AMPK and SREBP-1c mediate the anti-adipogenic effect of β-hydroxyisovalerylshikonin

Fulvic acid inhibits the differentiation of 3T3-L1 adipocytes by activating the Ca2+/CaMKⅡ/AMPK pathway

Type 2 diabetes increases the risk of developing obesity. Although fulvic acid alleviates back fat thickness in pigs, the mechanism underlying its anti-obesity effect remains unclear. Therefore, we investigated the anti-obesity mechanism of fulvic acid using 3T3-L1 adipocytes. We examined the effects of fulvic acid on adipocyte differentiation, cell viability, and lipid accumulation using molecular techniques. Fulvic acid treatment significantly decreased intracellular lipid accumulation in 3T3-L1 cells during the differentiation compared with that in the control group. Western blotting revealed fulvic acid-induced downregulated expression of the adipocyte differentiation-related markers peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha, and sterol regulatory element-binding protein 1. The fulvic acid treatment decreased the expression of the lipid uptake-related markers fatty acid-binding protein 4 and the cluster of differentiation 36 in 3T3-L1 cells. Moreover, fulvic acid significantly increased cytosolic Ca2+ concentration via Ca2+ sequestration from the endoplasmic reticulum, enhanced Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity, and upregulated AMP-activated protein kinase (AMPK), thereby reducing adipocyte differentiation. Conclusively, fulvic acid attenuates adipocyte differentiation by activating the Ca2+/CaMKⅡ/AMPK pathway, suggesting its anti-obesity potential.

Alkaline Mineral Complex Water Attenuates Transportation-Induced Hepatic Lipid Metabolism Dysregulation by AMPKα-SREBP-1c/PPARα Pathways

Transportation, an unavoidable process in livestock farming, causes metabolic disorders in the body, which then lead to endocrine disruption, being immunocompromised, and growth suppression. Lipid metabolism dysregulation is a critical phenotype induced by transportation. The liver is a vital organ in lipid metabolism, with a role in both lipid synthesis and lipolysis. However, the specific mechanisms by which transportation affects hepatic lipid metabolism remain unclear. This study employed rats as a model to investigate the effects of transportation on hepatic lipid metabolism. Rats subjected to transportation showed altered serum lipid profiles, including decreased serum triglyceride (TG), low-density lipoprotein cholesterol (VLDL-C), and non-esterified fatty acid (NEFA) immediately after transportation (IAT) and serum total cholesterol (TC) on day 3, and increasing serum TG, TC, and low-density lipoprotein cholesterol (LDL-C) on day 10. Meanwhile, fatty droplets in the liver were also reduced at IAT and increased on days 3 and 10. Notably, transportation also affected hepatic-lipid-metabolism-related enzyme activities and signaling pathways, such as increased AMP-activated protein kinase alpha (AMPKα) phosphorylation and modulations in key proteins and genes related to lipid metabolism, decreased hepatic acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) activities at IAT, and increased carnitine palmitoyl transferase 1 alpha (CPT-1α) at IAT and ACC and CPT-1α activities on days 3 and 10. Supplementation with alkaline mineral complex water (AMC) before and after transportation mitigated the adverse effects on hepatic lipid metabolism by modulating the AMPKα-SREBP-1c/PPARα pathway, enhancing lipid synthesis, and reducing the oxidative catabolism of fatty acids. AMC inhibited the transportation-induced activation of AMPKα and restored the balance of lipid-metabolism-related enzymes and pathways. These findings highlight AMC's potential as a therapeutic intervention to alleviate transportation-induced lipid metabolism disorders, offering significant implications for improving animal welfare and reducing economic losses in livestock farming.

Wulingsan Alleviates MAFLD by Activating Autophagy via Regulating the AMPK/mTOR/ULK1 Signaling Pathway

Here, we presented the study of the molecular mechanisms underlying the action of Wulingsan (WLS) in rats with metabolic-associated fatty liver disease (MAFLD) induced by a high-fat diet (HFD). High-performance liquid chromatography was employed to identify the chemical components of WLS. After 2 weeks of HFD induction, MAFLD rats were treated with WLS in three different doses for 6 weeks, a positive control treatment or with a vehicle. Lipid metabolism, liver function, oxidative stress, and inflammatory factors as well as pathomorphological changes in liver parenchyma were assessed in all groups. Finally, the expressions of autophagy-related markers, adenosine monophosphate-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR)/unc-51-like kinase-1 (ULK1) signaling pathway-related genes, and proteins in liver were detected. The results revealed that WLS significantly ameliorated liver injury, the dysfunction of the lipid metabolism, the oxidative stress, and overall inflammatory status. Furthermore, WLS increased the expressions of LC3B-II, Beclin1, p-AMPK, and ULK1, along with decreased p62, p-mTOR, and sterol regulatory element-binding protein-1c levels. In conclusion, we showed that WLS is capable of alleviating HFD-induced MAFLD by improving lipid accumulation, suppressing oxidative stress and inflammation, and promoting autophagy.

Screening of Platycodonis Radix Fractions for Antiobesity Activities and Elucidation of Its Molecular Mechanisms in High-Fat Diet-Fed C57BL/6 Mice

Obesity is a threat to public health and effective new medications are required. Platycodonis Radix (PR) is a traditional medicinal/dietary plant with activities against obesity. Using mice given a diet rich in fat, the antiobesity components of PR were identified and their molecular mechanisms were clarified further in this investigation. Initially, the impacts of PR fractions on liver histology and biochemical markers were assessed. Subsequently, the degrees of lipogenic and lipolytic gene and protein expressions were determined. Oral administration of PR polysaccharides (PG) (0.80 g/kg body weight) improved liver function (alanine aminotransferase and aspartate aminotransferase) and its antioxidant activities (total superoxide dismutase, glutathione peroxidase, and malondialdehyde), as well as alleviated blood lipid (total cholesterol, total triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) values, inflammatory systemic (TNF-α and IL-1β), and histological abnormalities within the liver. Furthermore, PG administration downregulated the expression for lipogenic genes (ACC and FAS) and upregulated the expression for the lipolytic gene (PPARα, LPL, CPT1, and HSL). Importantly, PG raised AMPK phosphorylation and decreased SREBP-1c protein synthesis. Thus, it is possible that PG stimulates the AMPK-LPL/HSL path (lipolytic route) plus the AMPK-ACC/PPARα-CPT1 path (associated to β-oxidation of fatty acids), while inhibiting the AMPK/(SREBP-1c)-ACC/FAS path (lipogenic route). In summary, PG has the ability to regulate lipid metabolism, and it may be useful to pharmacologically activate AMPK with PG to prevent and cure obesity.

Enterococcus faecalis: implications for host health

The microbiota represents a crucial area of research in maintaining human health due to its potential for uncovering novel biomarkers, therapies, and molecular mechanisms relevant to population identification and experimental model characterization. Among these microorganisms, Enterococcus faecalis, a Gram-positive bacterium found in the gastrointestinal tract of humans and animals, holds particular significance. Strains of this bacterial species have sparked considerable debate in the literature due to their dual nature; they can either be utilized as probiotics in the food industry or demonstrate resistance to antibiotics, potentially leading to severe illness, disability, and death. Given the diverse characteristics of Enterococcus faecalis strains, this review aims to provide a comprehensive understanding of their impact on various systems within the host, including the immunological, cardiovascular, metabolic, and nervous systems. Furthermore, we summarize the bacterium-host interaction characteristics and molecular effects to highlight their targets, features, and overall impact on microbial communities and host health.

Unraveling the rationale and conducting a comprehensive assessment of KD025 (Belumosudil) as a candidate drug for inhibiting adipogenic differentiation-a systematic review

Rho-associated kinases (ROCKs) are crucial during the adipocyte differentiation process. KD025 (Belumosudil) is a newly developed inhibitor that selectively targets ROCK2. It has exhibited consistent efficacy in impeding adipogenesis across a spectrum of in vitro models of adipogenic differentiation. Given the novelty of this treatment, a comprehensive systematic review has not been conducted yet. This systematic review aims to fill this knowledge void by providing readers with an extensive examination of the rationale behind KD025 and its impacts on adipogenesis. Preclinical evidence was gathered owing to the absence of clinical trials. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study's quality was assessed using the Joanna Briggs Institute (JBI) Checklist Critical Appraisal Tool for Systematic Reviews. In various in vitro models, such as 3T3-L1 cells, human orbital fibroblasts, and human adipose-derived stem cells, KD025 demonstrated potent anti-adipogenic actions. At a molecular level, KD025 had significant effects, including decreasing fibronectin (Fn) expression, inhibiting ROCK2 and CK2 activity, suppressing lipid droplet formation, and reducing the expression of proadipogenic genes peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα). Additionally, KD025 resulted in the suppression of fatty acid-binding protein 4 (FABP4 or AP2) expression, a decrease in sterol regulatory element binding protein 1c (SREBP-1c) and Glut-4 expression. Emphasis must be placed on the fact that while KD025 shows potential in preclinical studies and experimental models, extensive research is crucial to assess its efficacy, safety, and potential therapeutic applications thoroughly and directly in human subjects.

