An integrated network pharmacology and metabolomics approach to reveal the immunomodulatory mechanism of Brassica rapa L. (Tibetan Turnip) in fatigue mice.

Brassica rapa L. has been widely used as an edible, feeding and medicinal plant in the Qinghai-Tibet Plateau due to its several pharmacological effects of alleviating deficiency or weakness, anti-inflammation, and relieving acute mountain sickness. However, its therapeutic efficacy and the underlying mechanism against fatigue have not been elucidated. The aim of this study is to investigate the action mechanisms of Brassica rapa L. extract (BE) in treating fatigue, with emphasis on the fatigue-related biomarkers, targets and pathways, via network pharmacology and widely targeted metabolomics. Based on the UHPLC-MS results, a total of 33 components were identified and the energy metabolic homeostasis and inflammation related signaling pathways were considered crucial for BE against fatigue by gene functional enrichment analysis. Western blotting (WB) showed that BE significantly up-regulated Nrf2/HO-1, phosphorylation of AMPK, and expression of the downstream signaling pathway, which was further verified by quantitative real-time PCR (q Rt-PCR). The metabolic pathway analysis of BE showed that linoleic acid metabolism was mainly involved, as well as the generation and degradation of ketone bodies, and taurine and hypotaurine metabolism, which are closely related to the regulation of energy metabolism and immunoregulation. Furthermore, the drug-containing serum of BE attenuated intracellular ROS levels in macrophage Raw264.7 cells and reversed the M1 polarization by enhancing the level of IL-10 and Arg-1 and inhibiting that of IL-12 and iNOS in vitro. Hence, Brassica rapa L. has the potential to become a functional food or alternative therapy for fatigue management among immune-compromised people.

Role of Epigallocatechin Gallate in Glucose, Lipid, and Protein Metabolism and L-Theanine in the Metabolism-Regulatory Effects of Epigallocatechin Gallate.

Epigallocatechin gallate (EGCG) and L-theanine (LTA) are important bioactive components in tea that have shown promising effects on nutrient metabolism. However, whether EGCG alone or combined with LTA can regulate the glucose, lipid, and protein metabolism of healthy rats remains unclear. Therefore, we treated healthy rats with EGCG or the combination of EGCG and LTA (EGCG+LTA) to investigate the effects of EGCG on nutrient metabolism and the role of LTA in the metabolism-regulatory effects of EGCG. The results showed that compared with the control group, EGCG activated insulin and AMP-activated protein kinase (AMPK) signals, thus regulating glucose, lipid, and protein metabolism. Compared with EGCG, EGCG+LTA enhanced hepatic and muscle glycogen levels and suppressed phosphorylation of AMPK, glycogen synthase 2, mammalian target of rapamycin, and ribosomal protein S6 kinase. In addition, EGCG+LTA inhibited the expression of liver kinase B1, insulin receptor and insulin receptor substrate, and promoted the phosphorylation level of acetyl-CoA carboxylase. Furthermore, both EGCG and EGCG+LTA were harmless for young rats. In conclusion, EGCG activated AMPK and insulin pathways, thereby promoting glycolysis, glycogen, and protein synthesis and inhibiting fatty acid (FA) and cholesterol synthesis. However, LTA cooperated with EGCG to promote glycogen metabolism and suppressed the effect EGCG on FA and protein synthesis via AMPK signals.

SIRT 3 was involved in Lycium barbarum seed oil protection testis from oxidative stress: in vitro and in vivo analyses.

CONTEXT: Lycium barbarum L. (Solanaceae) seed oil (LBSO) exerts LBSO exerts protective effects in the testis in vivo and in vitro via upregulating SIRT3. OBJECTIVE: This study evaluates the effects and mechanism of LBSO in the d-galactose (d-gal)-induced ageing testis. MATERIALS AND METHODS: Male Sprague Dawley (SD) rats (n = 30, 8-week-old) were randomly divided into three groups: LBSO group (n = 10) where rats received subcutaneous injection of d-gal at 125 mg/kg/day for 8 weeks and intragastric administration of LBSO at 1000 mg/kg/day for 4 weeks, ageing model group (n = 10) received 8-week-sunbcutaneous injection of d-gal, and control group (n = 10) with same administration of normal saline. Lentivirus had established TM4 cells with SIRT3 overexpression or silencing before LBSO intervened in vitro. RESULTS: Treatment with LBSO, the levels of INHB and testosterone both increased, compared to ageing model. In vitro, we found the ED50 of LBSO was 86.72 ± 1.49 and when the concentration of LBSO at 100 µg/mL to intervene TM4 cells, the number of cells increased from 8120 ± 676.2 to 15251 ± 1119, and the expression of SIRT3, HO-1, and SOD upregulated. However, HO-1 and SOD were dysregulated by silencing SIRT3. On the other hand, the expression of AMPK and PGC-1α upregulated as an effect of SIRT3 overexpression by lentivirus, meanwhile the same increasing trend of that being found in cells treated with LBSO, compared to control group. DISCUSSION AND CONCLUSIONS: LBSO alleviated oxidative stress in d-gal-induced sub-acutely ageing testis and TM4 cells by suppressing the oxidative stress to mitochondria via SIRT3/AMPK/PGC-1α.

