Activation of the Nrf2/ARE signaling pathway ameliorates hyperlipidemia-induced renal tubular epithelial cell injury by inhibiting mtROS-mediated NLRP3 inflammasome activation.

Dyslipidemia is the most prevalent independent risk factor for patients with chronic kidney disease (CKD). Lipid-induced NLRP3 inflammasome activation in kidney-resident cells exacerbates renal injury by causing sterile inflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that modulates the cellular redox balance; however, the exact role of Nrf2 signaling and its regulation of the NLRP3 inflammasome in hyperlipidemia-induced kidney injury are poorly understood. In this study, we demonstrated that activation of the mtROS-NLRP3 inflammasome pathway is a critical contributor to renal tubular epithelial cell (RTEC) apoptosis under hyperlipidemia. In addition, the Nrf2/ARE signaling pathway is activated in renal tubular epithelial cells under hyperlipidemia conditions both in vivo and in vitro, and Nrf2 silencing accelerated palmitic acid (PA)-induced mtROS production, mitochondrial injury, and NLRP3 inflammasome activation. However, the activation of Nrf2 with tBHQ ameliorated mtROS production, mitochondrial injury, NLRP3 inflammasome activation, and cell apoptosis in PA-induced HK-2 cells and in the kidneys of HFD-induced obese rats. Furthermore, mechanistic studies showed that the potential mechanism of Nrf2-induced NLRP3 inflammasome inhibition involved reducing mtROS generation. Taken together, our results demonstrate that the Nrf2/ARE signaling pathway attenuates hyperlipidemia-induced renal injury through its antioxidative and anti-inflammatory effects through the downregulation of mtROS-mediated NLRP3 inflammasome activation.

Ox-LDL-induced CD80+ macrophages expand pro-atherosclerotic NKT cells via CD1d in atherosclerotic mice and hyperlipidemic patients.

Atherosclerosis is an inflammatory disease of blood vessels involving the immune system. Natural killer T (NKT) cells, as crucial components of the innate and acquired immune systems, play critical roles in the development of atherosclerosis. However, the mechanism and clinical relevance of NKT cells in early atherosclerosis are largely unclear. The study investigated the mechanism influencing NKT cell function in apoE deficiency-induced early atherosclerosis. Our findings demonstrated that there were higher populations of NKT cells and interferon-gamma (IFN-γ)-producing NKT cells in the peripheral blood of patients with hyperlipidemia and in the aorta, blood, spleen, and bone marrow of early atherosclerotic mice compared with the control groups. Moreover, we discovered that the infiltration of CD80+ macrophages and CD1d expression on CD80+ macrophages in atherosclerotic mice climbed remarkably. CD1d expression increased in CD80+ macrophages stimulated by oxidized low-density lipoprotein (ox-LDL) ex vivo and in vitro. Ex vivo coculture of macrophages with NKT cells revealed that ox-LDL-induced CD80+ macrophages presented lipid antigen α-Galcer (alpha-galactosylceramide) to NKT cells via CD1d, enabling NKT cells to express more IFN-γ. Furthermore, a greater proportion of CD1d+ monocytes and CD1d+CD80+ monocytes were found in peripheral blood of hyperlipidemic patients compared with that of healthy donors. Positive correlations were found between CD1d+CD80+ monocytes and NKT cells or IFN-γ+ NKT cells in hyperlipidemic patients. Our findings illustrated that CD80+ macrophages stimulated NKT cells to secrete IFN-γ via CD1d-presenting α-Galcer, which may accelerate the progression of early atherosclerosis. Inhibiting lipid antigen presentation by CD80+ macrophages to NKT cells may be a promising immune target for the treatment of early atherosclerosis.NEW & NOTEWORTHY This work proposed the ox-LDL-CD80+ monocyte/macrophage-CD1d-NKT cell-IFN-γ axis in the progression of atherosclerosis. The proinflammatory IFN-γ+ NKT cells are closely related to CD1d+CD80+ monocytes in hyperlipidemic patients. Inhibiting CD80+ macrophages to present lipid antigens to NKT cells through CD1d blocking may be a new therapeutic target for atherosclerosis.

Hypolipidemic Effect of Rice Bran Oil Extract Tocotrienol in High-Fat Diet-Induced Hyperlipidemia Zebrafish (Danio Rerio) Induced by High-Fat Diet.

