Hexane-Isopropanolic Extract of Tungrymbai, a North-East Indian fermented soybean food prevents hepatic steatosis via regulating AMPK-mediated SREBP/FAS/ACC/HMGCR and PPARα/CPT1A/UCP2 pathways

Alleviation of Diabetic Retinopathy by Glucose-Triggered Delivery of Vitamin D via Dextran-Gated Functionalized Mesoporous Silica Nanoparticles

Diabetic retinopathy (DR) is the most common retinal disorder, developed in 35% of patients with diabetes mellitus. Lower serum levels of 25-hydroxyvitamin D are associated with the increased risk of developing DR. High doses of the active form of vitamin D (VD), on the contrary, for a long period of time may lead to hypercalcemia and an imbalance in the regulation of bone metabolism. Herein, we studied the efficacy of dextran-gated carboxyphenylboronic acid (CPBA)-functionalized mesoporous silica nanoparticles (MSNs) for glucose-sensitive delivery of 1,25-dihydroxyvitamin D3 to modulate cellular oxidative stress and inflammation for managing DR. The physical adsorption technique was employed to load VD onto nanoparticles (263.63 μg/mg (w/w)). In the presence of glucose, the dextran molecules detach from pores, allowing VD to release since glucose has 1,2-cis diol groups which have very high affinity to CPBA. Approximately 75% of VD was released upon exposure to 25 mM glucose at a time point of 10 h, demonstrating glucose-responsive delivery. Furthermore, MSN-CPBA was able to deliver VD in a glucose-dependent manner and improve the bioavailability of VD. In high-glucose-supplemented human retinal cells, MSN-CPBA increased the bioavailability of VD and reduced cellular oxidative stress and inflammation. The results suggested that the VD-loaded nanocarrier exerted remarkable therapeutic capacity in reducing the risk of developing DR. By using MSN-CPBA as a delivery platform with dextran gating, the research proposes an effective treatment approach for improving the bioavailability and effectiveness of a hydrophobic molecule in the treatment of DR.

The attenuating effects of synbiotic containing Cetobacterium somerae and Astragalus polysaccharide against trichlorfon-induced hepatotoxicity in crucian carp (Carassius carassius)

This study aimed to investigate the hepatotoxic effects of trichlorfon on crucian carp (Carassius carassius) and the attenuating effects of a synbiotic combination of Cetobacterium somerae and Astragalus polysaccharide on hepatotoxicity. Results showed that trichlorfon did indeed induce hepatotoxicity in crucian carp and the synbiotic reversed this hepatotoxicity caused by trichlorfon. The synbiotic increased TC, TG, LDL-C, ALT and AST levels and decreased serum HDL-C levels caused by trichlorfon. H&E and Oil Red O staining demonstrated that the synbiotic ameliorated liver damage and abnormal lipid accumulation. The activity of antioxidant enzymes (T-SOD, CAT, GSH-Px) in the liver was also enhanced by the administration of the synbiotic. The supplementation of the synbiotic also increased the level of short-chain fatty acids in the intestine. In addition, the synbiotic balanced the gut microbial composition, leading to a reduction in the abundance of potentially pathogenic bacteria and an increase in the abundance of bacteria producing short-chain fatty acids. In conclusion, these findings indicate that trichlorfon can induce hepatotoxicity in crucian carp, whereas synbiotics can regulate gut microbiota, promote the growth of beneficial bacteria and increase the production of SCFAs, and alleviate trichlorfon-induced liver injury.

Oxidative Stress Induced by Lipotoxicity and Renal Hypoxia in Diabetic Kidney Disease and Possible Therapeutic Interventions: Targeting the Lipid Metabolism and Hypoxia

Oxidative stress, a hallmark pathophysiological feature in diabetic kidney disease (DKD), arises from the intricate interplay between pro-oxidants and anti-oxidants. While hyperglycemia has been well established as a key contributor, lipotoxicity emerges as a significant instigator of oxidative stress. Lipotoxicity encompasses the accumulation of lipid intermediates, culminating in cellular dysfunction and cell death. However, the mechanisms underlying lipotoxic kidney injury in DKD still require further investigation. The key role of cell metabolism in the maintenance of cell viability and integrity in the kidney is of paramount importance to maintain proper renal function. Recently, dysfunction in energy metabolism, resulting from an imbalance in oxygen levels in the diabetic condition, may be the primary pathophysiologic pathway driving DKD. Therefore, we aim to shed light on the pivotal role of oxidative stress related to lipotoxicity and renal hypoxia in the initiation and progression of DKD. Multifaceted mechanisms underlying lipotoxicity, including oxidative stress with mitochondrial dysfunction, endoplasmic reticulum stress activated by the unfolded protein response pathway, pro-inflammation, and impaired autophagy, are delineated here. Also, we explore potential therapeutic interventions for DKD, targeting lipotoxicity- and hypoxia-induced oxidative stress. These interventions focus on ameliorating the molecular pathways of lipid accumulation within the kidney and enhancing renal metabolism in the face of lipid overload or ameliorating subsequent oxidative stress. This review highlights the significance of lipotoxicity, renal hypoxia-induced oxidative stress, and its potential for therapeutic intervention in DKD.