Hypoglycemic and lipid lowering effects of theaflavins in high-fat diet-induced obese mice.

Theaflavins (TFs) are the characteristic components of black tea and have been widely acknowledged for their health benefits. The current study aimed to investigate the effects and mechanism of TFs, TF1, TF2a and TF3 on glycolipid metabolism in obese mice induced by a high-fat diet (HFD). Mice were randomly divided into seven groups (n = 8 per group) as follows: low-fat diet (LFD), HFD, HFD + metformin (Met, 100 mg kg-1 d-1), HFD + TFs (TFs, 200 mg kg-1 d-1), HFD + TF1 (TF1, 100 mg kg-1 d-1), HFD + TF2a (TF2a, 100 mg kg-1 d-1), and HFD + TF3 (TF3, 100 mg kg-1 d-1). All groups were studied for 9 weeks continuously. The levels of serum glucose, insulin, TC, TG, LDL and HLD in the plasma, lipid accumulation in the liver, and injury of the liver were investigated. In addition, the effects of TFs and their monomers on the SIRT6/AMPK/SREBP-1/FASN pathway were also evaluated. The results showed that oral administration of TFs, TF1, TF2a and TF3 not only dramatically suppressed weight gain, reduced blood glucose level, and ameliorated insulin resistance but also obviously lowered the levels of serum TC, TG and LDL, suppressed the activities of ALT and AST, and ameliorated hepatic damage in mice fed a HFD when compared to the HFD group. Western blot analysis showed that TFs, TF1, TF2a and TF3 treatments increased the expression of SIRT6 and suppressed the expression levels of SREBP-1 and FASN significantly in mice fed a HFD as compared to the HFD group. The phosphorylation of AMPK in mice fed a HFD was obviously elevated by TF2a and TF3 when compared to the HFD group. These results proved for the first time that TF1, TF2a and TF3 improved the glucolipid metabolism of mice fed a HFD, and activated the SIRT6/AMPK/SREBP-1/FASN signaling pathway to inhibit the synthesis and accumulation of lipids in the liver to ameliorate obesity in mice fed a HFD. These findings indicate that TFs, TF1, TF2a and TF3 as the main functional components of black tea might potentially be used as a food additive for improving glycolipid metabolism and ameliorating obesity, and TF3 may be the best choice.

V600EBRAF Inhibition Induces Cytoprotective Autophagy through AMPK in Thyroid Cancer Cells.

The dysregulation of autophagy is important in the development of many cancers, including thyroid cancer, where V600EBRAF is a main oncogene. Here, we analyse the effect of V600EBRAF inhibition on autophagy, the mechanisms involved in this regulation and the role of autophagy in cell survival of thyroid cancer cells. We reveal that the inhibition of V600EBRAF activity with its specific inhibitor PLX4720 or the depletion of its expression by siRNA induces autophagy in thyroid tumour cells. We show that V600EBRAF downregulation increases LKB1-AMPK signalling and decreases mTOR activity through a MEK/ERK-dependent mechanism. Moreover, we demonstrate that PLX4720 activates ULK1 and increases autophagy through the activation of the AMPK-ULK1 pathway, but not by the inhibition of mTOR. In addition, we find that autophagy blockade decreases cell viability and sensitize thyroid cancer cells to V600EBRAF inhibition by PLX4720 treatment. Finally, we generate a thyroid xenograft model to demonstrate that autophagy inhibition synergistically enhances the anti-proliferative and pro-apoptotic effects of V600EBRAF inhibition in vivo. Collectively, we uncover a new role of AMPK in mediating the induction of cytoprotective autophagy by V600EBRAF inhibition. In addition, these data establish a rationale for designing an integrated therapy targeting V600EBRAF and the LKB1-AMPK-ULK1-autophagy axis for the treatment of V600EBRAF-positive thyroid tumours.