In recent years, the potent influence of tocotrienol (T3) on diminishing blood glucose and lipid concentrations in both Mus musculus (rats) and Homo sapiens (humans) has been established. However, the comprehensive exploration of tocotrienol's hypolipidemic impact and the corresponding mechanisms in aquatic species remains inadequate. In this study, we established a zebrafish model of a type 2 diabetes mellitus (T2DM) model through high-fat diet administration to zebrafish. In the T2DM zebrafish, the thickness of ocular vascular walls significantly increased compared to the control group, which was mitigated after treatment with T3. Additionally, our findings demonstrate the regulatory effect of T3 on lipid metabolism, leading to the reduced synthesis and storage of adipose tissue in zebrafish. We validated the expression patterns of genes relevant to these processes using RT-qPCR. In the T2DM model, there was an almost two-fold upregulation in pparγ and cyp7a1 mRNA levels, coupled with a significant downregulation in cpt1a mRNA (p < 0.01) compared to the control group. The ELISA revealed that the protein expression levels of Pparγ and Rxrα exhibited a two-fold elevation in the T2DM group relative to the control. In the T3-treated group, Pparγ and Rxrα protein expression levels consistently exhibited a two-fold decrease compared to the model group. Lipid metabolomics showed that T3 could affect the metabolic pathways of zebrafish lipid regulation, including lipid synthesis and decomposition. We provided experimental evidence that T3 could mitigate lipid accumulation in our zebrafish T2DM model. Elucidating the lipid-lowering effects of T3 could help to minimize the detrimental impacts of overfeeding in aquaculture.

Depletion of ApoA5 aggravates spontaneous and diet-induced nonalcoholic fatty liver disease by reducing hepatic NR1D1 in hamsters.

Background: ApoA5 mainly synthesized and secreted by liver is a key modulator of lipoprotein lipase (LPL) activity and triglyceride-rich lipoproteins (TRLs). Although the role of ApoA5 in extrahepatic triglyceride (TG) metabolism in circulation has been well documented, the relationship between ApoA5 and nonalcoholic fatty liver disease (NAFLD) remains incompletely understood and the underlying molecular mechanism still needs to be elucidated. Methods: We used CRISPR/Cas9 gene editing to delete Apoa5 gene from Syrian golden hamster, a small rodent model replicating human metabolic features. Then, the ApoA5-deficient (ApoA5-/-) hamsters were used to investigate NAFLD with or without challenging a high fat diet (HFD). Results: ApoA5-/- hamsters exhibited hypertriglyceridemia (HTG) with markedly elevated TG levels at 2300 mg/dL and hepatic steatosis on a regular chow diet, accompanied with an increase in the expression levels of genes regulating lipolysis and small adipocytes in the adipose tissue. An HFD challenge predisposed ApoA5-/- hamsters to severe HTG (sHTG) and nonalcoholic steatohepatitis (NASH). Mechanistic studies in vitro and in vivo revealed that targeting ApoA5 disrupted NR1D1 mRNA stability in the HepG2 cells and the liver to reduce both mRNA and protein levels of NR1D1, respectively. Overexpression of human NR1D1 by adeno-associated virus 8 (AAV8) in the livers of ApoA5-/- hamsters significantly ameliorated fatty liver without affecting plasma lipid levels. Moreover, restoration of hepatic ApoA5 or activation of UCP1 in brown adipose tissue (BAT) by cold exposure or CL316243 administration could significantly correct sHTG and hepatic steatosis in ApoA5-/- hamsters. Conclusions: Our data demonstrate that HTG caused by ApoA5 deficiency in hamsters is sufficient to elicit hepatic steatosis and HFD aggravates NAFLD by reducing hepatic NR1D1 mRNA and protein levels, which provides a mechanistic link between ApoA5 and NAFLD and suggests the new insights into the potential therapeutic approaches for the treatment of HTG and the related disorders due to ApoA5 deficiency in the clinical trials in future.

Inhibition of SPARC signal by aerobic exercise to ameliorate atherosclerosis.

