Combination of high-fat diet-fed and low-dose streptozotocin-treated rat: a model for type 2 diabetes and pharmacological screening

Synergistic action of non-digestible xylooligosaccharide and Lactiplantibacillus plantarum ZDY2013 against high fat diet and streptozocin-induced type 2 diabetes mellitus in rats

Patients with type 2 diabetes mellitus (T2DM) often exhibit reduced Lactobacillus abundance, dysregulated immune responses, disrupted intestinal barrier integrity, and increased insulin resistance. Consumption of non-digestible oligosaccharides has been shown to support the persistence of Lactobacillus in the gut and improve gut homeostasis. Lactiplantibacillus plantarum ZDY2013, a probiotic capable of metabolizing various oligosaccharides, serves as a potent regulator of intestinal mucosal immunity. In this study, we investigated the potential ameliorative effects of xylooligosaccharides combined with L. plantarum ZDY2013 (synbiotic) on T2DM-induced intestinal injury and explored the underlying mechanisms. Our results showed that synbiotic improved glucose metabolism, reduced lipid accumulation, and alleviated insulin resistance in T2DM rats. Moreover, synbiotic outperformed L. plantarum ZDY2013 alone in restoring intestinal barrier integrity by suppressing oxidative stress and intestinal inflammation, while significantly enhancing the colonization of L. plantarum ZDY2013 and altering the abundance of key bacterial genera. Interestingly, synbiotic treatment also increased the production of short-chain fatty acids (SCFAs), which were strongly associated with specific bacterial taxa. Furthermore, gut microbiota-derived SCFAs were confirmed to ameliorate insulin resistance by promoting glucose uptake and glycogen synthesis in IR-HepG2 cells. Collectively, these findings suggest the potential use of synbiotics as a clinical intervention to ameliorate T2DM. This study provides a rationale for exploring dietary approaches as a mitigating strategy for managing long-standing diabetes.

UBC9 ameliorates diabetic cardiomyopathy by modulating cardiomyocyte mitophagy through NEDD4/RUNX2/PSEN2 axis

AIM

Diabetic cardiomyopathy (DCM) is one of the most significant cardiovascular complications in patients with diabetes. Ubiquitin conjugating enzyme 9 (UBC9) is the only SUMO-E2 enzyme that plays a key role in cardiomyocytes homeostasis. This study aimed to elucidate the roles and mechanisms of UBC9 in DCM development.

METHODS

We established cardiomyocyte-specific UBC9 knockout mice and UBC9-overexpressing mice in vivo. A DCM model was established by feeding a high-fat diet and administering a low-dose streptozotocin injection. Proteomics, H&E staining, Sirius Red staining, WGA staining, real-time PCR, and western blotting were performed to examine fibrosis, hypertrophy, and mitophagy in the myocardium. Neonatal mouse cardiomyocytes (NMCMs) were cultured in vitro and stimulated with palmitic acid, UBC9 overexpression adenovirus, and small interfering RNA to establish UBC9 overexpression or knockdown NMCMs. Real-time PCR, western blotting, and immunoprecipitation were employed to examine the roles and mechanisms of UBC9 in cardiomyocyte mitophagy.

RESULTS

The transcription and protein levels of UBC9 were significantly decreased in the myocardium of DCM mice. Cardiomyocyte-specific UBC9 knockout aggravated cardiac dysfunction, myocardial fibrosis, hypertrophy, and impaired mitophagy. Conversely, UBC9 overexpression produced opposite effects. UBC9 protected cardiomyocyte mitophagy independently of SUMOylation. UBC9 exerted protective effects against defective cardiomyocyte mitophagy by directly binding to NEDD4, enhancing RUNX2 ubiquitination and degradation, which in turn increased PSEN2 expression. Moreover, the impact of UBC9 on cardiomyocyte mitophagy was reversed upon PSEN2 knockdown.

CONCLUSIONS

UBC9 alleviated DCM development through the NEDD4/RUNX2/PSEN2 pathway. These findings offer novel insights into the potential of UBC9 as a therapeutic target for DCM.

Burdock Fructooligosaccharide Protects Against Diabetic Nephropathy in Mice by Regulating Nrf2 Signaling

Diabetic nephropathy (DN) is a common complication of diabetes mellitus, with oxidative stress playing a critical role in its development. Burdock fructooligosaccharide (BFO), a major compound in Burdock, exhibits antioxidative effects. However, its mechanisms of action and effects on diabetic nephropathy are not clear enough. This study aims to explore the mechanisms of BFO and its impact on streptozotocin-induced diabetic nephropathy in mice. Male C57BL/6J mice were randomly divided into normal control, DN, and BFO groups. Relevant serum biochemical parameters were detected using kits. Renal injury was evaluated through fluorescence microscopy, histopathology, and transmission electron microscopy. Nrf2/HO-1 signaling was analyzed via quantitative real-time PCR, western blotting, and immunohistochemistry. In DN mice, BFO significantly reduced fasting blood glucose, kidney index, urine protein, serum creatinine, blood urea nitrogen, total cholesterol, triglyceride, and low-density lipoprotein cholesterol, while significantly increasing high-density lipoprotein, SOD, and CAT levels. Additionally, BFO protected against streptozotocin-induced renal injury, restored podocyte function, increased both mRNA and protein expression of Nrf2, HO-1, and Bcl-2, and decreased those of Bax. In conclusion, BFO can be used to treat streptozotocin-induced renal injury in mice and is a promising candidate for diabetic nephropathy treatment.

Dendrobium nobile Lindl. Polysaccharides ameliorate the inflammatory microenvironment in the retina of diabetic rats: a multi-omics study of the gut-blood-retina axis

The global epidemic of type 2 diabetes (T2D) and its complications threaten human health and lives. Dendrobium nobile Lindl., a traditional Chinese medicinal herb, demonstrates anti-hyperglycemic and anti-hyperlipidemic effects. However, its protective role and mechanisms against diabetes-induced retinopathy remain unclear. This study aimed to investigate the impact of Dendrobium nobile Lindl. Polysaccharides (DNP) on the gut microbiota-metabolite-retinal inflammatory microenvironment in T2D rats. The results demonstrated that DNP could significantly ameliorate hyperglycemia, restore gut microbiota, and improve related microbial metabolites. Interestingly, DNP restored the damaged gut barrier and improved the metabolic profiles of circulating amino and organic acids. Specifically, DNP decreased the Firmicutes/Bacteroidota (F/B) ratio, restored gut morphology and the expression of ZO-1 and claudin-1, reduced serum lipopolysaccharides (LPS) levels, decreased gut and circulating branched-chain amino acids (BCAA) metabolism, increased gut and circulating hippurate metabolism, inhibited the TLR4/NF-κB signaling pathway, and ultimately ameliorated the inflammatory microenvironment of the retina. This comprehensive multi-omics study provides the first systematic evaluation of the therapeutic effects of DNP on T2D and its associated retinal inflammatory microenvironment, proposing the "gut-blood-retina" axis as a key mechanistic pathway. Consequently, DNP treatment emerges as a promising preventive or therapeutic strategy for mitigating these pathophysiological processes.

Characterization of the Skin Bacteriome and Histology Changes in Diabetic Pigs

Chronic wound is one of the most common complications that are associated with diabetes. The cutaneous microbiome is known to play essential roles in the regulation of barrier function and protecting against potential assault. Thus, it is necessary to gain a better understanding of the relationship between microbial community and skin structures in unwounded diabetic skin to explore possible preventive strategies. To achieve the same, a pig diabetic model was built in the present study. Further,16S rDNA sequencing was used to characterize the skin bacteriome. It was observed that the pigs showed skin bacteriome similar to humans in the non-diabetes group, while it varied in the case of diabetes. Further, the β-diversity analysis showed that the bacterial community was significantly different under the diabetes group. More species differences were identified between the two groups at genus level. The predictive function analysis also showed the involvement of significantly different pathways of microbial gene function in diabetes. In agreement with this, skin histology analysis also showed signs of reduced epidermal thickness and rete ridges in diabetic skin. Less proliferation of keratinocytes and impaired TJ barrier was also detected. This evidence suggested that pigs might serve as the best surrogate for cutaneous microbiome studies. Altogether, the present study reported that the skin bacteriome and histology changed significantly in unwounded diabetic skin, which provided a theoretical basis for the regulation of disordered skin bacteriome. The findings of the study would assist in the improvement of the skin environment and prevention of skin infection and chronic wounds.

Electroacupuncture at ST25 mediated glial cells pruning of pancreatic TRPV1 neural synapse responds to neuropathy-associated beta cell dysfunction

Electroacupuncture (EA) is verified to modulate glycemic changes in T2DM, and this is partially related to sensory neurotransmitters. However, EA-mediated communication mechanism between them and acupoint specificity have not been fully clarified. Thus, we replicated the diabetic rat model induced by a high-fat diet/streptozotocin (HFD-STZ), and investigated the alleviating effects on insulin resistance (IR) and inflammation severity after EA at ST25. We also compared the effect difference of EA at ST37. Furthermore, we studied the changes of pancreatic sensory neurotransmitters and β cells (and their surrounding components) in detail. Serum glucose, insulin, IR, TNF-α and IL-10 were significantly elevated in model rats, and β cell function was impaired, which reversed by EA at ST25 or ST37 to varying degrees. EA at ST25 can enhance the expression of calcitonin gene-related peptide (CGRP), attenuate transient receptor potential vanilloid 1(TRPV1) and correct the secretion mismatch between them, while EA at ST37 has no such effect. Subsequently, EA at ST25-mediated TRPV1-CGRP-β cell circuit demonstrates an advantage in regulating glucose metabolism via direct insulin inhibition by CGRP. EA at ST25 rather than ST37 regulates the activity of peri-ilset glial cells and macrophages, playing a neuro-protective role and controlling inflammation. EA at ST37 exhibits its partial therapeutic effect on T2DM as it improves serum GLP-1. It also implies that the dominant target organ of ST37 may not be the pancreas, but other associated viscera. Hence, our study elucidates the EA-mediated glial cell via TRPV1-CGRP pathway regulation of β cell dysfunction after nerve lesion, and the hypoglycemic effect of ST25 is significantly better than that of ST37.

