Arctigenin mitigates insulin resistance by modulating the IRS2/GLUT4 pathway via TLR4 in type 2 diabetes mellitus mice

Novel thiosemicarbazide-based β-carboline derivatives as α-glucosidase inhibitors: Synthesis and biological evaluation

In the quest for potent α-glucosidase inhibitors to combat diabetes, a series of novel thiosemicarbazide-based β-carboline derivatives (CTL1∼36) were synthesized and evaluated. CTL1∼36 exhibited remarkable inhibitory effects against α-glucosidase, with IC50 values ranging from 2.81 to 12.40 μM, significantly surpassing the positive control acarbose (IC50 = 564.28 μM). Notably, CTL26 demonstrated the most potent inhibition (IC50 = 2.81 μM) and was characterized as a non-competitive inhibitor. Through a combination assay with fluorescence quenching, 3D fluorescence spectra, CD spectra, and molecular docking, we elucidated that CTL26 formed a complex with α-glucosidase via hydrogen bondings and hydrophobic interactions, leading to α-glucosidase conformation changes that impaired enzymatic activity. In vivo studies revealed that oral administration of CTL26 (25 and 50 mg/kg/d) reduced fasting blood glucose levels, enhanced glucose tolerance, and ameliorated lipid abnormalities in diabetic mice. These findings positioned CTL26 as a promising candidate for the development of α-glucosidase inhibitors with anti-diabetic potential.

The promising antioxidant effects of lignans: Nrf2 activation comes into view

Lignans are biologically active compounds widely distributed, recognized, and identified in seeds, fruits, and vegetables. Lignans have several intriguing bioactivities, including anti-inflammatory, antioxidant, and anticancer activities. Nrf2 controls the expression of many cytoprotective genes. Activation of Nrf2 is a promising therapeutic approach for treating and preventing diseases resulting from oxidative injury and inflammation. Lignans have been demonstrated to stimulate Nrf2 signaling in a variety of in vitro and experimental animal models. The review summarizes the findings of fourteen lignans (Schisandrin A, Schisandrin B, Schisandrian C, Magnolol, Honokiol, Sesamin, Sesamol, Sauchinone, Pinoresinol, Phyllanthin, Nectandrin B, Isoeucommin A, Arctigenin, Lariciresinol) as antioxidative and anti-inflammatory agents, affirming how Nrf2 activation affects their pharmacological effects. Therefore, lignans may offer therapeutic candidates for the treatment and prevention of various diseases and may contribute to the development of effective Nrf2 modulators.

Water decoction of Pericarpium citri reticulatae and Amomi fructus ameliorates alcohol-induced liver disease involved in the modulation of gut microbiota and TLR4/NF-κB pathway

Introduction

Alcohol consumption alters the diversity and metabolic activities of gut microbiota, leading to intestinal barrier dysfunction and contributing to the development of alcoholic liver disease (ALD), which is the most prevalent cause of advanced liver diseases. In this study, we investigated the protective effects and action mechanism of an aqueous extraction of Pericarpium citri reticulatae and Amomi fructus (PFE) on alcoholic liver injury.

Methods

C57BL/6 mice were used to establish the mouse model of alcoholic liver injury and orally administered 500 and 1,000 mg/kg/d of PFE for 2 weeks. Histopathology, immunohistochemistry, immunofluorescence, Western blotting, qRT-PCR, and 16S rDNA amplicon sequencing were used to analyze the mechanism of action of PFE in the treatment of alcohol-induced liver injury.

Results

Treatment with PFE significantly improved alcohol-induced liver injury, as illustrated by the normalization of serum alanine aminotransferase, aspartate aminotransferase, total triglyceride, and cholesterol levels in ALD mice in a dose-dependent manner. Administration of PFE not only maintained the intestinal barrier integrity prominently by upregulating mucous production and tight junction protein expressions but also sensibly reversed the dysregulation of intestinal microecology in alcohol-treated mice. Furthermore, PFE treatment significantly reduced hepatic lipopolysaccharide (LPS) and attenuated oxidative stress as well as inflammation related to the TLR4/NF-κB signaling pathway. The PFE supplementation also significantly promoted the production of short-chain fatty acids (SCFAs) in the ALD mice.

