Hyperlipidemia is the fat particles excess in the serum. Hyperlipidemia increases the mortality rate that occurs with other metabolic disorders. Hyperlipidemia is classified into familial and acquired subgroups. Moreover, Hyperlipidemia etiology is based on environmental or genetic factors. For instance, abnormal HMG-CoA regulation down-regulates ubiquitin ligase and targets variable oxidative stress-related condition proteins. There has been proven reactive oxygen species (ROS) overshoot happens during hyperlipidemia occurrence. OS, directly and indirectly, regulates molecular cascades within the cell and leads to gene expression alteration. At this molecular juncture, AMPK is affected by ROS. AMPK is a serine-threonine kinase and a critical energy balance. Low energy conditions result in AMPK activation due to the down-regulation of protein and lipid synthesis. Furthermore, ER stress and activated unfolded protein proteasomal response and autophagy are AMPK mediated. Polyphenols are widespread dietary plant-based compounds that regulate gene expression and signal conduction. Through the hyperlipidemic state, FFAs releasing indirectly connect to AMPK/NF-κB pathway then polyphenols target them. AMPK, during this FFA exposure, down-regulates de novo lipid molecules generation. Likewise, if AMPK/mTOR pathway failure is prolonged, the hyperlipidemic state may be explicit, activated by natural herbal mediators, e.g., polyphenols. Polyphenols activate the AMPK signaling pathway and influence lipid metabolism. Polyphenol-mediated AMPK activation results in lipogenesis inhibition and lipophagy. Cholesterol efflux mediated polyphenols lipid-lowering effects, accessing LXR pathway. All these clues persist on direct or indirect AMPK-related polyphenolic anti-hyperlipidemic effects.

Laminopathies are a spectrum of diseases caused by LMNA mutations. In familial partial lipodystrophy of Dunnigan (FPLD), LMNA plays role in the differentiation and development of adipocytes and lipid metabolism. Changes in LMNA predict not only the differentiation of adipose-derived mesenchymal stem cells (AD-MSCs) but also the transformation of cancer cells. Hence, our in-depth study aimed to identify the molecular connection between disordered lipid metabolism and hepatic carcinogenesis. We first discovered significant positive correlations between pLMNA and two key rate-limiting enzymes in de novo fatty acid synthesis, acetyl-CoA-carboxylase 1 (ACC1) and fatty acid synthase (FASN), in the liver tissue but not in adipose tissue of obese model rats. Moreover, LMNA knockdown (KD) in rat AD-MSCs prevented the differentiation and maturation of adipocytes. To clarify the mechanistic relationship with lipogenesis, gain- and loss-of-function experiments in which functional changes and the related molecular pathways were investigated in a normal hepatocyte line (7701 cells). Adenosine 5'-monophosphate activated protein kinase α (AMPKα) was found to be activated by abnormalities in the LMNA structure under conditions of LMNA deletion, farnesyltransferase inhibitor (FTI) treatment and LMNA mutations associated with clinical FPLD pathogenic phenotype. Active AMPKα could directly phosphorylate ACC1 and thus inhibit lipid synthesis but induced glycolysis in both HCC cells and normal cells. The HCC cells could not survive with LMNA knockout (KO) or even KD. Lonafarnib (an FTI) combined with low-glucose conditions significantly decreased the proliferation of HepG2 and MHCC cells by inhibiting glycolysis and the maturation of prelamin A.

Emerging evidence suggests that sustained diabetes-associated factors such as inflammation, hyperinsulinemia, and hyperglycemia are major contributors to aberrant cell proliferation and subsequent neoplastic transformation. Epidemiological studies have also highlighted that diabetes promoting a sedentary lifestyle, with or without the direct involvement of insulin, is frequently linked to cancer. However, our knowledge regarding the molecular mechanisms that correlate hyperglycemia to oncogenic transformations remains limited. In this regard, a recent study has proved that hyperglycemia inactivates AMPK, which results in the destabilization of the TET2 and its tumour-suppressive role ultimately predisposing diabetes mellitus patients to cancer. To the management of hyperglycemia associated with oncogenesis, we need to explore a reverse pharmacology-based ethnopharmacological approach. Botanical-derived natural products are structurally and functionally more diverse with fewer or no side effects on humans. The present review discusses the molecular link between hyperglycemia and cancer progression with the effect of natural products as therapeutic agents on the hyperglycemia-cancer associated signalling pathway.