BACKGROUND AND AIMS: Inflammation and atherosclerosis (AS) are closely associated to Secreted Protein Acidic and Rich in Cysteine (SPARC) and its related factors. This study attempted to define the role and the potential mechanism of SPARC and its related factors in ameliorating hyperlipidemia and AS by aerobic exercise intervention. METHODS: The AS rat model was established with a high-fat diet plus vitamin D3 intraperitoneal injection. Treadmill exercises training (5 days/week at 14 m/min for 60 min/day) for 6 weeks was carried out for AS rat intervention method. Western blotting and qRT-PCR were used to analyze the mRNA and protein expression of SPARC and its related factors, respectively. H&E staining was applied to evaluate the morphological changes and inflammation damage. Von Kossa staining was used to measure the degree of vascular calcification. Fluorescence immunohistochemistry staining was used to detect the expression and distribution of SPARC signal molecules. RESULTS: SPARC was highly expressed and co-localization with the smooth muscle marker α-SMC in the AS rat. And its downstream factors, NF-κB, Caspase-1, IL-1ß and IL-18 were upregulated (P < 0.05 or P < 0.01), FNDC5 expression was downregulated in AS rat model. However, slight declined body weight, delayed AS progression, decreased hyperlipidemia and favorable morphology of skeletal muscle and blood vessels have been detected in AS rat with aerobic exercise intervention. Moreover, the expression of SPARC and its downstream factors were decreased (P < 0.05 or P < 0.01), while elevated the expression of FNDC5 (P < 0.01) was observed after aerobic exercise intervention. CONCLUSIONS: This study suggested that aerobic exercise ameliorated hyperlipidemia and AS by effectively inhibiting SPARC signal, and vascular smooth muscle cells may contribute greatly to the protection of AS.

The anti-hyperlipidemic effects of Poria cocos (Schw.) Wolf extract: Modulating cholesterol homeostasis in hepatocytes via PPARα pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Poria cocos (Schw.) Wolf (Polyporaceae, P.cocos), which is born on the pine root, has a history of more than two thousand years of medicine in China. P.cocos was first recorded in the Shennong's Herbal Classic, studies have proved its lipid-lowering effect. AIM OF STUDY: The aim of study was to investigate the underlying mechanism of P.cocos extract on hyperlipidemia. MATERIALS AND METHODS: Male Sprague-Dawley (SD) rats aged 9-12 weeks were intraperitoneally (IP) injected with Triton-WR 1339 to establish an acute hyperlipidemia model. At 0 h and 20 h after the model was established, low and high doses of P.cocos extract or simvastatin were given twice. After 48 h, the rats were sacrificed, and liver and serum samples were collected for analysis. The cell model was constructed by treating L02 cells with 1% fat emulsion-10% FBS-RPMI 1640 medium for 48 h. At the same time, low and high doses of P.cocos extract and simvastatin were administered. Oil red O staining was used to evaluate the lipid accumulation in the cells, and H&E staining was used to evaluate the liver lesions of rats. Real-time quantitative PCR and western blotting were used to detect the expressions of lipid metabolism-related genes. RESULTS: P.cocos extract relieved lipid accumulation in vitro and alleviated hyperlipidemia in vivo. Both gene and protein expressions of peroxisome proliferator-activated receptor α (PPARα) were shown to be up-regulated by P.cocos extract. Additionally, P.cocos extract down-regulated the expressions of fatty acid synthesis-related genes sterol regulatory element-binding protein-1 (SREBP-1), Acetyl-CoA Carboxylase 1 (ACC1) and fatty acid synthase (FAS), while up-regulated the expressions of cholesterol metabolism-related genes liver X receptor-α (LXRα), ATP-binding cassette transporter A1 (ABCA1), cholesterol 7alpha-hydroxylase (CYP7A1) and low density lipoprotein receptor (LDLR), which were reversed by the treatment with the PPARα inhibitor GW6471. CONCLUSION: P.cocos extract ameliorates hyperlipidemia and lipid accumulation by regulating cholesterol homeostasis in hepatocytes through PPARα pathway. This study provides evidence that supplementation with P.cocos extract could be a potential strategy for the treatment of hyperlipidemia.

Saponins from Chenopodium quinoa Willd. husks alleviated high-fat-diet-induced hyperlipidemia via modulating the gut microbiota and multiple metabolic pathways.