Conclusion

Administration of PFE effectively prevents alcohol-induced liver injury and may also regulate the LPS-involved gut-liver axis; this could provide valuable insights for the development of drugs to prevent and treat ALD.

Honokiol as an α-glucosidase inhibitor

Honokiol, a naturally occurring compound from Magnolia obovata Thunb., has many biological activities, but its anti-α-glucosidase activity is still unclear. Therefore, we determined its inhibitory effects against α-glucosidase. Activity assays showed that honokiol was a reversible mixed-type inhibitor of α-glucosidase, and its IC50 value was 317.11 ± 12.86 μM. Fluorescence results indicated that the binding of honokiol to α-glucosidase caused a reduction in α-glucosidase activity. 3D fluorescence and CD spectra results indicated that the binding of honokiol to α-glucosidase caused conformational change in α-glucosidase. Docking simulated the detailed interactions between honokiol and α-glucosidase, including hydrogen and hydrophobic bonds. All findings showed that honokiol could be used as a natural inhibitor to develop α-glucosidase agents.

Zn(II)-curcumin prevents cadmium-aggravated diabetic nephropathy by regulating gut microbiota and zinc homeostasis

Background: Diabetic nephropathy (DN) is known as the most common complication of diabetes, resulting from a complex inheritance-environment interaction without effective clinical treatments. Herein, we revealed the protective effects and mechanisms of Zn(II)-curcumin, a curcumin derivative, against streptozotocin-induced DN in rats in the presence or absence of cadmium exposure. Methods: The present study focused on investigating the therapy of Zn(II)-curcumin against cadmium-aggravated DN by regulating gut microbiota, metabolism, inflammation and zinc homeostasis based on pathological changes, TLR4/NF-κB signaling pathway, inductively coupled plasma-mass spectrometry (ICP-MS), 16S rRNA gene sequencing and gas chromatography-mass spectrometer (GC-MS). Results: We found Zn(II)-curcumin significantly mitigated the cadmium-aggravated phenotypes of diabetic nephropathy, as indicated by the remission of renal dysfunction, pathological changes, inflammation and zinc dyshomeostasis in streptozotocin-treated rats exposed to cadmium. Administration of Zn(II)-curcumin significantly alleviated the dysbiosis of gut microbiota and the changes of serum metabolite profiles in rats treated with streptozotocin in combination with cadmium. Notably, fecal microbial transplantation identified the ability of Zn(II)-curcumin to regulate renal function, inflammation and zinc homeostasis was partly dependent on the gut microbiota. Conclusion: These findings revealed that Zn(II)-curcumin alleviated cadmium-aggravated diabetic nephropathy by reshaping the gut microbiota and zinc homeostasis, which provided unique insights into the mechanisms of the treatment and prevention of diabetic nephropathy.

Sesamin ameliorates nonalcoholic hepatic steatosis by inhibiting CD36-mediated hepatocyte lipid accumulation in vitro and in vivo

Hepatic steatosis is a critical factor in the development of nonalcoholic steatohepatitis (NASH). Sesamin (Ses), a functional lignan isolated from Sesamum indicum, possesses hypolipidemic, liver-protective, anti-hypertensive, and anti-tumor properties. Ses has been found to improve hepatic steatosis, but the exact mechanisms through which Ses achieves this are not well understood. In this study, we observed the anti-hepatic steatosis effects of Ses in palmitate/oleate (PA/OA)-incubated primary mouse hepatocytes, AML12 hepatocytes, and HepG2 cells, as well as in high-fat, high-cholesterol diet-induced NASH mice. RNA sequencing analysis revealed that cluster of differentiation 36 (CD36), a free fatty acid (FA) transport protein, was involved in the Ses-mediated inhibition of hepatic fat accumulation. Moreover, the overexpression of CD36 significantly increased hepatic steatosis in both Ses-treated PA/OA-incubated HepG2 cells and NASH mice. Furthermore, Ses treatment suppressed insulin-induced de novo lipogenesis in HepG2 cells, which was reversed by CD36 overexpression. Mechanistically, we found that Ses ameliorated NASH by inhibiting CD36-mediated FA uptake and upregulation of lipogenic genes, including FA synthase, stearoyl-CoA desaturase 1, and sterol regulatory element-binding protein 1. The findings of our study provide novel insights into the potential therapeutic applications of Ses in the treatment of NASH.