Virgin Camellia Seed Oil Improves Glycolipid Metabolism in the Kidney of High Fat-Fed Rats through AMPK-SREBP Pathway

Camellia seed oil (CO) is used as edible oil in southern China because of its excellent fatty acid composition and abundant bioactive compounds. Chronic kidney disease (CKD) is one of the most common chronic degenerative diseases in China, and active compounds in vegetable oil, like virgin olive oil, have been demonstrated to be efficacious in the management of CKD. In this study, virgin CO was refined using a standard process. The refining had minimal impact on the fatty acid composition, but significantly reduced the presence of bioactive compounds like polyphenols in CO. Sprague-Dawley (SD) rats fed with high fat diet (Group G) were treated with either virgin (Group Z) or refined CO (Group R). The oral administration of CO alleviated lipid accumulation and decreased body and kidney weight gain. Furthermore, treatment with virgin CO increased the renal ATP content. The renal expression levels of AMPK and key enzymes involved in fatty acid oxidation (CPT-1 and ACOX1) and glycolysis (HK, PFK, PK and GAPDH) were up-regulated in Group Z, thereby enhancing the ATP production. Virgin CO treatment downregulated the expression level of SREBP2 and its downstream target genes, such as ACC, FAS, and HMGCR, which reduced lipid synthesis. These findings indicate that virgin CO improves glycolipid metabolism and restores energy homeostasis in the kidneys of rats fed with a high-fat diet by modulating the AMPK-SREBP-signaling pathway, suggesting the potential of active compounds in virgin CO for managing the renal failure associated with glycolipid dysmetabolism.

Lipid metabolic vulnerabilities of multiple myeloma

Multiple myeloma (MM) is the second most common hematological malignancy worldwide, characterized by abnormal proliferation of malignant plasma cells within a tumor-permissive bone marrow microenvironment. Metabolic dysfunctions are emerging as key determinants in the pathobiology of MM. In this review, we highlight the metabolic features of MM, showing how alterations in various lipid pathways, mainly involving fatty acids, cholesterol and sphingolipids, affect the growth, survival and drug responsiveness of MM cells, as well as their cross-talk with other cellular components of the tumor microenvironment. These findings will provide a new path to understanding the mechanisms underlying how lipid vulnerabilities may arise and affect the phenotype of malignant plasma cells, highlighting novel druggable pathways with a significant impact on the management of MM.

Raspberry ketone ameliorates nonalcoholic fatty liver disease in rats by activating the AMPK pathway

The current study aimed to investigate the effect of orally administered raspberry ketone (RK) on ameliorating nonalcoholic fatty liver disease (NAFLD) induced in rats by high-fat high-fructose diet (HFFD) in comparison to calorie restriction (CR) regimen. Thirty male Wistar rats were divided into two experimental groups; one was fed normal chow diet (NCD, n = 6) for 15 weeks to serve as normal control group and the other group was fed HFFD (n = 24) for 7 weeks to induce NAFLD. After induction, rats in the HFFD group were randomly allocated into four groups (n = 6 rats each). One group continued on HFFD feeding for 8 weeks (NAFLD control group). The remaining 3 groups received NCD, calorie-restricted diet, or NCD along with RK (55 mg/kg/day, orally) for 8 weeks. Like CR, RK effectively attenuated NAFLD and ameliorated the changes attained by HFFD. RK upregulated the expression of the phosphorylated AMP-activated protein kinase (P-AMPK) and fatty acid oxidation factors; peroxisome proliferator-activated receptor alpha (PPAR-α) and carnitine palmitoyltransferase-1 (CPT-1) and downregulated lipogenic factors; sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) in the hepatic tissue. Also, RK improved lipid profile parameters, liver enzymes and both body and liver tissue weights. Altogether, these findings suggest that oral administration of RK, along with normal diet, ameliorated NAFLD in a way similar to CR. This approach could be an alternative to CR in the management of NAFLD, overcoming the poor compliance to long term CR regimen.