Molecular Docking Study of Phytosterols in Lygodium microphyllum Towards SIRT1 and AMPK, the in vitro Brine Shrimp Toxicity Test, and the Phenols and Sterols Levels in the Extract

Background

Lygodium microphyllum is a fern plant with various pharmacological activities, and phytosterols were reported contained in the n-hexane and ethyl acetate extract of this plant. Phytosterols are known to inhibit steatosis, oxidative stress, and inflammation. Sirtuin 1 (SIRT1) and adenosine monophosphate-activated protein kinase (AMPK) are the key proteins that control lipogenesis. However, information about L. microphyllum on SIRT1 and AMPK is still lacking.

Purpose

This study aims to investigate the binding mode of phytosterols in L. microphyllum extract towards AMPK and SIRT1, and the toxicity of the extract against brine shrimp (Artemia salina) larvae, and to determine the phenols and sterols levels in the extract.

Methods

The molecular docking was performed towards SIRT1 and AMPK using AutoDock v4.2.6, the toxicity of the extract was assayed against brine shrimp (Artemia salina) larvae, and the phytosterols were analyzed by employing a thin layer chromatography densitometry, and the total phenols were by spectrophotometry.

Results

The molecular docking study revealed that β-sitosterol and stigmasterol could occupy the active allosteric-binding site of SIRT1 and AMPK by binding to important residues similar to the protein's activators. The cold extraction of the plant yields 15.86% w/w. Phytochemical screening revealed the presence of phenols, steroids, flavonoids, alkaloids, and saponins. The total phenols are equivalent to 126 mg gallic acid (GAE)/g dry extract, the total sterols are 954.04 µg/g, and the β-sitosterol level is 283.55 µg/g. The LC50 value of the extract towards A. salina larvae is 203.704 ppm.

Conclusion

Lygodium microphyllum extract may have the potential to be further explored for its pharmacology activities, particularly in the discovery of plant-based anti-dyslipidemic drug candidates. However, further studies are needed to confirm their roles in alleviating lipid disorders.

Sodium butyrate improves mitochondrial function and kidney tissue injury in diabetic kidney disease via the AMPK/PGC-1α pathway

PURPOSE

Investigate the mechanism of how sodium butyrate (NaBut) improves mitochondrial function and kidney tissue injury in diabetic kidney disease (DKD) via the AMPK/PGC-1α pathway.

METHODS

Assess the effects of NaBut on glucose and insulin tolerance, urine, and gut microbial composition in db/db and db/m mice. Use flow cytometry and western blotting to detect the effects of NaBut on apoptosis, kidney mitochondrial function, and AMPK/PGC-1α signaling. Use HK-2 cells induced by high glucose (HG) to establish the DKD model in vitro and detect changes in the AMPK/PGC-1α signaling pathway and mitochondrial function after NaBut intervention.

RESULTS

NaBut attenuated blood glucose levels and reversed increases in urine and serum levels of glucose, BUN, Ucr, TG, TC, and UAE in db/db mice. NaBut improved insulin tolerance, reversed PGC-1α and p-AMPK expression level in the kidneys of db/db mice, and improved lipid accumulation and mitochondrial function. NaBut was able to reverse the effects of elevated glucose, compound C, and siRNA-PGC on ROS and ATP levels. Additionally, it increased protein expression of PGC-1α and p-AMPK.

CONCLUSION

NaBut activates the kidney mitochondrial AMPK/PGC-1α signaling pathway and improves mitochondrial dysfunction in DKD, thus protecting kidney tissue in vitro and in vivo.

Krill oil inhibited adipogenic differentiation by inducing the nuclear Nrf2 expression and the AMPK activity

The current study investigated the antiadipogenic mechanism of krill oil from the 3T3-L1 adipocytes. The krill oil adhered to the criteria as a food standard by showing 50.8% of the total phospholipid, 5.27% myristic acid, and 1.63% linoleic acid. The lipid accumulation that was measured in the 3T3-L1 cells using oil red O staining was reduced up to 54% by the krill oil. The krill oil treatment reduced the adipogenic transcription factors by downregulating the sterol regulatory element binding protein 1 (SREBP1) and acetyl-CoA carboxylase (ACC), phospho-ACC, and AMP-activated protein kinase (AMPK) phosphorylation. The current study confirmed that the krill oil inhibited adipogenesis by downregulating SREBP1 and ACC via the upregulation of the AMPK and nuclear factors E2-related factor 2 (Nrf2) signaling pathway in the 3T3-L1 adipocytes. These findings suggest that krill oil is a good source of phospholipid and phosphatidylcholine, which could be a potential natural antiobesity ingredient by inhibiting adipogenesis.

Protopanaxadiol-Enriched Rice Exerted Antiadipogenic Activity during 3T3-L1 Differentiation and Anti-Inflammatory Activity in 3T3-L1 Adipocytes

Ginseng is a traditional medicine with health benefits for humans. Protopanaxadiol (PPD) is an important bioactive compound found in ginseng. Transgenic rice containing PPD has been generated previously. In the present study, extracts of this transgenic rice were evaluated to assess their antiadipogenic and anti-inflammatory activities. During adipogenesis, cells were treated with transgenic rice seed extracts. The results revealed that the concentrations of the rice seed extracts tested in this study did not affect cell viability at 3 days post-treatment. However, the rice seed extracts significantly reduced the accumulation of lipids in cells and suppressed the activation of CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), which in turn inhibited the expression of adipogenesis-related mRNAs, such as adiponectin, PPARγ, C/EBPα, sterol regulatory element-binding protein 1, glucose transport member 4, and fatty acid synthase. In adipocytes, the extracts significantly reduced the mRNA expression of inflammation-related factors following LPS treatment. The activation of NF-κB p65 and ERK 1/2 was inhibited in extract-treated adipocytes. Moreover, treatment with extract #8 markedly reduced the cell population of the G2/M phase. Collectively, these results indicate that transgenic rice containing PPD may act as an obesity-reducing and/or -preventing agent.

Germinated Rice Seeds Improved Resveratrol Production to Suppress Adipogenic and Inflammatory Molecules in 3T3-L1 Adipocytes

Obesity is a major risk factor for a variety of diseases and contributes to chronic inflammation. Resveratrol is a naturally occurring antioxidant that can reduce adipogenesis. In this study, the antiadipogenic and anti-inflammatory activities of resveratrol-enriched rice were investigated in 3T3-L1 adipocyte cells. Cotreatment of dexamethasone and isobutylmethylxanthin upregulated adipogenic transcription factors and signaling pathways. Subsequent treatment of adipocytes with rice seed extracts suppressed the differentiation of 3T3-L1 by downregulating adipogenic transcription factors (peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α) and signaling pathways (extracellular signal-regulated kinase 1/2 and protein kinase B Akt), this was especially observed in cells treated with germinated resveratrol-enriched rice seed extract (DJ526_5). DJ526_5 treatment also markedly reduced lipid accumulation in the cells and expression of adipogenic genes. Lipopolysaccharide (LPS)-induced inflammatory cytokines (prostaglandin-endoperoxide synthase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) decreased in cells treated with DJ526_5. Collectively, DJ526_5 exerts antiadipogenic effects by suppressing the expression of adipogenesis transcription factors. Moreover, DJ526_5 ameliorates anti-inflammatory effects in 3T3-L1 adipocytes by inhibiting the activation of phosphorylation NF-κB p65 and ERK ½ (MAPK). These results highlight the potential of resveratrol-enriched rice as an alternative obesity-reducing and anti-inflammatory agent.

