Fumaric acid production from fermented oil palm empty fruit bunches using fungal isolate K20: a comparison between free and immobilized cells.

This study investigated the potential of using steam-exploded oil palm empty fruit bunches (EFB) as a renewable feedstock for producing fumaric acid (FA), a food additive widely used for flavor and preservation, through a separate hydrolysis and fermentation process using the fungal isolate K20. The efficiency of FA production by free and immobilized cells was compared. The maximum FA concentration (3.25 g/L), with 0.034 g/L/h productivity, was observed after incubation with the free cells for 96 h. Furthermore, the production was scaled up in a 3-L air-lift fermenter using oil palm EFB-derived glucose as the substrate. The FA concentration, yield, and productivity from 100 g/L initial oil palm EFB-derived glucose were 44 g/L, 0.39 g/g, and 0.41 g/L/h, respectively. The potential for scaling up the fermentation process indicates favorable results, which could have significant implications for industrial applications.

Enhanced high ß-carotene yeast cell production by Rhodotorula paludigena CM33 and in vitro digestibility in aquatic animals.

This study assessed Rhodotorula paludigena CM33's growth and ß-carotene production in a 22-L bioreactor for potential use as an aquatic animal feed supplement. Optimizing the feed medium's micronutrient concentration for high-cell-density fed-batch cultivation using glucose as the carbon source yielded biomass of 89.84 g/L and ß-carotene concentration of 251.64 mg/L. Notably, using sucrose as the carbon source in feed medium outperforms glucose feeds, resulting in a ß-carotene concentration of 285.00 mg/L with a similar biomass of 87.78 g/L. In the fed-batch fermentation using Sucrose Feed Medium, R. paludigena CM33 exhibited high biomass production rates (Qx) of 0.91 g/L.h and remarkable ß-carotene production rates (Qp) of 2.97 mg/L.h. In vitro digestibility assays showed that R. paludigena CM33, especially when cultivated using sucrose, enhances protein digestibility affirming its suitability as an aquatic feed supplement. Furthermore, R. paludigena CM33's nutrient-rich profile and probiotic potential make it an attractive option for aquatic nutrition. This research highlights the importance of cost-effective carbon sources in large-scale ß-carotene production for aquatic animal nutrition.

Oral post-exercise garlic extract supplementation enhances glycogen replenishment but does not up-regulate mitochondria biogenesis mRNA expression in human-exercised skeletal muscle.

PURPOSE: Garlic extract (GA) is purported to enhance antioxidant and anti-inflammatory activity and glucose regulation in humans. The present study investigated the effects of post-exercise GA supplementation on GLUT4 expression, glycogen replenishment, and the transcript factors involved with mitochondrial biosynthesis in exercised human skeletal muscle. METHODS: The single-blinded crossover counterbalanced study was completed by 12 participants. Participants were randomly divided into either GA (2000 mg of GA) or placebo trials immediately after completing a single bout of cycling exercise at 75% Maximal oxygen uptake (VO2max) for 60 minutes. Participants consumed either GA (2000 mg) or placebo capsules with a high glycemic index carbohydrate meal (2 g carb/body weight) immediately after exercise. Muscle samples were collected at 0-h and 3-h post-exercise. Muscle samples were used to measure glycogen levels, GLUT4 protein expression, as well as transcription factors for glucose uptake, and mitochondria biogenesis. Plasma glucose, insulin, glycerol, non-esterified fatty acid (NEFA) concentrations, and respiratory exchange ratio (RER) were also analyzed during the post-exercise recovery periods. RESULTS: Skeletal muscle glycogen replenishment was significantly elevated during the 3-h recovery period for GA concurrent with no difference in GLUT4 protein expression between the garlic and placebo trials. PGC1-α gene expression was up-regulated for both GA and placebo after exercise (p < 0.05). Transcript factors corresponding to muscle mitochondrial biosynthesis were significantly enhanced under acute garlic supplementation as demonstrated by TFAM and FIS1. However, the gene expression of SIRT1, ERRα, NFR1, NFR2, MFN1, MFN2, OPA1, Beclin-1, DRP1 were not enhanced, nor were there any improvements in GLUT4 expression, following post-exercise garlic supplementation. CONCLUSION: Acute post-exercise garlic supplementation may improve the replenishment of muscle glycogen, but this appears to be unrelated to the gene expression for glucose uptake and mitochondrial biosynthesis in exercised human skeletal muscle.

Food perception promotes phosphorylation of MFFS131 and mitochondrial fragmentation in liver.