Kakonein restores diabetes-induced endothelial junction dysfunction via promoting autophagy-mediated NLRP3 inflammasome degradation.

In diabetes-induced complications, inflammatory-mediated endothelial dysfunction is the core of disease progression. Evidence shows that kakonein, an isoflavone common in Pueraria, can effectively treat diabetes and its complications. Therefore, we explored whether kakonein protects cardiovascular endothelial function by inhibiting inflammatory responses. In this study, C57BL/6J mice were injected with streptozocin to establish a diabetes model and treated with kakonein or metformin for 7 days. The protective effect of kakonein on cardiovascular endothelial junctions and NLRP3 inflammasome activation was verified through immunofluorescence and ELISA assay. In addition, the regulation of autophagy on the NLRP3 inflammasome was investigated through Western blot, immunofluorescence and RT-qPCR. Results showed that kakonein restored the function of endothelial junctions and inhibited the assembly and activation of the NLRP3 inflammasome. Interestingly, kakonein decreased the expression of NLRP3 inflammasome protein by not reducing the transcriptional levels of NLRP3 and caspase-1. Kakonein activated autophagy in an AMPK-dependent manner, which reduced the activation of the NLRP3 inflammasome. In addition, kakonein inhibited both hyperglycaemia-induced cardiovascular endothelial junction dysfunction and NLRP3 inflammasome activation, similar to autophagy agonist. Our findings indicated that kakonein exerts a protective effect on hyperglycaemia-induced chronic vascular disease by regulating the NLRP3 inflammasome through autophagy.

Daidzein alleviates cisplatin-induced muscle atrophy by regulating Glut4/AMPK/FoxO pathway.

Cisplatin (DDP) is widely used in cancer treatment, but DDP can cause skeletal muscle atrophy and cachexia. This study explored the effect and mechanism of daidzein (DAI) in reducing DDP-induced skeletal muscle atrophy and cachexia in vivo and in vitro. DAI alleviated the weight, food intake, muscle, adipose tissue, kidney weight and forelimb grip of LLC tumour-bearing mice after DDP treatment, and did not affect the antitumour effect of DDP. DAI can reduce the decrease of the cross-sectional area of skeletal muscle fibre-induced by DDP and prevent the change of fibre type proportion. In skeletal muscle, it can inhibit Glut4/AMPK/FoxO pathway, down-regulate the expression of atrogin1 and MuRF1, and inhibit skeletal muscle protein degradation. In DDP treated C2C12 myotubes, DAI could inhibit Glut4/AMPK/FoxO pathway to reduce myotubes atrophy, while AMPK agonist MK-3903 could reverse the protective effect of DAI. These results suggest that DAI can alleviate DDP-induced skeletal muscle atrophy by downregulating the expression of Atrogin1 and MuRF1 through the regulation of Glut4/AMPK/FoxO pathway.

Oral intake of Lactobacillus plantarum L-14 extract alleviates TLR2- and AMPK-mediated obesity-associated disorders in high-fat-diet-induced obese C57BL/6J mice.

OBJECTIVES: Whether periodic oral intake of postbiotics positively affects weight regulation and prevents obesity-associated diseases in vivo is unclear. This study evaluated the action mechanism of Lactobacillus plantarum L-14 (KTCT13497BP) extract and the effects of its periodic oral intake in a high-fat-diet (HFD) mouse model. MATERIALS AND METHODS: Mouse pre-adipocyte 3T3-L1 cells and human bone marrow mesenchymal stem cells (hBM-MSC) were treated with L-14 extract every 2 days during adipogenic differentiation, and the mechanism underlying anti-adipogenic effects was analysed at cellular and molecular levels. L-14 extract was orally administrated to HFD-feeding C57BL/6J mice every 2 days for 7 weeks. White adipose tissue was collected and weighed, and liver and blood serum were analysed. The anti-adipogenic mechanism of exopolysaccharide (EPS) isolated from L-14 extract was also analysed using Toll-like receptor 2 (TLR2) inhibitor C29. RESULTS: L-14 extract inhibited 3T3-L1 and hBM-MSC differentiation into mature adipocytes by upregulating AMPK signalling pathway in the early stage of adipogenic differentiation. The weight of the HFD + L-14 group (31.51 ± 1.96 g) was significantly different from that of the HFD group (35.14 ± 3.18 g). L-14 extract also significantly decreased the serum triacylglycerol/high-density lipoprotein cholesterol ratio (an insulin resistance marker) and steatohepatitis. In addition, EPS activated the AMPK signalling pathway by interacting with TLR2, consequently inhibiting adipogenesis. CONCLUSIONS: EPS from L-14 extract inhibits adipogenesis via TLR2 and AMPK signalling pathways, and oral intake of L-14 extract improves obesity and obesity-associated diseases in vivo. Therefore, EPS can be used to prevent and treat obesity and metabolic disorders.

