Search Results (1,273)

Background/Objectives: Diabetic wound healing faces significant challenges due to the harsh microenvironment of wounds such as high blood glucose levels, excessive inflammation, persistent infection, upregulated reactive oxygen species (ROS), and damaged new blood vessels. Therefore, developing hydrogel dressings with microenvironmental regulation functions has become an important strategy in treating diabetic wounds. Methods: In this study, an ultraviolet in situ crosslinked hydrogel (D@H/E) was developed using methacrylic anhydride modified hyaluronic acid (HA-MA) and glycidyl methacrylate modified ε-polylysine (EPL-GMA), loaded with the iron chelating agent desferrioxamine (DFO). The physicochemical and biochemical properties of the hydrogel were comprehensively characterized, and its efficacy as a dressing for diabetic wounds was evaluated in a STZ-induced hyperglycemic mouse model. Results: This hydrogel demonstrated remarkable multidimensional effects by alleviating oxidative stress damage, inhibiting bacterial infection, regulating inflammatory responses, mitigating ferroptosis, and promoting cell migration and tubule formation. Specifically, the DFO-loaded hydrogel achieved a high DPPH radical scavenging efficiency of 80.8% and exhibited excellent antibacterial activity, with over 99.8% inhibition against both S. aureus and E. coli. In streptozotocin (STZ)-induced diabetic mice, the hydrogel accelerated wound closure to near completion by day 14. Mechanistically, it significantly upregulated CD206 expression to promote M2 macrophage polarization, upregulated the expression of angiogenesis-related factors to promote angiogenesis at the wound site, and enhanced GPX4 expression to alleviate ferroptosis. Conclusions: By orchestrating multi-dimensional synergy that combines ROS scavenging, infection control, immune regulation, and anti-ferroptosis, this D@H/E hydrogel system effectively remodels the harsh diabetic wound microenvironment, offering a promising platform for chronic wound management. Full article

Diabetic retinopathy (DR), recognized as a progressive neurovascular and microvascular complication of diabetes, remains one of the leading causes of visual disability worldwide, within the context of a sustained increase in ophthalmic diseases and retinal vascular disorders that compromise vision. This study aimed to characterize the progression of diabetic retinopathy in a streptozotocin (STZ)-induced Wistar rat model. A single dose of 65 mg/kg body weight was administered, with follow-up periods at 2, 4, 8, and 10 weeks, compared to healthy controls. STZ-induced rats exhibited reduced weight gain compared to the control group. They also showed markedly variable hyperglycemia, with glucose concentrations ranging from 250 to 530 mg/dL. Histological analysis of retinal tissue at week 4 revealed early signs of vascular compromise, including early indications of a microenvironment conducive to neovascularization and edema. By week 8, retinal damage had progressed to hemorrhage, persistent edema, and layer-specific vascular disruption. At week 10, intensified neovascularization and exacerbated edema indicated advanced microvascular deterioration. Immunofluorescence analysis demonstrated a temporal accumulation of CD8⁺ T cells in the retina, correlating with photoreceptor degeneration. The coordinated dynamics of CD4⁺ and CD8⁺ T cells suggested transient immune activation during STZ-induced retinal degeneration. Gene expression profiling revealed a proinflammatory and pro-oxidative retinal microenvironment, characterized by the overexpression of angiogenic pathways and proliferative signals. Simultaneously, the antioxidant response appeared partially impaired. Collectively, these findings provide mechanistic perspective on the multifactorial nature of diabetic retinopathy. Oxidative stress, inflammation, and angiogenesis converge to disrupt retinal homeostasis. This experimental model may serve as a reliable platform for future studies aimed at elucidating disease pathophysiology, identifying novel therapeutic targets, and evaluating emerging ophthalmic antidiabetic interventions. Full article

Diabetic retinopathy (DR) is a major cause of adult blindness and is characterized by progressive retinal vascular dysfunction and pathological angiogenesis. To establish a DR model, streptozotocin (STZ) was intraperitoneally injected into rats. After 8 weeks, naïve placenta-derived mesenchymal stem cells (PD-MSCs) or PEDF-overexpressing PD-MSCs (PD-MSCs^PEDF) were intravitreally transplanted into the right eye for 4 weeks. Pathological neovascularization in DR is regulated by the balance between vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). In diabetic retinas, increased VEGF and decreased PEDF expression were reversed following PD-MSC transplantation. Notably, PD-MSCs^PEDF treatment resulted in higher PEDF, and lower VEGF expression compared with naïve PD-MSCs, with similar expression patterns observed in the contralateral non-transplanted eyes. These findings indicate that engineering PD-MSCs^PEDF enhances anti-angiogenic activity by modulating VEGF and PEDF balance, thereby alleviating vascular damage in STZ-induced diabetic retinas. Full article

