Type-2 Diabetic Rats Research Articles

Silibinin ameliorates the cardiovascular oxidative and inflammatory effects of type-2-diabetic rats exposed to air particulate matter

Polycyclic Aromatic Hydrocarbons present in Diesel exhaust particle (DEP) has been established in different studies to cause deleterious toxic effects by inducing oxidative and pro-inflammatory effects. Diabetes is among the world’s top diseases. Silibinin (SIL) is a plant bioflavolignan with numerous health benefits. This study examined the effects of SIL on the oxidative and inflammatory status in the heart and aorta of type-2-diabetic (T2D) Wistar rats exposed to DEP. Type 2 diabetes was induced using streptozocin 45 mg/kg b.w of Wistar rats, which were later exposed to DEP (0.4 and 0.5 mg/kg) and post-treated with SIL. Another group of nondiabetic rats were administered DEP and later post-treated with 40 mg/kg SIL and the results were compared to the diabetic group. The results showed that DEP caused a significant (p < 0.001) increase in malondialdehyde and conjugated diene levels in the heart and aorta of T2D rats but was significantly (p < 0.001) attenuated by SIL. DEP induced interleukin 1 beta IL-1β, forkhead box protein 1 (FOXO1), heme-oxygenase HO-1, and decreased interleukin 10 (IL-10) gene expression, all of these were reversed in the presence of SIL. The expression of PI3K-AKT-GLUT4 (phosphatidylinositol-3-kinase, protein kinase B, glucose transporter 4) was significantly reduced by DEP in both tissues of T2D rats while SIL ameliorates against these effects. This indicates the potential of SIL to protect against DEP-induced cardiotoxicity in T2D subjects.

Tiger nut (Cyperus esculentus L.) and date palm (Phoenix dactylifera L.) fruit blend mitigates hyperglycemia, insulin resistance and oxidative complications in type-2 diabetes models.

Tiger nut and date fruit are chewy with sweet taste and are popularly consumed as food either alone, mixed or paired with other fruits, seeds and vegetables. They are locally used to treat diabetes and were separately reported to attenuate hyperglycemia in various animal models of diabetes. However, effect of tiger nut and date fruit mixture on key diabetes related parameters has not yet been reported. Therefore, we investigated the antidiabetic and antioxidant effects of the tiger nut and date blend (TDB) using in vitro and in vivo models. The TDB was prepared in equal ratio (1:1). For the in vivo study, mixture was included in the diet at 5% and 10% and feed the type 2 diabetic rats for 4 weeks. The diabetic untreated rats showed significant (p < .05) hyperglycemia, hyperlipidemia, insulin resistance and oxidative stress. Consumption of the TDB blend, significantly (p < .05) reduced fasting blood glucose by 71% and 52% in the groups treated with high and low doses respectively. In addition, intake of TBD blend demonstrated significant (p < .05) antihyperlipidemic, ameliorated insulin resistance and oxidative stress in the treated groups. The effects were more prominent in group supplemented with the 10% of the TDB and attributed to some promising ingredients detected. In conclusion, dietary supplementation of TDB exhibited antidiabetic action and could be due to the phytochemicals assessed. PRACTICAL APPLICATIONS: Inclusion of functional foods such as tiger nut and date fruit in daily diet is proved to be highly beneficial in controlling type-2 diabetes and its associated complications. Our results show that tiger nut and date fruit blend can effectively reduce hyperglycemia and oxidative damage, improve insulin sensitivity in type-2 diabetes rat model. Hence, the data shows the potential of tiger nut and date fruit blend to promote scientific basis of the dietary application of tiger nut and date fruit blend as a functional food for the remedy of diabetes and its associated complications.

Effects of Combined Garcinia kola and Kigelia africana on Insulin and Paraoxonase 1 (PON1) Levels in Type 2 Diabetic Rats.

Individual extracts of Garcinia kola and Kigelia africana have been shown to have therapeutic effects against a variety of variables linked to the development of diabetes mellitus. However, there is still a lack of information about the combined effects of these extracts on Insulin and Paraoxonase 1 (PON-1) in Streptozotocin-Nicotinamide-induced type-2 diabetic Wistar rats. Forty-two young male rats (180-200g) were randomly divided into six groups (n = 7/group). Diabetes was intraperitoneally induced with 110 mg/kg of nicotinamide constituted in distilled water and fifteen minutes later with 65 mg/kg of streptozocin freshly prepared in 0.1M citrate buffer (pH of 4.5) and treated for six weeks as follows: the control rats received either 0.9% normal saline (NS) or 250 mg/kg extract by gavage. The remaining animals were diabetes induced and subsequently treated with either NS, graded doses of the extract (250 mg/kg and 500 mg/kg), or 5 mg/kg Glibenclamide + 100mg/kg Metformin. Gas chromatography-mass spectrometry (GCMS) of the combined extracts was also analyzed to identify the bioactive compounds present in it. Insulin, PON-1 levels, lipid profiles, and atherogenic index were assessed. Our findings show that Insulin and PON-1 levels in the plasma of diabetic rats treated with the combined extracts were significantly increased when compared to the control rats. Moreover, the GCMS of the extract shows the presence of both monounsaturated (oleic acid) and polyunsaturated (linoleic acid) fatty acids. The current findings suggest that the extract may help improve glucose homeostasis and prevent atherosclerosis through the established mechanism of the identified bioactive compounds.