Bile acids supplementation modulates lipid metabolism, intestinal function, and cecal microbiota in geese

Bile acids(BAs) are important components of bile and play a significant role in fat metabolism. However, there is currently no systematic evaluation of the use of BAs as feed additives for geese.This study aimed to investigate the effects of adding BAs to goose feed on growth performance, lipid metabolism, intestinal morphology, mucosal barrier function, and cecal microbiota. A total of 168 28-day-old geese were randomly assigned to four treatment groups and fed diets supplemented with 0, 75, 150, or 300 mg/kg of BAs for 28 days. The addition of 75 and 150 mg/kg of BAs significantly improved the feed/gain (F/G) (p  < 0.05).The addition of BAs decreased abdominal fat percentage and serum total cholesterol (TC) levels, with 150 mg/kg of BAs significantly reducing serum triglyceride levels and increased expression of Farnesoid X Receptor (FXR) mRNA in the liver(p  < 0.05), 300 mg/kg of BAs significantly increasing the expression level of liver peroxisome proliferator-activated receptor α (PPARα) (p < 0.05). In terms of intestinal morphology and mucosal barrier function, 150 mg/kg of BAs significantly increased villus height (VH) and VH/crypt depth (CD) in the jejunum (p < 0.05). The addition of 150 and 300 mg/kg of BAs significantly reduced the CD in the ileum, while increasing VH and VH/CD (p<0.05). Additionally, the addition of 150 and 300 mg/kg of BAs significantly increased the expression levels of zonula occludens-1 (ZO-1) and occludin in the jejunum. Simultaneously 150mg/kg and 300mg/kg BAs increased the total short-chain fatty acids (SCFA) concentrations in the jejunum and cecum(p < 0.05).Supplementation with BAs resulted in a significant increase in the ɑ-diversity of cecal microbiota and a decrease in the abundance of Proteobacteria in the cecum. The addition of 150 mg/kg of BAs significantly reduced the abundance of Bacteroidetes and increased the abundance of Firmicutes. Moreover,Linear discriminant analysis Effect Size analysis (LEfSe) showed that the abundances of bacteria producing SCFA and bile salt hydrolases (BSH) were increased in the BAs-treated group. Furthermore, Spearman's analysis showed that the genus Balutia, which is negatively correlated with visceral fat area, was positively correlated with serum high-density lipoprotein cholesterol (HDL-C), while Clostridium was positively correlated with intestinal VH and VH/CD. In conclusion, BAs can be considered an effective feed additive for geese, as they increased SCFA concentration, improve lipid metabolism and intestinal health by enhancing the intestinal mucosal barrier, improving intestinal morphology, and altering the cecal microbiota structure.

Xanthosine, a purine glycoside mediates hepatic glucose homeostasis through inhibition of gluconeogenesis and activation of glycogenesis via regulating the AMPK/ FoxO1/AKT/GSK3β signaling cascade

Type 2 Diabetes Mellitus (T2DM) is characterized by hepatic insulin resistance, which results in increased glucose production and reduced glycogen storage in the liver. There is no previous study in the literature that has explored the role of Xanthosine in hepatic insulin resistance. Moreover, mechanistic explanation for the beneficial effects of Xanthosine in lowering glucose production in diabetes is yet to be determined. This study for the first time investigated the beneficial effects of Tribulus terrestris (TT) and its active constituent, Xanthosine on gluconeogenesis and glycogenesis in Free Fatty Acid (FFA)-induced CC1 hepatocytes and streptozotocin (STZ)-induced Wistar rats. Xanthosine enhanced glucose uptake and decreased glucose production through phosphorylation of AMP-activated protein kinase (AMPK) and forkhead box transcription factor O1 (FoxO1), and downregulation of two rate limiting enzymes of gluconeogenesis, phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) expression in FFA-induced CC1 cells. Xanthosine also prevented FFA-induced decreases in the phosphorylation of AKT/Protein kinase B, glycogen synthase kinase-3β (GSK3β), and increased glycogen synthase (GS) phosphorylation to increase the glycogen content in the hepatocytes. Moreover, in STZ-induced diabetic rats, oral administration of TT n-butanol fraction (TTBF) enriched with compound Xanthosine (10, 50 & 100 mg/kg body weight) improved insulin sensitivity, reduced fasting blood glucose levels, improved glucose homeostasis by reducing gluconeogenesis via AMPK/FoxO1-mediated PEPCK and G6Pase down-regulation and increasing glycogenesis via AKT/GSK3β-mediated GS activation. Overall, Xanthosine may be developed further for treating insulin resistance and hyperglycemia in T2DM.

Fish oil and chicoric acid combination protects better against palmitate-induced lipid accumulation via regulating AMPK-mediated SREBP-1/FAS and PPARα/UCP2 pathways