Protective Effects of Lotus Seedpod Extract on Hepatic Lipid and Glucose Metabolism via AMPK-Associated Mechanisms in a Mouse Model of Metabolic Syndrome and Oleic Acid-Induced HepG2 Cells

Metabolic syndrome (MetS) poses considerable toxicological risks due to its association with an increased likelihood of metabolic dysfunction-associated steatotic liver disease (MASLD), and is characterized by hypertension, hyperglycemia, dyslipidemia, and obesity. This study aimed to investigate the therapeutic potential of flavonoid-rich lotus seedpod extract (LSE) in alleviating MetS and MASLD-related hepatic disturbances. In vivo, mice subjected to a high-fat diet (HFD) and streptozotocin (STZ) injection were supplemented with LSE or simvastatin for 6 weeks. Obesity indicators included body weight and epididymal fat, while insulin resistance was measured by fasting serum glucose, serum insulin, homeostasis model assessment-insulin resistance index (HOMA-IR), and oral glucose tolerance (OGTT). Also, the levels of serum lipid profiles and blood pressure were evaluated. Adipokines, proinflammatory cytokines, liver fat droplets, and peri-portal fibrosis were analyzed to clarify the mechanism of MetS. LSE significantly reduced the HFD/STZ-induced MetS markers better than simvastatin, as demonstrated by hypoglycemic, hypolipidemic, antioxidant, and anti-inflammatory effects. In vitro, LSE improved oleic acid (OA)-triggered phenotypes of MASLD in hepatocyte HepG2 cells by reducing lipid accumulation and enhancing cell viability. This effect might be mediated through proteins involved in lipogenesis that are downregulated by adenosine monophosphate-activated protein kinase (AMPK). In addition, LSE reduced reactive oxygen species (ROS) generation and glycogen levels, as demonstrated by enhancing insulin signaling involving reducing insulin receptor substrate-1 (IRS-1) Ser307 phosphorylation and increasing glycogen synthase kinase 3 beta (GSK3β) and protein kinase B (PKB) expression. These benefits were dependent on AMPK activation, as confirmed by the AMPK inhibitor compound C. These results indicate that LSE exhibits protective effects against MetS-caused toxicological disturbances in hepatic carbohydrate and lipid metabolism, potentially contributing to its efficacy in preventing MASLD or MetS.

Dehydrozingerone ameliorates renal structure compromised in diabetic nephropathy

Kidney structural integrity is critical for bodily excretory mechanism. Diabetes has been considered as one of the major risk factors for chronic kidney disease, but the underlying mechanism remains elusive. The present study investigates the transcriptomic and proteomic profiling of long-term impact of high-fat diet (HFD) on renal tissue in mice and role of dehydrozingerone (DH) in reinstating the normal kidney function. Animals were divided into four groups- healthy (NCD+Veh), diabetic (HFD-STZ+Veh), healthy+DH (NCD+DH) and treatment (HFD-STZ+DH). 65th days of HFD-fed C57BL/6J mice developed diabetes and kidney dysfunction evident by albuminuria, proteinuria, and glucotoxicity with accumulation of glucose, triglyceride, cholesterol, albumin, and total protein in blood serum. The HFD-fed kidney showed renal injuries, including prominent defects in the glomerular filtration system by downregulation of proteins involved in transport, metabolic process, energy production, anti-oxidation, etc. Downregulation of lipid metabolism is the most impacted metabolic process under diabetic condition. Downregulation of transport proteins mainly impact the functioning of podocytes, cell adhesion and cytoskeletal rearrangement. HFD feeding also increased oxidative stress and induced mitochondrial dysfunction, and thereby activating the pro-apoptotic pathway which is evident by activation of BAX led mitochondrial apoptosis and mitochondrial dysfunction under diseased condition. Progression of DNA damage under diabetic condition triggered the epigenetic alteration and subsequent downstream changes which is evident by activation of HDAC1 under diseased condition. Both transcriptomic and proteomic studies revealed the potential of DH in attenuating the diabetic condition by positively regulating transport system, mitochondrial function, lipid metabolism, DNA damage and epigenetic alteration, and oxidative stress, which ameliorate the kidney function.

Research on the effects of different sugar substitutes-Mogroside V, Stevioside, Sucralose, and Erythritol-On glucose, lipid, and protein metabolism in type 2 diabetic mice

Sugar substitutes that maintain the homeostasis of glucose, lipid, and protein metabolism are important for nutritional intervention in type 2 diabetes mellitus (T2DM). However, the specific metabolic effects remain unclear. The aim of this study was to systematically compare the effects of four common sugar substitutes on a high-fat diet (HFD) combined with a streptozotocin (STZ)-induced T2DM mouse model from the perspective of hepatic glucose, lipid, and protein metabolism. In this study, based on the establishment of a T2DM mouse model induced by an HFD combined with STZ and nontargeted metabolomics, the effects of four sugar substitutes on regulating and improving sugar, lipid, and protein metabolism were systematically evaluated. The results showed that mogroside V (MOG), stevioside (ST), and erythritol (ERT) enhanced protein synthesis via the mammalian target of the rapamycin/p-P70S6K pathway. MOG and ST also improved glucose and lipid metabolism by activating the phosphor-AMP-activated protein kinase (p-AMPK) pathway and upregulating peroxisome proliferator-activated receptor alpha/carnitine palmitoyltransferase 1. Sucralose primarily improves lipid metabolism by downregulating sterol regulatory element-binding protein 1, whereas ERT increases lipid droplet accumulation in the liver. These findings provide a foundation for the application of sugar substitutes in T2DM nutritional interventions.

Macrophage Depletion Alleviates Immunosenescence in Diabetic Kidney by Modulating GDF-15 and Klotho

Cellular senescence is a hallmark of aging and contributes to age-related diseases, including diabetic nephropathy (DN). Additionally, macrophage-mediated inflammation has been linked with DKD. Therefore, we investigated the effect of macrophage depletion on kidney cell senescence in DN, focusing on the relationship between the GDF-15 and Klotho signaling pathways. Wistar albino rats (n = 24) were divided into four groups: healthy control, liposomal clodronate (LC)-treated healthy, diabetic, and LC-treated diabetic groups. Rats in the LC-treated healthy, diabetic, and LC-treated diabetic groups were intravenously administered LC once a week for 4 weeks. Rat models of type 2 diabetes were successfully established via the administration of streptozotocin and a high-fat diet, as evidenced by increased blood glucose levels, kidney weight to body weight (KW/BW) ratio, serum albumin, creatinine, and urea levels, kidney damage, and oxidative stress. However, LC-mediated macrophage depletion reduced the KW/BW ratio, improved serum and oxidative parameters, decreased inflammatory markers (IL-6 and TNF-α), and ameliorated oxidative stress. Additionally, LC treatment promoted macrophage polarization towards the anti-inflammatory phenotype, downregulated GDF-15 expression, upregulated Klotho expression, and ameliorated kidney damage. In conclusion, macrophage depletion combats kidney senescence by modulating Klotho and GDF-15, indicating their potential as novel targets in DN treatment.

Metabolic intervention restores fertility and sperm health in non-obese diabetic rats

Background

In people with diabetes, the effect of sleeve gastrectomy on impaired sperm parameters, hormonal profile, and testis tissue remains controversial to some extent.

The context and purpose of the study

This study aimed to investigate the effects of sleeve gastrectomy on the hormonal profile, sperm parameters, and testis tissue in infertile rats with type II diabetes mellitus (TIIDM). This study included 32 rats with TIIDM with or without sleeve gastrectomy. All the rats underwent sperm, testis tissue, and serum hormone profile analyses before and 8 weeks after surgery.

Results

There was a significant correlation between weight loss after sleeve gastrectomy and a decrease in glucose profile (p < 0.05). In the hormonal profile, testosterone improved significantly after 8 weeks following sleeve gastrectomy. There was a significant increase in sperm count (p < 0.05) and improved sperm morphology during the follow-up after sleeve gastrectomy. The analysis also showed significant changes in testis tissue after surgery.

Conclusion

Sleeve gastrectomy significantly improved testosterone deficiency, testis tissue, and sperm count in rats with TIIDM. Further prospective clinical studies are needed to show how bariatric surgery affects infertility in patients with TIIDM.

Advanced nanofibers integrating vitamin D3 and cerium oxide nanoparticles for enhanced diabetic wound healing: Co-electrospun silk fibroin-collagen and chitosan-PVA systems

This study investigates the co-electrospinning of polyvinyl alcohol-chitosan (PVA-CS) with cerium oxide nanoparticles (CeNPs) and silk fibroin-collagen (SF-Col) with vitamin D3 for diabetic wound healing applications. The SEM results showed smooth, bead-free nanofiber structures. The diameters of the SF-Col and PVA-CS nanofibers ranged from 168 ± 51 nm to 1956 ± 450 nm and 211.4 ± 37.2 nm, respectively. By surface modification using fetal bovine serum (FBS), CeNPs dispersion was enhanced. The average diameter of the uniformly distributed fibers on the SF-Co-D/PVA-CS-CeNPs nanofibers was 621.4 ± 50.6 nm. The addition of CeNPs and vitamin D3 improved cytocompatibility at lower doses. The FTIR test confirmed polymer interactions. Contact angle measurements indicated increased hydrophilicity. SEM analysis demonstrated excellent adhesion and growth of L929 fibroblast cells and significant HUVEC migration on SF-Col-D/PVA-CS-CeNP mats, emphasizing their potential to support cell proliferation and tissue regeneration. Blood compatibility assays exhibited hemolysis percentages below 2 %, classifying the nanofibers as non-hemolytic. Antibacterial tests revealed significant reductions in Staphylococcus aureus and Pseudomonas aeruginosa survival, addressing infection concerns in chronic wounds. Furthermore, in vivo studies have demonstrated that the utilization of SF-Co-D/PVA-CS-CeNPs nanofibrous membrane as a dressing for full-thickness skin wounds in rats has resulted in accelerated tissue regeneration.