Resistance Training Prevents Muscle Atrophy In Diabetic Rats Via MSTN Pathway

Type 1 diabetes mellitus (T1DM) induces serious skeletal muscle atrophy. resistance training is one of the effective ways to improve muscle atrophy. However, the mechanisms underlying exercise preventing muscle atrophy are still not clear. PURPOSE: To explore the influence of resistance training on muscle atrophy of type1 diabetes rats. METHODS: Fifty male Sprague-Dawley rats (8 weeks, 200-240 g) were randomly assigned to either the normal control group (NC = 8) or the T1DM model group (T1DM, n = 42). T1DM was induced by a single intraperitoneal injection of streptozotocin (STZ) at 60 mg/kg. Once T1DM was induced, the diabetic rats were randomly allocated into three groups: sham-treated diabetic control rats (DC + Sham, DC, n = 8), T1DM rats treated with an insulin injection (DC + INS, DI, n = 8), and treated with resistance training (DC + Training, DT, n = 8). The body weight and muscle strength were measured after the resistance training. HE staining of rat gastrocnemius test morphological changes in muscle fiber cross-sectional area. The protein levels and gene expression of MSTN, Akt, and FoxO1 were measured by Western Blot and Quantitative Real-time PCR. RESULTS: The body weights of NC continued to be remarkably higher than those in the other three diabetic groups during the whole experimental period (P < 0.01). After 6 weeks of training, the body weight (295.40 g ± 20.44 vs. 212.79 g ± 13.26, P < 0.01) and average peak force (9.54 N ± 1.57 vs. 7.85 N ± 1.69, P < 0.01) of DT were significantly increased compared with the DC. The muscle fiber cross-sectional area in the DT significantly increased compared with the DC rats (23729.87 μm2 ± 774.69 vs. 11726.46 μm2 ± 755.66, P < 0.01). DT significantly decreased the mRNA expression of MSTN (1.51 ± 0.22 vs. 2.62 ± 0.26, P < 0.01) and FoxO1(1.37 ± 0.12 vs. 2.26 ± 0.19, P < 0.01) compared with the DC group, as were in protein expression of MSTN (1.66 ± 0.02 vs. 2.09 ± 0.08, P < 0.01), and FoxO1(0.76 ± 0.02 vs. 0.92 ± 0.11, P < 0.05). The mRNA expression of Akt (0.47 ± 0.17 vs. 0.03 ± 0.01, P < 0.01) were increased in the DT, as were the protein expression of Akt (2.83 ± 0.22 vs. 1.64 ± 0.08, P < 0.01). CONCLUSION: These results indicate that 6 weeks of resistance training improved muscle atrophy induced by type 1 diabetes, and the MSTN/Akt/FoxO1 signaling pathway may play a role in this improvement.

Therapeutic mechanisms of mulberry leaves in type 2 diabetes based on metabolomics.

Background: Type 2 diabetes (T2D) is considered as one of the most significant metabolic syndromes worldwide, and the long-term use of the drugs already on the market for T2D often gives rise to some side effects. The mulberry leaf (ML), Morus alba L., has advantages in terms of its comprehensive therapeutic efficacy, which are characterized as multicomponent, multitarget, multipathway, and matching with the complex pathological mechanisms of diabetes. Methods: T2D rats were established by a high-fat diet combined with an intraperitoneal injection of streptozotocin; an evaluation of the hypoglycemic effects of the ML in combination with fasting blood glucose and other indicators, in addition to the utilization of metabolomics technology, was performed to analysis the metabolite changes in serum of rats. Results: MLs significantly reduced the fasting blood glucose of T2D rats, while improving the symptoms of polyphagia and polyuria. ML treatment altered the levels of various metabolites in the serum of T2D rats, which are involved in multiple metabolic pathways (amino acid metabolism, carbohydrate metabolism, and lipid metabolism), played a role in antioxidative stress and anti-inflammation, modulated immune and gluconeogenesis processes, and improved obesity as well as insulin resistance (IR). Conclusion: The ML contains a variety of chemical components, and metabolomic results have shown that MLs regulate multiple metabolic pathways to exert hypoglycemic effects, suggesting that MLs may have great promise in the development of new hypoglycemic drugs.