Non-alcoholic fatty liver disease (NAFLD) is associated with lipid accumulation and lipotoxicity. The main aim of this study is to evaluate the synergistic treatment effect of fish oils (FOs) and chicoric acid (CA) in palmitate (PA)-induced NAFLD HepG2 model. HepG2 cells were pre-treated with palmitate (0.75 mM) for 24 h, and then were exposed to CA, FOs and combination of these chemicals for another 24 h. Gene expression and protein levels were determined using qRT-PCR and western blotting or ELISA analysing, respectively. The combination index (CI) values of FOs and CA in HepG2 cells were calculated according to the Chou-Talalay equation using the CompuSyn software. FOs and CA acid together synergistically reduced lipid accumulation as indicated by decreased oil red O staining (vehicle-treated control: 1 ± 0.1; PA-treated control: 4.7 ± 0.4; PA + CA100: 3.9 ± 0.4; PA + CA200: 2.4 ± 0.3; PA + FOs: 2.7 ± 0.1; PA + CA200 + FOs: 1.5 ± 0.1) and triglyceride (vehicle-treatedcontrol:10 ± 1.2; PA-treated control: 25.8 ± 2.7; PA + CA100: 18.9 ± 2.5; PA + CA200: 14.4 ± 1.8; PA + FOs: 15.2 ± 2.4; PA + CA200 + FOs: 11.9 ± 1.5) levels in PA-treated HepG2 cells. Gene expression and Immunoblotting analysis confirmed the combination effect of FOs and CA in up-regulation of AMPK-mediated PPARα/UCP2 and down-regulation of AMPK-mediated SREBP-1/FAS signalling pathways. Collectively, these results suggest that combining FOs with CA can serve as a potential combination therapy for NAFLD.

Taurine Attenuates Oxidized Fish Oil-Induced Oxidative Stress and Lipid Metabolism Disorder in Mice

The objective of this study was to determine the effect of dietary taurine on lipid metabolism and liver injury in mice fed a diet high in oxidized fish oil. The ICR mice (six weeks old) were randomly assigned to six groups and fed different diets for 10 weeks: control (CON), normal plus 15% fresh fish oil diet (FFO), normal plus 15% oxidized fish oil diet (OFO), or OFO plus 0.6% (TAU1), 0.9% (TAU2) or 1.2% (TAU3) taurine. Compared to the CON group, OFO mice showed increased liver index, aspartate aminotransferase (AST) and malondialdehyde (MDA) levels in serum (p < 0.05). In addition, OFO mice had increased cholesterol (CHOL)/high-density lipoprotein cholesterol (HDL-C) and decreased HDL-C/low-density lipoprotein cholesterol (LDL-C) and n-6/n-3 polyunsaturated fatty acid (PUFA) ratio in serum (p < 0.05) compared with CON mice. Notably, dietary taurine ameliorated the liver index and AST and MDA levels in serum and liver in a more dose-dependent manner than OFO mice. In addition, compared to OFO mice, decreased levels of CHOL and ratio of CHOL/HDL-C and n-6 PUFA/n-3 PUFA in serum were found in TAU3-fed mice. Supplementation with TAU2 and TAU3 increased the relative mRNA expression levels of peroxisome proliferator-activated receptor α, adipose triglyceride lipase, lipoprotein lipase, hormone-sensitive lipase and carnitine palmitoyl transferase 1 in liver compared with the OFO group (p < 0.05). Moreover, impaired autophagy flux was detected in mice fed with the OFO diet, and this was prevented by taurine. These findings suggested that dietary taurine might provide a potential therapeutic choice against oxidative stress and lipid metabolism disorder.

Plant-Based Alkaline Fermented Foods as Sustainable Sources of Nutrients and Health-Promoting Bioactive Compounds

Traditional food fermentation is a practice that precedes human history. Acidic products such as yogurts and sourdoughs or alcoholic beverages produced through lactic acid or yeast fermentations, respectively, are widely described and documented. However, a relatively less popular group of fermented products known as alkaline fermented foods are common traditional products in Africa and Asia. These products are so called “alkaline” because the pH tends to increase during fermentation due to the formation of ammonia resulting from protein degradation by Bacillus species. Plant-based alkaline fermented foods (AFFs) are generally produced from legumes including soybean, non-soybean leguminous seeds, and other non-legume plant raw materials. Alkaline fermented food products such as natto, douchi, kinema, doenjang, chongkukjang, thua nao, meitauza, yandou, dawadawa/iru, ugba, kawal, okpehe, otiru, oso, ogiri, bikalga, maari/tayohounta, ntoba mbodi, cabuk, and owoh are produced at small industrial scale or household levels and widely consumed in Asia and Africa where they provide essential nutrients and health-promoting bioactive compounds for the population. Alkaline food fermentation is important for sustainable food security as it contributes to traditional dietary diversity, significantly reduces antinutritional components in raw plant materials thereby improving digestibility, improves health via the production of vitamins, and may confer probiotic and post-biotic effects onto consumers. In this review, we present currently available scientific information on plant-based AFFs and their role as sustainable sources of nutrients and bioactive compounds for improved health. Finally, we provide perspectives on research needs required to harness the full potential of AFFs in contributing to nutrition and health.

