Quercetin administration post-weaning attenuates high-fructose, high-cholesterol diet-induced hepatic steatosis in growing, female, Sprague Dawley rat pups

Maternal fructose intake aggravates the harmful effects of a Western diet in rat male descendants impacting their cholesterol metabolism

Scope: fructose consumption from added sugars correlates with the epidemic rise in MetS and CVD. Maternal fructose intake has been described to program metabolic diseases in progeny. However, consumption of fructose-containing beverages is allowed during gestation. Cholesterol is also a well-known risk factor for CVD. Therefore, it is essential to study Western diets which combine fructose and cholesterol and how maternal fructose can influence the response of progeny to these diets. Methods and results: a high-cholesterol (2%) diet combined with liquid fructose (10%), as a model of an unhealthy Western diet, was administered to descendants from control and fructose-fed mothers. Gene (mRNA and protein) expression and plasma, fecal and tissue parameters of cholesterol metabolism were measured. Interestingly, progeny from fructose-fed dams consumed less liquid fructose and cholesterol-rich chow than males from control mothers. Moreover, descendants of fructose-fed mothers fed a Western diet showed an increased cholesterol elimination through bile and feces than males from control mothers. Despite these mitigating circumstances to develop a proatherogenic profile, the same degree of hypercholesterolemia and severity of steatosis were observed in all descendants fed a Western diet, independently of maternal intake. An increased intestinal absorption of cholesterol, synthesis, esterification, and assembly into lipoprotein found in males from fructose-fed dams consuming a Western diet could be the cause. Moreover, an augmented GLP2 signalling seen in these animals would explain this enhanced lipid absorption. Conclusions: maternal fructose intake, through a fetal programming, makes a Western diet considerably more harmful in their descendants than in the offspring from control mothers.

Potential Therapeutic Functions of PU-91 and Quercetin in Personalized Cybrids Derived from Patients with Age-Related Macular Degeneration, Keratoconus, and Glaucoma

The aim of this study is to investigate the therapeutic potential of higher doses of PU-91, quercetin, or in combination on transmitochondrial cybrid cell lines with various mtDNA haplogroups derived from patients with age-related macular degeneration (AMD), glaucoma (Glc), keratoconus (KC), and normal (NL) individuals. Cybrids were treated with PU-91 (P) (200 µM) alone, quercetin (Q) (20 µM) alone, or a combination of PU-91 and quercetin (P+Q) for 48 h. Cellular metabolism and the intracellular levels of reactive oxygen species (ROS) were measured by MTT and H2DCFDA assays, respectively. Quantitative real-time PCR was performed to measure the expression levels of genes associated with mitochondrial biogenesis, antioxidant enzymes, inflammation, apoptosis, and senescence pathways. PU-91(P) (i) improves cellular metabolism in AMD cybrids, (ii) decreases ROS production in AMD cybrids, and (iii) downregulates the expression of LMNB1 in AMD cybrids. Combination treatment of PU-91 plus quercetin (P+Q) (i) improves cellular metabolism in AMD, (ii) induces higher expression levels of TFAM, SOD2, IL6, and BAX in AMD cybrids, and (iii) upregulates CDKN1A genes expression in all disease cybrids. Our study demonstrated that the P+Q combination improves cellular metabolism and mitochondrial biogenesis in AMD cybrids, but senescence is greatly exacerbated in all cybrids regardless of disease type by the P+Q combined treatment.

Effects of coconut oil long-term supplementation in Wistar rats during metabolic syndrome - regulation of metabolic conditions involving glucose homeostasis, inflammatory signals, and oxidative stress

This study was designed to evaluate the long-term effects of Fructose (20%) feeding in rats, simulating metabolic syndrome (MetS), and the effects of coconut oil (C.O.) supplementation when administered in a MetS context. MetS is a cluster of systemic conditions that represent an increased chance of developing cardiovascular diseases and type 2 diabetes in the future. C.O. has been the target of media speculation, and recent studies report inconsistent results. C.O. improved glucose homeostasis and reduced fat accumulation in Fructose-fed rats while decreasing the levels of triglycerides (TGs) in the liver. C.O. supplementation also increased TGs levels and fructosamine in serum during MetS, possibly due to white adipose tissue breakdown and high fructose feeding. Pro-inflammatory cytokines IL-1β and TNF-α were also increased in rats treated with Fructose and C.O. Oxidative stress marker nitrotyrosine is increased in fructose-fed animals, and C.O. treatment did not prevent this damage. No significant changes were observed in lipoperoxidation marker 4-Hydroxynonenal; however, fructose feeding increased total conjugated dienes and caused conjugated dienes to switch their conformation from cis-trans to trans-trans, which was not prevented by C.O. treatment. Potential benefits of C.O. have been reported with inconsistent results, and indeed we observed some benefits of C.O. supplementation in aiding weight loss, fat accumulation, and improving glucose homeostasis. Nonetheless, we also demonstrated that long-term C.O. supplementation could present some problematic effects with higher risk for individuals suffering MetS, including increased TGs and fructosamine levels and conformational changes in dienes.