Roselle beverage residue (RBR), a by-product of Hibiscus sabdariffa L. processing, retains bioactive compounds, including soluble and insoluble dietary fiber and polyphenols. Its antihyperglycemic effect in type 2 diabetes mellitus (T2DM) has been previously demonstrated; however, its role in lipid metabolism remains unknown. This study assessed the preventive and therapeutic potential of RBR on dyslipidemia and hepatic steatosis in a rodent model of late-stage T2DM characterized by hyperglycemia and hypoinsulinemia. Male Wistar rats with T2DM induced by a high-fat and high-fructose diet combined with streptozotocin received 6% RBR supplementation as either a preventive intervention (starting at week 1 in healthy rats or week 9 in insulin-resistant rats) or a therapeutic intervention (starting at week 14 in diabetic rats). After 17 weeks, RBR supplementation significantly reduced serum triglycerides and total cholesterol, attenuating hepatic lipid accumulation regardless of the timing of intervention. Hepatic Acadm expression, involved in fatty acid β-oxidation, was significantly upregulated in rats treated with RBR from week 1 and 9, whereas no significant modulation was observed for genes related to fatty acid synthesis or uptake. These findings suggest that RBR supplementation may contribute to improving lipid metabolism and hepatic steatosis in a rat model of late-stage T2DM. Full article

Background/Objectives: Enteric glial cells (EGCs) are key players in regulating enteric neurons and gastrointestinal functions including disturbed gut motility in diabetic patients. Enteric neuronal damage has been shown in type 1 diabetes, but EGCs’ vulnerability to hyperglycaemic insults requires more investigation. Therefore, we aimed to study the quantitative changes in the EGC network enmeshing enteric plexuses, intestinal smooth muscle and mucosa in streptozotocin-induced acute (1-week) and chronic (10-weeks) diabetic rat models. Methods: Fluorescent immunohistochemistry using Sox10 glial and HuC/HuD pan-neuronal markers, immunogold electron microscopy and ELISA were performed on different gut segments. Results: In the submucosal ganglia of the ileum and colon, the density of Sox10-immunoreactive EGCs was significantly reduced in acute and increased in chronic hyperglycaemic rats without any changes in the duodenum. In the myenteric ganglia, regionally distinct alterations of glial density were noted in acute hyperglycaemia; however, a remarkable decrease was observed in chronic animals. Alterations of neuronal density did not follow the pattern of glial changes, resulting in shifts in the glia/neuron ratio. The presence of Sox10-HuC/HuD-immunoreactive cells and their diabetes-related quantitative changes were also revealed in enteric plexuses. The density of Sox10-labelling gold particles was significantly increased in the duodenal myenteric glia of diabetic rats. Muscular EGC density increased only in the colon after acute hyperglycaemia and changed in all segments after chronic hyperglycaemia. Glial fibrillary acidic protein levels decreased in the small intestine of chronic hyperglycaemic rats. Conclusions: Our present findings reveal time-dependent and regionally distinct changes in the EGC network in response to hyperglycaemia, contributing to diabetic enteric neuropathy and gut motility disturbances. Full article

Primary liver cancer, particularly hepatocellular carcinoma (HCC), remains a major global health burden, ranking as the fifth most common cancer and the third leading cause of cancer-related mortality worldwide. The rising incidence of HCC is closely linked to metabolic comorbidities, including non-alcoholic fatty liver disease (NAFLD), underscoring the need for improved diagnostic and therapeutic strategies. NAFLD can progress to metabolic dysfunction-associated steatohepatitis (MASH), characterized by inflammation and fibrosis, which markedly increases HCC risk, especially in individuals with obesity and type 2 diabetes (T2D). NAFLD has recently been redefined as metabolic dysfunction-associated steatotic liver disease (MASLD) to better reflect its metabolic basis. However, robust experimental models to study the progression from MASLD to MASH and ultimately HCC remain limited. This proof-of-concept study investigates sex-specific effects of metabolic dysregulation using the STAM (STelic Animal Model; streptozotocin and high-fat diet) mouse model, which recapitulates key features of human MASH and HCC. Neonatal C57BL/6J mice received streptozotocin to induce T2D-like symptoms followed by a high-fat diet. Streptozotocin (STZ) treated mice showed reduced body fat, lower insulin levels, impaired glucose tolerance, and increased expression of genes linked to inflammation, lipid metabolism, and apoptosis. These findings support the STAM model’s utility for MASLD research and highlight the importance of sex-specific strategies to limit HCC progression. Full article