Liver mitochondria play a central role in metabolic adaptations to changing nutritional states, yet their dynamic regulation upon anticipated changes in nutrient availability has remained unaddressed. Here, we found that sensory food perception rapidly induced mitochondrial fragmentation in the liver through protein kinase B/AKT (AKT)-dependent phosphorylation of serine 131 of the mitochondrial fission factor (MFFS131). This response was mediated by activation of hypothalamic pro-opiomelanocortin (POMC)-expressing neurons. A nonphosphorylatable MFFS131G knock-in mutation abrogated AKT-induced mitochondrial fragmentation in vitro. In vivo, MFFS131G knock-in mice displayed altered liver mitochondrial dynamics and impaired insulin-stimulated suppression of hepatic glucose production. Thus, rapid activation of a hypothalamus-liver axis can adapt mitochondrial function to anticipated changes of nutritional state in control of hepatic glucose metabolism.

Phytochemical Profiling and Assessment of Antidiabetic Activity of Curcuma Angustifolia Rhizome Methanolic Extract: An In Vitro and In Silico Analysis.

Curcuma angustifolia Roxb. is a plant with medicinal potential, traditionally used to treat different diseases. The present study aimed to determine the antidiabetic activity of C. angustifolia rhizome in vitro and in silico. The methanolic extract of C. angustifolia rhizome was analyzed by FTIR and GC-MS to determine the phytochemicals present. The antidiabetic potential of the extract was evaluated by different assays in vitro. The extract inhibited both α-amylase and α-glucosidase enzymes and the glucose diffusion through the dialysis membrane in a concentration-dependent manner with IC50 values of 530.39±0.09, 293.75±0.11, and 551.74±0.3 µg/ml respectively. The methanolic extract also improved yeast cell's ability to take up glucose across plasma membranes and the adsorption of glucose. The findings were supported by molecular docking studies. The results showed that the methanol extract of C. angustifolia rhizome has significant antidiabetic activity and thus can be also studied to isolate the potential compound with antidiabetic activities.

Yunvjian decoction mitigates hyperglycemia in rats induced by a high-fat diet and streptozotocin via reducing oxidative stress in pancreatic beta cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Yunvjian (YNJ), a traditional Chinese herbal formula first reported in Jing Yue Quan Shu, is commonly used in the clinical treatment of type 2 diabetes mellitus (T2DM). However, the mechanism by which YNJ affects T2DM remains unclear. AIM OF THE STUDY: This study aimed to assess the therapeutic effects of YNJ on T2DM and explore the potential mechanism involved. MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was used to identify the chemical compounds of YNJ. The anti-T2DM effects of YNJ were observed in a high-fat diet/streptozotocin induced rat model. The type 2 diabetic rats were prepared as follows: rats were fed a high-fat diet for four weeks and then intraperitoneally injected with a low dose (30 mg/kg) of streptozotocin. YNJ and the positive control metformin were used in these experiments. Biochemical assays were implemented to determine the fasting blood glucose, glucose tolerance, insulin sensitivity, serum lipid levels, and oxidative stress index of the pancreas. Hematoxylin-eosin (H&E) staining was used to assess histopathological alterations in the pancreas. The mechanism by which YNJ affects T2DM was evaluated in INS-1 cells treated with glucose and high sodium palmitate. YNJ-supplemented serum was used in these experiments. Methyl thiazolyl tetrazolium assays, enzyme-linked immunosorbent assays, Nile red staining, flow cytometric analysis, and Western blotting were used to assess apoptosis, insulin secretion, lipid accumulation, reactive oxygen species production, and protein levels. RESULTS: Five major compounds were identified in YNJ. In high-fat diet/streptozotocin-induced diabetic rats, YNJ-M notably decreased fasting blood glucose and lipid levels; ameliorated glucose tolerance, insulin sensitivity, and islet morphology; reduced Malondialdehyde levels; and restored superoxide dismutase activity in the pancreatic islets. Furthermore, the effect of YNJ-M was significantly greater than that of YNJ-L, and YNJ-H had little effect on diabetic rats. In vitro experiments revealed that YNJ-supplemented serum (10%, 15%, and 20%) dramatically suppressed apoptosis, mitigated intracellular lipid accumulation and reduced intracellular oxidative stress levels in a dose-dependent manner. Additionally, YNJ-supplemented serum increased the protein expression of Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, and superoxide dismutase 1 and inhibited the protein expression of Kelch-like ECH-associated protein 1. CONCLUSION: YNJ ameliorates high-fat diet/streptozotocin induced experimental T2DM. The underlying mechanism involves reducing oxidative stress in pancreatic beta cells. The findings of this study provide scientific justification for the application of the traditional medicine YNJ in treating T2DM.

Cathodal bilateral transcranial direct-current stimulation regulates selenium to confer neuroprotection after rat cerebral ischaemia-reperfusion injury.