Viral modulation of lipid rafts and their potential as putative antiviral targets

Lipid rafts are ubiquitous in cells. They are identified as cholesterol and glycosphingolipid enriched microdomains on cellular membranes. They serve as platforms for cellular communications by functioning in signal transduction and membrane trafficking. Such structural organisation fulfils cellular needs for normal function, but at the same time increases vulnerability of cells to pathogen invasion. Viruses rely heavily on lipid rafts in basically every stage of the viral life cycle for successful infection. Various mechanisms of lipid rafts modification exploited by diverse viruses for attachment, internalisation, membrane fusion, genome replication, assembly and release have been brought to light. This review focuses on virus-raft interactions and how a wide range of viruses manipulate lipid rafts at distinct stages of infection. The importance of virus-raft interactions in viral infections has inspired researchers to discover and develop antivirals that target this interaction, such as statins, methyl-β-cyclodextrin, viperin, 25-hydroxycholesterol and even anti-malarial drugs. The therapeutic modulations of lipid rafts as potential antiviral intervention from in vitro and in vivo evidence are discussed herein.

Luteolin loaded on zinc oxide nanoparticles ameliorates non-alcoholic fatty liver disease associated with insulin resistance in diabetic rats via regulation of PI3K/AKT/FoxO1 pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a worldwide health problem with high prevalence and morbidity associated with obesity, insulin resistance, type 2 diabetes mellitus (T2DM), and dyslipidemia. Nano-formulation of luteolin with Zn oxide in the form of Lut/ZnO NPs may improve the anti-diabetic property of each alone and ameliorate the insulin resistance thus management of NAFLD. This study aimed to measure the efficiency of Lut/ZnO NPs against insulin resistance coupled with NAFLD and T2DM.

METHODS

A diabetic rat model with NAFLD was induced by a high-fat diet and streptozotocin (30 mg/kg I.P). Serum diabetogenic markers levels, lipid profile, and activity of liver enzymes were measured beside liver oxidative stress markers. Moreover, the hepatic expressions of PI3K/AKT/FoxO1/SERBP1c as well as heme oxygenase-1 were measured beside the histopathological examination.

RESULTS

Lut/ZnO NPs treatment effectively reduced hyperglycemia, hyperinsulinemia, and ameliorated insulin resistance. Additionally, Lut/ZnO NPs improved the hepatic functions, the antioxidant system, and reduced the oxidative stress markers. Furthermore, the lipid load in the liver, as well as the circulating TG and TC, was minified via the suppression of lipogenesis and gluconeogenesis. Moreover, Lut/ZnO NPs activated the PI3K/AKT signaling pathway, hence inactivating FoxO1, therefore enhancing the hepatic cells' insulin sensitivity.

CONCLUSION

Lut/ZnO NPs have a hepatoprotective effect and may relieve the progression of NAFLD by alleviating insulin resistance, ameliorating the antioxidant status, and regulating the insulin signal pathway.

Revealing the Mechanism of Huazhi Rougan Granule in the Treatment of Nonalcoholic Fatty Liver Through Intestinal Flora Based on 16S rRNA, Metagenomic Sequencing and Network Pharmacology

Background: The incidence of Nonalcoholic Fatty Liver (NAFL) is increasing year by year, growing evidence suggests that the intestinal flora plays a causative role in NAFL. Huazhi Rougan Granule (HRG) is commonly used in the clinical treatment of NAFL. It is reported that it can reduce lipids and protect the liver, but no research has confirmed whether the drug's effect is related to the intestinal flora. Therefore, we investigated whether the effect of HRG is related to the regulation of intestinal flora to further explore the mechanism of HRG in the treatment of NAFL through intestinal flora. Methods: In this study, C57BL/6J mice were fed a high-fat diet for 8 weeks, and the high-fat diet plus HRG or polyene phosphatidylcholine capsules were each administered by gavage for 4 weeks. High-throughput sequencing, network pharmacology, and molecular docking were used to explore the mechanism of HRG in the treatment of NAFL through intestinal flora. Results: HRG treatment can reduce body weight gain, lipid accumulation in liver and lipogenesis and reduce serum biochemical indexes in high-fat-fed mice. Analysis of intestinal flora showed that HRG changed the composition of intestinal flora, which was characterized by a decrease in the Firmicutes/Bacteroidetes ratio. Moreover, the species distribution was significantly correlated with AKP, HDL-C, and TG. Metagenetic analysis showed that HRG altered the functional composition and functional diversity of microorganisms, which was mainly characterized by an increase in the abundance of metabolic pathways. The network pharmacology results show that the mechanism of HRG in the treatment of NAFL through intestinal flora is mainly reflected in the biological process of gene function and related to infectious diseases, immune systems, and signal transduction pathways, such as cytokine-cytokine receptor interaction, Chagas disease, IL-17 signaling pathway and other signaling pathways. Conclusion: These results strongly suggest that HRG may alleviate NAFL by preventing IFD.