Identification of 1,3,4-Thiadiazolyl-Containing Thiazolidine-2,4-dione Derivatives as Novel PTP1B Inhibitors with Antidiabetic Activity

Forty-one 1,3,4-thiadiazolyl-containing thiazolidine-2,4-dione derivatives (MY1-41) were designed and synthesized as protein tyrosine phosphatase 1B (PTP1B) inhibitors with activity against diabetes mellitus (DM). All synthesized compounds (MY1-41) presented potential PTP1B inhibitory activities, with half-maximal inhibitory concentration (IC50) values ranging from 0.41 ± 0.05 to 4.68 ± 0.61 μM, compared with that of the positive control lithocholic acid (IC50 = 9.62 ± 0.14 μM). The most potent compound, MY17 (IC50 = 0.41 ± 0.05 μM), was a reversible, noncompetitive inhibitor of PTP1B. Circular dichroism spectroscopy and molecular docking were employed to analyze the binding interaction between MY17 and PTP1B. In HepG2 cells, MY17 treatment could alleviate palmitic acid (PA)-induced insulin resistance by upregulating the expression of phosphorylated insulin receptor substrate and protein kinase B. In vivo, oral administration of MY17 could reduce the fasting blood glucose level and improve glucose tolerance and dyslipidemia in mice suffering from DM.

N-p-coumaroyloctopamine ameliorates hepatic glucose metabolism and oxidative stress involved in a PI3K/AKT/GSK3β pathway

Type 2 diabetes mellitus is regarded as a chronic metabolic disease characterized by hyperglycemia. Long-term hyperglycemia may result in oxidative stress, damage pancreatic β-cell function and induce insulin resistance. Herein we explored the anti-hypoglycemic effects and mechanisms of action of N-p-coumaroyloctopamine (N-p-CO) in vitro and in vivo. N-p-CO exhibited high antioxidant activity, as indicated by the increased activity of SOD, GSH and GSH-Px in HL-7702 cells induced by both high glucose (HG) and palmitic acid (PA). N-p-CO treatment significantly augmented glucose uptake and glycogen synthesis in HG/PA-treated HL-7702 cells. Moreover, administration of N-p-CO in diabetic mice induced by both high-fat diet (HFD) and streptozotocin (STZ) not only significantly increased the antioxidant levels of GSH-PX, SOD and GSH, but also dramatically alleviated hyperglycemia and hepatic glucose metabolism in a dose-dependent manner. More importantly, N-p-CO upregulated the expressions of PI3K, AKT and GSK3β proteins in both HG/PA-induced HL-7702 cells and HFD/STZ-induced mice. These findings clearly suggest that N-p-CO exerts anti-hypoglycemic and anti-oxidant effects, most probably via the regulation of a PI3K/AKT/GSK3β signaling pathway. Thus, N-p-CO may have high potentials as a new candidate for the prevention and treatment of diabetes.

Advances in Metabolic Regulation of Macrophage Polarization State

Macrophages are significant immune-related cells that are essential for tissue growth, homeostasis maintenance, pathogen resistance, and damage healing. The studies on the metabolic control of macrophage polarization state in recent years and the influence of polarization status on the development and incidence of associated disorders are expounded upon in this article. Firstly, we reviewed the origin and classification of macrophages, with particular attention paid to how the tricarboxylic acid cycle and the three primary metabolites affect macrophage polarization. The primary metabolic hub that controls macrophage polarization is the tricarboxylic acid cycle. Finally, we reviewed the polarization state of macrophages influences the onset and progression of cancers, inflammatory disorders, and other illnesses.

