attenuating oxidative stress and inflammatory cytokine expression. Some of the natural AR inhibitors have been reported to attenuate hepatic steatosis through the regulation of PPARα-mediated fatty acid oxidation. In this review, we propose that the natural AR inhibitors are potential therapeutic agents for NAFLD.

Mood disorders are associated with the reduction of brain derived neurotrophic factor in the hypocampus in rats submitted to the hipercaloric diet

Adipose tissue accumulation, resulting from the consumption of hypercaloric foods, can cause a dysfunction of the endocrine system. Such endocrine changes can influence the expression of various neurochemicals including brain-derived neurotrophic factor (BDNF) - associated with cognitive and emotional problems. Here, we investigated the effects of a hypercaloric diet on depression- and anxiety-like behaviors in young rats along with concomitant changes in BDNF expression levels in the hippocampus. Eight week-old Wistar rats (n = 20) were divided in: control diet (CD) group which received industrial food (n = 8) and hypercaloric diet (HD) group which received animal fat and soybean oil (n = 12). After 45 days on the diet, the animals were evaluated: body weight and blood biochemical analisys. Changes in mood disposition were evaluated using forced swim test and the elevated plus-maze, whereas hippocampal BDNF expression levels were quantified by ELISA. After 45 weeks, the CD group showed a significant increase in body weight relative to the HD group. However, the HD rats had a body fat percentage and exhibited increased level of the biochemical markers. Furthermore, the animals in the HD group presented increased immobility time in the forced swimming test, as well as reduced response to plus-maze test suggesting a depression- and anxiety-like emotional state. In addition, the HD group also showed lower BDNF expression levels in the hippocampus. This study demonstrates that a hypercaloric diet induced increase in adipose tissue concentration in young rats was associated with reduced hippocampal BDNF expression and resulted in an increase in depression- and anxiety-like behaviors. Graphical abstract.

Fisetin ameliorates atherosclerosis by regulating PCSK9 and LOX-1 in apoE-/- mice

The purpose of the current study was to investigate the mechanism by which fisetin improves atherosclerosis (AS) by regulating lipid metabolism and senescence in apolipoprotein E-deficient (apoE^-/-) mice. An AS model was established by feeding apoE^-/- mice a high-fat diet. Mice were randomly divided into the model group (n=18), the fisetin group (n=18) and the atorvastatin group (n=18). The control group (n=18) was composed of wild-type C57BL/6 mice of the same age and genetic background. The fisetin and atorvastatin groups were respectively treated with aqueous solutions of fisetin (12.5 mg/kg) and atorvastatin (2 mg/kg) via oral gavage daily for 12 weeks. The pathological morphology, lipid accumulation, collagen deposition of the aortic sinus were observed, serum lipids, superoxide dismutase (SOD) and malondialdehyde (MDA) levels and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were measured in the peripheral blood serum. Additionally, the expressions of proprotein convertase subtilisin/kexin type 9 (PCSK9), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), tumor suppressor protein p53 (p53), cyclin-dependent kinase inhibitor 1A (p21) and multiple tumor suppressor-1 (p16) were analyzed in the aorta. The results of the current study indicated that compared with the control group, a large area of AS plaque in the aortic sinus that contained a large amount of red-stained lipids and decreased collagen fiber content were found in the model group, which exhibited higher total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), oxidized low-density lipoprotein (ox-LDL) and MDA levels; higher ALT and AST activities, lower high-density lipoprotein cholesterol (HDL-C) and SOD levels and increased expression levels of PCSK9, LOX-1, p53, p21 and p16. Fisetin is a phytochemical and bioflavonoid that serves a potential role in chronic diseases including AS, obesity, diabetes and cancer due to its wide biological activities, such as regulating lipid metabolism and anti-aging, anti-oxidation and anti-inflammatory. Atorvastatin is recognized as a first-line treatment drug for AS; therefore it was used as a positive control in the current study. Following fisetin and atorvastatin treatment, both the AS plaque and the lipid accumulation in the aortic sinus were significantly reduced, and the expressions of PCSK9, LOX-1 and aging markers, including p53, p21 and p16 were downregulated.