Nicotinamide riboside ameliorates high-fructose-induced lipid metabolism disorder in mice via improving FGF21 resistance in the liver and white adipose tissue

NR supplementation could ameliorate high-fructose-induced lipid metabolism disorder by improving FGF21 resistance in the liver and WAT, which may be related to the inflammation state mediated by SIRT1/NF-κB signaling pathway.

Nonalcoholic fatty liver disease: The role of quercetin and its therapeutic implications

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease, affecting almost one-third of the general population and 75% of obese patients with type 2 diabetes. The aim of this article is to review the current evidence concerning the role of quercetin, a natural compound and flavonoid, and its possible therapeutic effects on this modern-day disease. Despite the fact that the exact pathophysiological mechanisms through which quercetin has a hepatoprotective effect on NAFLD are still not fully elucidated, this review clearly demonstrates that this flavonoid has potent antioxidative stress action and inhibitory effects on hepatocyte apoptosis, inflammation, and generation of reactive oxygen species, factors which are linked to the development of the disease. NAFLD is closely associated with increased dietary fat consumption, especially in Western countries. The hepatoprotective effect of quercetin against NAFLD merits serious consideration and further validation by future studies.

Quercetin as a protective agent for liver diseases: A comprehensive descriptive review of the molecular mechanism

Quercetin is the major representative of the flavonoid subgroup of flavones, with good pharmacological activities for the treatment of liver diseases, including liver steatosis, fatty hepatitis, liver fibrosis, and liver cancer. It can significantly influence the development of liver diseases via multiple targets and multiple pathways via antifat accumulation, anti-inflammatory, and antioxidant activity, as well as the inhibition of cellular apoptosis and proliferation. Despite extensive research on understanding the mechanism of quercetin in the treatment of liver diseases, there are still no targeted therapies available. Thus, we have comprehensively searched and summarized the different targets of quercetin in different stages of liver diseases and concluded that quercetin inhibited inflammation of the liver mainly through NF-κB/TLR/NLRP3, reduced PI3K/Nrf2-mediated oxidative stress, mTOR activation in autophagy, and inhibited the expression of apoptotic factors associated with the development of liver diseases. In addition, quercetin showed different mechanisms of action at different stages of liver diseases, including the regulation of PPAR, UCP, and PLIN2-related factors via brown fat activation in liver steatosis. The compound inhibited stromal ECM deposition at the liver fibrosis stage, affecting TGF1β, endoplasmic reticulum stress (ERs), and apoptosis. While at the final liver cancer stage, inhibiting cancer cell proliferation and spread via the hTERT, MEK1/ERK1/2, Notch, and Wnt/β-catenin-related signaling pathways. In conclusion, quercetin is an effective liver protectant. We hope to explore the pathogenesis of quercetin in different stages of liver diseases through the review, so as to provide more accurate targets and theoretical basis for further research of quercetin in the treatment of liver diseases.

Molecular basis of quercetin as a plausible common denominator of macrophage-cholesterol-fenofibrate dependent potential COVID-19 treatment axis

The world's largest randomized control trial against COVID-19 using remdesivir, hydroxychloroquine, lopinavir and interferon-β1a appeared to have little or no effect on hospitalized COVID-19 patients. This has again led to search for alternate re-purposed drugs and/or effective “add-on” nutritional supplementation, which can complement or enhance the therapeutic effect of re-purposed drug. Focus has been shifted to therapeutic targets of severe acute respiratory syndrome coronavirus (SARS-CoV-2), which includes specific enzymes and regulators of lipid metabolism. Very recently, fenofibrate (cholesterol-lowering drug), suppressed the SARS-CoV-2 replication and pathogenesis by affecting the pathways of lipid metabolism in lung cells of COVID-19 patients. A preclinical study has shown synergistic effect of quercetin (a flavonoid) and fenofibrate in reducing the cholesterol content, which might be useful in COVID-19 treatment. Based on the scientific literature, use of quercetin and fenofibrate in COVID-19 seems meaningful in pharmaceutical and biomedical research, and warrants basic, experimental and clinical studies. In this article, we have summarized the contemporary findings about drug fenofibrate and its effect on membrane synthesis of COVID-19 virus along with emphasizing on possible synergistic effects of quercetin with fenofibrate.