Non-invasive transcranial direct-current stimulation (tDCS) is a safe ischaemic stroke therapy. Cathodal bilateral tDCS (BtDCS) is a modified tDCS approach established by us recently. Because selenium (Se) plays a crucial role in cerebral ischaemic injury, we investigated whether cathodal BtDCS conferred neuroprotection via regulating Se-dependent signalling in rat cerebral ischaemia-reperfusion (I/R) injury. We first showed that the levels of Se and its transport protein selenoprotein P (SEPP1) were reduced in the rat cortical penumbra following I/R, whereas cathodal BtDCS prevented the reduction of Se and SEPP1. Interestingly, direct-current stimulation (DCS) increased SEPP1 level in cultured astrocytes subjected to oxygen-glucose deprivation reoxygenation (OGD/R) but had no effect on SEPP1 level in OGD/R-insulted neurons, indicating that DCS may increase Se in ischaemic neurons by enhancing the synthesis and secretion of SEPP1 in astrocytes. We then revealed that DCS reduced the number of injured mitochondria in OGD/R-insulted neurons cocultured with astrocytes. DCS and BtDCS prevented the reduction of the mitochondrial quality-control signalling, vesicle-associated membrane protein 2 (VAMP2) and syntaxin-4 (STX4), in OGD/R-insulted neurons cocultured with astrocytes and the ischaemic brain respectively. Under the same experimental conditions, downregulation of SEPP1 blocked DCS- and BtDCS-induced upregulation of VAMP2 and STX4. Finally, we demonstrated that cathodal BtDCS increased Se to reduce infract volume following I/R. Together, the present study uncovered a molecular mechanism by which cathodal BtDCS confers neuroprotection through increasing SEPP1 in astrocytes and subsequent upregulation of SEPP1/VAMP2/STX4 signalling in ischaemic neurons after rat cerebral I/R injury. KEY POINTS: Cathodal bilateral transcranial direct-current stimulation (BtDCS) prevents the reduction of selenium (Se) and selenoprotein P in the ischaemic penumbra. Se plays a crucial role in cerebral ischaemia injury. Direct-current stimulation reduces mitochondria injury and blocks the reduction of vesicle-associated membrane protein 2 (VAMP2) and syntaxin-4 (STX4) in oxygen-glucose deprivation reoxygenation-insulted neurons following coculturing with astrocytes. Cathodal BtDCS regulates Se/VAMP2/STX4 signalling to confer neuroprotection after ischaemia.

High-level production of Rhodiola rosea characteristic component rosavin from D-glucose and L-arabinose in engineered Escherichia coli.

Rosavin is the characteristic component of Rhodiola rosea L., an important medicinal plant used widely in the world that has been reported to possess multiple biological activities. However, the endangered status of wild Rhodiola has limited the supply of rosavin. In this work, we successfully engineered an Escherichia coli strain to efficiently produce rosavin as an alternative production method. Firstly, cinnamate: CoA ligase from Hypericum calycinum, cinnamoyl-CoA reductase from Lolium perenne, and uridine diphosphate (UDP)-glycosyltransferase (UGT) from Bacillus subtilis (Bs-YjiC) were selected to improve the titer of rosin in E. coli. Subsequently, four UGTs from the UGT91R subfamily were identified to catalyze the formation of rosavin from rosin, with SlUGT91R1 from Solanum lycopersicum showing the highest activity level. Secondly, production of rosavin was achieved for the first time in E. coli by incorporating the SlUGT91R1 and UDP-arabinose pathway, including UDP-glucose dehydrogenase, UDP-xylose synthase, and UDP-xylose 4-epimerase, into the rosin-producing stain, and the titer reached 430.5 ± 91.4 mg/L. Thirdly, a two-step pathway derived from L-arabinose, composed of L-arabinokinase and UDP-sugar pyrophosphorylase, was developed in E. coli to further optimize the supply of the precursor UDP-arabinose. Furthermore, 1203.7 ± 32.1 mg/L of rosavin was produced from D-glucose and L-arabinose using shake-flask fermentation. Finally, the production of rosavin reached 7539.1 ± 228.7 mg/L by fed-batch fermentation in a 5-L bioreactor. Thus, the microbe-based production of rosavin shows great potential for commercialization. This work provides an effective strategy for the biosynthesis of other valuable natural products with arabinose-containing units from D-glucose and L-arabinose.

Effects of replacing Na selenite in laying hen feed with selenized glucose on production performance, egg quality, egg selenium content, microbial population, immunological response, antioxidant enzymes, and fatty acid composition.