Dietary rhamnogalacturonan-Ⅰ rich extracts of molokhia ameliorate high fat diet-induced obesity and gut dysbiosis

Obesity is a global health issue associated with increased prevalence of disease and mortality. Molokhia (Corchorus olitorius L.) leaves, used as vegetables in Asia and Africa, comprise abundant water-soluble mucilage polysaccharides. The present study aimed to evaluate the effects of molokhia leaf polysaccharide fraction (MPF) on high-fat diet (HFD)-induced obesity and gut dysbiosis in mice. A significant decrease was observed in the body weight, adipocyte size, triglyceride serum, and low-density lipoprotein cholesterol levels, as well as in the expression of lipid synthesis-related proteins in mice treated with 4 mg/kg of MPF (MPF4). Moreover, the expression of the tight junction protein increased significantly; however, gut permeability and related inflammatory marker levels decreased in the MPF4 group. Furthermore, MPF ameliorated gut dysbiosis, whereas the MPF4 group presented a decreased Firmicutes to Bacteroidetes ratios and an increased abundance of Akkermansia during exposure to HFD. Our findings reveal that rhamnogalacturonan-Ⅰ rich MPF attenuates obesity in mice subjected to HFD by modulating the gut microbiota.

Iridoid glycoside isolated from Wendlandia glabrata and the role of its enriched fraction in regulating AMPK/PEPCK/G6Pase signaling pathway of hepatic gluconeogenesis

Phytochemical investigation of W. glabrata and antihyperglycemic potential of isolated novel iridoid glycoside enriched fraction in CC1 hepatocytes and STZ-induced diabetic mice.

Lipid metabolism in sickness and in health: Emerging regulators of lipotoxicity

Lipids play crucial roles in signal transduction, contribute to the structural integrity of cellular membranes, and regulate energy metabolism. Questions remain as to which lipid species maintain metabolic homeostasis and which disrupt essential cellular functions, leading to metabolic disorders. Here, we discuss recent advances in understanding lipid metabolism with a focus on catabolism, synthesis, and signaling. Technical advances, including functional genomics, metabolomics, lipidomics, lipid-protein interaction maps, and advances in mass spectrometry, have uncovered new ways to prioritize molecular mechanisms mediating lipid function. By reviewing what is known about the distinct effects of specific lipid species in physiological pathways, we provide a framework for understanding newly identified targets regulating lipid homeostasis with implications for ameliorating metabolic diseases.

Diversity of beneficial microorganisms and their functionalities in community-specific ethnic fermented foods of the Eastern Himalayas

The Eastern Himalayan regions of India, Nepal and Bhutan have more than 200 varieties of unsurpassed ethnic fermented foods and alcoholic beverages, which are lesser known outside the world. However, these ethnic foods are region- and community-specific, unique and some are exotic and rare, which include fermented vegetables, bamboo shoots, soybeans, cereals, milk (cow and yak), meats, fishes, and cereal-based alcoholic beverages and drinks. Ethnic communities living in the Eastern Himalayas have invented the indigenous knowledge of utilization of unseen microorganisms present in and around the environment for preservation and fermentation of perishable plant or animal substrates to obtain organoleptically desirable and culturally acceptable ethnic fermented food and alcoholic beverages. Some ethnic fermented products and traditionally prepared dry starters for production of alcoholic beverages of North Eastern states of India and Nepal were scientifically studied and reported till date, and however, limited publications are available on microbiological and nutritional aspects of ethnic fermented foods of Bhutan except on few products. Most of the beneficial microorganisms isolated from some ethnic fermented foods of the EH are listed in microbial food cultures (MFC) safe inventory. This study is aimed to review the updates on the beneficial importance of abundant microbiota and health-promoting benefits and functionalities of some ethnic fermented foods of the Eastern Himalayan regions of North East India, Nepal and Bhutan.

Theobromine ameliorates nonalcoholic fatty liver disease by regulating hepatic lipid metabolism via mTOR signaling pathway in vivo and in vitro

Theobromine, a methylxanthine present in cocoa, has been shown to possess many beneficial pharmacological properties such as anti-oxidative stress, anti-inflammatory property, and anti-microbial activity. In this study, we investigated the effects of theobromine on nonalcoholic fatty liver disease (NAFLD) and the possible underlying mechanisms in vivo and in vitro. The results showed that theobromine reduced body weight and fat mass and improved dyslipidemia. Theobromine mitigated liver injury and significantly reduced hepatic triglyceride level in mice with obesity. Histological examinations also showed hepatic steatosis was alleviated after theobromine treatment. Furthermore, theobromine reversed the elevated mRNA and protein expression of SREBP-1c, FASN, CD36, FABP4, and the suppressed expression of PPARα and CPT1a in the liver of mice with obesity, which were responsible for lipogenesis, fatty acid uptake, and fatty acid oxidation respectively. In vitro, theobromine also downregulated SREBP-1c, FASN, CD36, FABP4 and upregulated PPARα and CPT1a mRNA and protein levels in hepatocytes in a dose-dependent manner, while these changes were reversed by L-leucine, a mammalian target of rapamycin (mTOR) agonist. The present study demonstrated that theobromine improved NAFLD by inhibiting lipogenesis and fatty acid uptake and promoting fatty acid oxidation in the liver and hepatocytes, which might be associated with its suppression of mTOR signaling pathway. Novelty: Theobromine protects against high-fat diet - induced NAFLD. Theobromine inhibits lipogenesis and fatty acid uptake and promotes fatty acid oxidation in the liver and hepatocytes via inhibiting mTOR signaling pathway.