Purple-Grain Wheat Regulation of Blood Lipids and Blood Glucose in Diet-Induced Hyperlipidemic Mice and Type 2 Diabetic Mice

Background/Objectives: Disorders of glucose and lipid metabolism can easily lead to metabolic diseases such as hyperlipidemia and diabetes mellitus, with multiple complications. This study evaluated the regulatory effect of purple-grain wheat on glycolipid metabolism. Methods: In this study, we established a hyperlipidemic mouse model by means of a high-fat diet and a type 2 diabetic mouse model using a high-fat and high-sugar diet combined with streptozotocin, and the mice were intervened with 15 g/(kg·d), 7.5 g/(kg·d), and 3.75 g/(kg·d) doses of purple-grain wheat paste (PWP) for 4 and 5 weeks, respectively. Results: The results revealed that PWP reversed the increase in body weight; increased serum high-density lipoprotein cholesterol; and decreased serum total cholesterol, triglycerides, and low-density lipoproteins. In addition, PWP reversed the decrease in body weight and alleviated the sustained increase in blood glucose in type 2 diabetic mice. Conclusions: PWP shows a significant ability to regulate glycolipid levels, which is related to its functional composition and its ability to act as a prebiotic. In conclusion, PWP can be considered a potential functional food for lowering blood glucose and blood lipids.

Purple potato extract modulates fat metabolizing genes expression, prevents oxidative stress, hepatic steatosis, and attenuates high-fat diet-induced obesity in male rats

OBJECTIVE

In this investigation, the significance of purple potato (Solanum tuberosum L.) extract treatment was assessed against oxidative stress and fat metabolizing transcription factors in the liver of high-fat (HF) diet-fed rats.

METHODS

Wistar (male) rats were arranged into several groups and provided with a control and HF diet along with the purple potato extract. Body weights, oral glucose tolerance test (OGTT), insulin, plasma lipids, and oxidative stress-related indicators were analyzed in plasma and tissue samples. Additionally, real-time PCR was performed to evaluate the gene expression for oxidative stress and fat metabolism in the liver. Histological staining was also performed on pancreatic and hepatic tissues.

RESULTS

Purple potato extract lowered body weights and improved glucose utilization in the OGTT test in HF diet-fed rats. Purple potato extract also suppressed HF-diet-induced oxidative stress in plasma and hepatic tissues. Purple potato extract also restored the Nrf-2 expression in the liver, followed by the improved expression of HO-1, HO-2, and other antioxidant genes in HF diet-fed rats. In addition, genes involved in lipid metabolism were also positively modulated due to purple potato extract treatment. Furthermore, histological examination revealed the reduction of lipid accumulation and amelioration of inflammation due to the consumption of purple potato extract.

CONCLUSION

This investigation revealed that antioxidant-rich purple potato extract can modulate the antioxidant and fat metabolizing genes expression, ameliorated oxidative stress and glucose intolerance as well as lowered blood lipids in male rats.

Protective effects of Sulforaphene on kidney damage and gut dysbiosis in high-fat diet plus streptozotocin-induced diabetic mice

Diabetic nephropathy (DN) is one of the most serious and prevalent complications associated with diabetes. Consequently, antidiabetic drugs or foods potentially protecting the kidneys are of significant therapeutic value. Sulforaphene (SFE) is a natural isothiocyanate derived from radish seeds, known for its anti-inflammatory and antioxidant properties. However, no studies have investigated on the ability of SFE to prevent or treat DN. This study established a high-fat diet combined with a streptozotocin-induced type II diabetes mellitus mouse model. We administered SFE treatment to examine its protective effects on renal and intestinal homeostasis in DN mice. After 4 weeks of treatment, SFE (50 mg/kg b.w.) not only reduced blood glucose concentration (20.3 %, P < 0.001), kidney to body weight ratio (26.2 %, P < 0.01), and levels of serum total cholesterol (40.6 %, P < 0.001), triglycerides (38.2 %, P < 0.01), creatinine (36.7 %, P < 0.01), and urea nitrogen (45.0 %, P < 0.001) in DN mice compared to control mice but also increased the kidney superoxide dismutase (72.7 %, P < 0.001), catalase (51.1 %, P < 0.001), and glutathione peroxidase activities (31.6 %, P < 0.01), as well as glutathione levels (39.2 %, P < 0.01) in comparison to DN mice. Furthermore, SFE decreased levels of reactive oxygen species (55.4 %, P < 0.01), 4-hydroxyalkenals (36.9 %, P < 0.001), malondialdehyde (42.6 %, P < 0.001), and 8-hydroxy-deoxyguanosine (26.3 %, P < 0.001), accompanied by a meliorating kidney morphological abnormalities. Notably, a reduction in renal inflammatory factors was also observed in SFE-treated DN mice compared to untreated DN mice, particularly in the C-X-C motif chemokine ligand 8 factors (54.8 %, P < 0.001). Western blotting results indicated that SFE significantly down-regulated the protein expression of TLR4 and MyD88 (1.9, 1.7-fold, P < 0.001). Additionally, SFE improved gut microbiota (GM) dysbiosis and intestinal homeostasis, as evidenced by increased expression of antimicrobial peptides and tight junction proteins in colon tissue. SFE appeared to enhance the proliferation of probiotics, such as Bacteroidota, Lachnospiraceae_NK4A136_group and norank_f__Muribaculaceae, while also decreasing harmful bacteria to a greater extent compared to STZ treatment. These findings suggest that SFE modulates GM and improves intestinal homeostasis, providing a theoretical basis for its use in the treatment of DN.

Controlled induction of type 2 diabetes in mice using high fat diet and osmotic-mini pump infused streptozotocin

Type 2 diabetes (T2D) is a progressive metabolic disorder characterised by obesity, insulin resistance, impaired glucose tolerance, and hyperglycaemia. The long time-course of T2D in humans makes accurate modelling of sustained T2D in animal models difficult. The goal of this study was to develop and characterise an accurate and reproducible, non-transgenic model of sustained T2D in mice. Adult, male C57BL/6 mice were placed on a high-fat diet (HFD) for 17 weeks. From weeks 3-5, osmotic mini-pumps were implanted subcutaneously to slowly infuse streptozotocin (STZ; 200-350 mg/kg) for 14-days after which mini-pumps were removed. Body weight, blood glucose concentration, and glucose tolerance were monitored for 12 weeks post STZ treatment. Our data demonstrate that the combination of HFD and 200 mg/kg STZ delivered by mini-pump leads to increased blood glucose concentrations and impaired glucose tolerance, while maintaining obesity and hepatic dyslipidaemia. In week 17, plasma insulin concentration was assessed and showed that with STZ treatment, mice still produce insulin, but that this is reduced compared with mice on HFD only. Lastly, we examined pancreas sections using immunohistochemistry and show that there is no overt loss of beta cell mass. In conclusion, we demonstrate development of a reproducible in vivo model of T2D in mice that replicates a number of key pathophysiological changes seen in humans with T2D.

Lactobacillus casei Zhang prevents hippocampal atrophy and cognitive impairment in rats with type 2 diabetes by regulating blood glucose levels

PURPOSE

Lactobacillus casei Zhang (LCZ) has health benefits, such as the ability to improve blood glucose levels in individuals with type 2 diabetes mellitus (T2DM). However, little is known about the effects of LCZ on brain structural plasticity and cognitive function in T2DM. The aims of this study were to determine whether LCZ can prevent and alleviate brain damage and memory impairment in T2DM, and to understand the mechanisms underlying the effects of LCZ in T2DM.

METHODS

Forty-one male Sprague-Dawley rats were divided into the saline control (CON, n = 14), T2DM (n = 14) and T2DM + LCZ (n = 13) groups. Magnetic resonance imaging (MRI) was used to evaluate alterations in brain structure among these three groups. The novel object recognition and Y-maze tests were conductedto assess cognitive function. Histological and immunohistochemical analysis, including Nissl staining, Golgi-Cox staining and glial fibrillary acidic protein immunostaining, were performed to explore the pathophysiological mechanisms underlying brain structural changes.

RESULTS

T2DM rats presented hyperglycemia, cognitive decline, hippocampal atrophy, and damage to hippocampal neurons and astrocytes. Compared with those in the T2DM groups, rats in the T2DM + LCZ group presented lower blood glucose levels, better cognitive function, a larger hippocampal volume, and more normal hippocampal neurons and astrocytes. There was no significant difference in these metrics between rats in the T2DM + LCZ and CON groups.

CONCLUSION

Hyperglycemia-induced damage to hippocampal neurons and astrocytes may lead to hippocampal atrophy and cognitive dysfunction in T2DM. LCZ can effectively prevent this damage by regulating blood glucose levels, preventing brain atrophy and cognitive impairment in T2DM rats. These findings provide a scientific basis for the clinical application of LCZ.

Metformin and vitamin D combination therapy ameliorates type 2 diabetes mellitus-induced renal injury in male Wistar rats

Diabetic kidney disease is a major microvascular diabetes mellitus (DM) complication clinically associated with a gradual renal function decline. Although metformin is a common drug for managing DM, however, monotherapy treatment with any antidiabetic drug will necessitate dosage increment since type 2 DM (T2DM) deteriorates over time due to the increasing pancreatic β-cell dysfunction and will eventually require a combination therapy approach with another antidiabetic medication. Vitamin D is a food supplement that has been proven to have antidiabetic and reno-protective activities. Hence, we explore the combination of vitamin D and metformin on T2DM-induced renal dysfunction. Thirty male Wistar rats were randomized into five (5) groups: control, diabetes untreated, diabetics treated with metformin, vitamin D, and vitamin D + metformin. Vitamin D and metformin significantly reversed DM-induced hyperglycemia, electrolyte imbalance, and dyslipidemia. Also, vitamin D and metformin reversed T2DM-induced increase in serum creatinine and urea and renal lactate, LDH, and oxido-inflammatory response. These observed alterations were accompanied by an increase in proton pump activities and modulation of Nrf2/Nf-κB and XO/UA signaling. This study revealed that vitamin D and/or metformin ameliorated T2DM-induced renal injury.