BACKGROUND: Hyperlipidemia is characterized by abnormally elevated blood lipids. Quinoa saponins (QS) have multiple pharmacological activities, including antitumor, bactericidal and immune-enhancing effects. However, the lipid-lowering effect and mechanisms of QS in vivo have been scarcely reported. METHODS: The effect of QS against hyperlipidemia induced by high-fat diet in rats was explored based on gut microbiota and serum non-targeted metabolomics. RESULTS: The study demonstrated that the supplementation of QS could reduce serum lipids, body weight, liver injury and inflammation. 16S rRNA sequencing demonstrated that QS mildly increased alpha-diversity, altered the overall structure of intestinal flora, decreased the relative richness of Firmicutes, the ratio of Firmicutes/Bacteroidetes (P < 0.05) and increased the relative richness of Actinobacteria, Bacteroidetes, Bifidobacterium, Roseburia and Coprococcus (P < 0.05). Simultaneously, metabolomics analysis showed that QS altered serum functional metabolites with respect to bile acid biosynthesis, arachidonic acid metabolism and taurine and hypotaurine metabolism, which were closely related to bile acid metabolism and fatty acid ß-oxidation. Furthermore, QS increased protein levels of farnesoid X receptor, peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase 1, which were related to the screened metabolic pathways. Spearman correlation analysis showed that there was a correlation between gut microbiota and differential metabolites. CONCLUSION: QS could prevent lipid metabolism disorders in hyperlipidemic rats, which may be closely associated with the regulation of the gut microbiota and multiple metabolic pathways. This study may provide new evidence for QS as natural active substances for the prevention of hyperlipidemia. © 2023 Society of Chemical Industry.

Advances in Research on Marine-Derived Lipid-Lowering Active Substances and Their Molecular Mechanisms.

Hyperlipidemia (HLP) is a metabolic disorder caused by abnormal lipid metabolism. Recently, the prevalence of HLP caused by poor dietary habits in the population has been increasing year by year. In addition, lipid-lowering drugs currently in clinical use have shown significant improvement in blood lipid levels, but are accompanied by certain side effects. However, bioactive marine substances have been shown to possess a variety of physiological activities such as hypoglycemic, antioxidant, antithrombotic and effects on blood pressure. Therefore, the hypolipidemic efficacy of marine bioactive substances with complex and diverse structures has also attracted attention. This paper focuses on the therapeutic role of marine-derived polysaccharides, unsaturated fatty acids, and bioactive peptides in HLP, and briefly discusses the main mechanisms by which these substances exert their hypolipidemic activity in vivo.

Totum-070, a Polyphenol-Rich Plant Extract, Prevents Hypercholesterolemia in High-Fat Diet-Fed Hamsters by Inhibiting Intestinal Cholesterol Absorption.

Atherosclerotic cardiovascular disease is the leading cause of mortality worldwide, and hypercholesterolemia is a central risk factor for atherosclerosis. This study evaluated the effects of Totum-070, a plant-based polyphenol-rich supplement, in hamsters with high-fat diet (HFD)-induced dyslipidemia. The molecular mechanisms of action were explored using human Caco2 enterocytes. Totum-070 supplementation reduced the total cholesterol (-41%), non-HDL cholesterol (-47%), and triglycerides (-46%) in a dose-dependent manner, compared with HFD. HFD-induced hepatic steatosis was also significantly decreased by Totum-070, an effect associated with the reduction in various lipid and inflammatory gene expression. Upon challenging with olive oil gavage, the post-prandial triglyceride levels were strongly reduced. The sterol excretion in the feces was increased in the HFD-Totum-070 groups compared with the HFD group and associated with reduction of intestinal cholesterol absorption. These effects were confirmed in the Caco2 cells, where incubation with Totum-070 inhibited cholesterol uptake and apolipoprotein B secretion. Furthermore, a microbiota composition analysis revealed a strong effect of Totum-070 on the alpha and beta diversity of bacterial species and a significant decrease in the Firmicutes to Bacteroidetes ratio. Altogether, our findings indicate that Totum-070 lowers hypercholesterolemia by reducing intestinal cholesterol absorption, suggesting that its use as dietary supplement may be explored as a new preventive strategy for cardiovascular diseases.

Optimized Sugar-Free Citrus Lemon Juice Fermentation Efficiency and the Lipid-Lowering Effects of the Fermented Juice.