Rev-erbs agonist SR9009 alleviates ischemia-reperfusion injury by heightening endogenous cardioprotection at onset of type-2 diabetes in rats: Down-regulating ferritinophagy/ferroptosis signaling

The complex progression of type-2 diabetes (T2DM) results in inconsistent findings on myocardial susceptibility to ischemia-reperfusion (IR). IR injuries in multiple organs interconnect with ferroptosis. Targeting Rev-erbs might limit ferroptosis, with increasing attention turning to the application of circadian medicine against IR injuries. However, whether the Rev-erbs agonist SR9009 could mitigate diabetic IR injury remains unknown. Here, we investigated the susceptibility to IR at onset of T2DM in rats and its potential association between SR9009 and ferritinophagy/ferroptosis signaling. Onset of T2DM model was induced with a high-fat diet and the intraperitoneal injection of a low dose of streptozotocin. Myocardial IR model was established as well. Rats’ general characteristics, cardiac function, glycolipid profiles, serum biochemistry, apoptosis index (AI) and morphological histology were observed and analyzed. Western blot and immunofluorescence (IF) were employed to evaluate the expression of ferritinophagy/ferroptosis signaling and its co-localization. Glycolipid profiles and cardiac diastolic function were significantly impaired in diabetic rats. CK-MB, AI levels and ferritinophagy/ferroptosis-related proteins expression decreased towards myocardial IR in diabetic rats compared to non-diabetic rats’. The ferroptosis inducer Erastin up-regulated SOD, MDA, and AI levels, as well as the expression of ferritinophagy/ferroptosis-related proteins in diabetic rats towards IR. Treatment with SR9009 down-regulated the degree of myocardial injury and ferritinophagy/ferroptosis-related proteins expression compared to diabetic rats treated with or without Erastin. Onset of T2DM activated endogenous cardioprotection against the susceptibility to myocardial IR injury, and SR9009 exogenously enhanced this endogenous mechanism and alleviated myocardial IR injury at onset of T2DM by down-regulating ferritinophagy/ferroptosis signaling.

Diabetic microenvironment preconditioning of adipose tissue-derived mesenchymal stem cells enhances their anti-diabetic, anti-long-term complications, and anti-inflammatory effects in type 2 diabetic rats

BackgroundMesenchymal stem cells (MSCs) exert anti-diabetic effects and improve long-term complications via secretory effects that regulate macrophage polarisation and attenuate inflammation. Enhancing the efficacy of MSCs needs to be explored further. The in vitro culture microenvironment influences the secretory profile of MSCs. Therefore, we hypothesised that a diabetic microenvironment would promote the secretion of cytokines responsible for macrophage polarisation, further attenuating systemic inflammation and enhancing the effects of MSCs on type 2 diabetes (T2D) and long-term diabetic complications.MethodsPreconditioned adipose-derived mesenchymal stem cells (pre-ADSCs) were obtained after co-cultivating ADSCs in a diabetic metabolic environment (including high sugar, advanced glycation end-product, and lipopolysaccharides). The regulatory effects of pre-ADSCs on macrophages were observed in vitro. A T2D rat model was induced with a high-fat diet for 32 weeks combined with an intraperitoneal injection of streptozotocin. Sprague–Dawley (SD) rats were divided into four groups: normal group, diabetes without treatment group (PBS), ADSC treatment group, and pre-ADSC treatment group. ADSCs and pre-ADSCs were intravenously administered weekly to SD rats for 6 months, and then glucose homeostasis and long-term diabetic complications were evaluated in each group.ResultsThe secretion of cytokines related to M2 macrophage polarisation (IL-6, MCP-1, etc.) was increased in the pre-ADSC group in the in vitro model. Pre-ADSC treatment significantly maintained blood glucose homeostasis, reduced insulin resistance, promoted islet regeneration, and ameliorated the complications related to diabetes in rats (chronic kidney disease, non-alcoholic steatohepatitis, lung fibrosis, and cataract) compared to the ADSC group (P < 0.05). Additionally, the number of anti-inflammatory M2 macrophage phenotypes was enhanced in tissues following pre-ADSC injections. Moreover, the expression of pro-inflammatory genes (iNOS, TNF-α, IL-1β) was reduced whereas that of anti-inflammatory genes (Arg1, CD206, and Il-10) was increased after cultivation with pre-ADSCs.ConclusionDiabetic microenvironment-preconditioned ADSCs effectively strengthen the capacity against inflammation and modulate the progress of long-term T2D complications.

Inhibition of Endoplasmic Reticulum Stress Improves Acetylcholine-Mediated Relaxation in the Aorta of Type-2 Diabetic Rats.