It has been long recognized that under hypoxia conditions cancer cells reprogram their metabolism through shift from oxidative phosphorylation (OXPHOS) to glycolysis to meet elevated requirements in energy and nutrients for proliferation, migration and survival. However, data accumulated over the last years increasingly evidence that cancer cells can revert from glycolysis to OXPHOS and maintain both reprogrammed and oxidative metabolism even in the same tumor. The phenomenon denoted as cancer cell metabolic plasticity or hybrid metabolism depends on a tumor micro-environment, which is highly heterogeneous and influenced by intensity of vasculature and blood flow, oxygen concentration, nutrient and energy supply, and requires regulatory interplay between multiple oncogenes, transcription factors, growth factors, reactive oxygen species (ROS), etc. Hypoxia-inducible factor-1 (HIF-1) and AMP-activated protein kinase (AMPK) represent key modulators of switch between reprogrammed and oxidative metabolism. The present review focuses on cross-talks between HIF-1, GLUTs, and AMPK and other regulatory proteins including oncogenes such as c-Myc, p53 and KRAS, growth factor-initiated PKB/Akt, PI3K and mTOR signaling pathways and tumor suppressors such as LKB1 and TSC1 in controlling cancer cell metabolism. The multiple switches between metabolic pathways can underlie chemo-resistance to conventional anti-cancer therapy and should be taken into account in choosing molecular targets to discovery novel anti-cancer drugs.

Background: The world-wide rate of obesity is increasing continuously, representing a serious medical threat since it is associated with a variety of diseases including type 2 diabetes, cardiovascular disease, and numerous cancers. Sophora japonica is used as a traditional herb for medicinal purposes in eastern Asia. However, the anti-obesity effects of S. japonica fruit have not been explored. Objective: The aim of this study is to investigate the inhibition of adipocyte differentiation and adipogenesis by an ethanol extract of S. japonica fruit (EESF) in 3T3-L1 pre-adipocytes. Methods: MTT assay, Oil Red O staining, and Triglyceride contents were used to investigate lipid accumulation in 3T3-L1 cells to clarify adipocyte differentiation. The expression levels of various molecular signals associated with adipogenesis and lipogenesis were examined by western blot analysis. Results: Our results demonstrate that EESF suppressed the terminal differentiation of 3T3-L1 pre-adipocytes in a dose-dependent manner, as confirmed by a decrease in lipid droplet number and lipid content through Oil Red O staining. EESF significantly reduced the accumulation of cellular triglyceride, which was associated with a significant inhibition of the levels of pro-adipogenic transcription factors, downregulated the expression levels of adipocyte-specific proteins. Furthermore, EESF treatment effectively increased the phosphorylation of AMPK and ACC. Conclusions: These results together indicate that EESF has significant effects on the inhibition of adipogenesis and acts by stimulating the AMPK signaling pathway. Further studies will be needed to identify the active compounds in S. japonica.

Inosine 5'-monophoaphate (IMP) allows animals to sense umami. Intake of IMP in C57/KsJ-db/db (db/db) mice induced lipohyperplasia causing the liver cirrhosis, however, how to that of in normal mammals injure health is still unclear. Thus, we had investigated that intake of IMP in C57BL/6J mice effected its metabolic functions. We found that intake of 255 M/d IMP in C57BL/6J mice for 4 months induced hyperlipidemia and body fat rate raised. In mechanism, the expressions of ACC1 and phosphorylated ACC2 in hepatocytes were increased though IMP promoting phosphorylation of AMPK. The increased ACC1 promoted the conversion of acetyl-CoA into TG. These TG were transported out of hepatocytes to avoid NAFLD, causing a deficiency of acetyl-CoA in liver, and then the increased phosphorylated ACC2 promoted cytoplasm fatty acids into mitochondria to convert into acetyl-CoA though the fatty acids β-oxidation pathway, causing a deficiency of fatty acids. Therefore, liver enhanced the absorption of exogenous fatty acids, which were converted into TG caused lipohyperplasia. Moreover, intake of IMP in normal mice induced complement system weaken in liver causing mild inflammation. Our data not only alerted that humans avoid excessive intake of IMP, but also provided novel insights into the adipose of metabolic dysfunctions.