Altered leptin signaling and attenuated cardiac vagal activity in rats with type 2 diabetes

Introduction

The leading cause of death in type 2 diabetes mellitus (T2DM) patients is cardiovascular-related events, including myocardial infraction-induced ventricular arrhythmia. Previous studies have shown that T2DM-induced functional remodeling of cardiac vagal postganglionic (CVP) neurons contributes to ventricular arrhythmogenesis. As leptin resistance is common in T2DM patients, and CVP neurons are located in epicardial adipose pads, a tissue that secretes leptin, in this study we aimed to elucidate a correlation between leptin resistance and CVP neuronal dysfunction in T2DM.

Methods

A high fat-diet/low dose streptozotocin-induced T2DM rat model was used in this study to characterize T2DM-induced alterations in cardiac parasympathetic tone, determined by changes in baroreflex sensitivity and CVP neuronal excitability. The impact of leptin resistance on CVP neurons was also studied by examining the expression of leptin in epicardial adipose pads, and leptin receptors and uncoupling protein 2 (UCP2) in CVP neurons.

Results

T2DM rats exhibited diminished baroreflex sensitivity, and decreased CVP neuronal excitability, demonstrated by a reduced frequency of action potentials, diminished nAChR currents, and an attenuated response to nicotine stimulation. Additionally, compared to sham animals, the expression of leptin receptors and UCP2 in CVP neurons was reduced as early as 4 weeks post-T2DM although the leptin levels in epicardial adipose pads was increased during the progression of T2DM, which demonstrated the occurrence of leptin resistance in T2DM CVP neurons.

Conclusion

Cardiac parasympathetic dysfunction in T2DM rats is due, in part, to functional remodeling of CVP neurons. As leptin resistance develops as early as 4 weeks post-T2DM induction, diminished leptin receptors-UCP2 signaling may contribute to CVP neuronal dysregulation.

Microvessel co-transplantation improves poor remuscularization by hiPSC-cardiomyocytes in a complex disease model of myocardial infarction and type 2 diabetes

People with type 2 diabetes (T2D) are at a higher risk for myocardial infarction (MI) than age-matched healthy individuals. Here, we studied cell-based cardiac regeneration post MI in T2D rats modeling the co-morbid conditions in patients with MI. We recapitulated the T2D hallmarks and clinical aspects of diabetic cardiomyopathy using high-fat diet and streptozotocin in athymic rats, which were then subjected to MI and intramyocardial implantation of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with or without rat adipose-derived microvessels (MVs). hiPSC-CM alone engrafted poorly. Co-delivery of hiPSC-CMs with MVs yielded a smaller infarct area and a thicker left ventricle wall. Additionally, MVs robustly integrated into the infarcted hearts, improved the survival of hiPSC-CMs, and improved cardiac function. MV-conditioned media also promoted hiPSC-CM maturation in vitro, increasing cardiomyocyte (CM) size in an interleukin (IL)-6-dependent manner. Given the availability of MVs from human adipose tissue, MVs present great translational potential for the treatment of heart failure in people with T2D.

ZBiotics ameliorates T2DM-induced histopathological damage in liver, kidney and adipose tissues by modulating the NOD-like receptor signaling in Wistar rats

Probiotics serve as promising candidates in type 2 diabetes mellitus (T2DM) therapy. Not only they presumably reduce the T2DM prevalence, but also keep down its complications. In the present study, we explored the beneficial impact of ZBiotics, an engineered probiotic, on T2DM Wistar rats. In silico analysis was performed to construct a genetic-epigenetic network linked to STING-NOD pathway and autophagy signaling. Then, 30 Wistar rats were divided into 5 groups (each n = 6); normal group, diabetic model, B. subtilis, and ZBiotics treated rats at high and low doses. Experimental procedures were carried out including biochemical and histopathologic analyses. Samples were extracted from rats' blood, liver, kidney and adipose tissues. At the molecular aspect, the molecular players, chosen by the in silico analysis, were assessed using 2-ΔΔCt to estimate their relative quantification. With immunohistochemistry, TNF-alpha and LC3B were assessed as reflectors for inflammation and autophagy respectively. ZBiotics was reported to ameliorate the T2DM-induced histological damage. Besides, it downregulated TNF-alpha and upregulated LC3B expression levels. At the biochemical aspect, ZBiotics corrected LDL-c and improved serum creatinine and CK-MB levels. Inflammation relevant genes have been downregulated regarding CHUK, NFKB1 and miR-611. Therefore, ZBiotics is speculated to operate by modulating the genetic-epigenetic network linked to inflammatory cGAS-STING and autophagy signaling. ZBiotics is recommended for clinical trials as a separate candidate or as an adjuvant to the conventional T2DM therapy.

Citronellal Alleviates Insulin Resistance in High-Fat Diet/Streptozocin Model: Role of Asprosin/Olfactory Receptor Axis

Ectopic olfactory receptors are expressed in nonolfactory tissues and perform diverse roles including regulation of glucose homeostasis. We explored the effect of citronellal treatment on olfactory receptor 4M1 subtype (OR4M1) signaling in insulin resistance and Type II diabetes in rats. We aimed to validate the anti-diabetic effect of citronellal through Asprosin/OR4M1 modulation. Exploring new antidiabetics and pharmacological targets is important to improve quality of life and limit complications. The model was established in Sprague-Dawley rats by a high-fat diet for 4 weeks followed by a single low-dose streptozotocin (STZ) (35 mg/kg/ip). One week after STZ injection, oral citronellal (100 mg/kg) was administered for 4 weeks. Citronellal lowered serum glucose and triglycerides and ameliorated OGTT and HOMA-IR results. Docking results revealed that citronellal blocked the Asprosin binding site at OR4M1. The hepatic expression of OR4M1 and Asprosin was reduced. Citronellal lowered cAMP levels causing attenuated levels of protein kinase A and downstream gluconeogenic enzymes: glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. Citronellal also inhibited the expression of hepatic TLR-4 and inhibited JNK phosphorylation. Citronellal attenuated hepatic levels of NF-κB, p-NF-κB, and downstream proteins MCP-1 and TNF-α. These results suggest that citronellal alleviates insulin resistance by mitigating Asprosin/OR4M1 and Asprosin/TLR4/JNK signaling.

Aerobic exercise and metformin attenuate the cognitive impairment in an experimental model of type 2 diabetes mellitus: focus on neuroinflammation and adult hippocampal neurogenesis

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder that increases the prevalence of cognitive impairment in the geriatric population. Aerobic exercise is an excellent non-pharmacological therapeutic strategy to prevent Alzheimer's disease, the most common form of dementia. The exact molecular mechanism of aerobic exercise (Exe) as an intervention to counter cognitive decline is far from clear. Metformin is a first-line agent against T2DM with neuroprotective properties. The present study assessed the role of treadmill exercise in combination with a low dose of metformin (Met; 70 mg/kg) in cognitive impairment and its associated molecular mechanism in T2DM rats. The experimental model of T2DM-associated cognitive decline was created by administration of a high-fat diet (HFD) with a low dose of streptozotocin (STZ; 35 mg/kg). Neurobehavioral assessments were performed to evaluate spatial recognition and fear-conditioned memory across the groups: control, HFD + STZ, HFD + STZ + Exe, and HFD + STZ + Exe + Met. In addition, we performed immunohistochemistry and western blotting on the rat hippocampal tissue from the above groups for protein expression studies. T2DM rats showed a significant cognitive decline compared to the control group, which improved in the long-term exercise and metformin co-administered animals. The level of neuroinflammation was significantly elevated in the hippocampal tissue of T2DM rats compared to the control and lowered after exercise and metformin treatment. T2DM reduced mature neurons and neurogenesis while increasing astrogliosis and microgliosis, ameliorated by exercise and metformin treatment. Moreover, T2DM impaired hippocampal neurogenesis by reducing the canonical Wnt/β-catenin pathway, which got upregulated in exercise and metformin-co-administered rats. Long-term aerobic exercise with metformin treatment ameliorated neuroinflammation and promoted adult hippocampal neurogenesis via upregulating the canonical Wnt/β-catenin pathway in T2DM rats.

Saracatinib, a Src kinase inhibitor, enhances the renoprotective effect of metformin and losartan in diabetic nephropathy

OBJECTIVE

This research assesses renoprotective effects of saracatinib (Src) in diabetic nephropathy (DN) and the potential underlying processes.

MATERIALS AND METHODS

Rats were divided into: control, DN, DN + Met + Los, DN + Met + Src, and DN + Met + Los + Src. Rats' ABP, urinary albumin, urinary nephrin, and creatinine clearance were assessed. Blood samples were collected for measuring glycaemic state parameters, renal functions, oxidative stress markers, inflammatory mediators, aldosterone, and lipid profile. Kidneys were extracted for KIM-1 and nephrin gene expression, H&E, Masson's trichrome staining, and immunohistochemical assessment.

RESULTS

Significant increases in ABP, urinary albumin and nephrin, glycaemic measurements, urea, creatinine, aldosterone, inflammatory cytokines, MDA, lipids, renal fibrosis, H scores of VEGF and TGF-β, and renal KIM-1 expression were related to DN. However, there was a significant decrease in creatinine clearance, GSH, and nephrin expression in DN group compared with control group.

DISCUSSION AND CONCLUSION

The combination of metformin (Met), losartan (Los), and Src repaired DN alterations. Adding Src to Met and Los is superior to using them alone.

Terminalia catappa aqueous extract reduces hyperglycaemia and oxidative stress in diabetic-hypercholesterolemic rats

BACKGROUND

Terminalia catappa is an important medicinal plant. Plants from the genus Terminalia have been reported for antidiabetic effects.

OBJECTIVE

To study effect of Terminalia catappa leaves aqueous extract in type 2 diabetic rats.

MATERIALS AND METHODS

High-fat diet (HFD) and a low dose of streptozotocin (35 mg/kg, i.p.) were used for inducing type 2 diabetes in rats; streptozotocin was injected after two weeks of dietary modification with HFD. HFD was continued throughout the study. Doses of 500 and 1000 mg/kg of aqueous extract of Terminalia catappa were used as a treatment for six weeks. At the end of the study, biochemical and oxidative stress parameters were estimated. Histopathology and immunohistochemistry of pancreatic tissue were performed.