Berberine Improves Glucose and Lipid Metabolism in HepG2 Cells Through AMPKα1 Activation

Aim

This study is designed to investigate whether or not AMP-activated protein kinase α1 (AMPKα1) is required for natural product berberine (BBR) to improve glucose and lipid metabolism in HepG2 cells.

Methods

AMPKα1 knocked-out (KO, AMPKα1^-/-) cells were obtained by co-transfection of the CRISPR/Cas9 KO and HDR (homology-directed repair) plasmid into HepG2 cells, as well as subsequent screen with puromycin. The expression levels of target proteins or mRNAs were determined by western blot or real-time RT-PCR, respectively. Cellular AMPK activity, glucose consumption, lactate release, glucose production, and lipid accumulation were determined by kits.

Results

The results showed that the AMPKα1 gene was successfully KO in HepG2 cells. In AMPKα1^-/- cells, the protein expression of AMPKα1 and phosphorylated-AMPKα1 (p-AMPKα1) disappeared, the level of total AMPKα declined to about 45–50% of wild type (p < 0.01), while p-AMPKα level and AMPK activity were reduced to less than 10% of wild type (p < 0.001). BBR increased p-AMPKα1, p-AMPKα, AMPK activity, and stimulated glucose consumption, lactate release, inhibited glucose production in wild type HepG2 cells (p < 0.05 or p < 0.01). BBR also reduced intracellular lipid accumulation and suppressed the expression of lipogenic genes in oleic acid (OA) treated wild type HepG2 cells (p < 0.05 or p < 0.01). In AMPKα1^-/- HepG2 cells, the stimulating effects of BBR on p-AMPKα1, p-AMPKα, AMPK activity, and its improving effects on glucose and lipid metabolism were completely abolished.

Conclusion

Our study proves that AMPKα1 plays a critical role for BBR to improve glucose and lipid metabolism in HepG2 cells. Our results will provide new information to further understand the molecular mechanisms of BBR.

The novel long noncoding RNA Lnc19959.2 modulates triglyceride metabolism-associated genes through the interaction with Purb and hnRNPA2B1

Objective

Long noncoding RNAs (lncRNAs) are currently considered to have a vital and wide range of biological functions, but the molecular mechanism underlying triglycerides metabolism remains poorly understood. This study aims to identify novel lncRNAs differentially expressed in rat livers with hypertriglyceridemia and elucidated the function role in TG metabolism.

Methods

Differentially expressions of lncRNAs in rat livers with hypertriglyceridemia were identified by transcriptome sequencing and validated by real-time PCR. The role of lnc19959.2 in triglyceride metabolism was assessed both in vitro and in vivo. RNA pulldown and RIP assays were conducted to evaluate the interactions between lnc19959.2 and its target proteins. ChIP and Dual report assays were performed to detect the interactions between transcription factors and promoters of its target genes.

Results

We identified a novel lncRNA, and lnc19959.2 was upregulated in rat livers with hypertriglyceridemia. The knockdown of lnc19959.2 has profound TG lowering effects in vitro and in vivo. Subsequently, the genome-wide analysis identified that the knockdown of lnc19959.2 caused the deregulation of many genes during TG homeostasis. Further mechanism studies revealed that lnc19959.2 upregulated ApoA4 expression via ubiquitinated transcription inhibitor factor Purb, while it specifically interacted with hnRNPA2B1 to downregulate the expression of Cpt1a, Tm7sf2, and Gpam, respectively. In the upstream pathway, palmitate acid upregulated CCAAT/Enhancer-Binding Protein Beta (Cebpb) and facilitated its binding to the promoter of lnc19959.2, which resulted in significant promotion of lnc19959.2 transcriptional activity.

Conclusions

Our findings provide novel insights into a new layer regulatory complexity of an lncRNA modulating triglyceride homeostasis by a novel lncRNA lnc19959.2.

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lnc19959.2 was identified as a novel LncRNA in hypertriglyceridemic rat liver.

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lnc19959.2 was involved in triglyceride metabolism in vivo and in vitro.

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lnc19959.2 upregulated ApoA4 expression via ubiquitinated transcription inhibitor factor Purb.

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lnc19959.2 interacted with hnRNPA2B1 and cooperated with RNP II that controls expression of Cpt1a, Tm7sf2 and Gpam.