Cabernet sauvignon dry red wine ameliorates atherosclerosis in mice by regulating inflammation and endothelial function, activating AMPK phosphorylation, and modulating gut microbiota

Limited evidence suggests that the abundance of antioxidant polyphenols in dry red wine (DRW) may prevent cardiovascular diseases, a benefit likely attributed to abundant antioxidant polyphenols present in DRW. Here, we examined the anti-atherosclerotic effect of Cabernet Sauvignon DRW (CSDRW) in a mouse model of atherosclerosis (AS) using metabolomic profiling and molecular techniques. Oral administration of CSDRW reduced atherosclerotic lesion size in ApoE^-/- mice, alleviated hyperlipidemia, ameliorated hepatic lipid accumulation mediated by AMPK activation, and promoted lipid metabolism via PPARγ-LXR-α-ABCA1 pathway regulation. CSDRW increased the relative abundance of beneficial gut microbiota, including Bacteroidetes, Verrucomicrobiota, and Akkermansiaceae. Metabolic analysis using liquid chromatography-tandem mass spectrometry revealed that CSDRW contained various polyphenols, including flavanol, phenolic acid, flavonol, and resveratrol, which possibly mediate the beneficial effects in AS by reducing inflammation, restoring normal endothelial function, regulating hepatic lipid metabolism, and modulating gut microbiota composition.

Electromagnetic fields ameliorate hepatic lipid accumulation and oxidative stress: potential role of CaMKKβ/AMPK/SREBP-1c and Nrf2 pathways

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, and is related to disturbed lipid metabolism and redox homeostasis. However, a definitive drug treatment has not been approved for this disease. Studies have found that electromagnetic fields (EMF) can ameliorate hepatic steatosis and oxidative stress. Nevertheless, the mechanism remains unclear.

METHODS

NAFLD models were established by feeding mice a high-fat diet. Simultaneously, EMF exposure is performed. The effects of the EMF on hepatic lipid deposition and oxidative stress were investigated. Additionally, the AMPK and Nrf2 pathways were analysed to confirm whether they were activated by the EMF.

RESULTS

Exposure to EMF decreased the body weight, liver weight and serum triglyceride (TG) levels and restrained the excessive hepatic lipid accumulation caused by feeding the HFD. The EMF boosted CaMKKβ protein expression, activated AMPK phosphorylation and suppressed mature SREBP-1c protein expression. Meanwhile, the activity of GSH-Px was enhanced following an increase in nuclear Nrf2 protein expression by PEMF. However, no change was observed in the activities of SOD and CAT. Consequently, EMF reduced hepatic reactive oxygen species (ROS) and MDA levels, which means that EMF relieved liver damage caused by oxidative stress in HFD-fed mice.

CONCLUSIONS

EMF may activate the CaMKKβ/AMPK/SREBP-1c and Nrf2 pathways to control hepatic lipid deposition and oxidative stress. This investigation indicates that EMF may be a novel therapeutic method for NAFLD.

Allografts for Medial Patellofemoral Ligament (MPFL) Reconstruction in Adolescent Patients with Recurrent Patellofemoral Instability: A Systematic Review

This systematic review updates the currently available evidence on medial patella-femoral ligament (MPFL) reconstruction using allografts. The outcomes were measured with patient-reported outcome measures (PROMs), redislocation and complication rates. This study was performed according to the 2020 PRISMA guidelines using the PubMed, Scopus, Web of Science databases, accessed in February 2023. Studies examining the clinical outcomes of MPFL reconstruction with allografts in adolescents and children with recurrent patellofemoral instability (PFI) were included. Data from three trials, including 113 surgical procedures in 121 children, were retrieved. 40% (48/121) of the included patients were girls. The mean age of the patients was 14.7 ± 0.8 years, and the mean follow-up length was 38.1 ± 16.5 months. With MPFL allograft reconstruction, the Kujala score improved by 14.7% (p < 0.0001) and the IKDC by 38.8% (p < 0.0001). The rate of dislocations was 5% (6 of 121), reoperation for instability was 11% (13 of 121), and subluxation was 2% (1 of 47). Conclusion: These results encourage the use of allografts for MPFL reconstruction in adolescent patients with recurrent patellofemoral instability. Though patellofemoral instability is common in clinical practice, the current literature lacks clinical evidence on allograft MPFL reconstruction. Additional high-quality investigations are required to properly establish the long-term advantages of allograft MPFL and its complication rate.

Inhibition of nucleotide biosynthesis disrupts lipid accumulation and adipogenesis

Energy balance and nutrient availability are key determinants of cellular decisions to remain quiescent, proliferate or differentiate into a mature cell. After assessing its environmental state, the cell must rewire its metabolism to support distinct cellular outcomes. Mechanistically, how metabolites regulate cell fate decisions is poorly understood. We used adipogenesis as our model system to ascertain the role of metabolism in differentiation. We isolated adipose tissue stromal vascular fraction (SVF) cells and profiled metabolites before and after adipogenic differentiation to identify metabolic signatures associated with these distinct cellular states. We found that differentiation alters nucleotide accumulation. Furthermore, inhibition of nucleotide biosynthesis prevented lipid storage within adipocytes and downregulated the expression of lipogenic factors. In contrast to proliferating cells, in which mTORC1 is activated by purine accumulation, mTORC1 signaling was unaffected by purine levels in differentiating adipocytes. Rather, our data indicated that purines regulate transcriptional activators of adipogenesis, PPARγ and C/EBPα to promote differentiation. Although de novo nucleotide biosynthesis has mainly been studied in proliferation, our study points to its requirement in adipocyte differentiation.

Role of the AMPK/SIRT1 pathway in non‑alcoholic fatty liver disease (Review)

Non‑alcoholic fatty liver disease (NAFLD) is an increasingly prevalent ailment worldwide. Moreover, de novo lipogenesis (DNL) is considered a critical factor in the development of NAFLD; hence, its inhibition is a promising target for the prevention of fatty liver disease. There is evidence to indicate that AMP‑activated protein kinase (AMPK) and sirtuin 1 (SIRT1) may play a crucial role in DNL and are the regulatory proteins in type 2 diabetes mellitus, obesity and cardiovascular disease. Therefore, AMPK and SIRT1 may be promising targets for the treatment of NAFLD. The present review article thus aimed to summarize the findings of clinical studies published during the past decade that suggested the beneficial effects of AMPK and SIRT1, using their specific activators and their combined effects on fatty liver disease.

Expanding the Biological Properties of Alkannins and Shikonins: Their Impact on Adipogenesis and Life Expectancy in Nematodes

Alkannin, shikonin (A/S) and their derivatives are naturally occurring hydroxynaphthoquinones biosynthesized in some species of the Boraginaceae family. These natural compounds have been extensively investigated for their biological properties over the last 40 years, demonstrating a plethora of activities, such as wound healing, regenerative, anti-inflammatory, antitumor, antimicrobial and antioxidant. This study aims to extend the current knowledge by investigating the effects of various A/S compounds on two model systems, namely on 3T3-L1 pre-adipocytes and the nematode Caenorhabditis elegans. The former constitutes an established in vitro model for investigating anti-obesity and insulin-mimetic properties, while the latter has been widely used as a model organism for studying fat accumulation, lifespan and the anthelmintic potential. A set of chemically well-defined A/S derivatives were screened for their effect on pre-adipocytes to assess cell toxicity, cell morphology, and cell differentiation. The differentiation of pre-adipocytes into mature adipocytes was examined upon treatment with A/S compounds in the presence/absence of insulin, aiming to establish a structure-activity relationship. The majority of A/S compounds induced cell proliferation at sub-micromolar concentrations. The ester derivatives exhibited higher IC₅₀ values, and thus, proved to be less toxic to 3T3-L1 cells. The parent molecules, A and S tested at 1 μM resulted in a truncated differentiation with a reduced number of forming lipids, whereas compounds lacking the side chain hydroxyl group projected higher populations of mature adipocytes. In C. elegans mutant strain SS104, A/S enriched extracts were not able to inhibit the fat accumulation but resulted in a drastic shortage of survival. Thus, the set of A/S compounds were tested at 15 and 60 μg/ml in the wild-type strain N2 for their nematocidal activity, which is of relevance for the discovery of anthelmintic drugs. The most pronounced nematocidal activity was observed for naphthazarin and β,β-dimethyl-acryl-shikonin, followed by isovaleryl-shikonin. The latter 2 A/S esters were identified as the most abundant constituents in the mixture of A/S derivatives isolated from Alkanna tinctoria (L.) Tausch. Taken together, the findings show that the structural variations in the moiety of A/S compounds significantly impact the modulation of their biological activities in both model systems investigated in this study.