This study aimed to explore the effects of selenized glucose (SeGlu) and Na selenite supplementation on various aspects of laying hens such as production performance, egg quality, egg Se concentration, microbial population, antioxidant enzymes activity, immunological response, and yolk fatty acid profile. Using a 2 × 2 factorial design, 168 laying hens at 27-wk of age were randomly divided into 4 treatment groups with 7 replications. Se source (Na selenite and SeGlu) and Se level (0.3 and 0.6 mg/kg) were used as treatments. When 0.3 mg SeGlu/kg was compared to 0.3 mg Na selenite/kg, the interaction findings revealed that 0.3 mg SeGlu/kg increased egg production percent and shell ash (P < 0.05). When compared to 0.3 mg Na selenite/kg, dietary supplementation with 0.3 and 0.6 mg SeGlu/kg resulted in an increase in albumen height, Haugh unit, and yolk color of fresh eggs (P < 0.05). SeGlu enhanced albumen height, Haugh unit, shell thickness (P < 0.01), albumen index, yolk share, specific gravity, shell ash (P < 0.05) of fresh eggs and shell thickness (P < 0.05) of stored eggs as compared to Na selenite. The interaction showed that 0.6 mg SeGlu/kg enhanced yolk Se concentration while decreasing malondialdehyde levels in fresh egg yolk (P < 0.05). SeGlu enhanced Se concentration in albumen and glutathione peroxidase activity in plasma (P < 0.05) as compared to Na selenite. 0.6 mg Se/kg increased lactic acid bacteria, antibody response to sheep red blood cells, and lowered ∑n-6 PUFA/ ∑n-3 PUFA ratio (P < 0.05). As a result, adding SeGlu to the feed of laying hens enhanced egg production, egg quality, egg Se concentration, fresh yolk lipid oxidation, and glutathione peroxidase enzyme activity.

Phytic acid promotes high glucose-mediated bone marrow mesenchymal stem cells osteogenesis via modulating circEIF4B that sponges miR-186-5p and complexes with IGF2BP3.

Diabetes-related hyperglycemia inhibits bone marrow mesenchymal stem cell (BMSC) function, thereby disrupting osteoblast capacity and bone regeneration. Dietary supplementation with phytic acid (PA), a natural inositol phosphate, has shown promise in preventing osteoporosis and diabetes-related complications. Emerging evidence has suggested that circular (circ)RNAs implicate in the regulation of bone diseases, but their specific regulatory roles in BMSC osteogenesis in hyperglycemic environments remain elucidated. In this study, in virto experiments demonstrated that PA treatment effectively improved the osteogenic capability of high glucose-mediated BMSCs. Differentially expressed circRNAs in PA-induced BMSCs were identified using circRNA microarray analysis. Here, our findings highlight an upregulation of circEIF4B expression in BMSCs stimulated with PA under a high-glucose microenvironment. Further investigations demonstrated that circEIF4B overexpression promoted high glucose-mediated BMSC osteogenesis. In contrast, circEIF4B knockdown exerted the opposite effect. Mechanistically, circEIF4B sequestered microRNA miR-186-5p and triggered osteogenesis enhancement in BMSCs by targeting FOXO1 directly. Furthermore, circEIF4B inhibited the ubiquitin-mediated degradation of IGF2BP3, thereby stabilizing ITGA5 mRNA and promoting BMSC osteogenic differentiation. In vivo experiments, circEIF4B inhibition attenuated the effectiveness of PA treatment in diabetic rats with cranial defects. Collectively, our study identifies PA as a novel positive regulator of BMSC osteogenic differentiation through the circEIF4B/miR-186-5p/FOXO1 and circEIF4B/IGF2BP3/ITGA5 axes, which offers a new strategy for treating high glucose-mediatedBMSCosteogenic dysfunction and delayed bone regeneration in diabetes.

Fenugreek extract improves diabetes-induced endothelial dysfunction via the arginase 1 pathway.

Endothelial dysfunction (ED) is an initiating trigger and key factor in vascular complications, leading to disability and mortality in individuals with diabetes. The research concerning therapeutic interventions for ED has gained considerable interest. Fenugreek, a commonly used edible plant in dietary consumption, has attracted significant attention due to its management of diabetes and its associated complications. The research presented in this study examines the potential therapeutic benefits of fenugreek in treating ED and investigates the underlying mechanism associated with its effects. The analysis on fenugreek was performed using 70% ethanol extract, and its chemical composition was analyzed using ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). In total, we identified 49 compounds present in the fenugreek extract. These compounds encompass flavonoids, saponins, and phospholipids. Then, the models of ED in streptozotocin-induced diabetic mice and high glucose-induced isolated rat aortas were established for research. Through vascular function testing, it was observed that fenugreek extract effectively improved ED induced by diabetes or high glucose. By analyzing the protein expression of arginase 1 (Arg1), Arg activity, Arg1 immunohistochemistry, nitric oxide (NO) level, and the protein expression of endothelial nitric oxide synthase (eNOS), p38 mitogen-activated protein kinase (p38 MAPK), and p-p38 MAPK in aortas, this study revealed that the potential mechanism of fenugreek extract in anti-ED involves the downregulation of Arg1, leading to enhanced NO production. Furthermore, analysis of serum exosomes carrying Arg activity indicates that fenugreek may decrease the activity of Arg transported by serum exosomes, potentially preventing the increase in Arg levels triggered by the uptake of serum exosomes by vascular endothelial cells. In general, this investigation offers valuable observations regarding the curative impact of fenugreek extract on anti-ED in diabetes, revealing the involvement of the Arg1 pathway in its mechanism.

Thermodynamic Analysis to Evaluate the Effect of Diet on Brain Glucose Metabolism: The Case of Fish Oil.