Food as medicine: targeting the uraemic phenotype in chronic kidney disease

The observation that unhealthy diets (those that are low in whole grains, fruits and vegetables, and high in sugar, salt, saturated fat and ultra-processed foods) are a major risk factor for poor health outcomes has boosted interest in the concept of 'food as medicine'. This concept is especially relevant to metabolic diseases, such as chronic kidney disease (CKD), in which dietary approaches are already used to ameliorate metabolic and nutritional complications. Increased awareness that toxic uraemic metabolites originate not only from intermediary metabolism but also from gut microbial metabolism, which is directly influenced by diet, has fuelled interest in the potential of 'food as medicine' approaches in CKD beyond the current strategies of protein, sodium and phosphate restriction. Bioactive nutrients can alter the composition and metabolism of the microbiota, act as modulators of transcription factors involved in inflammation and oxidative stress, mitigate mitochondrial dysfunction, act as senolytics and impact the epigenome by altering one-carbon metabolism. As gut dysbiosis, inflammation, oxidative stress, mitochondrial dysfunction, premature ageing and epigenetic changes are common features of CKD, these findings suggest that tailored, healthy diets that include bioactive nutrients as part of the foodome could potentially be used to prevent and treat CKD and its complications.

The protective effects of walnut green husk polysaccharide on liver injury, vascular endothelial dysfunction and disorder of gut microbiota in high fructose-induced mice

This study aimed to investigate the protective effects of walnut green husk polysaccharide (WGHP) on liver injury, vascular endothelial dysfunction and disorder of gut microbiota in mice induced by high fructose (HF) diet. The chemical analysis results show that the walnut green husk polysaccharide is a low molecular weight acidic heteropolysaccharide, composed mainly of glucuronic acid, arabinose and galactose. Biochemical analysis showed that WGHP significantly improved glucose metabolism and lipid metabolism and decreased oxidative stress in HF-diet induced obesity mice. Histopathological observation of liver and cardiovascular aorta confirmed the protective effects of WGHP on hepatic steatosis and vascular endothelial dysfunction. Furthermore, 16S rRNA sequencing results demonstrated that WGHP reversed the disorders of gut microbiota caused by HF, decreased the relative abundance of Verrucomicrobia and increased the relative abundance of Deferribacteres at the phylum level, decreased the relative abundance of Akkermansia, Lachnoclostridium and norank_f__Muribaculaceae and increased the relative abundance of Prevotellaceae_UCG-001, Helicobacter, Alloprevotella and Allobaculum at the genus levels. Our results indicate that WGHP may act as a functional polysaccharide for protecting liver and cardiovascular in HF-fed mice.

Endoplasmic reticulum stress-induced iRhom2 up-regulation promotes macrophage-regulated cardiac inflammation and lipid deposition in high fat diet (HFD)-challenged mice: Intervention of fisetin and metformin

Endoplasmic reticulum stress (ERS) has been implicated in obesity-associated cardiac remodeling and dysfunction. Inactive rhomboid protein 2 (iRhom2), also known as Rhbdf2, is an inactive member of the rhomboid intramembrane proteinase family, playing an essential role in regulating inflammation. Nevertheless, the role of ERS-meditated iRhom2 pathway in metabolic stress-induced cardiomyopathy remains unknown. In the study, we showed that 4-PBA, as an essential ERS inhibitor, significantly alleviated high fat diet (HFD)-induced metabolic disorder and cardiac dysfunction in mice. Additionally, lipid deposition in heart tissues was prevented by 4-PBA in HFD-challenged mice. Moreover, 4-PBA blunted the expression of iRhom2, TACE, TNFR2 and phosphorylated NF-κB to prevent HFD-induced expression of inflammatory factors. Further, 4-PBA restrained HFD-triggered oxidative stress by promoting Nrf-2 signaling. Importantly, 4-PBA markedly suppressed cardiac ERS in HFD mice. The anti-inflammation, anti-ERS and anti-oxidant effects of 4-PBA were verified in palmitate (PAL)-incubated macrophages and cardiomyocytes. In addition, promoting ERS could obviously enhance iRhom2 signaling in vitro. Intriguingly, our data demonstrated that PAL-induced iRhom2 up-regulation apparently promoted macrophage to generate inflammatory factors that could promote cardiomyocyte inflammation and lipid accumulation. Finally, interventions by adding fisetin or metformin significantly abrogated metabolic stress-induced cardiomyopathy through the mechanisms mentioned above. In conclusion, this study provided a novel mechanism for metabolic stress-induced cardiomyopathy pathogenesis. Therapeutic strategy to restrain ROS/ERS/iRhom2 signaling pathway could be developed to prevent myocardial inflammation and lipid deposition, consequently alleviating obesity-induced cardiomyopathy.

Activated TNF-α/RIPK3 signaling is involved in prolonged high fat diet-stimulated hepatic inflammation and lipid accumulation: inhibition by dietary fisetin intervention

Increasing evidence indicates that high-fat diet (HFD) is a predisposing factor for metabolic syndrome-associated systemic inflammation and nonalcoholic fatty liver disease (NAFLD).