Aging and obesity make humans more prone to cardiovascular and metabolic syndrome diseases, leading to several serious health conditions, including hyperlipidemia, high blood pressure, and sleep disturbance. This study aimed to explore the hypolipidemic effect of fermented citrus lemon juice using a hyperlipidemic hamster model. The sugar-free lemon juice's fermentation was optimized, and the characteristics of fresh and fermented lemon juice (FLJ) were evaluated and compared, which contained polyphenols and superoxide dismutase-like activity. Results showed that the absorption and utilization efficiency of FLJ was higher compared with the unfermented lemon juice. This study's prefermentation efficiency evaluation found that 21-30 days of bacterial DMS32004 and DMS32005 fermentation of fresh lemon juice provided the best fermentation benefits, and 21-day FLJ was applied as a remedy after the efficiency compassion. After six weeks of feeding, the total cholesterol (TC) and triglyceride (TG) values in the blood and liver of the FLJ treatment groups were decreased compared with the high-fat diet (HFD) group. In addition, the blood low-density lipoprotein cholesterol (LDL-C) levels were significantly reduced in the FLJ treatment groups compared with the HFD group. In contrast, the blood high-density lipoprotein (HDL-C) to LDL-C ratio increased considerably in the FLJ treatment groups, and the total to HDL ratio was significantly lower than in the HFD group. Compared with the HFD group, the TC content in the FLJ treatment groups' feces increased significantly. This study demonstrated that the sugar-free fermentation method and fermentation cycle management provided FLJ with the potential to regulate blood lipids. Further research and verification will be carried out to isolate specific substances from the FLJ and identify their mechanisms of action.

Untargeted and Targeted Metabolomics Reveal the Active Peptide of Eupolyphaga sinensis Walker against Hyperlipidemia by Modulating Imbalance in Amino Acid Metabolism.

The active peptide (APE) of Eupolyphaga sinensis Walker, which is prepared by bioenzymatic digestion, has significant antihyperlipidemic effects in vivo, but its mechanism of action on hyperlipidemia is not clear. Recent studies on amino acid metabolism suggested a possible link between it and hyperlipidemia. In this study, we first characterized the composition of APE using various methods. Then, the therapeutic effects of APE on hyperlipidemic rats were evaluated, including lipid levels, the inflammatory response, and oxidative stress. Finally, the metabolism-regulating mechanisms of APE on hyperlipidemic rats were analyzed using untargeted and targeted metabolomic approaches. The results showed that APE significantly reduced the accumulation of fat, oxidative stress levels, and serum pro-inflammatory cytokine levels. Untargeted metabolomic analysis showed that the mechanism of the hypolipidemic effect of APE was mainly related to tryptophan metabolism, phenylalanine metabolism, arginine biosynthesis, and purine metabolism. Amino-acid-targeted metabolomic analysis showed that significant differences in the levels of eight amino acids occurred after APE treatment. Among them, the expression of tryptophan, alanine, glutamate, threonine, valine, and phenylalanine was upregulated, and that of arginine and proline was downregulated in APE-treated rats. In addition, APE significantly downregulated the mRNA expression of SREBP-1, SREBP-2, and HMGCR. Taking these points together, we hypothesize that APE ameliorates hyperlipidemia by modulating amino acid metabolism in the metabolome of the serum and feces, mediating the SREBP/HMGCR signaling pathway, and reducing oxidative stress and inflammation levels.

Lipid accumulation-mediated histone hypoacetylation drives persistent NK cell dysfunction in anti-tumor immunity.

Hyperlipidemia impairs anti-tumor immune responses and is closely associated with increased human cancer incidence and mortality. However, the underlying mechanisms are not well understood. In the present study, we show that natural killer (NK) cells isolated from high-fat-diet mice or treated with oleic acid (OA) in vitro exhibit sustainable functional defects even after removal from hyperlipidemic milieu. This is accompanied by reduced chromatin accessibility in the promoter region of NK cell effector molecules. Mechanistically, OA exposure blunts P300-mediated c-Myc acetylation and shortens its protein half-life in NK cells, which in turn reduces P300 accumulation and H3K27 acetylation and leads to persistent NK cell dysfunction. NK cells engineered with hyperacetylated c-Myc mutants surmount the suppressive effect of hyperlipidemia and display superior anti-tumor activity. Our findings reveal the persistent dysfunction of NK cells in dyslipidemia milieu and extend engineered NK cells as a promising strategy for tumor immunotherapy.

ApoE enhances mitochondrial metabolism via microRNA-142a/146a-regulated circuits that suppress hematopoiesis and inflammation in hyperlipidemia.