Inefficient glucose metabolism and decreased ATP production in the brain are linked to ageing, cognitive decline, and neurodegenerative diseases (NDDs). This study employed thermodynamic analysis to assess the effect of fish oil supplementation on glucose metabolism in ageing brains. Data from previous studies on glucose metabolism in the aged human brain and grey mouse lemur brains were examined. The results demonstrated that Omega-3 fish oil supplementation in grey mouse lemurs increased entropy generation and decreased Gibbs free energy across all brain regions. Specifically, there was a 47.4% increase in entropy generation and a 47.4 decrease in Gibbs free energy in the whole brain, indicating improved metabolic efficiency. In the human model, looking at the specific brain regions, supplementation with Omega-3 polyunsaturated fatty acids (n-3 PUFAs) reduced the entropy generation difference between elderly and young individuals in the cerebellum and particular parts of the brain cortex, namely the anterior cingulate and occipital lobe, with 100%, 14.29%, and 20% reductions, respectively. The Gibbs free energy difference was reduced only in the anterior cingulate by 60.64%. This research underscores that the application of thermodynamics is a comparable and powerful tool in comprehending the dynamics and metabolic intricacies within the brain.

Protective effect of alizarin on vascular endothelial dysfunction via inhibiting the type 2 diabetes-induced synthesis of THBS1 and activating the AMPK signaling pathway.

BACKGROUND: In this study, we investigated the protective effects of alizarin (AZ) on endothelial dysfunction (ED). AZ has inhibition of the type 2 diabetes mellitus (T2DM)-induced synthesis of thrombospondin 1 (THBS1). Adenosine 5'-monophosphate- activated protein kinase (AMPK), particularly AMPKα2 isoform, plays a critical role in maintaining cardiac homeostasis. PURPOSE: The aim of this study was to investigate the ameliorative effect of AZ on vascular injury caused by T2DM and to reveal the potential mechanism of AZ in high glucose (HG)-stimulated human umbilical vein endothelial cells (HUVECs) and diabetic model rats. STUDY DESIGN: HUVECs, rats and AMPK-/- transgenic mice were used to investigate the mitigating effects of AZ on vascular endothelial dysfunction caused by T2DM and its in vitro and in vivo molecular mechanisms. METHODS: In type 2 diabetes mellitus rats and HUVECs, the inhibitory effect of alizarin on THBS1 synthesis was verified by immunohistochemistry (IHC), immunofluorescence (IF) and Western blot (WB) so that increase endothelial nitric oxide synthase (eNOS) content in vitro and in vivo. In addition, we verified protein interactions with immunoprecipitation (IP). To probe the mechanism, we also performed AMPKα2 transfection. AMPK's pivotal role in AZ-mediated prevention against T2DM-induced vascular endothelial dysfunction was tested using AMPKα2-/- mice. RESULTS: We first demonstrated that THBS1 and AMPK are targets of AZ. In T2DM, THBS1 was robustly induced by high glucose and inhibited by AZ. Furthermore, AZ activates the AMPK signaling pathway, and recoupled eNOS in stressed endothelial cells which plays a protective role in vascular endothelial dysfunction. CONCLUSIONS: The main finding of this study is that AZ can play a role in different pathways of vascular injury due to T2DM. Mechanistically, alizarin inhibits the increase in THBS1 protein synthesis after high glucose induction and activates AMPKα2, which increases NO release from eNOS, which is essential in the prevention of vascular endothelial dysfunction caused by T2DM.

Lesion of NPY Receptor-expressing Neurons in Perifornical Lateral Hypothalamus Attenuates Glucoprivic Feeding.

Glucoprivic feeding is one of several counterregulatory responses (CRRs) that facilitates restoration of euglycemia following acute glucose deficit (glucoprivation). Our previous work established that glucoprivic feeding requires ventrolateral medullary (VLM) catecholamine (CA) neurons that coexpress neuropeptide Y (NPY). However, the connections by which VLM CA/NPY neurons trigger increased feeding are uncertain. We have previously shown that glucoprivation, induced by an anti-glycolygic agent 2-deoxy-D-glucose (2DG), activates perifornical lateral hypothalamus (PeFLH) neurons and that expression of NPY in the VLM CA/NPY neurons is required for glucoprivic feeding. We therefore hypothesized that glucoprivic feeding and possibly other CRRs require NPY-sensitive PeFLH neurons. To test this, we used the ribosomal toxin conjugate NPY-saporin (NPY-SAP) to selectively lesion NPY receptor-expressing neurons in the PeFLH of male rats. We found that NPY-SAP destroyed a significant number of PeFLH neurons, including those expressing orexin, but not those expressing melanin-concentrating hormone. The PeFLH NPY-SAP lesions attenuated 2DG-induced feeding but did not affect 2DG-induced increase in locomotor activity, sympathoadrenal hyperglycemia, or corticosterone release. The 2DG-induced feeding response was also significantly attenuated in NPY-SAP-treated female rats. Interestingly, PeFLH NPY-SAP lesioned male rats had reduced body weights and decreased dark cycle feeding, but this effect was not seen in female rats. We conclude that a NPY projection to the PeFLH is necessary for glucoprivic feeding, but not locomotor activity, hyperglycemia, or corticosterone release, in both male and female rats.