Endoplasmic reticulum (ER) stress contributes to insulin resistance and macro- and microvascular complications associated with diabetes. This study aimed to evaluate the effect of ER stress inhibition on endothelial function in the aorta of type-2 diabetic rats. Type-2 diabetes was developed in male Sprague–Dawley rats using a high-fat diet and low-dose streptozotocin. Rat aortic tissues were harvested to study endothelial-dependent relaxation. The mechanisms for acetylcholine-mediated relaxation were investigated using pharmacological blockers, Western blotting, oxidative stress, and inflammatory markers. Acetylcholine-mediated relaxation was diminished in the aorta of diabetic rats compared to control rats; supplementation with TUDCA improved relaxation. In the aortas of control and diabetic rats receiving TUDCA, the relaxation was mediated via eNOS/PI3K/Akt, NAD(P)H, and the KATP channel. In diabetic rats, acetylcholine-mediated relaxation involved eNOS/PI3K/Akt and NAD(P)H, but not the KATP channel. The expression of ER stress markers was upregulated in the aorta of diabetic rats and reduced with TUDCA supplementation. The expression of eNOS and Akt were lower in diabetic rats but were upregulated after supplementation with TUDCA. The levels of MDA, IL-6, and SOD activity were higher in the aorta of the diabetic rats compared to control rats. This study demonstrated that endothelial function was impaired in diabetes, however, supplementation with TUDCA improved the function via eNOS/Akt/PI3K, NAD(P)H, and the KATP channel. The improvement of endothelial function was associated with increased expressions of eNOS and Akt. Thus, ER stress plays a crucial role in the impairment of endothelial-dependent relaxation. Mitigating ER stress could be a potential strategy for improving endothelial dysfunction in type-2 diabetes.

Abstract P2067: Depleted Cardiac Energy Reservoirs And Type 2 Diabetes: The Unfulfilled Role Of Endogenous Creatine

To maintain contractility, the heart turns over the cellular ATP pool six times per minute, with up to half replenished via the creatine:phosphocreatine system (Cr:PCr). This ‘safe’ energy reservoir arises from endogenous sources, through biosynthesis in the kidney and liver for delivery to the heart. Exogenous PCr drastically improves contractility following myocardial ischemia/reperfusion injury (I/R), as exemplified by cardioplegic PCr supplements provided during coronary artery bypass surgery. Considering clinical outcomes following I/R are typically worse in patients with Type 2 Diabetes (T2D), we hypothesized that T2D comorbidities that impact physiology of the kidney and liver may impair endogenous production of Cr and limit cardiac Cr:PCr. We employed a rat model that combined obesity and steatosis (high-fat diet), with pancreatic insufficiency (streptozotocin), to produce elevated blood glucose, serum triglycerides and reduced insulin sensitivity, consistent with a T2DM phenotype. Heart, liver, kidney and blood were sampled from T2D rats for histology and metabolomics by targeted mass spectrometry. Renal microanatomy showed little variation in response to T2D, while nuclear displacement and vacuolation was apparent in liver sections. We identified no change in renal Cr substrate guanidinoacetate (GAA) (0.7996±0.09; n -fold±SEM, p -value=0.524) or the serum GAA levels (0.95±0.13; n -fold±SEM, p -value=0.993). In the liver, GAA levels were depleted (0.468±0.04; p &lt;0.0001), with a comparable reduction of hepatic creatine abundance (0.391±0.07; p =0.003). Cardiac levels of both Cr and PCr were significantly depleted in the heart (Cr: 0.392±0.02, p &lt;0.0001; and PCr: 0.642±0.07, p =0.02). To confirm that this decrease in cardiac Cr:PCr did not simply reflect increased metabolism, we monitored cardiac creatinine and found only a modest decrease in T2D hearts (0.783±0.05; p =0.003), confirming a depletion in Cr bioavailability. In summary, hepatic derangement indicative of steatosis promoted impaired creatine biosynthesis to limit availability of Cr:PCr for restoration of ATP in the diabetic heart. In the absence of adequate ‘safe’ energy reservoirs, such hearts are compromised further following I/R injury.

Preferential effect of Montelukast on Dapagliflozin: Modulation of IRS-1/AKT/GLUT4 and ER stress response elements improves insulin sensitivity in soleus muscle of a type-2 diabetic rat model

AimsMontelukast (MNK), a leukotriene receptor antagonist, has proven its antioxidant/anti-inflammatory capacity to guard against diabetes-induced complications and to enhance metformin antidiabetic effect. Nevertheless, here we evaluated the involvement of endoplasmic reticulum (ER) stress and insulin signaling cascade in the effect of MNK and/or dapagliflozin (DAPA) using the soleus muscle of type 2 diabetic (T2D)/insulin resistant (IR) rats. Main methodsTo induce T2D/IR, rats were fed a westernized diet (WD) for 8 weeks followed by a sub-diabetogenic dose of streptozotocin (STZ). Animals were divided into control (receiving normal diet; ND), diabetic untreated, and diabetic treated for 4 weeks with DAPA, MNK, or their combination (DAPA+MNK). Blood glucose and serum lipid profile were determined, and the soleus muscle was tested for ER stress-induced IR, besides histopathological examination. Key findingsTreatment with DAPA, MNK, and especially their combination decreased the fasting plasma levels of glucose and insulin while improving insulin sensitivity and lipid profile. This was achieved via the activation of insulin signaling IRS-1/AKT/GLUT4 pathway in the soleus muscle consequent to the deactivation of the ER stress response elements, namely IRE1α, ATF6, and PERK to suppress p-JNK and p-eIF2α. SignificanceImproved insulin signaling along with the deactivation of the ER stress response by MNK comparable to the DAPA are partly responsible for the enhanced soleus muscle insulin sensitivity, effects that nominate MNK as an add-on to DAPA to enhance its antidiabetic efficacy.