Therapeutic effect of oxyberberine on obese non-alcoholic fatty liver disease rats.

BACKGROUND: Berberine (BBR) has been widely used to treat non-alcoholic fatty liver disease (NAFLD). The metabolites of BBR were believed to contribute significantly to its pharmacological effects. Oxyberberine (OBB), a gut microbiota-mediated oxidative metabolite of BBR, has been firstly identified in our recent work. PURPOSE: Here, we aimed to comparatively investigate the anti-NAFLD properties of OBB and BBR. METHODS: The anti-NAFLD effect was evaluated in high-fat diet-induced obese NAFLD rats with biochemical/ELISA tests and histological staining. The related gene and protein expressions were detected by qRT-PCR and Western blotting respectively. Molecular docking and dynamic simulation were also performed to provide further insight. RESULTS: Results indicated OBB remarkably and dose-dependently attenuated the clinical manifestations of NAFLD, which (100 mg/kg) achieved similar therapeutic effect to metformin (300 mg/kg) and was superior to BBR of the same dose. OBB significantly inhibited aberrant phosphorylation of IRS-1 and up-regulated the downstream protein expression and phosphorylation (PI3K, p-Akt/Akt and p-GSK-3ß/GSK-3ß) to improve hepatic insulin signal transduction. Meanwhile, OBB treatment remarkably alleviated inflammation via down-regulating the mRNA expression of MCP-1, Cd68, Nos2, Cd11c, while enhancing Arg1 mRNA expression in white adipose tissue. Moreover, OBB exhibited closer affinity with AMPK in silicon and superior hyperphosphorylation of AMPK in vivo, leading to increased ACC mRNA expression in liver and UCP-1 protein expression in adipose tissue. CONCLUSION: Taken together, compared with BBR, OBB was more capable of maintaining lipid homeostasis between liver and WAT via attenuating hepatic insulin pathway and adipocyte inflammation, which was associated with its property of superior AMPK activator.

Fangchinoline exerts anticancer effects on colorectal cancer by inducing autophagy via regulation AMPK/mTOR/ULK1 pathway.

Autophagy has become a promising target for cancer therapy. Fangchinoline (Fan) has been shown to exert anticancer effects in some types of cancers. However, the anticancer effects on colorectal cancer (CRC) and the underlying mechanisms have never been elucidated. More specifically, regulation of autophagy in CRC by Fan has never been reported before. In the present study, Fan was found to induce apoptosis and autophagic flux in the CRC cell lines HT29 and HCT116, which was reflected by the enhanced levels of LC3-II protein and p62 degradation, and the increased formation of autophagosomes and puncta formation by LC3-II. Meanwhile, combination with the early-stage autophagy inhibitor 3-methyladenine (3-MA) but not the late-stage autophagy inhibitor chloroquine (CQ) further increased Fan-induced cell death, which suggested the cytoprotective function of autophagy induced by Fan in both HT29 and HCT116 cells. Moreover, Fan treatment demonstrated a dose- and time-dependently increase in the phosphorylation of AMPK and decrease in the phosphorylation of mammalian target of rapamycin (mTOR) and ULK1, leading to the activation of the AMPK/mTOR/ULK1 signaling pathway. Furthermore, in the HT29 xenograft model, Fan inhibited tumor growth in vivo. These results indicate that Fan inhibited CRC cell growth both in vitro and in vivo and revealed a new molecular mechanism involved in the anticancer effect of Fan on CRC, suggesting that Fan is a potent autophagy inducer and might be a promising anticancer agent.