Activation of NRF2 by epiberberine improves oxidative stress and insulin resistance in T2DM mice and IR-HepG2 cells in an AMPK dependent manner.

ETHNOPHARMACOLOGICAL RELEVANCE: Phytochemical compounds offer a distinctive edge in diabetes management, attributed to their multifaceted target mechanisms and minimal toxicological profiles. Epiberberine (EPI), an alkaloid derived from plants of the Rhizoma Coptidis, has been reported to have antidiabetic effects. However, the underlying molecular mechanism of EPI are not fully elucidated. AIM OF THE STUDY: This study explored the anti-diabetic effects of EPI and the role of the NRF2/AMPK signaling pathway in improving insulin resistance. MATERIALS AND METHODS: We utilized two distinct models: in vivo, we employed mice with type 2 diabetes mellitus (T2DM) induced by high-fat diet (HFD) and streptozotocin (STZ) to conduct a range of assessments including measuring physical parameters, conducting biochemical analyses, examining histopathology, and performing Western blot tests. In parallel, in vitro experiments were carried out using insulin resistance (IR)-HepG2 cells, through which we conducted a CCK8 assay, glucose uptake tests, Western blot analyses, and flow cytometry studies. RESULTS: In the EPI-treated group of T2DM mice, there was a significant reduction in hyperglycemia, IR, and hyperlipidemia, accompanied by beneficial changes in the liver and pancreas, as well as enhanced glucose uptake in IR-HepG2 cells. Herein, our finding also provided evidence that EPI could increase the expression of GLUT4 and activated the IRS-1/PI3K/AKT insulin signaling pathway to improve IR in vitro and in vivo. Moreover, EPI alleviated oxidative stress by enhancing SOD and GPX-px activity, decreasing reactive oxygen species (ROS) and malondialdehyde (MDA) content, and promoting nuclear factor (erythroid-derived 2)-like 2 (NRF2), total NRF2, NAD(P)H-quinone oxidoreductase (NQO1) and heme oxygenase-1 (HO-1) expression in the liver tissue of T2DM mice and IR-HepG2 cells. Furthermore, EPI decreased oxidative stress and improved IR, but these benefits were nullified by siNRF2 transfection. In particular, AMP-activated protein kinase (AMPK) deficiency by short-hairpin RNA (shRNA) partially reversed the effects of EPI on nuclear transcription, oxidative stress, and IR of NRF2 in IR-HepG2 cells. CONCLUSIONS: Taken together, EPI activated NRF2-dependent AMPK cascade to protect T2DM from oxidative stress, thereby alleviating IR.

Dosage-effect of selenium supplementation on blood glucose and oxidative stress in type 2 diabetes mellitus and normal mice.

BACKGROUND: The effectiveness of selenium (Se) supplementation on glycemic control is disparate. OBJECTIVE: This study aims to evaluate the effects of different dosages of Se diets on the blood glucose in type 2 diabetes mellitus (T2DM, db/db) and normal (db/m) mice. METHODS: The db/db and db/m mice were fed with different dosages of Se supplemented diets (0, 0.1, 0.3, 0.9, 2.7 mg/kg) for 12 weeks, respectively. Se concentrations of tissues, physical and biochemical characteristics, oxidative stress indexes and gene expression related to glucose, lipid metabolism and Se transporters of liver were detected. RESULTS: The Se concentrations in tissues were related to the dosages of Se supplementation in db/db (blood: slope=11.69, r = 0.924; skeletal muscle: slope=0.36, r = 0.505; liver: slope=22.12, r = 0.828; kidney: slope=11.81, r = 0.736) and db/m mice (blood: slope=19.89, r = 0.876; skeletal muscle: slope=2.80, r = 0.883; liver: slope=44.75, r = 0.717; kidney: slope=60.15, r = 0.960). Compared with Se2.7 group, the fasting blood glucose (FBG) levels of Se0.1 and Se0.3 group were decreased at week3 in db/db mice. Compared with control (Se0) group, the FBG levels of Se2.7 group were increased from week6 to week12 in db/m mice. The oral glucose tolerance test (OGTT) showed that the area under the curve (AUC) of Se0.3 group was lower than that of Se0.9 and Se2.7 group in db/m mice. Furthermore, compared with control group, the malondialdehyde (MDA) level in skeletal muscle of Se0.1 group was decreased, while that of Se2.7 group was increased in db/db mice; the glutathione peroxidase (GPx) activity in skeletal muscle of Se0.3, Se0.9 and Se2.7 group was increased both in db/db and db/m mice. For db/db mice, glucose-6-phosphatase catalytic (G6pc) expression of other groups were lower and fatty acid synthase (Fasn) expression of Se0.9 group were lower compared with Se0.3 group. For db/m mice, compared with Se0.3 group, (peroxisome proliferative activated receptor gamma coactivator 1 alpha) Pgc-1α expression of control and Se0.9 group were higher; (phosphoenolpyruvate carboxykinase 1) Pck1 expression of Se0.1, Se0.9, and Se2.7 group were higher. CONCLUSION: Low dosages (0.1 and 0.3 mg/kg) of Se supplementation exerted beneficial effects on FBG levels and glucose tolerance through regulating hepatic glycolysis and gluconeogenesis and inhibit the oxidative stress while high dosages of Se (0.9 and 2.7 mg/kg) supplementation enhanced FBG levels, impaired glucose tolerance and aggravate oxidative stress.

Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling.

OBJECTIVE: Obesity is a global health concern with management strategies encompassing bariatric surgery and anti-obesity drugs; however, concerns regarding complexities and side effects persist, driving research for more effective, low-risk strategies. The promotion of white adipose tissue (WAT) browning has emerged as a promising approach. Moreover, alisol B 23-acetate (AB23A) has demonstrated efficacy in addressing metabolic disorders, suggesting its potential as a therapeutic agent in obesity management. Therefore, in this study, we aimed to investigate the therapeutic potential of AB23A for mitigating obesity by regulating metabolic phenotypes and lipid distribution in mice fed a high-fat diet (HFD). METHODS: An obesity mouse model was established by administration of an HFD. Glucose and insulin metabolism were assessed via glucose and insulin tolerance tests. Adipocyte size was determined using hematoxylin and eosin staining. The expression of browning markers in WAT was evaluated using Western blotting and quantitative real-time polymerase chain reaction. Metabolic cage monitoring involved the assessment of various parameters, including food and water intake, energy metabolism, respiratory exchange rates, and physical activity. Moreover, oil red O staining was used to evaluate intracellular lipid accumulation. A bioinformatic analysis tool for identifying the molecular mechanisms of traditional Chinese medicine was used to examine AB23A targets and associated signaling pathways. RESULTS: AB23A administration significantly reduced the weight of obese mice, decreased the mass of inguinal WAT, epididymal WAT, and perirenal adipose tissue, improved glucose and insulin metabolism, and reduced adipocyte size. Moreover, treatment with AB23A promoted the expression of browning markers in WAT, enhanced overall energy metabolism in mice, and had no discernible effect on food intake, water consumption, or physical activity. In 3T3-L1 cells, AB23A inhibited lipid accumulation, and both AB23A and rapamycin inhibited the mammalian target of rapamycin-sterol regulatory element-binding protein-1 (mTOR-SREBP1) signaling pathway. Furthermore, 3-isobutyl-1-methylxanthine, dexamethasone and insulin, at concentrations of 0.25 mmol/L, 0.25 µmol/L and 1 µg/mL, respectively, induced activation of the mTOR-SREBP1 signaling pathway, which was further strengthened by an mTOR activator MHY1485. Notably, MHY1485 reversed the beneficial effects of AB23A in 3T3-L1 cells. CONCLUSION: AB23A promoted WAT browning by inhibiting the mTOR-SREBP1 signaling pathway, offering a potential strategy to prevent obesity. Please cite this article as: Han LL, Zhang X, Zhang H, Li T, Zhao YC, Tian MH, Sun FL, Feng B. Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling. J Integr Med. 2024; 22(1): 83-92.

Jinkui Shenqi pills ameliorate diabetes by regulating hypothalamic insulin resistance and POMC/AgRP expression and activity.

BACKGROUND: Research on the imbalance of proopiomelanocortin (POMC)/agouti-related protein (AgRP) neurons in the hypothalamus holds potential insights into the pathophysiology of diabetes. Jinkui Shenqi pills (JSP), a prevalent traditional Chinese medicine, regulate hypothalamic function and treat diabetes. PURPOSE: To investigate the hypoglycemic effect of JSP and explore the probable mechanism in treating diabetes. METHODS: A type 2 diabetes mouse model was used to investigate the pharmacodynamics of JSP. The glucose-lowering efficacy of JSP was assessed through various metrics including body weight, food consumption, fasting blood glucose (FBG), serum insulin levels, and an oral glucose tolerance test (OGTT). To elucidate the modulatory effects of JSP on hypothalamic mechanisms, we quantified the expression and activity of POMC and AgRP and assessed the insulin-mediated phosphoinositide 3-kinase (PI3K)/protein kinase A (AKT)/forkhead box O1 (FOXO1) pathway in diabetic mice via western blotting and immunohistochemistry. Additionally, primary hypothalamic neurons were exposed to high glucose and palmitic acid levels to induce insulin resistance, and the influence of JSP on POMC/AgRP protein expression and activation was evaluated by PI3K protein inhibition using western blotting and immunofluorescence. RESULTS: Medium- and high-dose JSP treatment effectively inhibited appetite, resulting in a steady declining trend in body weight, FBG, and OGTT results in diabetic mice (p < 0.05). These JSP groups also had significantly increased insulin levels (p < 0.05). Importantly, the medium-dose group exhibited notable protection of hypothalamic neuronal and synaptic structures, leading to augmentation of dendritic length and branching (p < 0.05). Furthermore, low-, medium-, and high-dose JSP groups exhibited increased phosphorylated (p) INSR, PI3K, pPI3K, AKT, and pAKT expression, as well as decreased FOXO1 and increased pFOXO1 expression, indicating improved hypothalamic insulin resistance in diabetic mice (p < 0.05). Treatment with 10% JSP-enriched serum produced a marked elevation of both expression and activation of POMC (p < 0.05), with a concurrent reduction in AgRP expression and activation within primary hypothalamic neurons (p < 0.05). Intriguingly, these effects could be attributed to the regulatory dynamics of PI3K activity. CONCLUSION: Our findings suggest that JSP can ameliorate diabetes by regulating POMC/AgRP expression and activity. The insulin-mediated PI3K/AKT/FOXO1 pathway plays an important regulatory role in this intricate process.