Oleuropein-Rich Jasminum Grandiflorum Flower Extract Regulates the LKB1-PGC-1α Axis Related to the Attenuation of Hepatocellular Lipid Dysmetabolism

Diets() rich in fat are a major() cause() of metabolic disease(), and nutritional() food has been widely() used() to counteract the metabolic disorders such() as obesity() and fatty() liver(). The present study investigated the effects of oleuropein-enriched extract() from Jasminum grandiflorum L. flowers (OLE-JGF) in high-fat diet() (HFD)-fed mice and oleic acid() (OA)-treated AML-12 cells. Treatment() of HFD-fed mice with 0.6% OLE-JGF for 8 weeks significantly reduced body and liver() weights, as well as attenuating lipid dysmetabolism and hepatic steatosis. OLE-JGF administration() prominently suppressed the mRNA expressions() of monocyte chemoattractant protein()-1 (MCP-1) and cluster of differentiation 68 (CD68), and it also downregulated acetyl-CoA carboxylase (ACC) and fatty() acid() synthase (FAS) as well as sterol-regulatory-element()-binding protein() (SREBP-1c) in the liver(). Meanwhile, mitochondrial DNA and uncoupling protein() 2 (UCP2) were upregulated along with the increased expression() of mitochondrial biogenic promoters including liver() kinase B1 (LKB1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear() factor()-erythroid-derived 2-like 2 (Nrf2), and mitochondrial transcription factor() A (Tfam), but did not change AMP-activated protein() kinase (AMPK) in liver(). The lipid droplets were decreased significantly after treatment() with 80 μM oleuropein for 24 h in OA-induced AML-12 cells. Furthermore, oleuropein significantly inhibited ACC mRNA expression() and upregulated LKB1, PGC-1α, and Tfam mRNA levels, as well as increasing the binding level of LKB1 to PGC-1α promoter in OA-induced cells. These findings indicate() that OLE-JGF reduces hepatic lipid deposition in HFD-fed mice, as well as the fact that OA-induced liver() cells may be partly() attributed to upregulation of the LKB1-PGC-1α axis, which mediates hepatic lipogenesis and mitochondrial biogenesis. Our study provides a scientific() basis() for the benefits and potential() use() of the J. grandiflorum flower as a food supplement() for the prevention() and treatment() of metabolic disease().

Correlations between class I glucose transporter expression patterns and clinical outcomes in non-small cell lung cancer

BACKGROUND

Glucose transporters (GLUTs) are highly expressed in various cancers. However, the implications of these variable expression patterns are unclear. This study aimed to clarify the correlation between class I GLUT expression patterns and clinical outcomes in non-small cell lung cancer (NSCLC), including their potential role in inflammatory signaling.

METHODS

Biopsy tissues from 132 patients with NSCLC (92 adenocarcinomas [ADC] and 40 squamous cell carcinomas [SQCC]) were analyzed. mRNA expression levels of class I GLUTs (solute carrier 2A [SLC2A]1, SLC2A2, SLC2A3, and SLC2A4) and inflammation-related molecules (toll-like receptors TLR4, RelA/p65, and interleukins IL8 and IL6) were measured. Cellular localization of GLUT3 and GLUT4 was investigated using immunofluorescence.

RESULTS

Single, combined, and negative GLUT (SLC2A) expression were observed in 27/92 (29.3%), 27/92 (29.3%), and 38/92 (41.3%, p < 0.001) of ADC and 8/40 (20.0%), 29/40 (72.5%, p < 0.001), and 3/40 (7.5%) of SQCC, respectively. In ADC, the single SLC2A3-expressed group had a significantly poorer prognosis, whereas the single SLC2A4-expressed group had a significantly better prognosis. The combined expression groups showed no significant difference. SLC2A expression was not correlated with SQCC prognosis. SLC2A4 expression correlated with lower IL8 expression. GLUT3 and GLUT4 expressions were localized in the tumor cytoplasm.

CONCLUSIONS

In lung ADC, single SLC2A3 expression correlated with poor prognosis, whereas single SLC2A4 expression correlated with better prognosis and lower IL8 expression. GLUT3 expression, which is increased by IL8 overexpression, may be suppressed by increasing the expression of GLUT4 through decreased IL8 expression.