Apolipoprotein E (ApoE) is recognized for its pleiotropic properties that suppress inflammation. We report that ApoE serves as a metabolic rheostat that regulates microRNA control of glycolytic and mitochondrial activity in myeloid cells and hematopoietic stem and progenitor cells (HSPCs). ApoE expression in myeloid cells increases microRNA-146a, which reduces nuclear factor κB (NF-κB)-driven GLUT1 expression and glycolytic activity. In contrast, ApoE expression reduces microRNA-142a, which increases carnitine palmitoyltransferase 1a (CPT1A) expression, fatty acid oxidation, and oxidative phosphorylation. Improved mitochondrial metabolism by ApoE expression causes an enrichment of tricarboxylic acid (TCA) cycle metabolites and nicotinamide adenine dinucleotide (NAD+) in macrophages. The study of mice with conditional ApoE expression supports the capacity of ApoE to foster microRNA-controlled immunometabolism. Modulation of microRNA-146a and -142a in the hematopoietic system of hyperlipidemic mice using RNA mimics and antagonists, respectively, improves mitochondrial metabolism, which suppresses inflammation and hematopoiesis. Our findings unveil microRNA regulatory circuits, controlled by ApoE, that exert metabolic control over hematopoiesis and inflammation in hyperlipidemia.

miR-32-5p induces hepatic steatosis and hyperlipidemia by triggering de novo lipogenesis.

BACKGROUND AND OBJECTIVES: MicroRNA-dependent regulation of hepatic lipid metabolism has been recognized recently as a key pathological mechanism contributing to the development of NAFLD. However, whether miR-32-5p (miR-32) plays a role in lipid metabolism or contributes to NAFLD remains unclear. METHODS AND RESULTS: A marked increase in miR-32 expression was observed in liver samples from patients and mice with NAFLD, as well as in palmitate-induced hepatocytes. Hepatocyte-specific miR-32 knockout (miR-32-HKO) dramatically ameliorated hepatic steatosis and metabolic disorders in high-fat diet-fed mice. Conversely, hepatic miR-32 overexpression markedly exacerbated the progression of these abnormalities. Further, combinational analysis of transcriptomics and lipidomics suggested that miR-32 was a key trigger for de novo lipogenesis in the liver. Mechanistically, RNA sequencing, luciferase assay and adenovirus-mediated downstream gene rescue assay demonstrated that miR-32 directly bound to insulin-induced gene 1 (INSIG1) and subsequently activated sterol regulatory element binding protein-mediated lipogenic gene programs, thereby promoting hepatic lipid accumulation and metabolic disorders. Notably, pharmacological administration of miR-32 antagonist significantly inhibited palmitate-induced triglyceride deposition in hepatocytes and markedly mitigated hepatic steatosis and metabolic abnormalities in obesity-associated NAFLD mice. CONCLUSION: miR-32 is an important checkpoint for lipogenesis in the liver, and targeting miR-32 could be a promising therapeutic approach for NAFLD treatment.

Polyphenol-rich extract from loquat fruit peel prevents hyperlipidemia and hepato-nephrotoxicity in mice: in vivo study and in silico prediction of possible mechanisms involving identified polyphenols and/or their circulating metabolites.

Hyperlipidemia is the most well-known cause of metabolic complications and tissue toxicity such as liver steatosis, atherosclerosis and obesity. This study aims to evaluate the preventive effect of loquat fruit peel extract (PE) against tyloxapol-induced hyperlipidemia and related tissue lipotoxicity in mice. The in vivo study was conducted on mice injected daily with tyloxapol at 100 mg per kg B.W. and treated simultaneously with the PE at concentrations of 100 and 200 mg kg-1 or fenofibrate for 28 days. Plasma and tissue lipid biochemical analyses were undertaken using enzymatic methods. The antioxidative stress was revealed by measuring the malondialdehyde content and activities of superoxide dismutase and catalase as well as the scavenging activity against lipoperoxyl radicals. The PE significantly prevented oxidative stress and restored lipid metabolism, plasma glucose, body weight, organ relative mass and biomarkers of hepato-nephrotoxicity as well as the histological structure of the liver and kidneys. It contains five major polyphenols, namely, ferulic acid, caffeic acid, neochlorogenic acid, chlorogenic acid and quercetin. According to molecular docking analysis, these compounds and their circulating metabolites could interact with major proteins implicated in lipid metabolism and oxidative stress. Overall, the study suggests that PE could prevent hyperlipidemia and related toxic tissue complications.

Lysimachia christinae polysaccharide attenuates diet-induced hyperlipidemia via modulating gut microbes-mediated FXR-FGF15 signaling pathway.