Lipidomics analysis of facial lipid biomarkers in females with self‐perceived skin sensitivity

Background and Aims

Self‐perception of sensitive skin (SPSS) has several consequences, including skin barrier damage, which is prevented by barrier sebum. We analyzed lipidome profiles of skin surface lipids (SSLs) in patients with SPSS and healthy controls and explored the mechanism of action of potential lipid markers on the repair of damaged barrier cells to better understand SSL abnormity in these patients.

Methods

Ultraperformance liquid chromatography–quadrupole time‐of‐flight mass spectrometry was used to investigate SSL variations in major lipid classes, subclasses, and species. Reverse‐transcription polymerase chain reaction (RT‐PCR) was used to examine changes in intracellular gene expression following cell barrier damage repair by potential lipid markers.

Results

There were significant differences in the lipidomes of individuals between groups. Individuals with SPSS showed significantly increased levels of two diacylglycerols and one very‐short‐chain free fatty acid and significantly decreased levels of three ceramides (Cers), four glycerophospholipids, and one very‐long‐chain free fatty acid. RT‐PCR revealed that after damage repair by Cer/Glucosylceramide (GlcCer), the expression of two genes in the sterol regulatory element‐binding protein and three in the peroxisome proliferator‐activated receptor pathway significantly increased. Causes of skin barrier damage in patients with SPSS are related to the amount and type of lipids.

Conclusion

Cer/GlcCer can promote lipid synthesis and secretion by upregulating lipid‐related gene expression to repair barrier damage.

Anti-Obesity and Anti-Hyperglycemic Effects of Meretrix lusoria Protamex Hydrolysate in ob/ob Mice

Meretrix lusoria (M. lusoria) is an economically important shellfish which is widely distributed in South Eastern Asia that contains bioactive peptides, proteins, and enzymes. In the present study, the extracted meat content of M. lusoria was enzymatic hydrolyzed using four different commercial proteases (neutrase, protamex, alcalase, and flavourzyme). Among the enzymatic hydrolysates, M. lusoria protamex hydrolysate (MLPH) fraction with MW ≤ 1 kDa exhibited the highest free radical scavenging ability. The MLPH fraction was further purified and an amino acid sequence (KDLEL, 617.35 Da) was identified by LC-MS/MS analysis. The purpose of this study was to investigate the anti-obesity and anti-hyperglycemic effects of MLPH containing antioxidant peptides using ob/ob mice. Treatment with MLPH for 6 weeks reduced body and organ weight and ameliorated the effects of hepatic steatosis and epididymal fat, including a constructive effect on hepatic and serum marker parameters. Moreover, hepatic antioxidant enzyme activities were upregulated and impaired glucose tolerance was improved in obese control mice. In addition, MLPH treatment markedly suppressed mRNA expression related to lipogenesis and hyperglycemia through activation of AMPK phosphorylation. These findings suggest that MLPH has anti-obesity and anti-hyperglycemic potential and could be effectively applied as a functional food ingredient or pharmaceutical.

Heat-Killed Enterococcus faecalis EF-2001 Attenuate Lipid Accumulation in Diet-Induced Obese (DIO) Mice by Activating AMPK Signaling in Liver

To explore the inhibitory mechanism of heat-killed Enterococcus faecalis, EF-2001 on hepatic lipid deposition, a diet-induced obese (DIO) animal model was established by high-fat diet (HFD). The DIO C57BL/6 mice were divided into four groups: the normal group without HFD (ND, n = 8), obesity group (HFD, n = 8), experimental group (HFD + EF-2001, 200 mg/kg, n = 8), and positive control group (HFD + Orlistat, 60 mg/kg, n = 8). After 4 weeks, liver and adipose tissue were fixed in 10% paraformaldehyde, followed by embedding in paraffin for tissue sectioning. The differences in body mass, body fat ratio, fatty cell area, and lipid profiling of the liver (TC, LDL, and HDL) were also determined. Moreover, Western blot was performed to analyze the expression of lipid accumulation-related proteins, including AMPK, PPARγ, SREBP-1, ACC, and FAS. Compared with the HFD group, the HFD + EF-2001 group exhibited decreased fat mass, liver index, adipocyte area, TC, and LDL, and an increased level of HDL. The results of liver hematoxylin and eosin (H&E), and oil red O staining showed that the mice in each intervention group were improved on hepatic lipid accumulation, and the mice in the HFD + EF-2001 group were the most similar to those in the normal group when compared with the HFD group. From the Western blot results, we proved that EF-2001 activated the AMPK signaling pathway. EF-2001 significantly upregulated the expressions of p-AMPK and p-ACC and downregulated PPARγ, SREBP-1, and FAS in murine liver. Taken together, these results suggest that EF-2001 decrease lipid accumulation in the DIO model mice through the AMPK pathway and ameliorate liver damage by HFD.

Quinizarin suppresses the differentiation of adipocytes and lipogenesis in vitro and in vivo via downregulation of C/EBP-beta/SREBP pathway

AIMS

Potential anti-obesity effects of quinizarin, a plant anthraquinone, were investigated using 3 T3-L1 preadipocyte cells and high-fat diet (HD)-induced obese mice.

MAIN METHOD

Cell viability was determined using the MTT assay. Triglyceride (TG) and lipid accumulation were determined using a TG assay kit and Oil Red O staining, respectively. Adipogenic, lipogenic, and lipolytic gene and protein expression was measured by RT-PCR or Western blot. Serum biochemical indices, including cholesterol and blood glucose, in HD-fed obese mice were determined using corresponding assay kits. Histological analysis was performed with haematoxylin and eosin (H&E) staining.

RESULTS

Quinizarin (0-10 μM) significantly reduced intracellular TG and lipid droplets during the differentiation of preadipocytes. Quinizarin significantly suppressed the expression of adipocyte differentiation marker proteins, such as CCAAT/enhancer-binding protein β (C/EBP-β), C/EBP-α, PPAR-γ, and aP2, and lipogenic marker proteins, including SREBP1c, SREBP2, fatty acid synthase (FAS), and acetyl-CoA carboxylase 1 (ACC1), reduced ACC2 expression and increased carnitine palmitoyltransferase 1 (CPT1) expression. Oral administration of quinizarin (15-30 mg/kg/day) to HD-fed mice for 6 weeks reduced the body weight gain and size of liver adipocytes and epididymal fat tissues, with significant reductions in liver TG and serum total cholesterol, blood glucose, LDL, and HDL levels.

SIGNIFICANCE

The results of this study indicated that quinizarin exerts anti-obesity effects by inhibiting both adipogenesis and lipogenesis and stimulating lipolysis in vitro and in vivo mainly by downregulating the SREBP signalling pathway; thus, it might be a potent candidate as a health-beneficial food or therapeutic agent to prevent or treat obesity.

Lipid-Lowering Effects of Inonotus obliquus Polysaccharide In Vivo and In Vitro

Excessive lipid intake will cause hyperlipidemia, fatty liver metabolism disease, and endanger people’s health. Edible fungus polysaccharide is a natural active substance for lipid lowering. In this study, the HepG2 cell model induced by oleic acid and mice model induced by a high-fat diet was established. The lipid-lowering effects of Inonotus obliquus polysaccharide (IOP) was investigated in vivo and in vitro. Glucose (251.33 mg/g), rhamnose (11.53 mg/g), ribose (5.10 mg/g), glucuronic acid (6.30 mg/g), and galacturonic acid (2.95 mg/g) are present in IOP, at a ratio of 85.2:3.91:1.73:2.14:1. The molecular weight of IOP is 42.28 kDa. Treatment with 60 mg/L of IOP showed a significant lipid-lowering effect in HepG2 cells compared with the oleic acid-treated group. In the oil red O-stained images, the red fat droplets in the IOP-treated groups were significantly reduced. TC and TG levels of IOP-treated groups decreased. IOP can alleviate the lipid deposition in the mice liver due to high-fat diet, and significantly reduce their serum TC, TG, and LDL-C contents. IOP could activate AMPK but decrease the SREBP-1C, FAS, and ACC protein expression related to adipose synthesis in mice. IOP has a certain potential for lipid-lowering effects both in vivo and in vitro.

Inhibitory effect of ethanolic extract of Abeliophyllum distichum leaf on 3T3-L1 adipocyte differentiation

BACKGROUND/OBJECTIVES

Abeliophyllum distichum is a plant endemic to Korea, containing several beneficial natural compounds. This study investigated the effect of A. distichum leaf extract (ALE) on adipocyte differentiation.