Chronic diabetic wounds remain difficult to heal because persistent inflammation, oxidative stress, and impaired regeneration delay repair, while effective noninvasive options are limited. In this study, graphene-based far-infrared radiation (FIR) therapy was evaluated in a streptozotocin (STZ)-induced diabetic rat full-thickness wound model, and mechanisms were examined in vivo and in vitro. Wound closure was quantified by serial imaging, whereas tissue remodeling and angiogenesis were assessed by H&E and Masson’s trichrome staining and CD34-based analyses. Transcriptomic responses were profiled by RNA sequencing with qRT-PCR validation, immune phenotypes were characterized by immunofluorescence, and high-glucose cell assays were performed. Re-epithelialization, collagen deposition, and neovascularization were quantified histologically. These datasets enabled integrated evaluation of inflammation, oxidative stress, and repair programs over time. Graphene FIR accelerated closure, reaching 83.9% healing by day 14 vs. 66.8% in untreated controls. Treatment was associated with downregulation of Cxcl2/Cxcl3, suppression of M1 polarization with enhanced M2 polarization, and reduced ROS accumulation. Consistently, NF-κB signaling was inhibited, supporting restoration of a pro-regenerative microenvironment. Collectively, graphene FIR represents a promising noninvasive strategy for diabetic wound repair via coordinated immunomodulatory and antioxidant actions. Full article

Diabetes mellitus (DM) is a major disorder contributing to human mortality and morbidity globally. The use of medicinal plants in the management of diabetes is gaining global popularity due to their accessibility and cost-effectiveness. In this study, we evaluated the ameliorative potential of Vernonia amygdalina leaves crude extract (CE), free phenol (FP), and bound phenol (BP) fractions (50 mg/kg body weight) in a rat model of streptozotocin (STZ)-induced type 1 diabetes (T1DM). The effects of these treatments for 28 days on glucose, insulin, glycated hemoglobin, hepatic injury indices, and lipid profile were assessed in the serum. Furthermore, redox biomarkers (liver) and inflammatory mediators (serum and liver) were analyzed. Our results indicated that CE, FP, and BP fractions of Vernonia amygdalina inhibited the deleterious effects of T1DM by attenuating hyperglycaemia, insulin deficiency, hepatic injury, and dyslipidemia. Also, CE, FP, and BP fractions differentially improved antioxidant enzymes activity and reduced oxidative and inflammatory markers production. Specifically, CE showed superior effects compared with FP, BP, and metformin across multiple biomarkers, including glycated hemoglobin, α-amylase, α-glucosidase, hepatic glycogen, total cholesterol, LDL-cholesterol, protein carbonyl, SOD, IL-1β, and IL-10. The antidiabetic effects produced by CE, FP, and BP fractions of Vernonia amygdalina may be ascribed to the presence of different bioactive phytochemicals as revealed by HPLC analysis. Overall, our data would suggest a potential therapeutic role for Vernonia amygdalina leaves extracts in addressing hepatic complications due to T1DM. Full article

Type 2 Diabetes Mellitus (T2DM) is a widespread metabolic disorder that can affect brain health, primarily through the damaging effects of prolonged hyperglycemia. This condition increases oxidative stress (OS), neuroinflammation, and neuroapoptosis, ultimately impairing cognitive function. Acrylamide (ACY), a neurotoxicant formed during high-temperature food processing and present in cigarette smoke, may further aggravate these neurological disturbances. The present experiment examined the exacerbating effects of T2DM and ACY exposure on cognitive function, neurodegeneration, OS, neuroinflammation, and neuroapoptosis in diabetic rats. T2DM was induced via intraperitoneal injections of nicotinamide and streptozotocin, followed by daily oral doses of ACY for a month. Behavioral assessments (EPM, NOR, and Y-maze) evaluated cognitive performance. Brain tissues were analyzed for biochemical markers of neurodegeneration (GSK-3β, AChE, BACE1), OS (MDA, GSH, Catalase), neuroinflammation (NF-κB, TNF-α, PGE2, COX-2), and neuroapoptosis (Bcl-2, Bax, Caspase-3). Immunohistochemistry of Bcl-2, Bcl-6, CD138, and NF assessed structural brain changes. Results indicated that T2DM and ACY exposure significantly increased the incidence of neurological disturbances. Notably, through increased COX-2, PGE2, MDA, Bax, Bcl-6, Caspase-3, and cognitive decline deficits. This study highlights the harmful neurotoxic amplification of T2DM and ACY exposure, emphasizing the importance of public health measures to reduce ACY exposure through dietary and lifestyle changes, particularly among T2DM populations. Further research into neuroprotective strategies and underlying mechanisms is necessary. Full article