Empagliflozin prohibits high-fructose diet-induced cardiac dysfunction in rats via attenuation of mitochondria-driven oxidative stress

SGLT2 inhibitors show promising cardio-protection in the diabetic populace. However, the defending effect of SGLT2 inhibition in diabetes-associated cardiac complications and the molecular mechanism behind this effect are not thoroughly studied. Therefore, we aimed to investigate the effect of Empagliflozin, an SGLT2 inhibitor, in type-2 diabetic rat hearts.We induced type-2 diabetes in SD rats by giving a high-fructose diet for 20 weeks. We administered Empagliflozin (10 mg/kg p.o.) daily from the 12th week to the 20th week, along with high-fructose diet. We weighed the cardiac structure and function by echocardiography, electrocardiography, and blood pressure in diabetic rats. Other parameters like cardiac fibrosis, oxidative stress, and mitochondrial dynamics by protein expression were measured. To simulate a similar in-vivo condition, we persuaded insulin resistance in H9c2 cells by palmitic acid (PA) treatment. We then examined glucose uptake, cellular ROS, mitochondrial ROS and membrane potential in the presence and absence of Empagliflozin treatment.We saw a significant perturbation of the majority of the parameters associated with cardiac structure and function in high-fructose diet-induced diabetic rats. We found that administration of Empagliflozin improved all the perturbed parameters by attenuating insulin resistance, oxidative stress, and cardiac fibrosis and also by promoting cardiac mitochondrial fusion in high-fructose diet-induced type-2 diabetic rats. Empagliflozin also reduced palmitate-induced insulin resistance, total cellular ROS, and mitochondrial ROS in H9c2 cells.Our study concluded that SGLT2 inhibition with Empagliflozin prevented the high-fructose diet-insulted cardiac function by suppressing insulin resistance and oxidative stress and promoting mitochondrial fusion.

Antidiabetic and antioxidant potential of Gardenia latifolia in type-2 diabetic rats fed with high-fat diet plus low-dose streptozotocin.

To test the antidiabetic potential of Gardenia latifolia extract (GLE) in rats with type 2 diabetes mellitus (T2DM) induced by a high-fat diet (HFD) + streptozotocin (STZ). The study was carried out in June 2021. Gardenia latifolia powdered leaves were subjected to Soxhlet extraction using ethanol. Male rats were administered a low dose-40mg/kg STZ by intraperitoneal route following 2 weeks of HFD to induce type-2 diabetic rats (T2DR). Rats were randomized into 5 groups (n=6). Group 1 (normal control; 10 ml/kg normal saline); Group 2 (diabetic control: DC); Group 3 (standard; DR + metformin, 100mg/kg per oral); Group 4 (DR + GLE 250mg/kg); Group 5 (DR + GLE 500mg/kg). The treatment period extended for 2 weeks. Body weight and fasting blood glucose were determined on days 0, 7, and 14. Fasting serum insulin (FSI) levels, fasting blood glucose (FBG), HOMA-IR, antioxidant enzyme level, Insulin tolerance test (ITT), and intraperitoneal glucose tolerance test (IPGTT) tests were estimated. Gardenia latifolia extract exhibited a marked decrease (p<0.001) in fasting blood glucose levels. T2DR receiving a higher dose of GLE showed a greater improvement in metabolic indices (FSI, FBG, Homeostatic Model Assessment of insulin resistance). The ITT and IPGTT results demonstrated that GLE could significantly enhance insulin tolerance, glucose tolerance, and antioxidant enzyme levels in T2DR. Gardenia latifolia can be an ideal medicinal plant candidate for treating T2DM, and it should be investigated further for its therapeutic potential.

Ginsenoside Rg1 improved diabetes through regulating the intestinal microbiota in high-fat diet and streptozotocin-induced type 2 diabetes rats.

Ginsenoside Rg1 is the active ingredient of the plant named genus Panax (ginseng), which exhibited significant bioactivities, including anti-inflammatory, antioxidation, and anti-diabetic effects. Herein, 4-week treatment of ginsenoside Rg1 remarkably decreased blood glucose levels and improved the resistance of insulin, oxidative stress, and inflammation along with lipid profile in T2D rats triggered via high-fat diet and streptozotocin (STZ). Ginsenoside Rg1 supplementation improved the intestinal microbial composition induced by type 2 diabetes (T2D), which increased the proportions of Lachnospiraceae_NK4A136_group and Lachnoclostridium and decreased the proportions of Lactobacillus. Additionally, Spearman's correlation test between the gut microflora and biomedical assays (|r| > .5) revealed that the Lachnospiraceae_NK4A136_group, Roseburia, and Romboutsia greatly affect intestinal microbiota, which may play pivotal roles in preventing T2D. Our findings illustrate the use of ginsenoside Rg1 as a dietary supplement along with prospective prebiotics due to its ability to alter the gut microflora and alleviate T2D-linked biochemical abnormalities. PRACTICAL APPLICATIONS: This was the first study to elucidate the influences of ginsenosides Rg1 in improving the intestinal microbiota of T2D in SD rats. The data illustrated that the ginsenosides Rg1 remarkably increased the proportions of SCFAs producing bacteria. Hence, ginsenoside Rg1 could be used as a potential prebiotic in the treatment of T2D through alteration of intestinal microbiota.