Si-Ni-San promotes liver regeneration by maintaining hepatic oxidative equilibrium and glucose/lipid metabolism homeostasis.

ETHNOPHARMACOLOGICAL RELEVANCE: The efficacy of clinical treatments for various liver diseases is intricately tied to the liver's regenerative capacity. Insufficient or failed liver regeneration is a direct cause of mortality following fulminant hepatic failure and extensive hepatectomy. Si-Ni-San (SNS), a renowned traditional Chinese medicine prescription for harmonizing liver and spleen functions, has shown clinical efficacy in the alleviation of liver injury for thousands of years. However, the precise molecular pharmacological mechanisms underlying its effects remain unclear. AIMS OF THE STUDY: This study aimed to investigate the effects of SNS on liver regeneration and elucidate the underlying mechanisms. MATERIALS AND METHODS: A mouse model of 70% partial hepatectomy (PHx) was used to analyze the effects of SNS on liver regeneration. Aquaporin-9 knockout mice (AQP9-/-) were used to demonstrate that SNS-mediated enhancement of liver regeneration was AQP9-targeted. A tandem dimer-Tomato-tagged AQP9 transgenic mouse line (AQP9-RFP) was utilized to determine the expression pattern of AQP9 protein in hepatocytes. Immunoblotting, quantitative real-time PCR, staining techniques, and biochemical assays were used to further explore the underlying mechanisms of SNS. RESULTS: SNS treatment significantly enhanced liver regeneration and increased AQP9 protein expression in hepatocytes of wild-type mice (AQP9+/+) post 70% PHx, but had no significant effects on AQP9-/- mice. Following 70% PHx, SNS helped maintain hepatic oxidative equilibrium by increasing the levels of reactive oxygen species scavengers glutathione and superoxide dismutase and reducing the levels of oxidative stress molecules H2O2 and malondialdehyde in liver tissues, thereby preserving this crucial process for hepatocyte proliferation. Simultaneously, SNS augmented glycerol uptake by hepatocytes, stimulated gluconeogenesis, and maintained glucose/lipid metabolism homeostasis, ensuring the energy supply required for liver regeneration. CONCLUSIONS: This study provides the first evidence that SNS maintains liver oxidative equilibrium and glucose/lipid metabolism homeostasis by upregulating AQP9 expression in hepatocytes, thereby promoting liver regeneration. These findings offer novel insights into the molecular pharmacological mechanisms of SNS in promoting liver regeneration and provide guidance for its clinical application and optimization in liver disease treatment.

Dietary Supplementation with Cholic Acid Reduces Insulin Secretion in Response to Intraperitoneal Glucose Administration in Rats.

The major characteristic of type 2 diabetes is insulin resistance, which is associated with plasma level of 12-hydroxylated bile acids (BAs) in humans. In this study, we investigated whether the rise of enterohepatic 12-hydroxylated BAs associates with glucose tolerance and/or insulin secretion using rats fed a diet supplemented with cholic acid (CA) at a level of 0.5 g/kg diet. Almost no increase was observed in plasma insulin in response to the intraperitoneal glucose administration in the CA-fed rats despite the significant increase of plasma insulin in control with the same treatment. In contrast, the changes in insulin secretion were observed in both groups and no difference was detected between the groups in the oral glucose tolerance test. Increases were observed in pancreatic expressions of Ins1 and Ins2 although the insulin protein content decreased in the pancreas without any sign in ectopic fat accumulation and histological damage in the CA-fed rats. Our results suggest that enterohepatic 12-hydroxylated BAs modulate insulin secretion in response to intraperitoneal glucose administration. The decrease in insulin store might be responsible for the reduction in the insulin secretion in the CA-fed rats.