Diabetes mellitus (DM) is associated with vascular complications that increase morbidity and mortality. Natural antioxidants play a vital role in reducing diabetes-related damage. This study investigated the protective effects of the phenolic monoterpene carvacrol (CAR) against diabetic complications. Thirty-two male Wistar Albino rats (4 months, 250–300 g) were divided into four groups: control, DM, DM + DMSO, and DM + CAR. Type 1 diabetes was induced via intraperitoneal injection of 50 mg/kg streptozotocin (STZ). The DM + CAR group received 20 mg/kg CAR daily for four weeks. Body weight and blood glucose levels were regularly monitored. At the end of the study, aortic tissues were examined using hematoxylin–eosin (H&E), Verhoeff–Van Gieson, and immunohistochemical staining, while cardiac tissues were analyzed with H&E and Masson’s trichrome. Serum levels of ischemia-modified albumin (IMA), cholesterol (CHOL), triglycerides (TG), and high-density lipoprotein (HDL) were measured. In the DM group, IMA and CHOL levels were increased (p = 0.0208 and p = 0.0207, respectively), apoptosis was elevated (caspase-3 expression, p = 0.0001), and marked tissue damage was observed. In contrast, in the DM + CAR group, IMA levels (p = 0.0228) and caspase-3 expression (p = 0.0457) were reduced, and notable improvements were detected in vascular and cardiac tissues. These results suggest that CAR protects against diabetic complications by modulating oxidative stress, inhibiting apoptosis, and preventing tissue injury. Full article

Diabetic nephropathy (DN) is a serious complication in diabetic patients, leading to kidney dysfunction and ultimately end-stage renal disease. Although several pharmacological agents have been developed, treating DN remains challenging due to its complex and multifaceted pathogenesis. Endoplasmic reticulum (ER) stress plays a crucial role in DN pathology; however, the molecular mechanisms underlying reduced ER stress remain poorly understood. This study investigated the protective effects of 4-phenylbutyrate (4-PBA), an ER stress inhibitor, on DN and the related regulatory molecules through gene expression network analysis. A C57BL/6 mouse model of DN was used in combination with a high-fat diet and streptozotocin after unilateral nephrectomy and treated with 4-PBA by intraperitoneal injection for 6 weeks. The 4-PBA treatment effectively improves DN-induced renal structural and functional abnormalities by reducing albuminuria, podocyte loss, glomerular and tubular injury, and renal inflammation and cell death. These changes induced by 4-PBA were associated with decreased expression of ER stress markers and increased autophagy activities in diabetic kidneys. Importantly, 4-PBA reduced components of the complement C1q pathway, the NADPH oxidase complex, and chemokines, thereby attenuating chronic renal dysfunction. Conclusively, inhibition of ER stress is a promising pharmacological target for treating patients with DN. Full article