Effect of Shenzhu Tiaopi granule on hepatic insulin resistance in diabetic Goto-Kakizakirats via liver kinase B1/adenosine 5'-monophosphate/mammalian target of rapamycin signaling pathway.

OBJECTIVE: To observe the therapeutic effect of Shenzhu Tiaopi granule (, STG) on insulin resistance (IR) in the liver of diabetic Goto-Kakizaki (GK) rat and investigate underlying mechanisms. METHODS: Ten 12-week-old male Wistar rats were assigned as normal control (NC) group, while 40 12-week-old male specific-pathogen-free GK rats were randomly divided into four experimental groups, 10 diabetic rats each. Animals were fed with a normal diet. Fasting blood glucose (FBG), water intake, and body weight were recorded during 6 weeks of daily single-dose treatment: STG low-dose group, 4.5 g/kg (STG-L); STG high-dose group,9 g/kg (STG-H); metformin group, 0.1 g/kg (MET); model control (MC) and NC groups, equal volume of 0.9% NaCl solution. The serum fasting insulin (FINS), C-Peptide and IR index (HOMA-IR) were detected every 2 weeks during treatment and glucose tolerance was measured in the 3rd day before the material was taken. After the 6-week STG treatment, Liver tissues were processed for hematoxylin-eosin staining to perform light microscopy analysis and for assessing expression and distribution of insulin receptor substrates (IRS-1) and glucose transporter (GLUT-4) by immunohistochemistry analysis. Expression levels of liver kinase B1 (LKB1) / adenosine 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway proteins, including LKB1, phospho-AMPK (p-AMPK)/AMPK, phospho-mTOR (p-mTOR)/mTOR, and ribosomal protein S6 kinase polypeptide 1 (S6K1),were detected by Western blotting. RESULTS: STG significantly reduced the FBG level and liver fat deposition in diabetic GK rats. After STG treatment completion, FINS, HOMA-IR, C-Peptide and area under blood glucose curve (AUC) were lower in STG groups than in the MC group, indicating that IR was reduced and liver fat lesions were resolved. In liver tissues, STG groups displayed significantly higher IRS-1 and GLUT-4 expression than the MC group, along with increasedLKB1 and p-AMPK/AMPK expression and decreased p-mTOR/mTOR and phospho-S6K1expression, suggesting that STG stimulatedLKB1 activation of AMPK and suppressed them TOR/S6K1 downstream pathway. CONCLUSION: Growing GK rats developed hepatic IR, but STG treatment significantly improved hyperglycemia and IR and resolved hepatic fatty lesions. Interestingly, STG treatment stimulated the expression of IRS-1 and GLUT-4 in the liver of diabetic GK rats, indicating a potential involvement in the regulation of theLKB1/AMPK/mTOR signaling pathway.

Negative regulation of AMPK signaling by high glucose via E3 ubiquitin ligase MG53.

As a master regulator of metabolism, AMP-activated protein kinase (AMPK) is activated upon energy and glucose shortage but suppressed upon overnutrition. Exaggerated negative regulation of AMPK signaling by nutrient overload plays a crucial role in metabolic diseases. However, the mechanism underlying the negative regulation is poorly understood. Here, we demonstrate that high glucose represses AMPK signaling via MG53 (also called TRIM72) E3-ubiquitin-ligase-mediated AMPKα degradation and deactivation. Specifically, high-glucose-stimulated reactive oxygen species (ROS) signals AKT to phosphorylate AMPKα at S485/491, which facilitates the recruitment of MG53 and the subsequent ubiquitination and degradation of AMPKα. In addition, high glucose deactivates AMPK by ROS-dependent suppression of phosphorylation of AMPKα at T172. These findings not only delineate the mechanism underlying the impairment of AMPK signaling in overnutrition-related diseases but also highlight the significance of keeping the yin-yang balance of AMPK signaling in the maintenance of metabolic homeostasis.

STK11 loss drives rapid progression in a breast cancer patient resulting in pulmonary tumor thrombotic microangiopathy.

We experienced a case of breast cancer in which liver metastases spread rapidly and the patient died of pulmonary tumor thrombotic microangiopathy (PTTM). PTTM is a fatal cancer-associated respiratory complication disease. To reveal genetic alterations of the clinical course, we performed next generation sequencing of the serial specimens using the Ion AmpliSeqTM Comprehensive Cancer Panel and RNA sequencing for transcriptomic data, followed by gene set analysis. The analysis revealed an oncogenic TP53 R213* mutation in all specimens and STK11 loss in tissues sampled after disease progression. Immunohistochemistry with an anti-STK11 antibody confirmed no STK11 expression in the samples after progression. Transcriptome analysis showed a significant downregulation of proteins associated with apoptosis in the specimens with STK11 loss. STK11 loss may have triggered the rapid progression of PTTM from a comprehensive genomic analysis.