Atorvastatin promotes AMPK signaling to protect against high fat diet-induced non-alcoholic fatty liver in golden hamsters

Non-alcoholic fatty liver disease (NAFLD) is characterized by diffuse fatty acid degeneration and excess fat accumulation in the liver. Notably, the currently available medications used to treat NAFLD remain limited. The aim of the present study was to investigate the protective role of atorvastatin (Ato) against NAFLD in golden hamsters fed a high fat diet (HFD) and in HepG2 cells treated with palmitate, and identify the underlying molecular mechanism. Ato (3 mg/kg) was administered orally every day for 8 weeks to the hamsters during HFD administration. Hamsters in the model group developed hepatic steatosis with high serum levels of triglyceride, cholesterol, insulin and C-reactive protein, which were effectively reduced by treatment with Ato. Additionally, the relative liver weight of hamsters treated with Ato was markedly lower compared with that of the model group. Hematoxylin and eosin, and oil red O staining indicated that the livers of the animals in the model group exhibited large and numerous lipid droplets, which were markedly decreased after Ato treatment. Western blot analysis indicated that Ato inhibited fat accumulation in the liver through the AMP-activated protein kinase (AMPK)-dependent activation of peroxisome proliferator activated receptor α (PPARα), peroxisome proliferator-activated receptor-γ coactivator 1 α and their target genes. Furthermore, in vitro, Ato inhibited PA-induced lipid accumulation in HepG2 cells. This inhibitory effect was attenuated following Compound C treatment, indicating that AMPK may be a potential target of Ato. In conclusion, the increase in AMPK-mediated PPARα and its target genes may represent a novel molecular mechanism by which Ato prevents NAFLD.

Maize extract rich in ferulic acid and anthocyanins prevents high-fat-induced obesity in mice by modulating SIRT1, AMPK and IL-6 associated metabolic and inflammatory pathways

The aim was to compare the antiobesity efficacy of different concentrations of a phenolic-rich water extract from purple maize pericarp (PPE) in a murine model of obesity for 12 weeks. Forty C57BL/6 mice (n=10/group) were randomized: standard diet (SD), high-fat diet (HFD), HFD+200 mg PPE/kg (200 PPE) and HFD+500 mg PPE/kg (500 PPE). PPE contained mainly ferulic acid, anthocyanins and other phenolics (total phenolics: 448.5 μg/mg dry weight, DW). Body weight (-27.9%), blood glucose (-26.5%) and blood triglycerides (-22.1%) were most attenuated (P<.05) in 500 PPE group compared to HFD group. Also, 500 PPE group had reduced (P<.05) plasma levels of TNF-α, MCP-1, resistin and leptin compared to HFD group. Fatty liver disease scores were highest for HFD (8.4), followed by 200 PPE (6.1), 500 PPE (2.7) and SD (0.4) groups. Relative adipose tissue was lower (P<.05) in 200 PPE (7.6%), 500 PPE (8.0%) and SD (0.8%) compared to HFD (12.1%) group. In 500 PPE group, compared to HFD group, important genes were modulated related to adipogenesis (Mmp3, fold-change [FC]=7.4), inflammation (Nfkb1, FC=-1.8) and glucose metabolism (Slc2a4, FC=23.6) in adipose tissue. In liver, 500 PPE group showed modulation of genes related to gluconeogenesis (Pck1, FC=-2.9), lipogenesis (Fasn, FC=-2.4) and β-oxidation (Cpt1b, FC=3.1). Maize rich in ferulic acid and anthocyanins prevented obesity through the modulation of TLR and AMPK signaling pathways reducing adipogenesis and adipose inflammation, and promoting energy expenditure.

Medium- and long-chain triglyceride propofol reduces the activity of acetyl-coenzyme A carboxylase in hepatic lipid metabolism in HepG2 and Huh7 cells

Medium- and long-chain triglyceride (MCT/LCT) propofol is widely used as an intravenous anesthetic, especially in the intensive care unit. The present study aimed to assess whether MCT/LCT propofol is safe in the hyperlipidemic population for long-term use. Free fatty acids (FFAs) were used to establish high-fat stimulation of HepG2 and Huh7 cells. Subsequently, these cells were treated with propofol at the concentration of 0, 4, or 8 µg/ml for 24 and 48 h. The results indicated that the cell viability was notably decreased when the cells were stimulated with 2 mmol/L FFAs and treated with 12 µg/ml MCT/LCT propofol. Accordingly, we chose 2 mmol/L FFAs along with 4 and 8 µg/ml MCT/LCT propofol for the subsequent experiments. Four and 8 µg/ml MCT/LCT propofol inhibited FFA-induced lipid accumulation in the cells and significantly reversed acetyl coenzyme A carboxylase (ACC) activity. In addition, MCT/LCT propofol not only significantly promoted the phosphorylation of AMPK and ACC, but also reversed the FFA-induced decreased phosphorylation of AMPK and ACC. In conclusion, MCT/LCT propofol reverses the negative effects caused by FFAs in HepG2 and Huh7 cells, indicating that MCT/LCT propofol might positively regulate lipid metabolism.