RESULTS

Significant decrease (p < 0.01, p < 0.001) was observed in glucose levels of diabetic animals treated with T. catappa extract at both dose levels when compared with diabetic control group. Treatment with aqueous extract reduced cholesterol levels significantly (p < 0.05). After receiving 1000 mg/kg of extract, the triglyceride level was significantly lowered (p < 0.01) in the diabetic rats. Extract treatment enhanced the insulin sensitivity index (ISI), while insulin levels and HOMA-IR were markedly reduced. Treatment with 1000 mg/kg of extract significantly enhanced the levels of GSH and catalase. Histopathological analysis of the pancreas showed that damage caused by hyperglycemia was prevented in the extract-treated groups. Pancreatic tissue showed an increased expression of SIRT1 in extract-treated animals.

CONCLUSION

The current study's findings prove that the extract has remarkable antidiabetic effects.

Evaluation of the effects of pioglitazone on perivascular adipose tissue function, properties, and structure in a rat model of type-2 diabetes

Perivascular adipose tissue (PVAT) plays an important role in many physiological and pathological processes, such as regulation of vascular tone. The aim of this study is to evaluate the effects of pioglitazone on functional, structural, and biochemical properties of PVAT in an experimental model of type-2 diabetes (T2DM). T2DM was induced by high-fat-diet/low-dose-streptozotocin in rats, and pioglitazone (20 mg/kg/p.o.) was administered for 6 weeks. Changes in biochemical parameters, PVAT-mass, vascular-reactivity in thoracic-aorta, as well as PVAT adipocytokine and PPARG-expression levels, and histopathology were evaluated. Pioglitazone administration improved blood glucose and lipid profiles in T2DM. Pioglitazone did not change the anticontractile effect of PVAT on aortic contractile reactivity and besides, had no influence on endothelium-dependent and -independent relaxation responses. Pioglitazone administration increased PVAT-mass and tumor necrotizing factor-α levels, while adiponectin, leptin, and interleukin-6 levels were unchanged. Also, a prominent increase was observed in PPARG-expression in T2DM-Pio group. Moreover, pioglitazone decreased liver steatosis, aortic wall thickening, and myocardial damage, whereas increased adipocyte size and adiposity in PVAT. Overall, pioglitazone treatment changed the mass and in part the inflammatory profile of PVAT but did not modify vasoreactivity in T2DM. This study provides novel findings in relationship with the adipogenic effect of pioglitazone and PVAT function.

Scientific Validation of Using Active Constituent as Research Focus in Traditional Chinese Medicine: Case Study of Pueraria lobata Intervention in Type 2 Diabetes

Objectives: Traditional Chinese Medicine (TCM) is recognized for its complex composition and multiple therapeutic targets. However, current pharmacological research often concentrates on extracts or individual components. The former approach faces numerous challenges, whereas the latter oversimplifies and disregards the synergistic effects among TCM components. This study aims to investigate the scientific validity of focusing on the active constituent in TCM efficacy research, using Pueraria lobata (P. lobata) as a case study. Methods: Through spectrum-effect correlation analysis, network pharmacology, and molecular docking, five active ingredients of P. lobata were identified: puerarin, formononetin, tuberosin, 4',7-dihdroxy-3'-methoxyisoflavone, and Daidzein-4,7-diglucoside. These ingredients were combined to form an active constituent, which was subsequently tested in vitro and in vivo. Results: In in vitro, the active constituent exhibited superior effects in enhancing glucose consumption and glycogen synthesis compared to both the P. lobata extract and individual components. In vivo experiments demonstrated that medium and high doses of the active constituent were significantly more effective than P. lobata extract, with effects comparable to those of metformin in reducing blood sugar levels. Conclusions: The active constituent effectively improves T2DM by lowering blood glucose levels, promoting glycogen synthesis, and modulating glycolipid metabolism. Both in vitro and in vivo studies indicate that it outperformed the P. lobata extract and individual components. This study establishes the scientific validity and feasibility of utilizing the active constituent as the focus for investigating the efficacy of TCM, thereby offering novel insights and a new research paradigm for future TCM investigations.

Ethyl gallate ameliorates diabetes-induced Alzheimer's disease-like phenotype in rats via activation of α7 nicotinic receptors and mitigation of oxidative stress

Cognitive decline, an important comorbidity of type 2 diabetes (T2D), is attributed to oxidative stress and impaired cholinergic signaling in the brain. The α7 nicotinic acetylcholine receptor (α7nAChR) is densely distributed in the hippocampus and cortex, and exerts neuroprotective and procognitive actions. Ethyl gallate (EG), a natural phenolic antioxidant compound, showed high in-silico binding affinity towards α7nAChR and brain penetrability. Therefore, the present study aimed to evaluate the involvement of α7nAChR in the potential of EG to ameliorate T2D-induced Alzheimer's disease-like condition. T2D was induced by intraperitoneal (i.p.) injection of streptozotocin (35 mg/kg) in rats on high-fat diet. Diabetic animals were treated with EG (10 and 20 mg/kg, i.p.) for four weeks, and their learning and memory performance was evaluated by the Morris water maze (MWM). Further, the brains were subjected to biochemical analysis of antioxidants like glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), and oxidative stress marker malonaldehyde (MDA). While diabetic rats showed a significant decline in cognitive performance in the MWM, a substantial improvement was noticed following EG treatment. Further, the diabetes-associated reductions in GSH, SOD, and CAT levels, along with increased MDA contents in the brain, were effectively restored by EG. Interestingly, pre-treatment with α7nAChR antagonist methyllycaconitine (1 mg/kg, i.p.) attenuated the effects of EG on behavioral and biochemical parameters. The results suggest that EG may augment cholinergic signaling in the brain via α7nAChR to mitigate oxidative stress, consequently alleviating T2D-associated dementia. Therefore, EG could be a potential candidate for addressing cognitive impairment comorbid with T2D.

Renoprotective effect of liraglutide on diabetic nephropathy by modulation of Krüppel-like transcription factor 5 expression in rats

OBJECTIVES

Diabetic nephropathy (DN) is a serious consequence of diabetes that can develop through the lysophosphatidic acid axis. The purpose of this study was to determine whether the antidiabetic drug liraglutide can slow the development of diabetic kidney damage by altering the lysophosphatidic acid axis via KLF5.

METHODS

Wistar albino rats were divided into nondiabetic and diabetic rats (resulting from an intraperitoneal streptozotocin dose of 30 mg/kg and a high-fat diet). These rats were further divided into four groups: nondiabetic control, liraglutide-treated nondiabetic, diabetic control, and liraglutide-treated diabetic. The nondiabetic and diabetic control groups received normal saline for 42 days, while the liraglutide-treated nondiabetic and diabetic groups received normal saline for 21 days, followed by a subcutaneous dose of liraglutide (200 μg/kg/day) for 21 days. Subsequently, serum levels of DN biomarkers were evaluated, and kidney tissues were histologically examined. The protein expression of PCNA, autotaxin, and KLF5 was detected.

KEY FINDINGS

Liraglutide treatment in diabetic rats decreased DN biomarkers, histological abnormalities in kidney tissues, and the protein expression of PCNA, autotaxin, and KLF5.

CONCLUSION

Liraglutide can slow the progression of DN by modulating KLF5-related lysophosphatidic acid axis. Thus, liraglutide may be an effective treatment for preventing or mitigating diabetes-related kidney damage.

A reliable strategy for establishment of an animal model of diabetic cardiomyopathy: Induction by a high-fat diet combined with single or multiple injections of low-dose streptozotocin

BACKGROUND

Diabetic cardiomyopathy (DCM) is one of the leading causes of death in patients with diabetes mellitus (DM). This study aimed to identify a reliable method for establishing an animal model of DCM for investigation of new targets and treatments.

METHODS

Eighty-four 4-week-old male Sprague-Dawley rats were randomly allocated to receive a normal diet or a high-fat diet (HFD) in an approximate ratio of 1:3. At 9 weeks of age, rats in the HFD group received streptozotocin (STZ) 30 mg/kg by intraperitoneal injection and rats in the control group received the same volume of buffer solution. The rodent model of DM was deemed to be successfully established when a random blood glucose measurement was >16.7 mmol/L on three consecutive occasions. If necessary, STZ was readministered.

RESULTS

Three of the 64 rats in the HFD group died after a second STZ injection. DM was induced in 14, 39, and 8 rats after one, two, and three injections, respectively, with cumulative success rates of 21.9 %, 82.8 %, and 95.3 %. Three months later, the rats with DM showed persistent hyperglycemia and insulin resistance and developed histopathological changes indicating cardiac hypertrophy, myocardial fibrosis, and diastolic dysfunction. The metabolic and cardiac histopathological changes were consistent regardless of whether DM was induced by one, two, or three injections of STZ.

CONCLUSION

An HFD combined with one or more intraperitoneal injections of low-dose STZ is a straightforward and reliable method for inducing DCM in rats. When a single dose of STZ fails to induce DM, repeated injections can be considered.

Lactobacillus reuteri TISTR 2736 alleviates type 2 diabetes in rats via the hepatic IRS1/PI3K/AKT signaling pathway by mitigating oxidative stress and inflammatory mediators

PURPOSE

This study investigated the beneficial effects of Lactobacillus reuteri TISTR 2736 on glucose homeostasis, carbohydrate metabolism, and the underlying mechanisms of its actions in type 2 diabetic (T2D) rats.

METHODS

A rat model of T2D was established by a combination of a high-fat diet and streptozotocin. The diabetic rats were treated daily with L. reuteri TISTR 2736 (2 × 108 CFU/day) for 30 days. Biochemical, histopathological, and molecular analyses were carried out to determine insulin signaling, carbohydrate metabolism, oxidative stress, and inflammation.