Protective effect of acetylcysteine, histidine, and their combination against diabetes vascular complications in type-2 diabetic rats via reducing NF-kβ pathway signaling.

The nuclear factor-kappa B (NF-κB) signaling participates in diabetes complications. Therefore, the reduction of NF-κB signaling may be a goal to prevent or improve them. Thus, we investigated the effects of acetylcysteine (AC), histidine (His), and their combination on the NF-κB expression and its different activators in type 2 diabetic rats. The survey was performed on 50 rats that were allotted equally into five groups composed of control, diabetic, diabetic treated with (AC, 0.06%), (His, 0.1%), and (AC & His) groups. Treated groups have received the treatments daily in drinking water for two months. Metabolic profile (glucose, insulin resistance indices, lipid profile, and cardiovascular indices) and renal dysfunction parameters (creatinine and urinary protein excretion) were measured. Plus, diverse glycation (early, intermediate, and end), oxidative stress (Oxidized LDL, Reduced glutathione), and inflammatory markers (interleukine-1β, myeloperoxidase, and NF-kβ expression) were determined. Glucose, insulin resistance indices, cardiovascular indices, renal dysfunction parameters, different markers of glycation, oxidative stress, and inflammation as well as NF-κB expression, were the lowest in the (AC & His) treated diabetic rats. Besides, the cited parameter was lower in the Ac treated one than His treated (p > 0.001). The combination of AC and His had the most protective effect against diabetes complications and advantageous effect on metabolism, β-cell activity, and insulin function due to the most reductive effect on the NF-κB pathway rather than More than any of the amino acids alone.

Highly active antiretroviral therapy-silver nanoparticle conjugate interacts with neuronal and glial cells and alleviates anxiety-like behaviour in streptozotocin-induced diabetic rats

The inception of highly active antiretroviral therapy (HAART) has changed the management of human immunodeficiency virus (HIV) positive patients, with an improvement in life expectancy. However, neurological complications associated with high dosage and chronic administration of HAART have not been fully addressed. Therefore, this study evaluated the potential benefits of silver nanoparticles (AgNPs) conjugated-HAART (HAART-AgNPs) and its interaction with neuronal and glial cells in type-2 diabetic rats. Forty-two (n = 42) adult male Sprague-Dawley rats (250 ± 13 g) were divided into non-diabetic and diabetic groups. Each rat was administered with either distilled water, HAART, or HAART-AgNPs for eight weeks. After that, the prefrontal cortex (PFC) was excised for immunohistochemical, biochemical, and ultrastructural analysis. The formulated HAART-AgNPs were characterised by Ultraviolet-Visible, Transmission electron microscope, Energy Dispersive X-ray and Fourier transform infrared spectroscopy. Of the various concentrations of HAART-AgNPs, 1.5 M exhibited 20.3 nm in size and a spherical shape was used for this study. Administration of HAART-AgNPs to diabetic rats significantly decreased (p < 0.05) blood glucose level, number of faecal pellets, malondialdehyde (MDA), tumour necrosis factor-alpha (TNF-α), Interleukin-1 beta (IL-1β) compared with HAART-treated diabetic rats. Notably, there was a significant increase (p < 0.05) in antioxidant biomarkers (SOD and GSH), improvement in PFC-glial fibrillary acid protein (PFC-GFAP) positive cells and alleviation of anxiety-like behaviour in HAART-AgNPs treated diabetic rats. These results showed that HAART-AgNPs alleviates the anxiogenic effect and neuronal toxicity aggravated by HAART exposure via the reduction of oxidative and neuroinflammatory injury as well as preserving PFC GFAP-positive cells and neuronal cytoarchitecture.

Testicular ultrastructure and hormonal changes following administration of tenofovir disoproxil fumarate-loaded silver nanoparticle in type-2 diabetic rats