Alzheimer’s disease (AD) is a chronic neurodegenerative disease, and typical pathologic findings include abnormally hyperphosphorylated tau aggregation and neurofibrillary tangles. Insulin resistance and hyperglycemia have been assessed as risk factors for AD development. As the maintenance of optimal blood glucose levels is an important indicator of diabetes mellitus (DM) treatment, diet control is essential. AMPK is a crucial sensor of cellular bioenergetics for controlling anabolic and catabolic metabolism. Diet restriction to achieve euglycemia can increase AMPK activity in the liver and heart. Since AMPK is a direct regulator of tau phosphorylation, we hypothesized that strict diet control to achieve euglycemia affects tau protein phosphorylation through increased AMPK activity in the hippocampus of DM rats. To confirm this hypothesis, we generated insulin-deficient DM rats by subtotal pancreatectomy. Animals were categorized into the restriction (R) group, control (C) group and ad libitum (AL) group according to the diet. We found that tau phosphorylation was significantly increased in the R group compared with the C or AL group. AMPK activity in the R group significantly increased compared to that of the C group or AL group, as expected. Furthermore, the R group showed more critical tau pathology in the hippocampus than the other groups. These results suggest that diet control to achieve euglycemia in insulin-deficient DM conditions is harmful because of the increased possibility of AD development through increased tau phosphorylation by AMPK activation in the hippocampus. We propose that not only hyperglycemia but also euglycemia, which is beneficial in DM patients, must be considered a potential risk factor for AD development, especially when euglycemia is achieved by diet control during insulin deficiency.

The energy sensor AMP-activated protein kinase (AMPK) is a key player in the control of energy metabolism. AMPK regulates hepatic lipid metabolism through the phosphorylation of its well-recognized downstream target acetyl CoA carboxylase (ACC). Although AMPK activation is proposed to lower hepatic triglyceride (TG) content via the inhibition of ACC to cause inhibition of de novo lipogenesis and stimulation of fatty acid oxidation (FAO), its contribution to the inhibition of FAO in vivo has been recently questioned. We generated a mouse model of AMPK activation specifically in the liver achieved by expression of a constitutively active AMPK using adenoviral delivery. Indirect calorimetry studies revealed that liver-specific AMPK activation is sufficient to induce a reduction in the respiratory exchange ratio and an increase in FAO rates in vivo. This led to a more rapid metabolic switch from carbohydrate to lipid oxidation during the transition from fed to fasting. Finally, mice with chronic AMPK activation in the liver display high fat oxidation capacity evidenced by increased [C14]-palmitate oxidation and ketone body production leading to reduced hepatic TG content and body adiposity. Our findings suggest a role for hepatic AMPK in the remodeling of lipid metabolism between the liver and adipose tissue.

It has been proposed that procedures which up-regulate mitochondrial biogenesis and autophagy by replacing damaged mitochondria with healthy ones, may prevent the development of several heart diseases. A member of serine and threonine kinases, AMPK, could play essential roles in the autophagy and/or mitophagy. AMPK is widely distributed in various cells, which might play diverse regulatory roles in different tissues and/or organs. In fact, changes in the kinase function of AMPK due to alteration of activity have been linked with diverse pathologies including cardiac disorders. AMPK can regulate mitochondrial biogenesis via PGC1α signaling and also improve oxidative mitochondrial metabolism through inhibition of mTOR pathway, which may also modulate the autophagy/mitophagy through ULK1 and/or TGF-β signaling. Therefore, the modulation of AMPK in autophagy/mitophagy pathway might be considered as a therapeutic tactic for several cardiac disorders. As kinases are amongst the most controllable proteins, in general, the design of small molecules targeting kinases might be an eye-catching avenue to modulate the cardiac function. Some analyses of the molecular biology underlying mitophagy suggests that nutraceuticals and/or drugs including specific AMPK modulator as well as physical exercise and/or dietary restriction that could modulate AMPK may be useful against several heart diseases. In particular, some nutraceutical regimens may have encouraging potential for controlling some of cardiac disorders.