RESULTS

The results demonstrated that treatment with L. reuteri TISTR 2736 significantly ameliorated fasting blood glucose and glucose intolerance, and improved insulin sensitivity indices in the diabetic rats. The hepatic histopathology was improved with L. reuteri TISTR 2736 treatment, which was correlated with a reduction of hepatic lipid profiles. L. reuteri TISTR 2736 significantly reduced glycogen content, fructose 1,6-bisphosphatase activity, and phosphoenolpyruvate carboxykinase 1 protein expression, and enhanced hexokinase activity in the diabetic liver. The downregulation of IRS1 and phosphorylated IRS1Ser307 and upregulation of PI3K and phosphorylated AKTSer473 proteins in the liver were found in the L. reuteri TISTR 2736-treated diabetic group. Furthermore, it was able to suppress oxidative stress and inflammation in the diabetic rats, as demonstrated by decreased malondialdehyde and protein levels of NF-κB, IL-6 and TNF-α, but increased antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase.

CONCLUSION

By inhibiting oxidative and inflammatory stress, L. reuteri TISTR 2736 alleviated hyperglycemia and improved carbohydrate metabolism through activating IRS1/PI3K/AKT pathway in the T2D rats.

Neem seed oil ameliorates diabetic phenotype by suppressing redox imbalance, dyslipidaemia and pro-inflammatory mediators in a rodent model of type 2 diabetes

The neem plant (Azadirachta indica) has popular ethnomedicinal applications. The anti-diabetic potential and mechanism of neem seed oil (NSO) in a rodent model of type 2 diabetes mellitus was evaluated in the present study. Experimentally-induced diabetic animals were administered NSO (200 and 400 mg/kg) or metformin (150 mg/kg) orally for 30 days, with some animals serving as positive and negative controls. NSO significantly (p < .05) reversed diabetes-induced impaired glucose metabolism, dyslipidaemia, and oxido-inflammatory imbalances typified by changes in the NADH/NAD+ ratio (p < .001) and increases in the mRNA or protein levels of C-reactive protein, 4-hydroxynonenal, and pro-inflammatory cytokines (TNF-α and Il-1β) among others in the hepatic or pancreatic tissues of diabetic animals. The histological evaluation of the pancreatic tissue corroborated the protective effect of NSO. The findings showed that the antidiabetic effect of NSO proceeded through its hypolipidemic effect and modulation of redox and inflammatory signalling events in the tissues of animals.

Sustainable Intervention: Grape Pomace Flour Ameliorates Fasting Glucose and Mitigates Streptozotocin-Induced Pancreatic Damage in a Type 2 Diabetes Animal Model

Background/Objectives: Type 2 Diabetes Mellitus (T2DM) is characterized by hyperglycemia, increased risk of cardiovascular diseases, and oxidative imbalances. This study aimed to investigate the impact of dietary supplementations with 'Arinto' grape pomace flour (GPF) (WGPF) and 'Touriga Nacional' GPF (RGPF) in an animal model of T2DM. Methods: T2DM was induced by a high-fat diet (HFD) for 28 days and a single dose of streptozotocin (STZ) (35 mg/kg) on the 21st day. Forty adult male Wistar rats were divided into five groups: Control (CT), T2DM, T2DM + Metformin (250 mg/kg), T2DM + 10% 'Arinto' GPF (WGPF), and T2DM + 10% 'Touriga Nacional' GPF (RGPF). On the 21st day of the experimental protocol, animals were submitted to an oral glucose tolerance test. An oral glucose tolerance test, oxidative stress parameters, biochemical analysis, and pancreas histological analyses were performed. Results: T2DM impaired glucose tolerance, elevated serum triglycerides and cholesterol, increased oxidative damage in the liver, and induced pancreatic histological abnormalities. However, supplementation with WGPF and RGPF demonstrated positive effects, mitigating glycemic and lipid disruptions, ameliorating oxidative stress, and protecting pancreatic Islets β-cells. Conclusions: Our findings highlight the protective effects of WGPF and RGPF in the adverse impacts of T2DM. Additionally, our study emphasizes the innovative use of grape pomace, a winemaking by-product, promoting sustainability by transforming waste into functional foods with significant health benefits.

Oxidative and endoplasmic reticulum stress in diabetes-related hearing loss: Protective effects of thioredoxin

Diabetes mellitus (DM) induces complex physiological changes in the inner ear environment. This study investigates the roles of oxidative stress (OS) and endoplasmic reticulum stress (ERS) in diabetes-related hearing loss (DRHL) and explores the potential of thioredoxin (Trx) in regulating OS, ERS, and apoptosis-related factors to mitigate the progression of hearing impairment. We conducted auditory and serological assessments in 63 patients with type 2 diabetes and 30 healthy controls. Type 2 diabetes models were induced in wild-type and Trx transgenic (Tg) mice, with auditory brainstem response (ABR) used to evaluate hearing changes. Cochlear tissues were isolated to analyse markers of apoptosis, OS, and ERS. Both patients with diabetes and mouse models exhibited hearing loss, alongside increased serum levels of Trx1, TXNIP, and AOPP, indicating oxidative damage. H&E and succinate dehydrogenase (SDH) staining revealed varying degrees of hair cell loss from the base to the apex of the cochlea in diabetic mice, with decreased expression of the hair cell protein prestin gene. Notably, Tg mice showed significant delay in hearing loss progression. In vitro, advanced glycation end-products (AGEs) induced OS and ERS in cochlear-like HEI-OC1 cells, while Trx overexpression enhanced Nrf2 activity, alleviating AGE-induced cellular stress. In conclusion, Trx exhibits protective effects against DRHL, potentially by enhancing Nrf2/HO-1/SOD2 function to reduce OS and ERS.

Exploring the combined therapeutic efficacy of bexarotene and icariin in type 2 diabetic rats

OBJECTIVES

The aim of this study was to determine the single and combined antidiabetic activity and side effects of the retinoid X receptor agonist bexarotene and the thioredoxin-interacting protein inhibitor and peroxisome proliferator-activated receptor γ and AMP-activated protein kinase activator icariin.

METHODS

The rats were grouped as healthy (control), diabetes, diabetes + bexarotene (20 mg/kg), diabetes + icariin (60 mg/kg), diabetes + bexarotene (10 mg/kg) + icariin (30 mg/kg) low-dose combination and diabetes + bexarotene (20 mg/kg) + icariin (60 mg/kg) high-dose combination groups.

KEY FINDINGS

Icariin treatment led to a significant reduction in glucose levels compared with the diabetes control group, a remarkable outcome observed 45 days after the initial application. HbA1c levels of the icariin and low-dose combination treatment groups were significantly lower than in the diabetes group. Notably, icariin treatment also significantly elevated HOMA-β levels, which is indicative of improved β-cell function. Icariin significantly decreased glucose levels at 30 and 120 min in the oral glucose tolerance test. Moreover, it ameliorated hepatocyte degeneration, hepatic cord dissociation, congestion, mononuclear cell infiltration in the liver, and degeneration in the pancreas.

CONCLUSIONS

Icariin treatment exhibited robust antidiabetic effects with fewer side effects than other treatment options in this study. In future studies, long-term and varying doses of icariin will contribute to the development of novel antidiabetic drugs.

The Influence of Atorvastatin Treatment on Homocysteine Metabolism and Oxidative Stress in an Experimental Model of Diabetic Rats

OBJECTIVE

In our experimental study, we evaluated the influence of treatment with atorvastatin on the antioxidant activity of intracellular and extracellular systems factors, homocysteine levels (Hcy), and lipid profiles in obese and diabetic rats.

METHOD

Twenty-one male Wistar rats, aged 6 months, 450-550 g, were allocated into three groups. From the beginning of the study, the first group (G-I, control) received only standard food, while the second and third groups (G II-obese, G III-diabetic) were administered a high-fat diet (HFD) with 2% cholesterol. After 2 weeks of accommodation, the specimens in G-III were injected intraperitoneal (i.p.) streptozotocin (35 mg of body weight, pH 4.5), intervention followed by the onset of type 2 diabetes mellitus. Following confirmation of diabetes onset, the specimens in G III were administered concomitantly with the HFD a daily gavage of atorvastatin 20 mg of body weight/day for 20 days. We measured, at the beginning and the end of the study, the Hcy levels, lipid profile, vitamin B12, B6, folic acid, and various parameters of oxidative stress (OS)-total antioxidant status (TAS), glutathione peroxidase (GPX) and superoxide dismutase (SOD).

RESULTS

After treatment with atorvastatin, the lipid profile in G III significantly improved compared to the other two groups, but enzymatic markers of oxidative stress did not closely parallel this trend. However, after the treatment of statin, we observed an important reduction in Hcy values.

CONCLUSION

Our results demonstrate that treatment with atorvastatin can be used not only for its lipid-lowering properties and antioxidant effects but also to reduce Hcy concentration in this experimental model of diabetic rats. Moreover, atorvastatin therapy improves lipid profiles, reduces inflammation, suppresses oxidation, and decreases Hcy levels, potentially preventing major adverse cardiovascular events.

Fibroblast growth factor 21 improves insulin sensitivity by modulating the bile acid-gut microbiota axis in type Ⅱ diabetic mice

BACKGROUND

Fibroblast growth factor 21 (FGF21) is an important regulator of glycolipid metabolism. However, whether the gut microbiota is related to the anti-diabetic and obesity effects of FGF21 remains unclear.

METHODS

Our research used KO/KO db/db male mice and streptozotocin (STZ)-induced to simulate the construction of two type II diabetic mellitus (T2DM) models, and detected impaired glucose tolerance in the model by using the ipGTT and ITT assays, and collected feces from the model mice for sequencing of the intestinal flora and the content of short-chain fatty acids. H＆E staining was used to detect changes in intestinal tissue, the serum levels of LPS and GLP-1 were detected by ELISA.

RESULTS

In this study, we found that FGF21 significantly improved insulin sensitivity, attenuated intestinal lesions, and decreased serum lipopolysaccharide (LPS) concentrations in T2DM mice. Moreover, FGF21 reshaped the gut microbiota and altered their metabolic pathways in T2DM mice, promoting the production of short-chain fatty acids (SCFAs) and the secretion of glucagon-like peptide 1 (GLP-1). Fecal transplantation experiments further confirmed that feces from FGF21-treated diabetic mice demonstrated similar effects as FGF21 in terms of anti-diabetic activity and regulation of gut microbiota dysbiosis. Additionally, the antibiotic depletion of gut microbiota abolished the beneficial effects of FGF21, including increased GLP-1 secretion and fecal SCFA concentration. Additionally, the FGF21 effects of ameliorating intestinal damage and suppressing plasma LPS secretion were suppressed. All these findings suggest that FGF21 prevents intestinal lesions by modifying the gut microbiota composition. Furthermore, FGF21 affected bile acid synthesis by inhibiting CYP7A1, the key enzyme of bile acid synthesis.