Sex-dimorphic Rostro-caudal Patterns of 5'-AMP-activated Protein Kinase Activation and Glucoregulatory Transmitter Marker Protein Expression in the Ventrolateral Ventromedial Hypothalamic Nucleus (VMNvl) in Hypoglycemic Male and Female Rats: Impact of Estradiol.

The ventromedial hypothalamic nucleus-ventrolateral part (VMNvl) is an estradiol-sensitive structure that controls sex-specific behavior. Electrical reactivity of VMNvl neurons to hypoglycemia infers that cellular energy stability is monitored there. Current research investigated the hypothesis that estradiol elicits sex-dimorphic patterns of VMNvl metabolic sensor activation and gluco-regulatory neurotransmission during hypoglycemia. Rostral-, middle-, and caudal-VMNvl tissue was separately micropunch-dissected from letrozole (Lz)- or vehicle-injected male and estradiol- or vehicle-implanted ovariectomized (OVX) female rats for Western blot analysis of total and phosphorylated 5'-AMP-activated protein kinase (AMPK) protein expression and gluco-stimulatory [neuronal nitric oxide synthase (nNOS); steroidogenic factor-1 (SF1) or -inhibitory (glutamate decarboxylase65/67 (GAD)] transmitter marker proteins after sc insulin (INS) or vehicle injection. In both sexes, hypoglycemic up-regulation of phosphoAMPK was estradiol-dependent in rostral and middle, but not caudal VMNvl. AMPK activity remained elevated after recovery from hypoglycemia over the rostro-caudal VMNvl in female, but only in the rostral segment in male. In each sex, hypoglycemia correspondingly augmented or suppressed nNOS profiles in rostral and middle versus caudal VMNvl; these segmental responses persisted longer in female. Rostral and middle segment SF1 protein was inhibited by estradiol-independent mechanisms in hypoglycemic males, but increased by estradiol-reliant mechanisms in female. After INS injection, GAD expression was inhibited in the male rostral VMNvl without estradiol involvement, but this hormone was required for broader suppression of this profile in the female. Neuroanatomical variability of VMNvl metabolic transmitter reactivity to hypoglycemia underscores the existence of functionally different subgroups in that structure. The regional distribution and estradiol sensitivity of hypoglycemia-sensitive VMNvl neurons of each neurochemical phenotype evidently vary between sexes.

Coniferaldehyde ameliorates the lipid and glucose metabolism in palmitic acid-induced HepG2 cells via the LKB1/AMPK signaling pathway.

Impaired lipid and glucose metabolism in the liver is a crucial characteristic of nonalcoholic fatty liver disease (NAFLD). Coniferaldehyde (CA), a kind of phenolic compound found in many edible plants, has multiple biological and pharmacological functions. However, since the effect and molecular mechanism of CA on hepatic lipid and glucose metabolism disorders in NAFLD remain unknown, this study investigated its impact on the lipid and glucose metabolism of palmitic acid (PA)-induced HepG2 cells. Compared with the HepG2 cells treated only with PA, supplementation with 25, 50, and 100 µM CA reduced the levels of intracellular triglyceride (by 7.11%, 19.62%, and 31.57%) and total cholesterol (by 8.46%, 23.32%, and 27.17%), and enhanced glucose uptake (by 40.91%, 57.49%, and 61.32%) and intracellular glycogen content (by 12.75%, 41.27%, and 53.77%). Moreover, CA supplementation downregulated the expression of sterol regulatory element-binding protein-1, fatty acid synthase, and stearoyl-CoA desaturase 1 related to lipogenesis while upregulating the expression of carnitine palmitoyltransferase 1α related to fatty acid oxidation. CA supplementation also upregulated the glucose transporter 2 protein expression and phosphorylation of glycogen synthase kinase 3ß while downregulating the phosphorylation of glycogen synthase. Most importantly, most of these effects of CA were reversed by pretreatment with AMP-activated protein kinase (AMPK) inhibitor and small interfering RNA-liver kinase B1 (LKB1). In conclusion, CA ameliorated the lipid and glucose metabolism in PA-induced HepG2 cells via the LKB1/AMPK signaling pathway. PRACTICAL APPLICATION: In this study, coniferaldehyde appeared to be effective in ameliorating hepatic lipid and glucose metabolism disorders in nonalcoholic fatty liver disease by reducing the levels of intracellular triglyceride and total cholesterol and enhancing glucose uptake and intracellular glycogen content via the LKB1/AMPK signaling pathway in vitro. Therefore, our findings provide new evidence in support of that supplementation with coniferaldehyde or food rich in coniferaldehyde might be considered as a viable dietary intervention strategy for preventing and treating nonalcoholic fatty liver disease.