MATERIALS/METHODS

The cytotoxic effect of ALE was analyzed using cell viability assay. 3T3-L1 preadipocytes were differentiated using induction media in the presence or absence of ALE. Lipid accumulation was confirmed using Oil Red O staining. The mRNA expression of adipogenic markers was measured using RT-PCR, and the protein expressions of mitogen-activated protein kinase (MAPK) and peroxisome proliferator-activated receptor gamma (PPARγ) were measured using western blot. Cell proliferation was measured by calculating the incorporation of Bromodeoxyuridine (BrdU) into DNA.

RESULTS

ALE reduced lipid accumulation in differentiated adipocytes, as indicated by Oil Red O staining and triglyceride assays. Treatment with ALE decreased the gene expression of adipogenic markers such as Pparγ, CCAAT/enhancer binding protein alpha (C/ebpα), lipoprotein lipase, adipocyte protein-2, acetyl-CoA carboxylase, and fatty acid synthase. Also, the protein expression of PPARγ was reduced by ALE. Treating the cells with ALE at different time points revealed that the inhibitory effect of ALE on adipogenesis is higher in the early period treatment than in the terminal period. Furthermore, ALE inhibited adipocyte differentiation by reducing the early phase of adipogenesis and mitotic clonal expansion. This was indicated by the lower number of cells in the Synthesis phase of the cell cycle (labeled using BrdU assay) and a decrease in the expression of early adipogenic transcription factors such as C/ebpβ and C/ebpδ. ALE suppressed the phosphorylation of MAPK, confirming that the effect of ALE was through the suppression of early phase of adipogenesis.

CONCLUSIONS

Altogether, the results of the present study revealed that ALE inhibits lipid accumulation and may be a potential agent for managing obesity.

β-Hydroxyisovalerylshikonin inhibits IL-1β-induced chondrocyte inflammation via Nrf2 and retards osteoarthritis in mice

Osteoarthritis is a chronic degenerative disease characterized by cartilage destruction. It is the fourth most disabling disease worldwide and is currently incurable. Inflammation and extracellular matrix (ECM) degradation are considered to be substantial reasons for accelerating the progression of OA. β-Hydroxyisoamylshikonin (β-HIVS) is a natural naphthoquinone compound with anti-inflammatory and antioxidant activity. However, the effect of β-HIVS on OA is still unclear. In this study, we found that β-HIVS can down-regulate the expression of NO, PEG2, IL-6, TNF-α, COX-2, and iNOS, suggesting its anti-inflammatory effects in chondrocytes; we also found that β-HIVS may down-regulate the expression of ADAMTS5 and MMP13 and up-regulate the expression of aggrecan and collagen II to inhibit the degradation of ECM. Mechanistically, β-HIVS inhibited the NFκB pathway by activating the Nrf2/HO-1 axis, thereby exerting its anti-inflammatory and inhibitory effects on ECM degradation. In vivo experiments also proved the therapeutic effects of β-HIVS on OA in mice, and Nrf2 is the target of β-HIVS. These findings indicate that β-HIVS may become a new drug for the treatment of OA.

Anti-Obesity Effect of Erigeron annuus (L.) Pers. Extract Containing Phenolic Acids

Erigeron annuus (L.) Pers. water extract (EAW) was investigated for its anti-obesity effects in C57BL/6J mice on a high-fat diet. Mice were divided into groups fed normal and high-fat diets (ND and HFD, respectively), and HFD mice were treated with EAW (50, 100, and 200 mg/kg/day) for 8 weeks. Inhibition of HFD-induced obesity by EAW was evaluated using biochemical parameters, immunohistochemistry, real-time PCR, and immunoblot assay. EAW supplementation significantly diminished the final body weight, adipose tissue size, and epididymal adipose tissue volume compared with mice with obesity induced by HFD (p < 0.05 for all). EAW also decreased serum triglyceride (TG) and LDL-cholesterol (LDL-c) levels in obese mice. EAW attenuated HFD-induced obesity by down-regulating C/EBPα, PPARγ, and SREBP-1c to suppress adipogenesis. Moreover, this study indicated that EAW activates the AMPK pathway and increases ACC phosphorylation and downstream CPT1 expression in HFD-induced obese mice. Furthermore, several phenolic acids with anti-obesity properties have been identified in EAW, including quinic acid, caffeic acid, chlorogenic acid, and 3,4-dicaffeoylquinic acid. Based on these data, EAW has anti-obesity effects in vivo, which indicates that it is an excellent candidate for the development of anti-obesity functional foods.

Therapeutic effects of herbal formula Huangqisan on metabolic disorders via SREBF1, SCD1 and AMPK signaling pathway

OBJECTIVE

Metabolic syndrome is a complex medical condition that has become an alarming epidemic, but an effective therapy for this disease is still lacking. The use of the herbal formula Huangqisan (HQS) to treat diabetes is documented in the Chinese medical literature as early as 1117 A.D.; however, its therapeutic effects and underlying mechanisms remain elusive.

METHODS

To investigate the beneficial effects of HQS on metabolic disorders, high-fat diet-induced obesity (DIO), leptin receptor dysfunction (db/db) and low-density lipoprotein receptor-knockout (LDLR^-/-) mice were used. Obese mice were treated with either HQS or vehicle. Blood, liver tissue, white fat tissue and brown adipose tissue were harvested at the end of the treatment. Metabolic disease-related parameters were evaluated to test effects of HQS against diabetes, obesity and hyperlipidemia. Aortic arches from LDLR^-/- mice were analyzed to investigate the effects of HQS on atherosclerosis. RNA-sequence, quantitative real-time polymerase chain reaction and Western blot were performed to investigate the mechanisms of HQS against metabolic disorder.

RESULTS

HQS lowered body weight, fasting blood glucose and serum lipid levels and improved glucose tolerance and insulin sensitivity in DIO mice and db/db mice (P < 0.05). HQS also blocked atherosclerotic plaque formation in LDLR^-/- mice. HQS suppressed de novo lipid synthesis by reducing the expression of messenger RNA for sterol regulatory element-binding factor 1, stearyl coenzyme A desaturase 1 and fatty acid synthase, and enhancing adenosine 5'-monophosphate-activated protein kinase signaling in both in vivo and in vitro experiments, indicating potential mechanisms for HQS's activity against diabetes.

CONCLUSION

HQS is effective for reversing metabolic disorder and has the potential to be used as therapy for metabolic syndrome.

Salvia hispanica L. (chia) seed promotes body fat depletion and modulates adipocyte lipid handling in sucrose-rich diet-fed rats

The aim of this study was to analyze the effects of Salvia hispanica L. (chia) seed upon metabolic pathways that play a key role in adipose tissue lipid handling which could be involved in visceral adiposity reduction developed in rats fed a sucrose-rich diet (SRD). Male Wistar rats were fed with a reference diet (RD) -6 months- or SRD-3 months. Then, the last group was randomly divided into two subgroups. One subgroup continued receiving the SRD up to 6 months and the other was fed with a SRD where whole chia seed was incorporated as the source of dietary fat for the next 3 months (SRD + CHIA). Results showed that chia seed in the SRD-fed rat reduced the abdominal and thoracic circumferences, carcass fat content, adipose tissue weights, and visceral adiposity index. This was accompanied by an improvement in insulin sensitivity and plasma lipid profile. In epididymal adipose tissue, the decreased fat cell triglyceride content was associated with a reduction in both, FAT/CD 36 plasma membrane levels and the fat synthesis enzyme activities. There were not changes in oxidative CPT enzyme activities. PKCβ and the precursor and mature forms of SREBP-1 protein levels were decreased, while pAMPK was increased. Our findings suggest that chia seed supplementation can modulate essential pathways of lipid metabolism in adipose tissue, contributing to reduced visceral fat accumulation in SRD-fed rats.