CONCLUSSION

Therefore, FGF21 enriched beneficial bacteria by preventing bile acid synthesis and stimulating the secretion of the intestinal hormone GLP-1 via the increased production of gut microbiota metabolites, thereby exerting its anti-diabetic effects.

Streptozotocin-induced morphological changes in rat lungs

Streptozotocin (STZ) is a commonly used compound for the induction of type 2 diabetes (T2D) in animal models, but its effects on non-pancreatic tissues like the lungs are not well understood. This study aimed to examine the histopathological impact of STZ on the lungs using male Sprague-Dawley rats. The rats were divided into two groups: a control group on a normal diet and an STZ-treated group receiving a high-fat diet and 10% sucrose water for 8 weeks, followed by an STZ injection (30 mg/kg body weight). All rats were terminated 9 days after STZ administration, and lung samples were collected for light microscopy, transmission electron microscopy (TEM), and confocal laser scanning microscopy. Light microscopy revealed thickening of alveolar septa, narrowing of alveoli, and inflammatory infiltrates in the STZ group. TEM showed mitochondrial damage in type 2 pneumocytes, including membrane fragmentation, cristae loss, and formation of mitochondrial-derived vesicles. Confocal microscopy revealed significantly higher expression of myeloperoxidase, neutrophil elastase, and citrullinated histone 3 in the STZ group compared to controls. These findings suggest that STZ induces considerable lung damage, emphasizing the need to consider lung toxicity in studies involving STZ.

Vitamin K2 Ameliorates Diabetes-Associated Cognitive Decline by Reducing Oxidative Stress and Neuroinflammation

Diabetes, a chronic metabolic disease, affects approximately 422 million people and leads to 1.5 million deaths every year, It is found that 45% of individuals with diabetes eventually develop cognitive impairment. Here we study effects of Vitamin K2 on diabetes-associated cognitive decline (DACD) and its underlying mechanism. Diabetes was induced in adult Swiss albino mice with high-fat diet and a low dose (35 mg/kg) of streptozotocin and measured by fasting glucose and HbA1c levels. After one week of development of diabetes, one group of animals received Vitamin K2 (100 µg/kg) via oral gavage for 21 days. Then different behavioural studies, including the elevated plus maze, Morris water maze, passive avoidance test and novel object recognition test were performed followed by biochemical tests including AchE, different oxidative stress parameters (SOD, GSH, MDA, catalase, SIRT1, NRF2), inflammatory markers (TNFα, IL1β, MCP1, NFκB), apoptosis marker (Caspase 3). Hippocampal neuronal density was measured using histopathology. Vitamin K2 treatment in diabetic animals led to reduced fasting glucose and HbA1c, It could partially reverse DACD as shown by behavioural studies. Vitamin K2 adminstration reduced corticohippocampal AchE level and neuroinflammation (TNFα, IL1β, MCP1, NFκB, SIRT1). It reduced oxidative stress by increasing antioxidant enzymes (SOD, GSH, catalase), transcription factor NRF2 while reducing caspase 3. This eventually increased CA1 and CA3 neuronal density in diabetic animals. Vitamin K2 partially reverses DACD by increasing ACh while reducing the oxidative stress via Nrf2/ARE pathway and neuroinflammation, thus protecting the hippocampal neurons from diabetes associated damage.

Nanocarrier-Assisted Delivery of Berberine Promotes Diabetic Alveolar Bone Regeneration by Scavenging ROS and Improving Mitochondrial Dysfunction

Purpose

Oxidative stress and mitochondrial dysfunction are potential contributors to the compromised tissue regeneration capacity of alveolar bone in diabetic patients. Berberine, an active plant alkaloid, exhibits multiple pharmacological effects including antioxidation, blood glucose- and blood lipid-lowering properties. However, it remains uncertain whether berberine can improve impaired osteogenesis in type 2 diabetes mellitus (T2DM), and its poor solubility and oral bioavailability also constrain its applications in bone regeneration. Thus, our study aimed to probe the effects of berberine on bone marrow stem cells (BMSCs) in a diabetic microenvironment, with a greater emphasis on developing a suitable nano-delivery system for berberine and assessing its capability to repair diabetic alveolar bone defects.

Methods

Firstly, BMSCs were exposed to berberine within a high glucose and palmitate (HG+PA) environment. Reactive oxygen species levels, mitochondrial membrane potential, ATP generation, cell apoptosis, and osteogenic potential were subsequently assessed. Next, we explored the regulatory mechanism of autophagy flux in the positive effects of berberine. Furthermore, a nanocarrier based on emulsion electrospinning for sustained local delivery of berberine (Ber@SF/PCL) was established. We assessed its capacity to enhance bone healing in the alveolar bone defect of T2DM rats through micro-computed tomography and histology analysis.

Results

Berberine treatment could inhibit reactive oxygen species overproduction, mitochondrial dysfunction, apoptosis, and improve osteogenesis differentiation by restoring autophagy flux under HG+PA conditions. Notably, Ber@SF/PCL electrospun nanofibrous membrane with excellent physicochemical properties and good biological safety had the potential to promote alveolar bone remodeling in T2DM rats.

Conclusion

Our study shed new lights into the protective role of berberine on BMSCs under T2DM microenvironment. Furthermore, berberine-loaded composite electrospun membrane may serve as a promising approach for regenerating alveolar bone in diabetic patients.

Sesame oil downregulates the expression of ADAMTS-4 in high-fat diet-induced atherosclerosis

Atherosclerosis is a chronic inflammatory disease forming plaques in medium and large-sized arteries. ADAMTS-4 (a disintegrin and metalloproteinase with thrombospondin motifs-4) is an extracellular-matrix remodelling enzyme involved in the degradation of versican in the arterial wall. Recent reports indicated that increased expression of ADAMTS-4 is associated with plaque progression and vulnerability. Bioactive components of dietary oil, like sesame oil, are reported to have anti-inflammatory and antioxidant properties. Here, we studied the effect of sesame oil on regulating ADAMTS-4 in high-fat diet-induced atherosclerosis rat model. Our results indicated that sesame oil supplementation improved the anti-inflammatory and anti-oxidative status of the body. It also reduced atherosclerotic plaque formation in high-fat diet-fed rats. Our results showed that the sesame oil supplementation significantly down-regulated the expression of ADAMTS-4 in serum and aortic samples. The versican, the large proteoglycan substrate of ADAMTS-4 in the aorta, was downregulated to normal control level on sesame oil supplementation. This study, for the first time, reveals that sesame oil could down-regulate the expression of ADAMTS-4 in high-fat diet-induced atherosclerosis, imparting a new therapeutic potential for sesame oil in the management of atherosclerosis.

Dyslipidemia and hyperglycemia induce overexpression of Syndecan-3 in erythrocytes and modulate erythrocyte adhesion

Erythrocytes are important vascular components that play vital roles in maintaining vascular homeostasis, in addition to carrying oxygen. Previously, we reported that the changes in the internal milieu (e.g. hyperglycemia or hypercholesterolemia) increase erythrocyte adhesion to various extracellular matrix components, potentially through altering glycosaminoglycans (GAGs). In this study, we have investigated the expression of syndecan (Sdc) family members that could be involved in mediating cytoadherence under conditions of dyslipidemia and hyperglycemia. Among the Sdc family members analysed, we found significant overexpression of Sdc-3 in erythrocyte membranes harvested from high-fat-fed control and diabetic animals. Animal studies revealed a positive correlation between Sdc-3 expression, blood sugar levels and erythrocyte adhesion. In the human study, diabetic cohorts with body mass index >24.9 showed significantly increased expression of Sdc-3. Interestingly, blocking the Sdc-3 moiety with an anti-Sdc-3 antibody revealed that the core protein might not be directly involved in erythrocyte adhesion to fibronectin despite the GAGs bringing about adhesion. Lastly, Nano liquid chromatography-mass spectrometry/MS verified the presence of Sdc-3 in erythrocyte membranes. In conclusion, the high-fat diet and diabetes modulated Sdc-3 expression in the erythrocyte membrane, which may alter its adhesive properties and promote vascular complications.

Enhanced Effects of Intermittent Fasting by Magnetic Fields in Severe Diabetes

Intermittent fasting (IF) is a convenient dietary intervention for multiple diseases, including type 2 diabetes. However, whether it can be used as a long-term antidiabetic approach is still unknown. Here, we confirm that IF alone is beneficial for both moderate and severe diabetic mice, but its antidiabetic effects clearly diminish at later stages, especially for severe diabetic db/db mice, which have obviously impaired autophagy. We found that static magnetic fields can directly promote actin assembly and boost IF-induced autophagy. Consequently, the pancreatic islet and liver were improved, and the antidiabetic effects of IF were boosted. In fact, at later stages, combined static magnetic field and IF could reduce the blood glucose level of moderate type 2 diabetic mice by 40.5% (P < 0.001) and severe type 2 diabetes by 34.4% (P < 0.05), when IF alone no longer has significant blood glucose reduction effects. Therefore, although IF is generally beneficial for diabetes, our data reveal its insufficiency for late-stage diabetes, which can be compensated by a simple, noninvasive, long-lasting, and nonpharmacological strategy for effective long-term diabetic control.