Protective effect of Yi-Qi-Huo-Xue Decoction against ischemic heart disease by regulating cardiac lipid metabolism.

Yi-Qi-Huo-Xue Decoction (YQHX) is the recombination of Dang-Gui-Bu-Xue Decoction (DBD), which is one of the well-known traditional Chinese Medicine (TCM) prescription, and has long been shown to have significant protective effects against myocardial ischemic injury. In previous studies, we found that YQHX could regulate lipid and glucose metabolism, promote angiogenesis, attenuate inflammatory response, and ameliorate left ventricular function in myocardial ischemia rat models. However, the underlying mechanism of how YQHX involves in lipid metabolism remains unclear so far. In this study, the underlying mechanism of YQHX in lipid metabolism disorders was elucidated in a myocardial ischemia rat model and a hypoxia-induced H9c2 cell injury model. YQHX (8.2 g·kg-1) and positive-control drug trimetazidine (10 mg·kg-1) were administered daily on the second day after left anterior descending (LAD) operation. At 7 days and 28 days after surgery, changes of cardiac morphology, structure, and function were evaluated by H&E staining and echocardiography, respectively. The plasma lipid levels and mitochondrial ATP content were also evaluated. Western blot and RT-PCR were used to determine the protein and mRNA expressions of AMPK, PGC-1α, CPT-1α, and PPARα. YQHX improved cardiac function and ameliorated lipid metabolism disorders. Furthermore, YQHX increased the expression of p-AMPK, PGC-1α, and CPT-1α without changing PPARα in ischemic rat myocardium. In vitro, YQHX activated the protein and mRNA expression of PGC-1α, CPT-1α, and PPARα in hypoxia-induced H9c2 cells injury, whereas AMPK inhibitor Compound c blocked the effects of YQHX. Taken together, the results suggest that YQHX reduces lipid metabolism disorders in myocardial ischemia via the AMPK-dependent signaling pathway.

Two polyphenol-rich Brazilian fruit extracts protect from diet-induced obesity and hepatic steatosis in mice.

Consumption of polyphenol-rich food is associated with better metabolic health. Tucum-do-Pantanal (Bactris setosa Mart) and taruma-do-cerrado (Vitex cymosa Bertero ex Spreng) are underexploited native Brazilian fruits with an important source of phytochemicals. In this study, we assessed the effects of 100 mg kg-1 tucum (TPE) and taruma (TCE) extracts on diet-induced obesity (DIO) C57BL/6J mice. After 8 weeks of daily treatment, TPE and TCE were found to significantly prevented the diet-induced body weight gain and fully protected against hepatic steatosis associated with a tendency to stimulate hepatic AMPK phosphorylation. TPE reduced visceral obesity and improved glucose metabolism as revealed by an improvement of the insulin tolerance test, a reduction in the insulin fasting level, and a decreased glucose-induced hyperinsulinemia during an oral glucose tolerance test. TPE and TCE showed promising effects on the treatment of obesity and NAFLD, furthermore, TPE on insulin resistance.

Human skeletal muscle metabolic responses to 6 days of high-fat overfeeding are associated with dietary n-3PUFA content and muscle oxidative capacity.