Sleep fragmentation (SF) can increase inflammation and production of reactive oxygen species (ROS), leading to metabolic dysfunction. SF is associated with inflammation of adipose tissue and insulin resistance. Several studies suggested that melatonin may have beneficial metabolic effects by activating AMP-activated protein kinase (AMPK). However, it is unclear whether melatonin affects the AMPK signaling pathway in SF-induced metabolic dysfunction. Therefore, we hypothesize that SF induces metabolic impairment and inflammation in white adipose tissue (WAT), as well as altered intracellular homeostasis. We further hypothesize that these conditions could be improved by melatonin treatment. We conducted an experiment using adult male C57BL/6 mice, which were divided into three groups: control, SF, and SF with melatonin treatment (SF+Mel). The SF mice were housed in SF chambers, while the SF+Mel mice received daily oral melatonin. After 12 weeks, glucose tolerance test, insulin tolerance test, adipose tissue inflammation, and AMPK assessments were performed. The SF mice showed increased weight gain, impaired glucose regulation, inflammation, and decreased AMPK in WAT compared to the controls. Melatonin significantly improved these outcomes by mitigating SF-induced metabolic dysfunction, inflammation, and AMPK downregulation in adipose tissue. The therapeutic efficacy of melatonin against cardiometabolic impairments in SF may be due to its ability to restore adipose tissue homeostatic pathways.

Serelaxin (RLX), the recombinant form of human Relaxin-2 hormone, protects the heart from the ischemia/reperfusion (I/R)-induced damage due to its anti-inflammatory, anti-apoptotic and antioxidant properties. RLX exerts its actions by binding to its specific RXFP1 receptor whereby it regulates multiple cellular transduction pathways. In this in vitro study we offer first evidence for the involvement of AMP kinase/Sirtuin1 (AMPK/SIRT1) pathway in the protection afforded by RLX against H/R-induced damage in H9c2 cells. Treatment of the H/R-exposed cells with RLX (17 nmol L−1) enhanced SIRT1 expression and activity. Inhibition of SIRT1 signaling with EX527 (10 µmol L-1) reduced the beneficial effect of the hormone on mitochondrial efficiency and cell apoptosis. Moreover, RLX upregulated AMPK pathway, as shown by the increase in the expression of phospho-AMPK active protein. Finally, AMPK pathway inhibition by Compound C (10 and 20 μmol L−1) abrogated the increase in SIRT1 expression induced by RLX, thus suggesting the involvement of AMPK pathway in this effect of RLX. The results of this study strengthen the concept that RLX exerts its cardioprotective effects against H/R-induced injury by multiple pathways which also include AMPK/SIRT1.

Anti-diabetic effects of Glycine soja seed extract (GS) on Type 2 diabetes mellitus mouse model and human hepatocytes induced insulin resistance were investigated. 3 weeks old db/db mice were divided into 5 groups (n = 6) including two control groups and 3 GS treated groups with different doses. Oral administration of GS for 6 weeks to diabetic db/db mice reduced blood glucose level significantly in a dose dependent manner by 44.7% (300 mg/kg/day), 30.9% (150 mg/kg/day) and 21.1% (75 mg/kg/day). GS treatment also lowered significantly plasma level of HbA1c, insulin, IGF-1 and leptin, and increased that of adiponectin. GS treatment activated AMPK, and down-regulated GLUT2 in liver tissues of mice while up-regulated GLUT4 in muscle tissues of mice. In in vitro study with insulin resistance induced human hepatocyte, GS treatment increased glucose uptake and increased the activities of Akt and PPAR-γ in response to insulin. Treatment of GS appears to reduce blood glucose level by regulating energy metabolism positively through various metabolic pathways and reducing insulin resistance in Type 2 diabetes mellitus.

Anti-diabetic effects of Glycine soja seed extract (GS) on Type 2 diabetes mellitus mouse model and human hepatocytes induced insulin resistance were investigated. 3 weeks old db/db mice were divided into 5 groups (n = 6) including two control groups and 3 GS treated groups with different doses. Oral administration of GS for 6 weeks to diabetic db/db mice reduced blood glucose level significantly in a dose dependent manner by 44.7% (300 mg/kg/day), 30.9% (150 mg/kg/day) and 21.1% (75 mg/kg/day). GS treatment also lowered significantly plasma level of HbA1c, insulin, IGF-1 and leptin, and increased that of adiponectin. GS treatment activated AMPK, and down-regulated GLUT2 in liver tissues of mice while up-regulated GLUT4 in muscle tissues of mice. In in vitro study with insulin resistance induced human hepatocyte, GS treatment increased glucose uptake and increased the activities of Akt and PPAR-γ in response to insulin. Treatment of GS appears to reduce blood glucose level by regulating energy metabolism positively through various metabolic pathways and reducing insulin resistance in Type 2 diabetes mellitus.

The Abnormal increase in the mass of adipose tissue during adipogenesis results in obesity. Obesity is a predominant disorder and its widespread has become a critical concern worldwide. This is due to the burden of its associated co-morbidities like cancer, cardiovascular diseases and diabetes. Over-nutrition and the sedentary lifestyle are considered as the most significant causes of abnormal adipose tissue development. Appropriate lifestyle and behavioural interventions are the corner stones of successful weight loss, but to maintain such a lifestyle is highly challenging. Accordingly, natural products from plants either as crude extracts or purified phytochemicals have shown to have anti-obesogenic properties and are generally non-toxic and cost-effective. In this review, we discuss the comparative analysis of molecular mechanisms involved in adipogenesis and the recently reported anti-obesogenic effects of various plant products. We will provide a common platform for understanding obesity and adipogenesis, and a possible mechanism of action for anti-obesogenic plant products through AMP-activated protein kinase (AMPK), which will support the scientific development of traditional herbal medicine.

Regulated autophagy is involved in the repair of renal ischemia-reperfusion injury (IRI). ω3-Polyunsaturated fatty acids (ω3-PUFAs) show protective effects against various renal injuries. It was recently reported that ω3-PUFAs regulate autophagy. We assessed whether ω3-PUFAs attenuated IR-induced acute kidney injury (AKI) and evaluated associated mechanisms. C57Bl/6 background fat-1 mice and wild-type mice (wt) were divided into four groups: wt sham (n = 10), fat-1 sham (n = 10), wt IRI (reperfusion 35 min after clamping both the renal artery and vein; n = 15), and fat-1 IRI (n = 15). Kidneys and blood were harvested 24 h after IRI. Renal histological and molecular data were collected. The kidneys of fat-1 mice showed better renal cell survival, renal function, and pathological damage than those of wt mice after IRI. In addition, fat-1 mice showed less oxidative stress and autophagy impairment; greater amounts of LC3, Beclin-1, and Atg7; lower amounts of p62; and higher levels of renal cathepsin D and ATP6E than wt kidneys. They also showed more AMPK activation, which resulted in the inhibition of phosphorylation of the mammalian target of rapamycin (mTOR). Collectively, ω3-PUFAs in fat-1 mice contributed to AMPK mediated autophagy activation, leading to a renoprotective response.

Non-alcoholic steatohepatitis (NASH) is diagnosed by the occurrence of fat buildup, inflammation, and fibrotic changes within the liver. NASH has the capacity to proceed to the advancement of decompensated cirrhosis and carcinoma by inflammation and oxidative stress. Although Agrimonia pilosa has traditionally been used medicinal purposes, its effects on the liver remains incompletely elucidated. In this research, we assessed the therapeutic outcomes of Agrimonia pilosa extract (APE) on free fatty acid (FFA)-treated HepG2 cellular hepatic steatosis and in a choline-deficient, L-amino acid-defined, high-fat diet with 0.1% methionine (CDAHFD)-induced NASH mouse model. In FFA-treated cells, APE inhibited intracellular lipid accumulation, and regulated the mRNA and protein expressions of modulators of fatty acid (FA) synthesis as well as FA oxidation proteins, through down-regulation of the AMP-activated protein kinase/sirtuin 1 signaling pathway. In the CDAHFD-induced NASH mouse model, APE significantly enhanced liver histology and serum levels of liver damage. APE also significantly attenuated hepatic expression of mRNA and proteins related to FA synthesis, inflammation, and fibrosis. Furthermore, APE mitigated the expression levels of oxidative stress and endoplasmic reticulum stress. Overall, these discoveries indicate that Agrimonia pilosa has the potential to treat NASH by regulating hepatic lipid metabolism, alleviating inflammation, and mitigating oxidative stress.