Cardioprotective Effects of 'Vasant Kusumakar Rasa,' a Herbo-metallic Formulation, in Type 2 Diabetic Cardiomyopathy in Rats

Diabetic cardiomyopathy (DCM) is one of the serious complications of type 2 diabetes mellitus. Vasant Kusumakar Rasa (VKR) is a Herbo-metallic formulation reported in Ayurveda, an Indian system of medicine. The present work was designed to study the effect of VKR in cardiomyopathy in type 2 diabetic rats. Diabetes was induced by feeding a high-fat diet (HFD) for 2 weeks followed by streptozotocin (STZ) administration (35 mg/kg i.p.). VKR was administered orally at dose of 28 and 56 mg/kg once a day for 16 weeks. The results of the study indicated that VKR treatment significantly improved the glycemic and lipid profile, serum insulin, CK-MB, LDH, and cardiac troponin-I when compared to diabetic control animals. VKR treatment in rats significantly improved the hemodynamic parameters and cardiac tissue levels of TNF-α, IL-1β, and IL- 6 were also reduced. Antioxidant enzymes such as GSH, SOD, and catalase were improved in all treatment groups. Heart sections stained with H & E and Masson's trichome showed decreased damage to histoarchitecture of the myocardium. Expression of PI3K, Akt, and GLUT4 in the myocardium was upregulated after 16 weeks of VKR treatment. The study data suggested the cardioprotective capability of VKR in the management of diabetic cardiomyopathy in rats.

The role of PCSK9 in glomerular lipid accumulation and renal injury in diabetic kidney disease

AIMS/HYPOTHESIS

Glomerular lipid accumulation is a defining feature of diabetic kidney disease (DKD); however, the precise underlying mechanism requires further elucidation. Recent evidence suggests a role for proprotein convertase subtilisin/kexin type 9 (PCSK9) in intracellular lipid homeostasis. Although PCSK9 is present in kidneys, its role within kidney cells and relevance to renal diseases remain largely unexplored. Therefore, we investigated the role of intracellular PCSK9 in regulating lipid accumulation and homeostasis in the glomeruli and podocytes under diabetic conditions. Furthermore, we aimed to identify the pathophysiological mechanisms responsible for the podocyte injury that is associated with intracellular PCSK9-induced lipid accumulation in DKD.

METHODS

In this study, glomeruli were isolated from human kidney biopsy tissues, and glomerular gene-expression analysis was performed. Also, db/db and db/m mice were used to perform glomerular gene-expression profiling. We generated DKD models using a high-fat diet and low-dose intraperitoneal streptozocin injection in C57BL/6 and Pcsk9 knockout (KO) mice. We analysed cholesterol and triacylglycerol levels within the kidney cortex. Lipid droplets were evaluated using BODIPY staining. We induced upregulation and downregulation of PCSK9 expression in conditionally immortalised mouse podocytes using lentivirus and siRNA transfection techniques, respectively, under diabetic conditions.

RESULTS

A significant reduction in transcription level of PCSK9 was observed in glomeruli of individuals with DKD. PCSK9 expression was also reduced in podocytes of animals under diabetic conditions. We observed significantly higher lipid accumulation in kidney tissues of Pcsk9 KO DKD mice compared with wild-type (WT) DKD mice. Additionally, Pcsk9 KO mouse models of DKD exhibited a significant reduction in mitochondria number vs WT models, coupled with a significant increase in mitochondrial size. Moreover, albuminuria and podocyte foot process effacement were observed in WT and Pcsk9 KO DKD mice, with KO DKD mice displaying more pronounced manifestations. Immortalised mouse podocytes exposed to diabetic stimuli exhibited heightened intracellular lipid accumulation, mitochondrial injury and apoptosis, which were ameliorated by Pcsk9 overexpression and aggravated by Pcsk9 knockdown in mouse podocytes.

CONCLUSIONS/INTERPRETATION

The downregulation of PCSK9 in podocytes is associated with lipid accumulation, which leads to mitochondrial dysfunction, cell apoptosis and renal injury. This study sheds new light on the potential involvement of PCSK9 in the pathophysiology of glomerular lipid accumulation and podocyte injury in DKD.

Mitigation of ROS-triggered endoplasmic reticulum stress by upregulating Nrf2 retards diabetic nephropathy

Endoplasmic reticulum stress (ERS) plays a crucial role in the pathogenesis of diabetic nephropathy (DN), and it is often accompanied by an increase in reactive oxygen species (ROS) production. However, the precise relationship between NFE2-related factor-2 (Nrf2), a key regulator of ROS balance, and ERS in DN remains elusive. This study aimed to investigate the impact of Nrf2 on ERS and its therapeutic potential in DN. Herein, ERS-related changes, including increased activating transcription factor-6 (ATF6), glucose-regulated protein 78 (GRP78), and transcription factor C/EBP homologous protein (CHOP) expression, were observed in the renal tissues of streptozotocin-induced DN mice and high glucose cultured human renal proximal tubular (HK-2) cells. Nrf2 knockdown increased the sensitivity of HK-2 cells to ERS under high glucose conditions, underscoring the regulatory role of Nrf2 in ERS modulation. Notably, upregulating Nrf2 in ezetimibe-treated diabetic mice restored ERS markers and ameliorated albuminuria, glomerular hypertrophy, mesangial expansion, and tubulointerstitial fibrosis. Furthermore, the inhibition of ERS in HK-2 cells by the ROS scavenger, N-acetylcysteine, highlights the interplay between ROS and ERS. This study, for the first time, elucidates that the upregulation of Nrf2 may alleviate the negative influence of ROS-mediated ERS, presenting a promising therapeutic avenue for delaying the progression of DN. These findings suggest a potential strategy for targeting Nrf2 and ERS in developing novel therapeutic interventions for DN.

Cardioprotective effect of CB1 receptor antagonist AM251 against β receptor-stimulated myocardial infarction via modulation of NF-kB signaling pathway in diabetic mice

We substantiated the effect of AM251, a cannabinoid receptor-1 (CB1R) antagonist, against β-receptor stimulated myocardial infarction (MI) in streptozotocin (STZ)-induced diabetic mice via modulation- of the NF-kB signaling pathway. The different parameters were assessed such as ECG, hemodynamic, cardiac injury markers, oxidative stress parameters, pro-inflammatory cytokines, and histopathological abnormalities. Mice were fed a high-fat diet for 30 days. On day 7, to trigger diabetes, 150 mg/kg of STZ was injected intraperitoneally. On day 10, to determine whether diabetes developed, the blood level of glucose was monitored. From days 11-30, diabetic mice were injected with either CB1R agonist oleamide or antagonist AM251 or both, with concurrent administrations of β-agonist isoproterenol on days 28 and 29 to induce MI. In comparison to normal, the myocardial infarcted diabetic animals demonstrated alterations in ECG, hemodynamic profiles, and diminished enzymatic activities (CK-MB, LDH, SOD, GSH, catalase), with concurrently increased MDA levels, which indicated increased oxidative stress in the myocardium. Additionally, higher concentrations of cytokines that signal myocardial inflammation, such as IL-1β, IL-6, and TNF-α, were also noted. Furthermore, elevated myonecrosis, edema, and cell infiltration which is confirmed by histopathology of heart tissue. Treatment with AM251 significantly ameliorated myocardial redox status, reduced cytokines, and repaired enzymatic activities leading to subsequent recovery in cardiac function. AM251 effectively suppressed myonecrosis and edema. This study also showed that AM251 protects against myocardial inflammation and oxidative stress triggered by isoproterenol by blocking NF-kB signalling pathway. However, upregulation of the CB1R through oleamide showed significant cardiac toxicity. Conversely, the concurrent administration of oleamide and AM251 failed to induce cardiotoxic effects in isoproterenol-induced MI in diabetic mice which indicates downregulation of the CB1R might be associated with the cardioprotective effect.

Seed Disinfection Treatments Minimized Microbial Load and Enhanced Nutritional Properties of Fenugreek Sprouts Which Alleviated Diabetes-Negative Disorders in Diabetic Rats

Sprouts are an attractive food product that contains high amounts of nutritional substances and has pro-health features. Sprout consumption has strongly increased despite its potential risk to health due to its microbial load. Both the safety and shelf life of sprouts may be negatively affected by a high microbial load. To reduce the microbial contamination in sprouts before consumption, the initial microbial load on the seeds needs to be controlled. Many herbal sprouts have been recommended for diabetes, and fenugreek is one of these sprouts. Thus, the current experiment aimed at disinfecting fenugreek seeds using microwave (5, 10, and 20 s) and hot water (30, 45, and 60 s) treatments for different durations. The best-disinfected sprouts with the highest nutritional properties were used to evaluate their influence on streptozocin-induced diabetic rats in comparison with fenugreek seed feeding. Microwave treatments showed the highest sprout length, fresh weight, total free amino acids, antioxidants, reducing sugars, and total phenols. Additionally, microwave seed treatments showed the lowest bacteria and mold counts on sprouts produced relative to hot water treatments, and the best seed treatment was a microwave for 20 s, which gave the best values in this respect. Feeding diabetic rats with different fenugreek seeds or sprout rates (0, 5, 7.5, and 10% w/w) improved body weight, restricted the growth of glucose levels, lowered total cholesterol and triglycerides, and improved HDL compared with the positive control group, and fenugreek sprouts at higher rates showed the maximum improvements in blood glucose, total cholesterol, and triglycerides. Treating fenugreek seed with microwave radiation for 20 s to disinfect the seeds before sprouting is recommended for lowering the microbial load with optimum nutritional and antioxidant activity, and feeding diabetic rats with these sprouts at the rate of 7.5 and 10% had promising effects on hyperglycemia and associated disorders.

A male mouse model for metabolic dysfunction-associated steatotic liver disease and hepatocellular carcinoma

The lack of an appropriate preclinical model of metabolic dysfunction-associated steatotic liver disease (MASLD) that recapitulates the whole disease spectrum impedes exploration of disease pathophysiology and the development of effective treatment strategies. Here, we develop a mouse model (Streptozotocin with high-fat diet, STZ + HFD) that gradually develops fatty liver, metabolic dysfunction-associated steatohepatitis (MASH), hepatic fibrosis, and hepatocellular carcinoma (HCC) in the context of metabolic dysfunction. The hepatic transcriptomic features of STZ + HFD mice closely reflect those of patients with obesity accompanying type 2 diabetes mellitus, MASH, and MASLD-related HCC. Dietary changes and tirzepatide administration alleviate MASH, hepatic fibrosis, and hepatic tumorigenesis in STZ + HFD mice. In conclusion, a murine model recapitulating the main histopathologic, transcriptomic, and metabolic alterations observed in MASLD patients is successfully established.