Polysaccharides are one of the most abundant and active components of Lysimachia christinae (L. christinae), which is widely adopted for attenuating abnormal cholesterol metabolism; however, its mechanism of action remains unclear. Therefore, we fed a natural polysaccharide (NP) purified from L. christinae to high-fat diet mice. These mice showed an altered gut microbiota and bile acid pool, which was characterized by significantly increased Lactobacillus murinus and unconjugated bile acids in the ileum. Oral administration of the NP reduced cholesterol and triglyceride levels and enhanced bile acid synthesis via cholesterol 7α-hydroxylase. Additionally, the effects of NP are microbiota-dependent, which was reconfirmed by fecal microbiota transplantation (FMT). Altered gut microbiota reshaped bile acid metabolism by modulating bile salt hydrolase (BSH) activity. Therefore, bsh genes were genetically engineered into Brevibacillus choshinensis, which was gavaged into mice to verify BSH function in vivo. Finally, adeno-associated-virus-2-mediated overexpression or inhibition of fibroblast growth factor 15 (FGF15) was used to explore the farnesoid X receptor-fibroblast growth factor 15 pathway in hyperlipidemic mice. We identified that the NP relieves hyperlipidemia by altering the gut microbiota, which is accompanied by the active conversion of cholesterol to bile acids.

Averrhoa carambola L. fruit polyphenols ameliorate hyperlipidemia, hepatic steatosis, and hyperglycemia by modulating lipid and glucose metabolism in mice with obesity.

BACKGROUND: Hyperlipidemia, hepatic steatosis, and hyperglycemia are common metabolic complications of obesity. The objective of the present study is to investigate the in vivo protective effect of Averrhoa carambola L. fruit polyphenols (ACFP) on hyperlipidemia, hepatic steatosis, and hyperglycemia in mice with high-fat diet (HFD)-induced obesity and elucidate the mechanisms of action underlying the beneficial effects of ACFP. Thirty-six specific pathogen-free male C57BL/6J mice (4 weeks old, weighing 17.1-19.9 g) were randomly divided into three groups and fed with a low-fat diet (LFD, 10% fat energy), HFD (45% fat energy), or HFD supplemented with ACFP by intragastric administration for 14 weeks. Obesity-related biochemical indexes and hepatic gene expression levels were determined. The statistical analyses were conducted using one-way analysis of variance (ANOVA) followed by Duncan's multiple range test. RESULTS: The results showed that the body weight gain, serum triglycerides, total cholesterol, glucose, insulin resistance index, and steatosis grade in the ACFP group decreased by 29.57%, 26.25%, 27.4%, 19.6%, 40.32%, and 40%, respectively, compared to the HFD group. Gene expression analysis indicated that ACFP treatment improved the gene expression profiles involved in lipid and glucose metabolism compared to the HFD group. CONCLUSION: ACFP protected from HFD-induced obesity and obesity-associated hyperlipidemia, hepatic steatosis, and hyperglycemia by improving lipid and glucose metabolism in mice. © 2023 Society of Chemical Industry.

Marein reduces lipid levels via modulating the PI3K/AKT/mTOR pathway to induce lipophagy.

ETHNOPHARMACOLOGICAL RELEVANCE: The capitulum of Coreopsis tinctoria Nutt. (CT, Xue-Ju in Chinese) is a precious medicine in Xinjiang Uygur Autonomous region of China. The Coreopsis tinctoria Nutt. is used to prevent and treat dyslipidemia, coronary heart disease, etc. Recent studies have shown that its extract has a pharmacological effect on hyperlipidemia and hyperglycemia. AIM OF THE STUDY: The study aimed to systematically evaluate the lipid-lowering activity of CT through a mice model of hyperlipidemia and a human hepatoma G2 (HepG2) cells model of lipid accumulation, and to investigate its main active components and mechanism. MATERIALS AND METHODS: Biochemical analysis of blood/liver lipids and liver histopathology were used to evaluate the effect of the aqueous extract of Coreopsis tinctoria Nutt. (AECT) on hyperlipidemia mice. High-performance liquid chromatography (HPLC) analysis was used to identify the main components in the AECT. Oil red O staining, immunofluorescence, western blotting, and determination of the total cholesterol (TC), total triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were used to further study the effect and potential mechanism of the AECT main components on sodium oleate-induced lipid accumulation in HepG2 cells. RESULTS: We confirmed the lipid-lowering activity of the aqueous extract and further identified flavonoids as its main components. Among them, five Coreopsis tinctoria Nutt. flavonoids mixture (FM) significantly reduced lipid droplet area, lipid content, TC, TG, and LDL-C levels, and elevated HDL-C levels in HepG2 cells induced by sodium oleate. Furthermore, they increased lipophagy in HepG2 lipid-accumulating cells, while decreasing the ratio of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. Most importantly, marein may be a key component. CONCLUSIONS: Our study demonstrated that AECT, with flavonoids as the main component, can improve diet-induced hyperlipidemia in obese mice. Among the main five flavonoids, marein plays a key role in promoting lipophagy by regulating the PI3K/AKT/mTOR pathway, resulting in a lipid-lowering effect.