The Role of PKM2 in Metabolic Reprogramming: Insights into the Regulatory Roles of Non-Coding RNAs

Pyruvate kinase is a key regulator in glycolysis through the conversion of phosphoenolpyruvate (PEP) into pyruvate. Pyruvate kinase exists in various isoforms that can exhibit diverse biological functions and outcomes. The pyruvate kinase isoenzyme type M2 (PKM2) controls cell progression and survival through the regulation of key signaling pathways. In cancer cells, the dimer form of PKM2 predominates and plays an integral role in cancer metabolism. This predominance of the inactive dimeric form promotes the accumulation of phosphometabolites, allowing cancer cells to engage in high levels of synthetic processing to enhance their proliferative capacity. PKM2 has been recognized for its role in regulating gene expression and transcription factors critical for health and disease. This role enables PKM2 to exert profound regulatory effects that promote cancer cell metabolism, proliferation, and migration. In addition to its role in cancer, PKM2 regulates aspects essential to cellular homeostasis in non-cancer tissues and, in some cases, promotes tissue-specific pathways in health and diseases. In pursuit of understanding the diverse tissue-specific roles of PKM2, investigations targeting tissues such as the kidney, liver, adipose, and pancreas have been conducted. Findings from these studies enhance our understanding of PKM2 functions in various diseases beyond cancer. Therefore, there is substantial interest in PKM2 modulation as a potential therapeutic target for the treatment of multiple conditions. Indeed, a vast plethora of research has focused on identifying therapeutic strategies for targeting PKM2. Recently, targeting PKM2 through its regulatory microRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) has gathered increasing interest. Thus, the goal of this review is to highlight recent advancements in PKM2 research, with a focus on PKM2 regulatory microRNAs and lncRNAs and their subsequent physiological significance.

Ultrasonic-microwave assisted extraction of total triterpenoid acids from Corni Fructus and hypoglycemic and hypolipidemic activities of the extract in mice

Triterpene acids, the main component of Corni Fructus, could improve diabetes mellitus, for which the underlying hypoglycemic mechanism is still unclear, in patients. In this study, total triterpenoid acids were extracted by ultrasonic-microwave assisted extraction optimized by the response surface methodology. The extract was then purified with an X-5 macroporous resin, and the yield of total triterpenoid acids increased to 281.24 mg g^-1 as compared with the 35.71 mg g^-1 obtained by unassisted extraction. The contents of five components were determined by ultrafast performance liquid chromatography. In addition, the hypoglycemic and hypolipidemic activities of total triterpenoid acids in diabetic mice induced by streptozotocin and a high fat diet were studied. The results indicated that all parameters (oral glucose tolerance, insulin resistance and liver damage) related to diabetes were significantly improved by total triterpenoid acids. Furthermore, total triterpenoid acids significantly recovered the expression level of AMP-activated protein kinase and its downstream proteins, including acetyl-CoA carboxylase, carnitine palmityltransferase-1, peroxisome proliferator-activated receptor alpha, sterol regulatory element-binding protein 1c and fatty acid synthase. Altogether, total triterpenoid acids could ameliorate hyperlipidemia and hyperglycemia in diabetic mice, probably by activating the AMP-activated protein kinase-peroxisome proliferator-activated receptor signaling pathway and inhibiting the sterol regulatory element-binding protein 1c and fatty acid synthase signaling pathways. Therefore, total triterpene acids, isolated from Corni Fructus which is a prevailing health food, could be a functional food ingredient with therapeutic and commercial values.

Inhibitory Effects of Twenty-Nine Compounds From Potentilla longifolia on Lipid Accumulation and Their Mechanisms in 3T3-L1 Cells

Potentilla longifolia Willd. ex D.F.K.Schltdl., which is a kind of traditional Chinese herb, is often referred to as "Ganyancao" in China, which means "the herb is effective in the treatment of liver inflammation". Three new (ganyearmcaoosides A and B and ganyearmcaoic acid A; 1-3) and 26 known compounds (4-29) were isolated from the 95% ethanol extract of the dried aerial parts of this plant, of which 21 were isolated for the first time from this plant. The chemical structures of these compounds were elucidated using NMR and HR-ESI-MS analysis. The inhibitory effects of the 29 compounds with safe concentrations on the lipid accumulation in 3T3-L1 cells were evaluated using photographic and quantitative assessments of lipid contents by Oil Red O staining, and measurement of the triglyceride levels. Comprehensive analysis showed that compound 12 (3,8-dimethoxy-5,7,4'- trihydroxyflavone) showed the best inhibitory effect on lipid accumulation such as reducing the accumulation of oil droplets and triglyceride level, and was superior to the reference in positive control. Western blot analysis and RT-PCR results showed that compound 12 enhanced the phosphorylations of AMPK and ACC, and inhibited the expressions of adipogenesis-related proteins or genes including SREBP1c, FAS, SCD1, GPAT, PPARγ and C/EBPα, and thereby significantly inhibited lipid accumulation in a concentration-dependent manner. P. longifolia and its bioactive compounds could be promising as potential therapeutic agents for diseases related to lipid accumulation in the future.

Sinensol-C Isolated from Spiranthes sinensis Inhibits Adipogenesis in 3T3-L1 Cells through the Regulation of Adipogenic Transcription Factors and AMPK Activation

Obesity is an abnormal medical condition caused by accumulation of body fat that presents negative health impacts. Adipocyte hyperplasia, also known as adipogenesis, is one of the major manifestations of obesity. In the present study, we isolated six phenanthrene derivatives (compounds 1–6) from the ethyl acetate fraction of Spiranthes sinensis and investigated their anti-adipogenic activity. We found that among the six phenanthrene derivatives, compound 6 (sinensol-C) exhibited strong inhibitory activity against intracellular lipid accumulation in 3T3-L1 adipocytes, with an IC₅₀ value of 12.67 μM. Sinensol-C remarkably suppressed the accumulation of lipid droplets and adipogenesis, via down-regulation of adipogenic transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein α (C/EBPα), sterol regulatory element binding protein-1 (SREBP-1c), fatty acid synthase (FAS), and fatty acid binding protein 4 (FABP4), during adipocyte differentiation in 3T3-L1 cells. In addition, treatment with sinensol-C significantly increased the adenosine monophosphate-activated protein kinase (AMPK) activity in 3T3-L1 cells. Taken together, these data strongly suggest that sinensol-C regulates adiogenesis via down-regulation of adipogenic transcription factors and up-regulation of AMPK. Furthermore, this is the first study that demonstrates that sinensol-C has the capacity to modulate adipogenesis.

Inhibitory effects of compounds from the roots of Potentilla longifolia on lipid accumulation

Potentilla longifolia is a kind of Chaoyao medicine, which is a branch of traditional Chinese medicine. The plant is often referred to as ganyancao or ganyearmcao, which means that it has a significant therapeutic effect on liver inflammation. In previous experiments, we found that a water extract of ganyearmcao inhibited lipid accumulation. In the present study, we isolated one new (ganyearmcaoone A, 1) and eight known compounds (2–9) from a water extract of the dried roots of ganyearmcao; all of the compounds were isolated for the first time from this medicinal plant. We elucidated the chemical structures of these compounds using comprehensive analyses of HR-ESI-MS and 1D, 2D NMR. We evaluated the inhibitory effects of the nine compounds on lipid accumulation in 3T3-L1 cells; we did so using photographic and quantitative assessments of the lipid content with oil red O staining and by measuring triglyceride levels. Compared with the control, compounds 6 and 9 significantly inhibited differentiation of 3T3-L1 cells and lipid accumulation. Compound 1 showed potential inhibitory effects on lipid accumulation. Molecular docking results indicated that compounds 6 and 9 may efficiently bind to AMPK and its downstream kinase (SCD1), thereby inhibiting lipid accumulation. Our results demonstrate that ganyearmcao and its components may play an important role in treating diseases related to lipid accumulation in the future.

Shikonin Attenuates Hepatic Steatosis by Enhancing Beta Oxidation and Energy Expenditure via AMPK Activation

Shikonin, a natural plant pigment, is known to have anti-obesity activity and to improve insulin sensitivity. This study aimed to examine the effect of shikonin on hepatic steatosis, focusing on the AMP-activated protein kinase (AMPK) and energy expenditure in Hepa 1-6 cells and in high-fat fed mice. Shikonin increased AMPK phosphorylation in a dose- and time-dependent manner, and inhibition of AMPK with compound C inhibited this activation. In an oleic acid-induced steatosis model in hepatocytes, shikonin suppressed oleic acid-induced lipid accumulation, increased AMPK phosphorylation, suppressed the expression of lipogenic genes, and stimulated fatty acid oxidation-related genes. Shikonin administration for four weeks decreased body weight gain and the accumulation of lipid droplets in the liver of high-fat fed mice. Furthermore, shikonin promoted energy expenditure by activating fatty acid oxidation. In addition, shikonin increased the expression of PPARγ coactivator-1α (PGC-1α), carnitine palmitoyltransferase-1 (CPT1) and other mitochondrial function-related genes. These results suggest that shikonin attenuated a high fat diet-induced nonalcoholic fatty liver disease by stimulating fatty acid oxidation and energy expenditure via AMPK activation.