Dietary Bile Acids Enhance Growth, and Alleviate Hepatic Fibrosis Induced by a High Starch Diet via AKT/FOXO1 and cAMP/AMPK/SREBP1 Pathway in Micropterus salmoides

A 10-week feeding trial was conducted to investigate the effects of dietary bile acids (BA) on growth, glucose and lipid metabolism, liver histopathology, and the underlying regulation mechanism on AKT/FOXO1 (forkhead box O1) and cAMP/AMPK/SREBP1 (sterol regulatory element-binding protein 1) pathway in largemouth bass (Micropterus salmoides) fed with a high starch diet. Six experimental diets were prepared with BA levels at 0 (B0), 80 (B80), 160 (B160), 240 (B240), 300 (B300), and 600 (B600) mg/kg in a basal diet with 18.7% starch. Each diet was fed to six replicates with 30 fish (6.17 ± 0.03 g) in each tank. The highest weight gain rate (WGR) was observed in B300 group and the optimal level of BA was estimated at 475 mg/kg by a monistic cubic equation regression analysis. Dietary BA inclusion decreased hepatosomatic index (HSI) and hepatic lipid content significantly. The fish in B300 group clearly showed alleviated hepatic fibrosis, but more steatohepatitis symptoms diagnosed with various histopathological and immunofluorescence analysis. 10 out of 12 samples were observed hepatic fibrosis in B0 group while only two fibrosis samples in B300 group. The promoted liver histopathology by dietary BA was related to improved glucose and lipid metabolism. Dietary BA inhibited the expression of G6Pase by activating AKT and reducing FOXO1 transcription, which improved the regulation ability of gluconeogenesis, activated cAMP/AMPK and repressed SREBP1 transcription to inhibit hepatic lipogenesis, which prevented hepatic lipid accumulation. In conclusion, dietary BA enhanced the growth and alleviated liver fibrosis induced by a high starch diet to steatohepatitis/recovery symptom via improving glucose and lipid metabolism, which regulated by AKT/FOXO1 and cAMP/AMPK/SREBP1 pathway in largemouth bass.

Xiexin Tang ameliorates dyslipidemia in high-fat diet-induced obese rats via elevating gut microbiota-derived short chain fatty acids production and adjusting energy metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional herbal medicine has been taken as a new and effective approach to treat many chronic diseases. Xiexin Tang (XXT), a compound recipe composed of Dahuang (Rheum palmatum L.), Huangqin (Scutellaria baicalensis Georgi) and Huanglian (Coptis chinensis Franch.), has been reported to have hypoglycemic and hypolipidemic effects, but its mechanism remains unclear. Our previous study found that Xiexin Tang markedly ameliorated the composition of the gut microbiota, especially for some short chain fatty acids (SCFAs) producing bacteria, and then notably increased SCFAs production. However, the mechanism of XXT on the fermentation of gut bacteria and further improvement of obesity is not yet clear.

AIM OF THE STUDY

This study aimed to unravel the molecular mechanism of XXT on the amelioration of obesity.

MATERIALS AND METHODS

Here, high-fat diet-induced obese rat model was established to investigate the intervention efficacy following oral administration of XXT. Additionally, the expressions of key enzymes of gut microbe-derived SCFAs biosynthesis and key targets in the signaling pathway of energy metabolism were investigated by ELISA and qPCR analysis.

RESULTS

Results showed that XXT could notably correct lipid metabolism disorders, alleviate systematic inflammation, improve insulin sensitivity and reduce fat accumulation. Additionally, XXT could increase gut microbiota-derived SCFAs-producing capacity by enhancing mRNA levels and activities of SCFA-synthetic key enzymes such as acetate kinase (ACK), methylmalonyl-CoA decarboxylase (MMD), butyryl-CoA: acetate CoA transferase (BUT) and butyrate kinase (BUK), which markedly decreased the adenosine triphosphate (ATP) contents, elevated adenosine diphosphate (ADP) and adenosine monophosphate (AMP) levels and further lowered the energy charge (EC) in obese rats via activating peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)/uncoupling protein-2 (UCP-2) signaling pathway. What's more, XXT could notably ameliorate dyslipidemia via increasing the gene expression of 5'-AMP-activated protein kinase (AMPK) and blocking mammalian target of rapamycin (mTOR) signaling pathway.

CONCLUSIONS

Taken together, our data provided a novel insight into the role of XXT in losing weight from energy metabolism regulation, which unraveled the molecular mechanism of XXT on the alleviation of dyslipidemia and fat heterotopic accumulation. The study provided useful information for XXT in clinical application to treat obesity.