The X-linked FMR1 gene contains a non-coding trinucleotide repeat in its 5’ region that in normal, healthy individuals contains 20-44 copies. Large expansions of this region (>200 copies) cause fragile X syndrome (FXS), but expansions of 55-199 copies (referred to as premutation alleles) predispose carriers to a neurodegenerative disease called fragile X-associated tremor/ataxia syndrome (FXTAS). The cytopathological mechanisms underlying FXTAS are poorly understood, but abnormalities in mitochondrial function are believed to play a role. We previously reported that lymphoblastoid cell lines (LCLs, or lymphoblasts) of premutation carriers have elevated mitochondrial respiratory activities. In the carriers, especially those not clinically affected with FXTAS, AMPK activity was shown to be elevated. In the FXTAS patients, however, it was negatively correlated with brain white matter lesions, suggesting a protective role in the molecular mechanisms. Here we report an enlarged and extended study of mitochondrial function and associated cellular stress-signalling pathways in lymphoblasts isolated from male and female premutation carriers, regardless of their clinical status, and healthy controls. The results confirmed the elevation of AMPK and mitochondrial respiratory activities and reduction of reactive O2 species (ROS) levels in premutation cells and revealed for the first time that TORC1 activities are reduced. Extensive correlation, multiple regression and Principal Components analysis revealed the best fitting statistical explanations of these changes in terms of the other variables measured. These suggested which variables might be the most “proximal” regulators of the others in the extensive network of known causal interactions amongst the measured parameters of mitochondrial function and cellular stress signalling. In the resulting model, the premutation alleles activate AMPK and inhibit both TORC1 and ROS production, the reduced TORC1 activity contributes to activation of AMPK activation and of nonmitochondrial metabolism, and the higher AMPK activity results in elevated catabolic metabolism, mitochondrial respiration and ATP steady state levels. In addition the results suggest a separate CGG repeat number-dependent elevation of TORC1 activity that is insufficient to overcome the inhibition of TORC1 in premutation cells, but may presage the previously reported activation of TORC1 in FXS cells.

Non-alcoholic fatty liver disease (NAFLD), a frequent complication of metabolic syndrome and visceral obesity, is characterized by marked accumulation of lipids in hepatocytes, accompanied by oxidant stress. In a substantial minority of cases, this progresses to steatohepatitis, which in turn can lead to life-threatening hepatic fibrosis and/or hepatocarcinogenesis. This essay analyzes the molecular biology underlying fat accumulation and oxidant stress in NAFLD, and identifies targets that can be addressed by nutraceutical or dietary measures. Nutraceuticals with potential for prevention or control of NAFLD – as suggested on theoretical grounds, and borne out by experience in rodent studies and/or clinical trials - include ferulic acid, melatonin, methylnicotinamide, tetrahydrocurcumin, nicotinamide riboside, carnosic acid, urolithin A, quercetin, high-dose biotin, citrulline, astaxanthin, long-chain omega-3 fatty acids, berberine, lipoic acid, silibinin, N-acetylcysteine, taurine, capsaicin, spermidine, spirulina, and carnitine. Some of these agents can also address the NLRP3 inflammasome activation and transforming growth factor-β signaling that play a role in driving the transition to steatohepatitis and fibrosis. In addition, soy isoflavones, via estrogen receptor-beta agonism, have anti-fibrotic potential, and supplemental glycine may blunt the contribution of Kupffer cells to the progression of NAFLD. Whole-food plant-based diets of modest protein content, owing to their impact on hormones such as fibroblast growth factor 21 and adiponectin, as well as on the obesity and metabolic syndrome underlying NAFLD, may also be protective in this syndrome. There is considerable potential for complex medical foods or nutraceutical supplementation regimens of rational design to aid prevention and control of NAFLD.