Understanding human physiological responses to high-fat energy excess (HFEE) may help combat the development of metabolic disease. We aimed to investigate the impact of manipulating the n-3PUFA content of HFEE diets on whole-body and skeletal muscle markers of insulin sensitivity. Twenty healthy males were overfed (150% energy, 60% fat, 25% carbohydrate, 15% protein) for 6 d. One group (n = 10) received 10% of fat intake as n-3PUFA rich fish oil (HF-FO), and the other group consumed a mix of fats (HF-C). Oral glucose tolerance tests with stable isotope tracer infusions were conducted before, and following, HFEE, with muscle biopsies obtained in basal and insulin-stimulated states for measurement of membrane phospholipids, ceramides, mitochondrial enzyme activities, and PKB and AMPKα2 activity. Insulin sensitivity and glucose disposal did not change following HFEE, irrespective of group. Skeletal muscle ceramide content increased following HFEE (8.5 ± 1.2 to 12.1 ± 1.7 nmol/mg, p = .03), irrespective of group. No change in mitochondrial enzyme activity was observed following HFEE, but citrate synthase activity was inversely associated with the increase in the ceramide content (r=-0.52, p = .048). A time by group interaction was observed for PKB activity (p = .003), with increased activity following HFEE in HF-C (4.5 ± 13.0mU/mg) and decreased activity in HF-FO (-10.1 ± 20.7 mU/mg) following HFEE. Basal AMPKα2 activity increased in HF-FO (4.1 ± 0.6 to 5.3 ± 0.7mU/mg, p = .049), but did not change in HF-C (4.6 ± 0.7 to 3.8 ± 0.9mU/mg) following HFEE. We conclude that early skeletal muscle signaling responses to HFEE appear to be modified by dietary n-3PUFA content, but the potential impact on future development of metabolic disease needs exploring.

The Root of Polygonum multiflorum Thunb. Alleviates Non-Alcoholic Steatosis and Insulin Resistance in High Fat Diet-Fed Mice.

Non-alcoholic steatosis and insulin resistance are critical health problems and cause metabolic complications worldwide. In this study, we investigated the molecular mechanism of Polygonum multiflorum Thunb. (PM) against hepatic lipid accumulation and insulin resistance by using in vitro and in vivo models. PM extract significantly attenuated the accumulation of lipid droplets and hepatic triglyceride in free fatty acid (FFA)-exposed HepG2 cells. PM extract increased the AMPK and ACC phosphorylation and GLUT4 expression, whose levels were downregulated in FFA-exposed cells. PM extract also decreased precursor and mature forms of SREBP-1 in FFA-exposed cells. C57BL/6 mice fed with normal diet (ND) or high-fat diet (HFD) were administered PM extract (100 mg/kg) or vehicle orally for 16 weeks. PM extract attenuated the increases of the epididymal and perirenal fats on HFD feeding. PM extract markedly reduced hepatic lipid accumulation and fasting glucose levels, and improved glucose and insulin sensitivity in HFD-fed mice. HFD-fed mice decreased the AMPK and ACC phosphorylation and GLUT4 expression, and increased precursor and mature forms of SREBP-1; these changes were significantly restored by PM extract. In conclusion, PM extract alleviates non-alcoholic steatosis and insulin resistance through modulating the expression of proteins on lipid metabolism and glucose transport in the liver.

ROS Mediate xCT-Dependent Cell Death in Human Breast Cancer Cells under Glucose Deprivation.

xCT, also known as solute carrier family 7 member 11 (SLC7A11), the light chain of the cystine/glutamate antiporter, is positively correlated with cancer progression due to antioxidant function. During glucose deprivation, the overexpression of xCT does not protect cancer cells but instead promotes cell death. Further understanding the mechanism of glucose deprivation-induced cell death is important for developing anticancer treatments targeting the glucose metabolism. In this study, we found that breast cancer cells with a high expression of xCT demonstrated increased levels of reactive oxygen species (ROS) and were more sensitive to glucose deprivation than the cells with a low expression of xCT. However, AMP-activated protein kinase (AMPK) did not significantly affect glucose-deprivation-induced cell death. The antioxidant N-acetyl-cysteine prevented glucose-deprivation-induced cell death, and the glutathione biosynthesis inhibitor L-buthionine-S, R-sulfoximine enhanced glucose-deprivation-induced cell death. The inhibition of xCT by sulfasalazine or a knockdown of xCT reduced the glucose-deprivation-increased ROS levels and glucose-deprivation-induced cell death. Glucose deprivation reduced the intracellular glutamate, and supplementation with α-ketoglutarate prevented the glucose-deprivation-increased ROS levels and rescued cell death. The knockdown of sirtuin-3 (SIRT3) further enhanced the ROS levels, and promoted xCT-related cell death after glucose deprivation. In conclusion, our results suggested that ROS play a critical role in xCT-dependent cell death in breast cancer cells under glucose deprivation.