Quercetin and non-alcoholic fatty liver disease: A review based on experimental data and bioinformatic analysis

Quercetin, a polyphenol widely present in the plant kingdom, has received great interest due to pleiotropic effects. As evidenced by animal and cellular studies, quercetin exerts hepatoprotection against non-alcoholic fatty liver disease (NAFLD), particularly in hepatic steatosis and hepatitis. Mechanically, various hypotheses of such protective effects have been actively proposed, including improving fatty acid metabolism, anti-inflammation, anti-oxidant, modulating gut microbiota and bile acid, etc. Here, the role of quercetin in NAFLD was summarized. With a particular focus on molecular mechanism, we comprehensively discussed the pathways of quercetin on NAFLD based on the analysis from Gene Expression Omnibus (GEO) database and experimental evidence.

Research progress in use of traditional Chinese medicine monomer for treatment of non-alcoholic fatty liver disease

With the improvement of people's living standards and the change of eating habits, non-alcoholic fatty liver disease (NAFLD) has gradually become one of the most common chronic liver diseases in the world. However, there are no effective drugs for the treatment of NAFLD. Therefore, it is urgent to find safe, efficient, and economical anti-NAFLD drugs. Compared with western medicines that possess fast lipid-lowering effect, traditional Chinese medicines (TCM) have attracted increasing attention for the treatment of NAFLD due to their unique advantages such as multi-targets and multi-channel mechanisms of action. TCM monomers have been proved to treat NAFLD through regulating various pathways, including inflammation, lipid production, insulin sensitivity, mitochondrial dysfunction, autophagy, and intestinal microbiota. In particular, peroxisome proliferator-activated receptor α (PPAR-α), sterol regulatory element-binding protein 1c (SREBP-1c), nuclear transcription factor kappa (NF-κB), phosphoinositide 3-kinase (PI3K), sirtuin1 (SIRT1), AMP-activated protein kinase (AMPK), p53 and nuclear factor erythroid 2-related factor 2 (Nrf2) are considered as important molecular targets for ameliorating NAFLD by TCM monomers. Therefore, by searching PubMed, Web of Science and SciFinder databases, this paper updates and summarizes the experimental and clinical evidence of TCM monomers for the treatment of NAFLD in the past six years (2015-2020), thus providing thoughts and prospects for further exploring the pathogenesis of NAFLD and TCM monomer therapies.

Administration of low-dose resveratrol attenuated hepatic inflammation and lipid accumulation in high cholesterol-fructose diet-induced rat model of nonalcoholic fatty liver disease

Resveratrol (RSV) has been demonstrated to ameliorate nonalcoholic fatty liver disease (NAFLD) in animal studies. However, RSV was given with the dosage that ranged from 7 to 300 mg/kg body weight (BW). Hence, the study aimed to investigate the efficacy of RSV at a lower dosage on high cholesterol-fructose diet (HCFD)-induced rat model of NAFLD. In the study, male Sprague-Dawley rats were fed with HCFD for 15 weeks. RSV was also given at a daily dose of 1 mg/kg BW for 15 days or 15 weeks by oral delivery. At sacrifice, plasma and liver specimens were acquired for detections of alanine and aspartate aminotransferases, proinflammatory cytokines, and lipid contents. Histological examinations and Western blotting analysis were performed using liver tissues. The results showed that RSV administration reduced plasma levels of aminotransferases and proinflammatory cytokines including interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α) in HCFD-induced NAFLD. RSV also mitigated hepatic lipid accumulation and expression of IL-1β, IL-6, and TNF-α. Besides, phosphorylation of signal transducer and activator of transcription 3 (STAT3) was reduced with RSV supplementation in the liver of HCFD-fed rats. We concluded that low-dose RSV supplementation attenuated hepatic inflammation and lipid accumulation in HCFD-induced NAFLD. The ameliorative effect of RSV on NAFLD could be associated with downregulation of phosphorylated STAT3.

Cholesterotropic and cuprotropic chemicals

A dozen or so chemicals modify both cholesterol and copper metabolism. Ascorbic acid and cadmium, etc., inhibit copper metabolism and raise cholesterol. Calcium and clofibrate, etc., enhance copper and lower cholesterol. Perhaps the doses of dietary cholesterol and fructose in this experiment were too severe to permit fenofibrate to lower cholesterol in a manner similar to clofibrate. © 2020 Society of Chemical Industry.