Regulation effects of rosemary (Rosmarinus officinalis Linn.) on hepatic lipid metabolism in OA induced NAFLD rats

Rosmarinus officinalis Linn. is a kind of medicinal and edible homologous plant, which is popular in the Mediterranean region with a significant effect on mind tranquilization, anti-oxidation, and metabolic improvement. However, the hypolipidemic effects and mechanism of rosemary ethanol extract (RO) and their metabolites are less known. In this study, the hypolipidemic effects of RO and its active compounds were clarified. The results showed that RO, rosmarinic acid (RA) and carnosic acid (CA) significantly reduced the contents of liver triglyceride (TG), total cholesterol (TC), free fatty acids (FFA) and improved cell hypertrophy, vacuolation, and cell necrosis in the liver of orotic acid induced non-alcoholic fatty liver disease (NAFLD) model rats. The mechanism and related pathways of RO and its main metabolites against lipid disorder were related to the up-regulation of the phosphorylation of adenosine 5'-monophosphate(AMP)-activated protein kinase (AMPK) and the inhibition of the sterol regulatory element binding protein-1c (SREBP-1c) cracking into the nucleus, following the down-regulation of fatty acid synthesis. In conclusion, our study demonstrates that RA and CA are active substances of RO, and provides scientific evidence to support functional food product development for improving NAFLD.

Efficacy and Mechanism of Polymerized Anthocyanin from Grape-Skin Extract on High-Fat-Diet-Induced Nonalcoholic Fatty Liver Disease

We investigated the therapeutic potential of polymerized anthocyanin (PA) on a nonalcoholic fatty liver disease (NAFLD) model in mice. C57BL/6 mice were fed a high-fat diet (HFD) for 8 weeks to establish the NAFLD mouse model and randomly divided into four groups: control diet (con), NAFLD mice treated with saline (NAFLD), NAFLD mice treated with PA (PA), and NAFLD mice treated with orlistat (Orlistat) for four weeks. Mice were euthanized at the end of the four weeks. Total cholesterol (TC) and triglyceride (TG) levels were estimated, and pathological changes in the liver, white adipose tissue, and signaling pathways related to lipid metabolism were evaluated. Results revealed that the body, liver, and white fat weight of the NAFLD group was significantly increased compared to that of the con group, while that of the PA group showed significant reduction. NAFLD led to an increase in blood lipids in mice (except for HDL). Conversely, PA effectively reduced TC and LDL-C. Compared to the control group, the degree of steatosis in the mice of PA group was decreased. Moreover, PA also regulated the NAFLD signaling pathway. In agreement with improved lipid deposition, PA supplementation inhibited the activation of inflammatory pathways, depressing oxidative stress through increased antioxidant levels, and increasing β-oxidation to inhibit mitochondrial dysfunction. Taken together, our results demonstrate that PA can improve the liver function of NAFLD mice, regulating blood lipids, reducing liver-fat accumulation, and regulating lipid metabolism.

Mitochondrial dysfunction, AMPK activation and peroxisomal metabolism: A coherent scenario for non-canonical 3-methylglutaconic acidurias

The occurrence of 3-methylglutaconic aciduria (3-MGA) is a well understood phenomenon in leucine oxidation and ketogenesis disorders (primary 3-MGAs). In contrast, its genesis in non-canonical (secondary) 3-MGAs, a growing-up group of disorders encompassing more than a dozen of inherited metabolic diseases, is a mystery still remaining unresolved for three decades. To puzzle out this anthologic problem of metabolism, three clues were considered: (i) the variety of disorders suggests a common cellular target at the cross-road of metabolic and signaling pathways, (ii) the response to leucine loading test only discriminative for primary but not secondary 3-MGAs suggests these latter are disorders of extramitochondrial HMG-CoA metabolism as also attested by their failure to increase 3-hydroxyisovalerate, a mitochondrial metabolite accumulating only in primary 3-MGAs, (iii) the peroxisome is an extramitochondrial site possessing its own pool and displaying metabolism of HMG-CoA, suggesting its possible involvement in producing extramitochondrial 3-methylglutaconate (3-MG). Following these clues provides a unifying common basis to non-canonical 3-MGAs: constitutive mitochondrial dysfunction induces AMPK activation which, by inhibiting early steps in cholesterol and fatty acid syntheses, pipelines cytoplasmic acetyl-CoA to peroxisomes where a rise in HMG-CoA followed by local dehydration and hydrolysis may lead to 3-MGA yield. Additional contributors are considered, notably for 3-MGAs associated with hyperammonemia, and to a lesser extent in CLPB deficiency. Metabolic and signaling itineraries followed by the proposed scenario are essentially sketched, being provided with compelling evidence from the literature coming in their support.

Arctigenin improves lipid metabolism by regulating AMP-activated protein kinase and downstream signaling pathways

Although it has been reported that arctigenin (ARG) can reduce the body weight and inhibit adipogenic differentiation by activating AMP-activated protein kinase (AMPK), the exact signals responsible for the ARG-mediated antiobesity mechanism through AMPK are not well understood. In this study, we investigated the potential improvement of AGR on lipid metabolism using a high-fat diet (HFD)-induced hyperlipidemia rats and 3T3-L1 mature adipocytes. The levels of AMPK and its downstream factors were examined by Western blot analysis and real-time fluorescent quantitative polymerase chain reaction. We observed that ARG lowered the HFD-induced body weight and the levels of serum lipid. Moreover, ARG clearly alleviated fat deposition in the liver and reduced epididymal fat accumulation. ARG also suppressed lipogenesis and lipolysis but promoted fatty acid β-oxidation in adipocytes. Most importantly, ARG increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) and upregulated the messenger RNA levels of downstream genes related to fatty acid β-oxidation, such as carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 but downregulated the expression of peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding transcription factor 1 (SREBP1c) and their targets, including lipogenesis-related genes such as CCAAT/enhancer-binding protein α, lipoprotein lipase, adipocyte protein 2, and fatty acid synthase (FAS), as well as lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase. The activity of FAS was also decreased by ARG. We conclude that AMPK activation is important for the pharmacological effects of ARG. ARG may improve lipid metabolism by regulating the AMPK-ACC and AMPK-PPARγ/SREBP1c signaling pathways.

Synergistic Inhibitory Effects of Acacetin and 11 Other Flavonoids Isolated from Artemisia sacrorum on Lipid Accumulation in 3T3-L1 Cells

Artemisia sacrorum Ledeb., a Compositae forage plant in China, has been found to have an inhibitory effect on lipid accumulation. We selected 12 flavonoids, which we had isolated from A. sacrorum and had the potential to inhibit lipid accumulation in the literature or in our preliminary experiments, and grouped them into 11 compound combinations; we investigated their synergistic inhibitory effects on lipid accumulation in 3T3-L1 cells. In screening experiments, Oil-Red O staining, triglyceride levels, and lipid accumulation levels all indicated that combined acacetin and apigenin displayed a significant synergistic inhibitory effect and the best repeatability. Subsequent research showed that this combination could synergistically promote the phosphorylations of AMPK and ACC. Furthermore, to a different extent, that combination had significant synergistic inhibitory effects on various genes or proteins related to adipogenesis and lipogenesis. Thus, that combination could significantly reduce triglyceride levels and lipid accumulation compared with acacetin or apigenin acting alone.

R-Limonene Enhances Differentiation and 2-Deoxy-D-Glucose Uptake in 3T3-L1 Preadipocytes by Activating the Akt Signaling Pathway

Adipocyte is an important place for lipid storage. Defects in lipid storage in adipocytes can lead to lipodystrophy and lipid accumulation in muscle, liver, and other organs. It is the condition of mixed dyslipidemia which may favor the development of insulin resistance via lipotoxic mechanisms. Our objective of the study was to investigate the potential role of R-limonene (LM) on differentiation, lipid storage, and 2-deoxy-D-glucose (2DG) uptake in 3T3-L1 preadipocytes. Genes and proteins associated with differentiation, lipid accumulation, 2DG uptake and its signaling pathways in the adipocytes were analyzed using qPCR and western blot methods. LM treatment increased differentiation, lipid accumulation, and the expression of adipogenic and lipogenic markers such as C/EBP-α, C/EBP-β, PPARγ, SREBP-1, RXR, FAS, and adiponectin. However, the LM concentration at 10μM decreased (p < 0.05) adipogenesis and lipogenesis via regulating key transcriptional factors. LM treatment increased activation of Akt by increasing its phosphorylation, but p44/42 activation was not altered. MK-2206, an Akt specific inhibitor, reduced the activation of Akt phosphorylation whereas LM treatment aborted the MK-2206 mediated inhibition of Akt activation. LM enhanced glucose uptake in differentiated adipocytes. Overall data suggested that LM treatment favored lipid storage and glucose uptake in adipocytes via activation of key transcriptional factors through activation of Akt phosphorylation in 3T3-L1 adipocytes.