Reproductive dysfunctions (RDs) characterized by impairment in testicular parameters, and metabolic disorders such as insulin resistance and type 2 diabetes mellitus (T2DM) are on the rise among human immunodeficiency virus (HIV) patients under tenofovir disoproxil fumarate (TDF) and highly active antiretroviral therapy (HAART). These adverse effects require a nanoparticle delivery system to circumvent biological barriers and ensure adequate ARVDs to viral reservoir sites like testis. This study aimed to investigate the effect of TDF-loaded silver nanoparticles (AgNPs), TDF-AgNPs on sperm quality, hormonal profile, insulin-like growth factor 1 (IGF-1), and testicular ultrastructure in diabetic rats, a result of which could cater for the neglected reproductive and metabolic dysfunctions in HIV therapeutic modality. Thirty-six adult Sprague–Dawley rats were assigned to diabetic and non-diabetic (n = 18). T2DM was induced by fructose-streptozotocin (Frt-STZ) rat model. Subsequently, the rats in both groups were subdivided into three groups each (n = 6) and administered distilled water, TDF, and TDF-AgNP. In this study, administration of TDF-AgNP to diabetic rats significantly reduced (p < 0.05) blood glucose level (268.7 ± 10.8 mg/dL) from 429 ± 16.9 mg/dL in diabetic control and prevented a drastic reduction in sperm count and viability. More so, TDF-AgNP significantly increased (p < 0.05) Gonadotropin-Releasing Hormone (1114.3 ± 112.6 µg), Follicle Stimulating Hormone (13.2 ± 1.5 IU/L), Luteinizing Hormone (140.7 ± 15.2 IU/L), testosterone (0.2 ± 0.02 ng/L), and IGF-1 (1564.0 ± 81.6 ng/mL) compared to their respective diabetic controls (383.4 ± 63.3, 6.1 ± 1.2, 76.1 ± 9.1, 0.1 ± 0.01, 769.4 ± 83.7). Also, TDF-AgNP treated diabetic rats presented an improved testicular architecture marked with the thickened basement membrane, degenerated Sertoli cells, spermatogenic cells, and axoneme. This study has demonstrated that administration of TDF-AgNPs restored the function of hypothalamic-pituitary–gonadal axis, normalized the hormonal profile, enhanced testicular function and structure to alleviate reproductive dysfunctions in diabetic rats. This is the first study to conjugate TDF with AgNPs and examined its effects on reproductive indices, local gonadal factor and testicular ultrastructure in male diabetic rats with the potential to cater for neglected reproductive dysfunction in HIV therapeutic modality.

LncXIST Facilitates Iron Overload and Iron Overload-Induced Islet Beta Cell Injury in Type 2 Diabetes through miR-130a-3p/ALK2 Axis.

Iron overload is directly associated with diabetes mellitus, loss of islet beta cell, and insulin resistance. Likewise, long noncoding RNA (lncRNA) is associated with type 2 diabetes (T2D). Moreover, lncRNAs could be induced by iron overload. Therefore, we are going to explore the molecular mechanism of lncRNA XIST in iron overload-related T2D. Real-time quantitative PCR and Western blot were used to detect gene and protein levels, respectively. TUNEL and MTT assay were performed to examine cell survival. The glucose test strip, colorimetric analysis kit, ferritin ELISA kit, and insulin ELISA kit were performed to examine the levels of glycolic, iron, and total iron-binding capacity, ferritin, and insulin in serum. Fluorospectrophotometry assay was used to examine labile iron pool level. XIST was higher expressed in T2D and iron overload-related T2D rat tissues and cells, and iron overload-induced promoted XIST expression in T2D. Higher XIST expression was associated with iron overload in patients with T2D. Knockdown of XIST alleviated iron overload and iron overload-induced INS-1 cells injury. Further, we found that XIST can sponge miR-130a-3p to trigger receptor-like kinase 2 (ALK2) expression. Moreover, knockdown of ALK2 alleviated iron overload and iron overload-induced INS-1 cells injury by inhibiting bone morphogenetic protein 6 (BMP6)/ALK2/SMAD1/5/8 axis but reversed with XIST upregulation, which was terminally boosted by overexpression of miR-130a-3p. XIST has the capacity to promote iron overload and iron overload-related T2D initiation and development through inhibition of ALK2 expression by sponging miR-130a-3p, and that targeting this axis may be an effective strategy for treating patients with T2D.

9-LB: Increased Islet Expression of Somatostatin and Glucagon in Male Rats with Insulin-Dependent Type 2 Diabetes

Background: Pancreatic islet remodelling in type 1 diabetes increases somatostatin (SST) expression, which inhibits glucagon counterregulation to hypoglycemia. Here, we characterized islet morphology and hormone composition in a rodent model of insulin-deficient type 2 diabetes (T2D) . Methods: Hypoinsulinemic T2D was induced in 8-9-week-old, male, Sprague-Dawley rats (n=4) via 3 weeks of high-fat feeding and a low-dose injection of streptozotocin (STZ; 35 mg/kg) . After 2 weeks of basal insulin treatment, pancreas tissue was extracted from T2D and healthy control (n=5) rats for immunohistochemical staining of representative islets. Results: Fasted plasma C-peptide levels of hyperglycemic (24.8±3.3 mmol/l) T2D rats were reduced by ∼44% (624±64 vs. 1107±121 pmol/l; p&amp;lt;0.001) , while glucagon was unchanged (75±31 vs. 98±39 pg/ml) . Fractional islet area of glucagon and SST were elevated by 40% (21±15 vs. 15±10%; p&amp;lt;0.001) and 83% (11±8 vs. 6±5%; p&amp;lt;0.001) , respectively, as compared to control rats (Figure) , which was most pronounced in small and medium-sized islets. Conclusions: Fractional area expression of glucagon and SST increased per islet in insulin-treated rats with advanced T2D. These findings may help account for the increase in SST signaling that underscores defective glucagon counterregulation to hypoglycemia in insulin-deficient diabetic states. Disclosure E. G. Hoffman: None. S. C. Atherley: None. N. Akbarian: None. N. Dsouza: None. R. Liggins: Employee; Zucara Therapeutics, Stock/Shareholder; Zucara Therapeutics. M. Riddell: Advisory Panel; Zealand Pharma A/S, Zucara Therapeutics, Consultant; Eli Lilly and Company, Jaeb Center for Health Research, Speaker’s Bureau; Dexcom, Inc., Eli Lilly and Company, Novo Nordisk. Funding GlycoNet