Effects of the polypeptide from peanut meal mixed fermentation on lipid metabolism and intestinal flora of hyperlipidemic mice.

BACKGROUND: Hyperlipidemia is one of the metabolic disorders posing great threat to human health. Our previous studies have shown that the nutritional properties of peanut meal after fermentation are markedly improved, and can effectively improve hyperlipidemia caused by high-fat diet in mice. In this study, in order to facilitate the further utilization of peanut meal, the effect of peanut polypeptide (PP) from peanut meal mixed fermentation on lipid metabolism in mice fed with high-fat diet (HFD) and its possible mechanism were investigated. Fifty male C57BL/6J mice were randomly divided into five groups: normal control group (N), high-fat model group (M), PP low-dose group (PL), PP high-dose group (PH), and atorvastatin positive control group (Y). RESULTS: The results show that PP supplementation can effectively reduce the body weight of mice, decrease the serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and leptin levels (P < 0.05), increase the high-density lipoprotein cholesterol (HDL-C) levels (P < 0.05), up-regulate the expression levels of ileal tight junction proteins ZO-1 and occludin (P < 0.05), reduce the hepatocyte injury and lipid accumulation caused by high-fat diet and increase the species richness of intestinal flora. CONCLUSION: PP can significantly improve hyperlipidemia and regulate intestinal flora disorders caused by hyperlipidemia. The possible mechanism may be related to the reduction of serum leptin levels and up-regulating the expression levels of the ileal tight junction proteins ZO-1 and occludin. This study provides evidence for its regulatory role in lipid metabolism and intestinal function, and provides a research basis for the potential nutritional benefits of underutilized food by-products. © 2023 Society of Chemical Industry.

Oleoylethanolamide alleviates hyperlipidaemia-mediated vascular calcification via attenuating mitochondrial DNA stress triggered autophagy-dependent ferroptosis by activating PPARα.

Vascular calcification, a prevalent pathological alteration in metabolic syndromes, is tightly related with cardiometabolic risk events. Ferroptosis, a newly iron-dependent programmed cell death, induced by palmitic acid (PA), the major saturated free fatty acid in hyperlipidemia, is a vital mechanism of vascular calcification. Recent studies reported that ferroptosis is a distinctive type of cell death dependent on autophagy, with the lipotoxicity of PA on cell viability being closely linked with autophagy. Oleoylethanolamide (OEA), an endogenous bioactive mediator of lipid homeostasis, exerts vascular protection against intimal calcification, atherosclerosis; however, its beneficial effect on vascular smooth muscle cell (VSMC)-associated medial calcification has not been investigated. Our aim was to characterize the effect of OEA on vascular calcification and ferroptosis of VSMCs under hyperlipidaemia/PA exposure. In vivo, vascular calcification model was induced in rats by high-fat diet and vitamin D3 plus nicotine; in vitro, VSMCs ferroptosis was induced by PA or plus ß-glycerophosphate mimicking vascular calcification. The calcium deposition in hyperlipidaemia-mediated rat thoracic aortas, the PA-induced ferroptosis and subsequent calcium deposition in VSMCs, were suppressed by OEA treatment. Additionally, CGAS-STING1-induced ferritinophagy, the main molecular mechanism of PA-triggered ferroptosis of VSMCs, was activated by mitochondrial DNA damage; however, early administration of OEA alleviated these phenomena. Intriguingly, overexpression of peroxisome proliferator activated receptor alpha (PPARα) contributed to a decrease in PA-induced ferroptosis, whereas PPARɑ knockdown inhibited the OEA-mediated anti-ferroptotic effects. Collectively, our study demonstrated that OEA serves as a prospective candidate for the prevention and treatment of vascular calcification in metabolic abnormality syndromes.