Heat shock protein 70 promotes lipogenesis in HepG2 cells

Background

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) has followed the international rise in obesity rates. Multiple mechanisms are involved in NAFLD, including endoplasmic reticulum stress and oxidative stress. Heat shock protein 70 (HSP70), which is abundant in most organisms, is sensitive to stress. However, the role of HSP70 in NAFLD has not been investigated. Here, we investigated the possible role of HSP70 in lipid synthesis.

Methods

C57BL/6 mice were fed a high-fat diet, and HepG2 cells were treated with 0.5 mM palmitic acid (PA). HSP70 expression was detected by qPCR, Western blot and immunohistochemistry. Total cholesterol (TC) and triglyceride (TG) levels were detected by enzyme-linked immunosorbent assay (ELISA). After Hsp70 overexpression and knockdown, TC and TG levels and FAS, SCD, and ACC expression were detected.

Results

HSP70 expression was significantly increased in the livers of obese mice. In vitro, HSP70 expression was markedly induced by PA in HepG2 cells. Notably, HSP70 overexpression in HepG2 cells enhanced TC and TG synthesis, in parallel with the upregulation of lipogenic genes, including FAS, SCD and ACC. By contrast, HSP70 knockdown decreased the levels of cellular lipids and the expression of FAS, SCD, and ACC in HepG2 cells. Together, our results suggest that HSP70 may promote lipogenesis in HepG2 cells.

Conclusions

Heat shock protein 70 promotes lipogenesis in HepG2 cells.

Mangiferin Improves Hepatic Lipid Metabolism Mainly Through Its Metabolite-Norathyriol by Modulating SIRT-1/AMPK/SREBP-1c Signaling

Objective: Mangiferin (MGF) is a natural xanthone, with regulation effect on lipid metabolism. However, the molecular mechanism remains unclear. We purposed after oral administration, MGF is converted to its active metabolite(s), which contributes to the effects on lipid metabolism. Methods: KK-A^y mice were used to validate the effects of MGF on lipid metabolic disorders. Liver biochemical indices and gene expressions were determined. MGF metabolites were isolated from MGF administrated rat urine. Mechanism studies were carried out using HepG2 cells treated by MGF and its metabolite with or without inhibitors or small interfering RNA (siRNA). Western blot and immunoprecipitation methods were used to determine the lipid metabolism related gene expression. AMP/ATP ratios were measured by HPLC. AMP-activated protein kinase (AMPK) activation were identified by homogeneous time resolved fluorescence (HTRF) assays. Results: MGF significantly decreased liver triglyceride and free fatty acid levels, increased sirtuin-1 (SIRT-1) and AMPK phosphorylation in KK-A^y mice. HTRF studies indicated that MGF and its metabolites were not direct AMPK activators. Norathyriol, one of MGF's metabolite, possess stronger regulating effect on hepatic lipid metabolism than MGF. The mechanism was mediated by activation of SIRT-1, liver kinase B1, and increasing the intracellular AMP level and AMP/ATP ratio, followed by AMPK phosphorylation, lead to increased phosphorylation level of sterol regulatory element-binding protein-1c. Conclusion: These results provided new insight into the molecular mechanisms of MGF in protecting against hepatic lipid metabolic disorders via regulating SIRT-1/AMPK pathway. Norathyriol showed potential therapeutic in treatment of non-alcoholic fatty liver disease.

Lithospermum erythrorhizon Root and its Naphthoquinones Repress SREBP1c and Activate PGC1α Through AMPKα

OBJECTIVE

To examine specific molecular mechanisms involved in modulating hepatic lipogenesis and mitochondria biogenesis signals by Lithospermum erythrorhizon (gromwell) root extract.

METHODS

Stable cell lines with luciferase reporter constructs were generated to examine sterol regulatory element binding protein 1c (SREBP1c) and peroxisome proliferator-activated receptor gamma, coactivator 1 (PGC1) α promoter activity and estrogen-related receptor (ERR) α response element activity. Gene expression of SREBP1c, stearoyl coenzyme A desaturase 1, and PGC1α was measured by using reverse transcription polymerase chain reaction. Lipogenesis was measured in human hepatoma cells with Nile red staining and flow cytometry. Phosphorylation of AMP-activated protein kinase (AMPK) α was determined by using ELISA and Western blot.

RESULTS

Gromwell root extract and its naphthoquinones dose-dependently repressed high glucose and liver X receptor α induction of SREBP1c promoter activity and gene expression. Hepatic lipogenesis was repressed, and PGC1α promoter and gene expression and ERRα response element activity were increased by gromwell root extract. Gromwell root extract, shikonin, and α-methyl-n-butyrylshikonin increased AMPKα phosphorylation, and inhibition of AMPK blunted the repression in SREBP1c promoter activity by gromwell root extract and its naphthoquinones.

CONCLUSIONS

Data suggest that gromwell root extract and its naphthoquinones repress lipogenesis by increasing the phosphorylated state of AMPKα and stimulating mitochondrial biogenesis signals.

Preventing subclinical necrotic enteritis through Lactobacillus johnsonii BS15 by ameliorating lipid metabolism and intestinal microflora in broiler chickens

Increasing studies have focused on the beneficial effects of Lactobacillus johnsonii in certain diseases. Here, we studied the prevention ability of a probiotic strain, L. johnsonii BS15 on subclinical necrotic enteritis (SNE), and its underlying mechanism. 180 male Cobb 500 chicks were randomly allotted into three groups and administrated with BS15 (1 × 10⁶ cfu/g) or Man Rogosa Sharpe liquid medium throughout a 28-day experimental period. With the exception of the normal group, SNE infection was treated for the remaining experimental period after the chicks were fed with normal diet 14 days. Results showed that BS15 notably suppressed the SNE-induced loss of average daily gain and liver functional abnormality. Additionally, BS15 facilitated lipid metabolism of SNE boilers when the contents of peroxisome proliferator activated receptor γ and adipose triglyceride lipase in adipose tissue and serum high-density lipoprotein cholesterol decreased. BS15 also attenuated the hepatic lipid accumulation of stricken chicks by suppressing the genes expression of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element binding protein-1c as well as stimulating the genes expression of peroxisome proliferator activated receptor α and carnitine palmitoyltransferase-1. Moreover, BS15 enhanced the development of SNE gut by improving the intestinal development and digestion as well as adjusting the gut microflora. Therefore, BS15 may provide a promising natural preventative strategy against SNE, which may be contributed to the amelioration of lipid metabolism and intestinal microflora.

CBMG, a novel derivative of mansonone G suppresses adipocyte differentiation via suppression of PPARγ activity

Mansorins and mansonones have been isolated from Mansonia gagei heartwoods, a traditional herbal medicine used to treat heart failure, and characterized to have anti-oxidant, anti-bacterial, anti-tumor, and anti-estrogenic activities. However, there is as yet no information on their effects on adipogenesis and lipid storage associated with heart disease. In this study, we investigated the effects of naturally occurring compounds on adipogenic differentiation and sought to develop more potent anti-adipogenic compound. We found that mansonone G (MG) suppressed adipocyte differentiation of 3T3-L1 cells, with a 40% decrease in lipid accumulation at 10 μM. MG derivatives including ether and ester analogues were then synthesized and assayed for their ability to suppress adipogenesis. A novel MG derivative, chlorobenzoyl MG (CBMG) most potently suppressed adipocyte differentiation with the decreased level of aP2 and adiponectin. Interestingly, CBMG treatment decreased the expression of CCAAT enhancer binding protein-α (C/EBPα) and peroxisome proliferator-activated receptor-γ (PPARγ). Further analysis confirmed that CBMG suppressed both the expression and activity of PPARγ, a master regulator of adipogenesis, and subsequently led to decreases in transcription of C/EBPα, aP2, and adiponectin in adipogenesis, thereby attenuating adipocyte differentiation. Our results suggest that a novel MG derivative, CBMG may have beneficial applications in the control of obesity through the suppression of PPARγ-induced adipocyte differentiation and lipid accumulation.