823-P: The Long-Acting Dual Amylin and Calcitonin Receptor Agonist KBP Has Increased Efficacy on Weight Loss and Glucose Control Compared with Cagrilintide in Obese and Diabetic Rats

Long-acting dual amylin and calcitonin receptor agonists (DACRAs) are novel candidates for treatment of type 2 diabetes (T2D) and obesity due to their beneficial effects on both body weight, glucose control and insulin action. Cagrilintide, which is currently in clinical trials, has shown promising effects on weight loss. In this study we compared a new long-acting DACRA (KBP) to cagrilintide in pre-clinical models of obesity and T2D. In vitro potencies were assessed using receptor assays. In vivo efficacies were investigated head-to-head in high fat diet (HFD) fed obese and T2D (ZDF) rat models. In vitro data showed that both peptides active both the amylin and the calcitonin receptor, with KBP being more potent on both receptors. This was further confirmed in vivo by assessment of acute effects on food intake and CTX suppression. KBP (1.5, 4.5 and 13.5 nmol/kg) and cagrilintide (10, 30 and 100 nmol/kg) induced a potent and dose-dependent weight loss in HFD rats, with the highest dose of KBP being superior to cagrilintide. In diabetic ZDF rats, DACRA treatment improved glucose control and preserved plasma insulin compared to vehicle. Interestingly, despite similar levels of plasma insulin, KBP treatment was superior to cagrilintide in improving glucose control. This was further reflected in the HbA1c levels at study end, where KBP treatment resulted in significantly lower levels compared to cagrilintide. In summary, both DACRAs induced weight loss and improved glucose tolerance, insulin action as well as glucose control. However, KBP treatment results in superior efficacy on both weight loss and glucose control. These findings highlight KBP as a promising once-weekly agent for treatment of obesity and T2D. Disclosure A.T.Larsen: Employee; Nordic Bioscience. N.Sonne: None. K.Mohamed: None. E.Bredtoft: None. F.Andersen: None. M.A.Karsdal: Employee; Nordic Bioscience A/S, Nordic Bioscience A/S, Nordic Bioscience A/S. K.Henriksen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S.

Effects of continuous subcutaneous insulin infusion on the microstructures, mechanical properties and bone mineral compositions of lumbar spines in type 2 diabetic rats

BackgroundContinuous subcutaneous insulin infusion (CSII) for the treatment of type 2 diabetes (T2D) can improve the structure and strength of femur of rats, but the effect of CSII treatment on the lumbar spine of T2D rats is unknown. The purpose of this study is to investigate the effects of CSII on the microstructure, multi-scale mechanical properties and bone mineral composition of the lumbar spine in T2D rats.MethodsSeventy 6-week-old male Sprague–Dawley (SD) rats were divided into two batches, each including Control, T2D, CSII and Placebo groups, and the duration of insulin treatment was 4-week and 8-week, respectively. At the end of the experiment, the rats were sacrificed to take their lumbar spine. Microstructure, bone mineral composition and nanoscopic-mesoscopic-apparentand-macroscopic mechanical properties were evaluated through micro-computed tomography (micro-CT), Raman spectroscopy, nanoindentation test, nonlinear finite element analysis and compression test.ResultsIt was found that 4 weeks later, T2D significantly decreased trabecular thickness (Tb.Th), nanoscopic-apparent and partial mesoscopic mechanical parameters of lumbar spine (P < 0.05), and significantly increased bone mineral composition parameters of cortical bone (P < 0.05). It was shown that CSII significantly improved nanoscopic-apparent mechanical parameters (P < 0.05). In addition, 8 weeks later, T2D significantly decreased bone mineral density (BMD), bone volume fraction (BV/TV) and macroscopic mechanical parameters (P < 0.05), and significantly increased bone mineral composition parameters of cancellous bone (P < 0.05). CSII treatment significantly improved partial mesoscopic-macroscopic mechanical parameters and some cortical bone mineral composition parameters (P < 0.05).ConclusionsCSII treatment can significantly improve the nanoscopic-mesoscopic-apparent-macroscopic mechanical properties of the lumbar spine in T2D rats, as well as the bone structure and bone mineral composition of the lumbar vertebrae, but it will take longer treatment time to restore the normal level. In addition, T2D and CSII treatment affected bone mineral composition of cortical bone earlier than cancellous bone of lumbar spine in rat. Our study can provide evidence for clinical prevention and treatment of T2D-related bone diseases.