Background: This study investigated the effects of Laurocerasus officinalis Roem (cherry laurel; CL), a traditionally consumed fruit, on cognitive performance and selected neurobiochemical and metabolic pathways in a nontransgenic streptozotocin (STZ)-induced Alzheimer’s disease (i.c.v. STZ) model and an STZ-induced type 2 diabetes mellitus (T2DM; i.p. STZ) model. Method: Fifty-seven adult male Sprague–Dawley rats were allocated to control, T2DM, and Alzheimer (ALZ) model groups, with subgroup interventions including CL supplementation and, in the T2DM model, metformin as a comparator. Spatial learning and memory were assessed using the Morris Water Maze. Serum and brain tissue levels of GSK3-β, glutathione (GSH), interleukin-1 (IL-1), GLUT4, GLP-1, β-amyloid (Aβ), and acetylcholinesterase (AChE) were quantified. Results: Serum GSK3-β levels did not differ significantly between groups, whereas brain tissue GSK3-β showed significant between-group differences. CL increased GSH levels in both models, with significant elevations in serum and brain tissue GSH in the ALZ model following CL administration; in the T2DM model, GSH increased after both CL and metformin. In the ALZ model, CL was associated with decreased serum Aβ and AChE levels and improved Morris Water Maze performance, reflected by reduced escape latencies. Conclusions: CL supplementation was associated with antioxidant enhancement and modulation of amyloid- and cholinergic-related measures, alongside improved spatial learning performance in the STZ-induced nontransgenic ALZ model. In addition, CL reduced blood glucose in the T2DM model. Given the likely contribution of fruit phytochemicals (including total phenolics), further studies are warranted to better define the bioactive composition and mechanisms underlying these effects. Full article

The present study was to evaluate the analgesic activity of two newly synthesized 1H-pyrrolo[3,4-c]pyridine-1,3(2H)-dione derivatives, designated DSZ-13 and DSZ-19. To achieve the desired result, the in vitro XTT cell proliferation assay, serotonin 5-HT_1A receptor affinity and COX-1 and COX-2 enzyme inhibition potential of the compounds were conducted by real-time qPCR. Non-compartmental analysis was used to estimate the pharmacokinetic parameters of the compounds in serum and brain tissue. The analgesic activity was evaluated using various in vivo pain models, encompassing acute pain (hot plate test), tonic pain (formalin test), neurogenic pain (capsaicin test), carrageenan-induced acute inflammation, and neuropathic pain models. Both compounds showed moderate affinity for serotonin 5-HT_1A receptors, a lack of cytotoxic activity, desirable pharmacokinetic parameters and slightly reduced mRNA expression for COX-1 and COX-2. Only the DSZ-19 revealed central/supraspinal analgesic activity and did not affect movement. Both compounds attenuated tonic and neurogenic pain, in the formalin and capsaicin tests, respectively. In addition, the involvement of the 5-HT_1A receptors in the formalin test was confirmed. Both compounds also showed antiallodynic activity in the oxaliplatin- and streptozotocin-induced neuropathy models. Slightly weaker than indomethacin, DSZ-13 and DSZ-19 attenuated carrageenan-induced inflammation (edema) and hyperalgesia in rat models. Full article

Type 2 diabetes (T2D) features insulin resistance that promotes cerebrovascular injury, yet the immune signals linking metabolic stress to vascular dysfunction remain unclear. We tested the hypothesis that insulin resistance and soluble vascular cell adhesion molecule-1 (sVCAM1) act through complementary pathways in mast cells (MCs) to raise circulating histamine levels and impair cerebral vascular function. In a high-fat diet (HFD) plus low-dose streptozotocin (STZ) model, plasma histamine rose sharply after the onset of insulin resistance and remained elevated. Plasma sVCAM1 levels also increased after insulin resistance. In vitro, recombinant sVCAM1 upregulated histidine decarboxylase (HDC) in native MCs in a dose-dependent manner, indicating a shift toward histamine synthesis, but did not enhance degranulation. In contrast, pharmacological inhibition of Akt with MK2206 activated Glycogen Synthase Kinase 3 beta (GSK3β) and increased MC degranulation without affecting HDC expression. Diabetic endothelial cell monolayers exhibited a ~twofold reduction in transendothelial electrical resistance consistent with impaired blood–brain barrier (BBB) integrity. Diabetic cerebral arteries showed receptor remodeling that favored constriction with histamine H1 receptor (H1R) expression increasing in vascular smooth muscle, while endothelial H1R and histamine H2 receptor (H2R) decreased. Functionally, insulin treatment lowered HOMA2-IR in T2D mice but did not restore cerebral artery myogenic tone or improve stroke outcomes after distal middle cerebral artery occlusion (dMCAO). Neutralizing VCAM1 with a monoclonal antibody reduced circulating sVCAM1 and histamine levels, and, together with the GSK3β inhibitor Tideglusib, stabilized MCs, normalized cerebral artery tone, and reduced post-MCAO infarct size and edema. These findings identify two distinct yet complementary mast cell pathways in T2D, highlight an immune-vascular interface that drives cerebrovascular dysfunction, and propose sVCAM1 blockade plus GSK3β inhibition as rational strategies to protect cerebral vascular function in the diabetic brain. Full article