Natural compounds improve diabetic nephropathy by regulating the TLR4 signaling pathway

Degradation of sweet corn cob polysaccharides by ultrasound-assisted H2O2/Vc treatment: Structural characterization and hypoglycemic effects in vitro and in vivo

To investigate the inhibitory potential of plant-degraded polysaccharides on glycosidases and elucidate the mechanism by which they alleviate type 2 diabetes mellitus (T2DM), a degraded sweet corn cob polysaccharide (UHDSCP) was prepared using ultrasound-assisted hydrogen peroxide-ascorbic acid oxidation (H2O2/Vc). UHDSCP was subsequently characterized using various analytical techniques, including UV spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Our findings indicated that UHDSCP has a molecular weight of 14.82 kDa and is composed primarily of mannose, glucose, galactose, and fucose at a molar ratio of 1.705:93.301:1.077:2.501. Additionally, UHDSCP exhibited α- and β-glycosidic bonds. Our findings revealed that UHDSCP can inhibit the activity of α-amylase and α-glucosidase and reduce oxidative stress in vitro. UHDSCP also exerted a hypoglycemic effect in T2DM mice, as determined by a decrease in the activities of disaccharidases in the small intestine, including maltase, sucrase, and lactase. Additionally, UHDSCP could modulate lipid metabolism in T2DM mice and alleviate oxidative stress in hepatic and pancreatic tissues. Moreover, UHDSCP ameliorated T2DM-induced inflammatory responses in the intestine and liver by restoring the integrity of the intestinal barrier. Considering these results, this study can serve as a reference for the inclusion of UHDSCP in the diet to exert hypoglycemic effects and alleviate T2DM through multiple pathways.

Crosstalk between ferroptosis and innate immune in diabetic kidney disease: mechanisms and therapeutic implications

Diabetic kidney disease (DKD) is a prevalent complication of diabetes mellitus (DM), and its incidence is increasing alongside the number of diabetes cases. Effective treatment and long-term management of DKD present significant challenges; thus, a deeper understanding of its pathogenesis is essential to address this issue. Chronic inflammation and abnormal cell death in the kidney closely associate with DKD development. Recently, there has been considerable attention focused on immune cell infiltration into renal tissues and its inflammatory response's role in disease progression. Concurrently, ferroptosis-a novel form of cell death-has emerged as a critical factor in DKD pathogenesis, leading to increased glomerular filtration permeability, proteinuria, tubular injury, interstitial fibrosis, and other pathological processes. The cardiorenal benefits of SGLT2 inhibitors (SGLT2-i) in DKD patients have been demonstrated through numerous large clinical trials. Moreover, further exploratory experiments indicate these drugs may ameliorate serum and urinary markers of inflammation, such as TNF-α, and inhibit ferroptosis in DKD models. Consequently, investigating the interplay between ferroptosis and innate immune and inflammatory responses in DKD is essential for guiding future drug development. This review presents an overview of ferroptosis within the context of DKD, beginning with its core mechanisms and delving into its potential roles in DKD progression. We will also analyze how aberrant innate immune cells, molecules, and signaling pathways contribute to disease progression. Finally, we discuss the interactions between ferroptosis and immune responses, as well as targeted therapeutic agents, based on current evidence. By analyzing the interplay between ferroptosis and innate immunity alongside its inflammatory responses in DKD, we aim to provide insights for clinical management and drug development in this area.

Vitamin B1 and calcitriol enhance glibenclamide suppression of diabetic nephropathy: Role of HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories

Glibenclamide is one of the most prescribed insulin secretagogues in diabetes due to its low cost, but its efficacy on suppressing diabetic complications is limited. Here, we examine whether addition of either vitamin B1 or calcitriol to glibenclamide could produce more suppression of diabetic nephropathy. Type 2 diabetes was induced by high fructose (10 % in drinking water), high salt (3 % in diet), and high fat diet (25 % in diet) for 3 weeks, followed by single dose of STZ (40 mg/kg, i.p.). Diabetic rats were treated with either glibenclamide (0.6 mg/kg), vitamin B1 (70 mg/kg), glibenclamide/vitamin B1, calcitriol (0.1 μg/kg), or glibenclamide/calcitriol. Addition of either vitamin B1 or calcitriol to glibenclamide therapy enabled more suppression of diabetic nephropathy development as evidenced by more preserved creatinine clearance and less renal damage scores. Combination therapy resulted in mild enhancement in the effect of glibenclamide on glucose tolerance without affecting the area under the curve. Combination therapy was associated with more suppression of inflammatory cascades as evidenced by reducing the expression of high mobility group box-1 (HMGB1), toll-like receptor-4 (TLR4), nuclear factor-kappa B (NF-κB), and tumor necrosis factor-α (TNF-α). In addition, combination therapy enhanced the antioxidant mechanisms as evidenced by increased expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione content and reducing malondialdehyde and nitric oxide levels. Furthermore, combination therapy provided more suppression of fibrotic pathways as appear from reducing collagen deposition and the expression of α- smooth muscle actin (α-SMA). In conclusion, addition of vitamin B1 or calcitriol to glibenclamide therapy can enhance the therapeutic efficiency of glibenclamide in suppressing diabetic nephropathy progression to the same extend, the protective effect is mediated through modulating HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories.