Protective effect of magnesium on renal function in STZ-induced diabetic rats

Impact of magnesium sulfate therapy in improvement of renal functions in high fat diet-induced diabetic rats and their offspring

The role of magnesium sulfate (MgSO₄) administration to prevent diabetic nephropathy (DN) by reducing insulin resistance (IR) and the relationship of this action with gender and the expression of NOX4 and ICAM1 genes in the parents and their offspring were studied. Males and females rat, and their pups were used. Type 2 diabetes induced by high-fat diet (HFD) administration and a low dose of streptozotocin. Animals were divided into the: non-treated diabetic (DC), the diabetic group received insulin (Ins), and the diabetic group received MgSO₄. Two groups of parents received just a normal diet (NDC). Following each set of parents for 16 weeks and their pups for 4 months, while eating normally. We assessed the amount of water consumed, urine volume, and blood glucose level. The levels of glucose, albumin, and creatinine in the urine were also measured, as well as the amounts of sodium, albumin, and creatinine in the serum. Calculations were made for glomerular filtration rate (GFR) and the excretion rates of Na and glucose fractions (FE Na and FE G, respectively). The hyperinsulinemic-euglycemic clamp was done. NOX4 and ICAM1 gene expressions in the kidney were also measured. MgSO₄ or insulin therapy decreased blood glucose, IR, and improved GFR, FE Na, and FE G in both parents and their offspring compared to D group. MgSO₄ improved NOX4 and ICAM1 gene expressions in the parents and their offspring compared to D group. Our results indicated that MgSO₄ could reduce blood glucose levels and insulin resistance, and it could improve kidney function.

The Effect of Intragastric Gavage of High Dose Green Tea Extract on Serum Status of Magnesium, Calcium, and Zinc

OBJECTIVE

Green tea (GT) contains polyphenolic flavonoids, different minerals like magnesium, calcium, and zinc, vitamins, amino acids, carbohydrates, proteins, and others. It has a different health benefit. The aim of the present study was to investigate the effect of intragastric gavage of a high dose GT extract on serum biochemical analysis of magnesium, calcium, and zincin juvenile Wistar albino rats.

METHODS

Twelve rats were used in the study and divided in to two equal groups. All the animals in the control group were intragastically gavaged by distilled water and continues for ten days, from day 24 to day 34 of age, while the animals in the study group were intragastically gavaged by GT extract (300mg/kg/day) which continues also for ten days from day 24 to day 34 of age. On day 34 of age, and two hours after the last dose, the rats were anaesthetized and blood collection by cardiac puncture was taken.

RESULTS

The results showed that the intragastric gavage of a high dose of GT extract caused a non-significant increase in serum magnesium, and calcium levels (p>0.05), but a significant increase in zinc serum level was seen(p< 0.05).

CONCLUSION

GT can cause a significant increase in zinc serum level, and this may explain the significant role of GT in the response to different oxidative stress. It is recommended to measure the Zn serum level in rats after a period longer than two hrs from the time of the last dose of intragastric gavage of GT extract.

Captopril and Spironolactone Can Attenuate Diabetic Nephropathy in Wistar Rats by Targeting ABCA1 and microRNA-33

Background:

Nephropathy diabetes is one of the important causes of death and a more prevalent cause of end-stage renal disease.

Objective:

The present study investigated the effect of applying spironolactone and captopril and their combination on some renal performance indices and cholesterol-efflux-related gene expression in nephropathy diabetic rats.

Methods:

Intraperitoneal injection of streptozotocin was used to induce diabetes in rats. FBS, creatinine, and BUN were assayed using the calorimetry technique; also, urine microalbumin was assayed by ELISA. Hepatic gene expressions of ABCA1, ABCG1, and miR-33 were evaluated by the real-time PCR method.

Results:

FBS levels in the captopril-treated group were significantly decreased compared with the untreated diabetic group. BUN levels of treated groups with captopril and a combination of captopril + spironolactone were significantly increased. GFR of both treated diabetic groups with captopril and spironolactone was significantly lower than an untreated diabetic group. ABCA1 gene expression in hepatic cells of the combination of spironolactone + captopril treated group was significantly increased compared to other treated and untreated diabetic groups. The hepatic expression of the ABCG1 gene in the treated and untreated diabetic groups was significantly lower than in the control group. Treatment of the diabetic group with only combination therapy decreased the hepatic gene expression of miR-33 significantly.

Conclusion:

Obtained results suggest that S+C combination therapy can improve nephropathy and diabetes disorders by targeting the ABCA1 and miR-33 gene expression. It is suggested miR-33 and ABCA1 genes evaluation could be a new therapeutic strategy for nephropathy diabetes remediation.

Intravenous Administration of Cisplatin with Magnesium Sulfate Supplement May Prevent Kidney Toxicity in Rats: The Role of Gender and Magnesium Sulfate Dose

Background. Cisplatin (CP) is widely used to treat various kinds of malignancies, but to avoid its side effects of nephrotoxicity and hypomagnesemia, magnesium supplementation is a subject of debate. The current study was designed to determine the protective role of intravenous magnesium sulfate (MgSO4) against intravenous administration of CP in male and female rats. Method. In this case-control experimental study, 80 Wistar male and female rats in 12 groups of experiments were subjected to receive intravenous administration of CP accompanied with intravenous infusion of different doses (1, 3, and 10 mg/ml solution) of MgSO4 and were compared with the control groups. Results. CP administration increased blood urea nitrogen (BUN), creatinine (Cr), kidney tissue damage score (KTDS), and kidney weight (KW), and they were attenuated by the mid-dose of MgSO4 supplementation in female rats. However, in male rats, the increase of Cr, BUN, KTDS, and KW induced by CP was ameliorated by low, mid-, and high doses of MgSO4 supplements. The levels of these markers were significantly different between male and female rats in the mid-dose of MgSO4-treated group (BUN: $P=0.002$ , Cr: $P=0.005$ , KTDS: $P=0.002$ , and KW: $P=0.031$ ). CP reduced clearance of Cr (ClCr) in both male and female rats significantly compared to the control group of saline alone (Pmale = 0.002 and Pfemale = 0.001), and the mid- and high doses of MgSO4 supplements improved ClCr in female rats. There were also sex differences in ClCr in mid- ( $P=0.05$ ) and high ( $P=0.032$ ) doses of MgSO4-treated groups. CP accompanied with the mid-dose of MgSO4 supplement reduced the KTDS (Pmale = 0.04 and Pfemale = 0.004) and KW (Pmale = 0.002 and Pfemale = 0.042) in both male and female rats significantly when compared with the CP-alone-treated group, while there were also significant differences between the sexes (KTDS: $P=0.002$ and KW: $P=0.031$ ). CP accompanied with three different doses of MgSO4 supplements did not improve the serum levels of lactate dehydrogenase, urine level of sodium, malondialdehyde, urine flow, and nitrite statistically when compared with the CP-alone-treated group. Conclusion. The renal protective effect of MgSO4 could be dose and gender related.

Investigation of the Effects of L-carnitine and magnesium on Oxidative Stress and Cytokines in the Tissue of Experimental diabetic rats

The aim of this study was to determine the effects of L-carnitine and magnesium on the levels of tissue malondialdehyde, 8-hydroxy-2’-deoxyguanosine, and cytokines (tumor necrosis factor alpha, interleukin-6) in streptozotocin-induced experimental diabetes in rats. Eighty male Wistar albino rats (200-250 g) were divided into 8 groups with 10 rats in each group. The groups received the following treatments: Control group; 2 ml distilled water (by gavage); Group 2: 50 mg/kg (b.w.) i.p. streptozotocin; Group 3: 125 mg/kg (b.w.) magnesium; Group 4: 300 mg/kg (b.w.) L-carnitine; Group 5: 125 mg/kg (b.w.) magnesium +300 mg/kg (b.w.) L-carnitine; Group 6: 50 mg/kg (b.w.) streptozotocin +125 mg/kg (b.w.) magnesium; Group 7: 50 mg/kg (b.w.) streptozotocin +300 mg/kg (b.w.) L-carnitine and Group 8: 50 mg/kg (b.w.) streptozotocin +125 mg/ kg (b.w.) magnesium+300 mg/kg (b.w.) L-carnitine administered for 4 weeks. Liver and kidney malondialdehyde, 8-hydroxy-2’-deoxyguanosine, tumor necrosis factor alpha and interleukin-6 levels did not change in the magnesium, L-carnitine, and magnesium + L-carnitine groups compared to the control. The highest levels of malondialdehyde, 8-hydroxy-2’-deoxyguanosine, tumor necrosis factor alpha and interleukin-6 were determined only in the group with diabetes (Group 2). Lipid peroxidation, DNA damage, and cytokine levels were significantly reduced in diabetic animals with the administration of magnesium and L-carnitine separately or in combination. Based on the obtained results it can be concluded that magnesium and L-carnitine may have antidiabetic effects, especially in combination.

Effect of magnesium sulfate in oxidized lipid bilayers properties by using molecular dynamics

Magnesium sulfate (MgSO₄) has been used as a protector agent for many diseases related to oxidative stress. The effect of MgSO₄ on the oxidized lipid bilayer has not yet been studied using molecular dynamics calculations. In this work, the effects of oxidation were evaluated by using a POPC membrane model at different concentrations of its aldehyde (-CHO) and hydroperoxide (-OOH) derivatives with and without MgSO₄. Several quantitative and qualitative properties were evaluated, such as membrane thickness, area per lipid, area compressibility modulus, snapshots after simulation finish, density distributions, time evolutions of oxidized group positions, and radial distributions of oxidized group concerning Mg. Results indicate that in the absence of MgSO₄ the mobility of oxidized groups, particularly –CHO, toward the surface interface is high. At a low oxidation level of the bilayer there is an increase in the compressibility modulus as compared to the unoxidized bilayer. MgSO₄, at a low oxidation level, tends to lessen the oxidation effects by lowering the dispersion in the distribution of oxidized species toward the membrane surface and the water region. However, MgSO₄ does not change the trends of decreasing membrane thickness and area compressibility modulus and increasing area per lipid upon oxidation. In this regard, MgSO₄ diminishes the electrostatic long-distance attractive interactions between the oxidized groups and the charged headgroups of the interface, owing to the Mg⁺² and SO₄^-2 screening effects and an electrostatic stabilization of the headgroups, preventing the pore formation, which is well-known to occur in oxidized membranes.

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MgSO₄ in vitro restores oxidized membranes but its molecular mechanism is unclear.

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MD simulations of oxidized lipid bilayers were performed with and without of MgSO₄.

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A restriction in the mobility of oxidized groups is produced by MgSO₄.

•

Mg⁺² and SO₄⁼ produce screening effects on the oxidized membranes.

•

MgSO₄ produce a diminution of electrostatic long-distance attractive interactions.

Synergistic effect of micronutrients and metformin in alleviating diabetic nephropathy and cardiovascular Dysfunctioning in diabetic rat

Purpose

Diabetic nephropathy (DN) and Cardiovascular Dysfunctioning (CVD) are interlinked with each other and one of the leading causes of irreversible renal damage and cardiovascular disease. Micronutrients play an effective role in type-2 diabetes (T2D) and its related complications. Our work aimed to elucidate the effect of micronutrients alone and in combination with standard anti-diabetic drug metformin on DN and CVD using streptozotocin induced diabetes in rats.

Methods

T2D was induced with a single intraperitoneal (i.p.) injection of freshly prepared streptozotocin (55 mg/kg), 15 min after intraperitoneal injection of nicotinamide (230 mg/kg). Commercially available kits were used to measure kidney parameters and cardiac marker level. Creatinine clearance was calculated by using formula and heart rate was recorded using powerlab software.

Results

Significant decrease in blood glucose levels were observed 14 days after initial administration in metformin treated, micronutrients treated and metformin with micronutrients treated groups compared with diabetic group. After 6 weeks of metformin and micronutrients treatment, serum creatinine, blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) levels were significantly decreased as compared to diabetic group. Moreover, urine creatinine level, creatinine clearance and heart rate (HR) was increased significantly in metformin and micronutrients treated group compared with a diabetic group. Micronutrients therapy also normalised the general symptoms of diabetes.

Conclusion

The results obtained from this study indicate the synergistic effect of metformin and micronutrients against diabetic heart and kidney. Therefore, micronutrients may be used as an effective add-on therapy for DN and CVD.

Bridelia ferruginea Benth leaves attenuates diabetes nephropathy in STZ-induced rats via targeting NGAL/KIM-1/cystatin c gene

Background

Renal failure is among the main complications of diabetes disorders and free radical from hyperglycemia is the major cause of this nephrotic complication. This study investigated the therapeutic effects of Bridelia ferruginea Benth on nephrotic damage in streptozotocin (STZ) induced diabetic rats. Diabetes mellitus was induced by injection of 50 mg/kg b. w. of STZ (intraperitoneal) in rats fasted overnight. Effect on nephropathy was assessed using biochemical, histological indices and gene expression of kidney tissue.

Results

The total flavonoids and phenolic content of petroleum ether fraction of B. ferruginea (PEFBF) was observed to be higher compared to diethyl ether fraction of B. ferruginea (DEFBF). The 1,1-diphenyl-2-picryl-hydrazyl scavenging activity of the fractions were significantly (P < 0.05) reduced across the concentrations compared to the standard (gallic acid). The STZ-induced diabetic animals treated with 100 and 200 mg/kg b.w. of PEFBF and DEFBF showed significant (P < 0.05) reduction in blood glucose level on days 7, 11 and 14 compared to untreated diabetic rats. STZ-induced diabetic rats significantly (P < 0.05) exhibited increase plasma urea, creatinine, protein and albumin level while treatment with both fractions of B. ferruginea reduced the level of these parameters in treated diabetic rats. B. ferruginea also caused down-regulation of neutrophil gelatinase-associated lipocalin, kidney injury molecule-1 and cystatin c genes.

Conclusion

These results revealed that, the plant has hypoglycemic activity therefore provides a pharmacological basis for its folkloric use in the management of hyperglycemia and its associated renal dysfunction.

Korean red ginseng attenuates hyperglycemia-induced renal inflammation and fibrosis via accelerated autophagy and protects against diabetic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C.A. Mey. (Korean ginseng) has been widely used in traditional medicine to treat diabetes mellitus for thousands of years. It also plays a key role in health maintenance owing to its anti-oxidant and anti-fatigue properties, and is quite popular as a dietary supplement.

AIM OF THE STUDY

This study was designed to offer a complementary and alternative medicine to manage the diabetic kidney disease (DKD), which causes long-term damage to the renal structure. We also investigated the regulation of the autophagy mechanism, which is the underlying the pathogenesis of DKD.

MATERIALS AND METHODS

The effect of Korean red ginseng (KRG) on DKD was evaluated using human kidney proximal tubular cells and streptozotocin (STZ)-treated Sprague-Dawley rat models. In vitro experiments were conducted to evaluate the proteins related to fibrosis and autophagy. This was followed by in vivo experiments involving rats treated with single intraperitoneal administration of STZ (60 mg/kg) and then with KRG solution orally for 4 weeks. Proteins related to renal injury, fibrosis, and autophagy were determined by immunoblotting. Hematoxylin and eosin (H&E), Periodic acid-Schiff (PAS), Sirius red, and immunostaining were processed for histological studies.

RESULTS

KRG diminished the levels of metabolic measurements and blood parameters. Western blotting showed a decreased expression of proteins, such as TGF-β1, KIM1, and AGE, which are responsible for renal inflammation, injury, and fibrosis. Histological studies also supported these results and revealed that the KRG-treated groups recovered from renal injury and fibrosis. Furthermore, the autophagy marker, LC3, was upregulated, whereas p62 was downregulated. The levels of proteins related to the autophagy mechanism, such as ATG7, increased, while mammalian target of rapamycin (mTOR) decreased with the KRG treatment and exhibited accelerated autophagy compared to the STZ alone group.

CONCLUSIONS

KRG can suppress renal inflammation, injury, and fibrosis by blocking TGF-β1 activation and can induce cellular autophagy. Therefore, this study strongly suggests that KRG exhibits a renoprotective effect against the STZ-induced DKD.

The Importance of Precision Medicine in Type 2 Diabetes Mellitus (T2DM): From Pharmacogenetic and Pharmacoepigenetic Aspects

BACKGROUND

Type 2 Diabetes Mellitus (T2DM) is a worldwide disorder as the most important challenges of health-care systems. Controlling the normal glycaemia greatly profit long-term prognosis and gives explanation for early, effective, constant, and safe intervention.

MATERIAL AND METHODS

Finding the main genetic and epigenetic profile of T2DM and the exact molecular targets of T2DM medications can shed light on its personalized management. The comprehensive information of T2DM was earned through the genome-wide association study (GWAS) studies. In the current review, we represent the most important candidate genes of T2DM like CAPN10, TCF7L2, PPAR-γ, IRSs, KCNJ11, WFS1, and HNF homeoboxes. Different genetic variations of a candidate gene can predict the efficacy of T2DM personalized strategy medication.

RESULTS

SLCs and AMPK variations are considered for metformin, CYP2C9, KATP channel, CDKAL1, CDKN2A/2B and KCNQ1 for sulphonylureas, OATP1B, and KCNQ1 for repaglinide and the last but not the least ADIPOQ, PPAR-γ, SLC, CYP2C8, and SLCO1B1 for thiazolidinediones response prediction.

CONCLUSION

Taken everything into consideration, there is an extreme need to determine the genetic status of T2DM patients in some known genetic region before planning the medication strategies.

The Impact Of Succinate Dehydrogenase Gene (SDH) Mutations In Renal Cell Carcinoma (RCC): A Systematic Review

INTRODUCTION

Renal cell cancer (RCC) syndrome is linked to Krebs cycle compartments and their coding genes' alterations like succinate dehydrogenase genes (SDHx). Here we present a systematic review of the SDH genes' mutations and their impact on both RCC diagnosis and prognosis.

METHODS

This systematic review includes any study in which tissue samples of RCC are considered in correlation with the SDHx mutations, microsatellite instability (MSI), and protein expression. For this purpose, a systematic search of MEDLINE (PubMed), Scopus, Embase, and Web of Science databases was conducted and finally 5384 articles were recruited. All studies' content was checked to find the related ones which were 145 articles, which with data extraction were limited to nineteen.

RESULTS

The final selected nineteen studies investigating the SDHx role in RCC tumor genesis were included, among which fifteen were mutation analysis, three were just SDHx protein expression, and two were MSI and mutation analysis studies. A total of 432 RCC patients were reported by SDH mutations, and 64 patients with MSI and SDH expression change were reported in 514 surgically resected renal epithelial tumors. The most common mutation was the single nucleotide variant rs772551056 (c.137G>A) of SDHB. For SDHC, c.380A>G presented in 48 RCC patients, and for SDHA a novel germline mutation c.2T>C: p.M1T in an occasional case of gastrointestinal stromal tumor intricate with RCC.

CONCLUSION

RCC as an aggressive type of kidney cancer needs some biomarkers to be diagnosed exactly. It was shown recently that the succinate dehydrogenase gene variations can provide this diagnostic and prognostic biomarker. For this purpose, SDHB rs772551056 associated with its protein expression alterations can be taken into account. It is possible that a novel mutation of SDHA (c.2T>C: p.M1T) can provide evidence of GIST associated with RCC as well.

Personalized treatment options for thyroid cancer: current perspectives

Thyroid cancer is one of the most common endocrine malignancies, with increasing incidence all over the world. In spite of good prognosis for differentiated thyroid carcinoma, for an unknown reason, about 5–10% of the patients, the cancer will show aggressive behavior, develop metastasis, and be refractory to treatment strategies like radioactive iodine. Regarding the genetic information, each thyroid cancer patient can be considered as an individual unique one, with unique genetic information. Contrary to standard chemotherapy drugs, target therapy components aim at one or more definite molecular pathway on cancer cells, so their selection is underlying patient’s genetic information. Nowadays, several mutations and rearrangements including BRAF, VEGF receptors, RET, and RET/PTC, KDR, KIT, PDGFRA, CD274, and JAK2 are taken into account for the therapeutic components like larotrectinib (TRK inhibitor), vemurafenib, sunitinib, sorafenib, selumetinib, and axitinib. With the new concept of personalized treatment of thyroid cancer diagnoses, planning treatment, finding out how well treatment will work, and estimating a prognosis has changed for the better over the last decade.

The dipeptidyl peptidase 4 inhibitor sitagliptin improves oxidative stress and ameliorates glomerular lesions in a rat model of type 1 diabetes

AIMS

Oxidative stress has been linked to the development and progression of diabetic nephropathy (DN). The present study evaluated whether the dipeptidyl peptidase-4 inhibitor sitagliptin attenuates glomerular lesions and oxidative stress evoked by chronic hyperglycemia, by a mechanism independent of insulin secretion and glycemia normalization.

MAIN METHODS

A rat model of DN caused by streptozotocin injection was established and the effects of sitagliptin (5 mg/kg/day) were evaluated after two weeks of treatment.

KEY FINDINGS

Sitagliptin treatment did not change body weight, glycemic and lipid profiles. However, histopathological observation revealed that sitagliptin attenuates diabetes-induced glomerular lesions on diabetic rats. Sitagliptin also ameliorated the increase in DPP-4 content and promoted the stabilization of GLP-1 in the diabetic kidney. Furthermore, sitagliptin treatment significantly attenuated the increase of free-radical formation and the decrease of antioxidant defenses, attenuating therefore the oxidative stress in the kidneys of diabetic animals.

SIGNIFICANCE

The results suggest that sitagliptin treatment alleviates kidney oxidative stress in type 1 diabetic rats, which could play a key role in reducing the progression of DN.

Retrospective analysis of the association between intraoperative magnesium sulfate infusion and postoperative acute kidney injury after major laparoscopic abdominal surgery

Magnesium sulfate can be used as a co-adjuvant drug during the perioperative period and has multiple benefits. Recent evidence suggested that perioperative magnesium sulfate infusion may lower the risk of postoperative acute kidney injury (AKI). We investigated the association between intraoperative magnesium sulfate infusion and incidence of AKI after major laparoscopic abdominal surgery. We retrospectively analyzed the medical records of adult patients 20 years or older who underwent elective major laparoscopic abdominal surgery (>2 hours) between 2010 and 2016. We investigated the association between intraoperative magnesium sulfate infusion and the incidence of postoperative AKI until postoperative day (POD) 3 using a multivariable logistic regression analysis. We included 3,828 patients in this analysis; 357 patients (9.3%) received an intraoperative magnesium sulfate infusion and 186 patients (4.9%) developed postoperative AKI by POD 3. A multivariable logistic regression analysis showed that magnesium infusion was associated with a significant decrease (63%) in postoperative AKI (odds ratio, 0.37; 95% confidence interval, 0.14–0.94; P = 0.037). Our study suggested that intraoperative magnesium sulfate infusion is associated with a reduced risk of postoperative AKI until POD 3 for patients who underwent laparoscopic major abdominal surgery. Well-designed, prospective studies should be conducted to further substantiate these findings.

Protective role of nano-selenium-enriched Bifidobacterium longum in delaying the onset of streptozotocin-induced diabetes

Bifidobacterium longum (B. longum) could accumulate Selenium (Se) and nano-Se in the form of Se-B. longum and Nano-Se-B. longum, respectively. In this study, the effect of Nano-Se-B. longum in diabetic mice was evaluated. Physiological and metabolic parameters such as blood glucose, body weight, serum insulin level, intraperitoneal glucose tolerance test (IPGTT), food intake, water consumption and urine output were evaluated. The expression of insulin signalling pathway-related proteins was evaluated by western blotting. Haematoxylin and eosin (H&E) was used for histological examination of the liver, pancreas and kidney sections. Creatinine levels in serum (SCr) and blood urea nitrogen (BUN) were measured. Nano-Se-B. longum was the best in terms of delaying the onset of diabetes. Nano-Se-B. longum decreased blood glucose and body weight compared with those noted for the model group. IPGTT, food intake, water consumption and urine output significantly increased and serum insulin levels significantly decreased in the model group compared with those in all the Nano-Se-B. longum-treated mice. Histological results showed that the Nano-Se-B. longum-treated mice were better than the model group mice in terms of pathological changes. The expression of insulin signalling pathway-related proteins was upregulated in the Nano-Se-B. longum-treated groups. A significant increase in SCr and BUN levels was noted in the model group. This study for the first time reported the dose-dependent preventive effect of Nano-Se-B. longum on the onset of diabetes and renal damage. The mechanism may be related to changes in insulin signalling.

Effect of magnesium sulfate administration to improve insulin resistance in type 2 diabetes animal model: using the hyperinsulinemic-euglycemic clamp technique

This study attempted to elucidate the possible mechanism of magnesium sulfate (MgSO₄ ) administration on reducing insulin resistance in type 2 diabetic rats. Fifty Wistar rats were divided into five groups: NDC was fed the normal diet, CD received high-fat diet with 35 mg/kg of streptozotocin, CD-Mg animals received MgSO₄ via drinking water, CD-Ins1, and CD-Ins2 animals treated with low or high dose of insulin. Body weight and blood glucose levels were measured weekly. Intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test, and metabolic cage assessment were performed monthly. After 12 weeks, the hyperinsulinemic-euglycemic clamp was performed for all animals and blood sample was taken to measure glycated hemoglobin (HbA1c), plasma insulin, glucagon, calcium, and magnesium levels. Liver and gastrocnemius muscle were isolated to measure glucagon receptor (GR), Glucose 6 phosphatase (G6Pase), Phosphoenolpyruvate carboxykinase (Pepck) and Glucose transporter 4 (Glut4) genes expression and GLUT4 protein translocation into the cell membrane. Consuming of high-fat diet generated insulin-resistant rats. Magnesium or insulin therapy altered insulin resistance, blood glucose, IPGTT, gluconeogenesis pathway, GR, body weight, the percentage of body fat, and HbA1C in diabetic rats. Administrations of MgSO₄ or insulin in Type 2 diabetes mellitus animals increase GLUT4 gene and protein expression. Mg could improve glucose tolerance via stimulation of Glut4 gene expression and translocation and also suppression of the gluconeogenesis pathway and GR gene expression. Mg also increased glucose infusion rate and displayed beneficial effects in the treatment of glucose metabolism and improved insulin resistance.

Magnesium Replacement to Protect Cardiovascular and Kidney Damage? Lack of Prospective Clinical Trials

Patients with advanced chronic kidney disease exhibit an increase in cardiovascular mortality. Recent works have shown that low levels of magnesium are associated with increased cardiovascular and all-cause mortality in hemodialysis patients. Epidemiological studies suggest an influence of low levels of magnesium on the occurrence of cardiovascular disease, which is also observed in the normal population. Magnesium is involved in critical cellular events such as apoptosis and oxidative stress. It also participates in a number of enzymatic reactions. In animal models of uremia, dietary supplementation of magnesium reduces vascular calcifications and mortality; in vitro, an increase of magnesium concentration decreases osteogenic transdifferentiation of vascular smooth muscle cells. Therefore, it may be appropriate to evaluate whether magnesium replacement should be administered in an attempt to reduce vascular damage and mortality in the uremic population In the present manuscript, we will review the magnesium homeostasis, the involvement of magnesium in enzymatic reactions, apoptosis and oxidative stress and the clinical association between magnesium and cardiovascular disease in the general population and in the context of chronic kidney disease. We will also analyze the role of magnesium on kidney function. Finally, the experimental evidence of the beneficial effects of magnesium replacement in chronic kidney disease will be thoroughly described.

Effect of the Administration of Solanum nigrum Fruit on Prevention of Diabetic Nephropathy in Streptozotocin-induced Diabetic Rats

Background

Our previous study showed antidiabetic effect of aqueous extract of Solanum nigrum Linn fruit (SNE).

Objective

This study was designed to explore the antidiabetic and nephroprotective effects of SNE in diabetic rats.

Materials and Methods

Animals were divided into nine groups to undergo two experiment protocols: Two groups served as nondiabetic controls (NDCs), while the other groups had diabetes induced with a single injection of streptozotocin. SNE-treated diabetic (D-SNE) and SNE-treated controls (NDC-SNE) received 1 g/L of SNE added to the drinking water and insulin-treated diabetic (D-I) for 8 weeks. Furthermore, there were four groups (D-SNE, NDC-SNE, D-I, D) in the second protocol to examine diabetic nephropathy (DN) for 16 weeks. Blood urea nitrogen (BUN), creatinine (Cr) magnesium, nitric oxide (NO), and malondialdehyde (MDA) levels were measured. Both kidneys were isolated to measure MDA, NO levels, and renal damage.

Results

SNE could decrease blood glucose level in diabetic rats. In addition, SNE was more effective than insulin in controlling blood glucose. SNE could decrease BUN, Cr levels, and kidney weight and damage after 8 and 16 weeks of administration. Plasma and kidney levels of NO and MDA also decreased.

Conclusion

Our results support the hypothesis that SNE could play a role in the management of diabetes and the prevention of DN.

SUMMARY

The aqueous extract of Solanum nigrum Linn fruit (SNE) (1 g/L via drinking water) was studied on streptozotocin-induced diabetic rats to prevent diabetic nephropathy (DN). The results suggest that SNE in addition to the management of diabetes could have a beneficial effect on the prevention of DN. Abbreviations Used: SNE: Extract of Solanum nigrum Linn fruit, NDCs: Nondiabetic controls, STZ: Streptozotocin, D-SNE: SNE-treated diabetic, NDC-SNE: SNE-treated controls, D-I: Insulin-treated diabetic, BUN: Blood urea nitrogen, Cr: Creatinine, Mg: Magnesium, NO: Nitric oxide, MDA: Malondialdehyde, DN: Diabetic nephropathy, BW: Body weight, FBG: Fed blood glucose, KW: Kidney weight, TBA: Thiobarbituric acid, IPGTT: Intraperitoneal glucose tolerance test, AUC: Aria under the curve, GFR: Glomerular filtration rate.

The Role of Mitochondrial DNA (mtDNA) in the Development of Diabetic Retinopathy (DR): A Systematic Review

Diabetic Retinopathy (DR) is the most prevalent health problem, which is influenced by environmental and genetic factors with an increasing prevalence. The current systematic review is focused on mtDNA modification, including polymorphism and mutation/deletion, with a direct effect on DR.This systematic search was initially done through PubMed, Cochrane, EMBASE, SCOPUS, and Web of Science without a restriction on the years of publication. The terms searched included ''mtDNA'', ''mitochondrial DNA'', ''diabetes'', ''diabetic'', ''retina'', and ''diabetic retinopathy''. Animal, cohort, cross-sectional, and in vitro studies, as well as case series, case reports, review articles, and Letters to Editor were excluded from this research.From 1528 resulting searched articles, only 12papers were finally chosen as the case-control studies considering mtDNA gene and DR. Actually, of these 12 articles, 8 studies were concerned with mtDNA polymorphisms (UCP1, UCP2, ROMO-1, and Mn-SOD) and 4 articles were related to mtDNA mutation (A3243G mutation in tRNA^Leu(UUR) gene and mtDNA deletion (ΔmtDNA 4977)).Some conflicting results were found between the selected genetic modifications of mtDNA, such as Mn-SOD, UCP1, ΔmtDNA 4977, tRNALeu (UUR), and ROMO-1.Finally, A3243G mutation in the tRNA^{Leu (UUR)} gene and rs660339 and V16A polymorphisms of UCP2 and Mn-SOD genes were respectively considered as the most important factors in the pathogenesis of DR.

Dietary zinc modifies diabetic-induced renal pathology in rats

This study was conducted to investigate how far dietary zinc (Zn) modifies the histomorphological alterations induced by diabetes in rat kidneys. The animals were divided into negative control group (10 rats). Diabetes was induced in thirty animals by streptozotocin. After confirming diabetes, the animals were divided into three groups (n = 10). Group II served as the positive control group (fed on standard diet), group III was fed on Zn deficient diet, and group IV was fed on Zn supplemented diet. Caspase-3 immune staining was used to estimate the caspase activity. Stereological procedures were used to measure the quantity of the immune stain and the surface area of the Bowman’s space. The renal cortices of group II rats revealed apparent widening of Bowman’s spaces with few apoptotic figures. The filtration barrier showed thickening of the basement membrane. The proximal convoluted tubules showed patchy loss of the apical microvilli with swollen mitochondria. The distal convoluted tubules revealed area of irregular basal enfolding. The picture was aggravated by Zn deficiency in group III besides areas of cortical interstitial fibrosis. The histopathological alterations were minimal in the cortices of group IV. A significant increase of the Bowman’s space surface area in group II and IV while decrease in group III compared with group I. The expression of Caspase-3 density was significantly increased in group II and III compared with group I while in group IV was non significant. In conclusion, dietary Zn modulated renal cortical changes caused by diabetes in rats.

Antidiabetic and hypolipidemic activities of hydroethanolic root extract of Uvaria chamae in streptozotocin induced diabetic albino rats

Background

Diabetes mellitus is a metabolic disorder of multiple aetiology characterised by hyperglycemia resulting from defects in insulin secretion, insulin action or both. It is a global epidemic ravaging both developed and developing countries. The situation will worsen if nothing is done urgently. In fact, the need to identify natural products with antidiabetic potentials is of great importance as supported by several research efforts all over the world, in search of antidiabetic plant based products that are safe and efficacious. Available literatures show that several phytochemicals with antidiabetic properties have been identified in certain plants amongst which include Uvaria chamae. The potentials of Uvaria chamae as an antidiabetic and hypolipidemic drug-candidate are thus tested.

Methods

Diabetes mellitus was experimentally induced after the rats were fasted overnight by administering intraperitoneally, 60 mg/kg streptozotocin. After 72 h, the rats with plasma glucose levels >200 mg/dl were classified as diabetic. A total of six groups containing five rats per group were used. One group of diabetic rats was untreated. Three diabetic groups, each were treated orally with 100, 250 and 400 mg/kg body weight of the extract. Another diabetic group was treated with insulin (0.5 IU/kg) subcutaneously. The control received 0.5 ml (2% solution) of acacia orally. The treatment was for 8 days. The effects of the extract on weight, plasma glucose and other biochemical parameters were evaluated using standard procedures.

Results

The diabetic rats treated with the extract showed significant reductions (p < 0.05) in weight, plasma glucose levels, low density lipoprotein and cholesterol compared with the control. The 100, 250 and 400 mg/kg body weight of the extract showed maximum glucose reduction of 85.16, 81.50 and 86.02% respectively. Histologically the pancreas of the diabetic rats treated with the extract, showed clusters of variably sized regenerated islet of Langerhans within sheets of normal exocrine pancreas, while the pancreas of diabetic rats treated with insulin showed no islet of Langerhans.

Conclusion

The study showed that Uvaria chamae caused weight loss and has good hypoglycemic and hypolipidemic activities that may reduce the risk of developing cardiovascular diseases.

Low serum magnesium levels are associated with impaired peripheral nerve function in type 2 diabetic patients

The aim of this study was to explore the relationship between serum magnesium and peripheral nerve function in patients with type 2 diabetes (T2DM). A total of 978 T2DM patients were included in the study. Patients were divided into tertiles according to serum magnesium concentration (low tertile: ≤0.85 mmol/L; medium tertile: 0.85 to 0.92 mmol/L; and high tertile: >0.92 mmol/L). All participants underwent nerve conduction (NC) studies. Composite z scores of conduction velocity, latency, and amplitude were constructed, respectively. The serum magnesium levels were significantly lower in patients with abnormal NC than in those with normal NC (0.87 [0.82, 0.92] vs. 0.88 [0.83, 0.93] mmol/L, P = 0.048). The composite z score of amplitude significantly increased with increasing tertiles of magnesium (−0.60 ± 0.02 vs. −0.57 ± 0.02 vs. −0.48 ± 0.03, P for trend = 0.001). After adjusting for all potential confounders, lower serum magnesium levels were still associated with lower composite z score of amplitude (β = 0.095, P = 0.014). In patients with T2DM, lower serum magnesium levels were significantly associated with lower composite z score of amplitude, indicating magnesium might affect peripheral nerve function through axonal degeneration.

Apocynin influence on oxidative stress and cardiac remodeling of spontaneously hypertensive rats with diabetes mellitus

PURPOSE

Although increased oxidative stress is a major component of diabetic hypertensive cardiomyopathy, research into the effects of antioxidants on cardiac remodeling remains scarce. The actions of antioxidant apocynin include inhibiting reactive oxygen species (ROS) generation by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and ROS scavenging. We evaluated the effects of apocynin on cardiac remodeling in spontaneously hypertensive rats (SHR) with diabetes mellitus (DM).

METHODS

Male SHR were divided into four groups: control (SHR, n = 16); SHR treated with apocynin (SHR-APO; 16 mg/kg/day, added to drinking water; n = 16); diabetic SHR (SHR-DM, n = 13); and SHR-DM treated with apocynin (SHR-DM-APO, n = 14), for eight weeks. DM was induced by streptozotocin (40 mg/kg, single dose). Statistical analyzes: ANOVA and Tukey or Mann-Whitney.

RESULTS

Echocardiogram in diabetic groups showed higher left ventricular and left atrium diameters indexed for body weight, and higher isovolumetric relaxation time than normoglycemic rats; systolic function did not differ between groups. Isolated papillary muscle showed impaired contractile and relaxation function in diabetic groups. Developed tension was lower in SHR-APO than SHR. Myocardial hydroxyproline concentration was higher in SHR-DM than SHR, interstitial collagen fraction was higher in SHR-DM-APO than SHR-APO, and type III collagen protein expression was lower in SHR-DM and SHR-DM-APO than their controls. Type I collagen and lysyl oxidase expression did not differ between groups. Apocynin did not change collagen tissue. Myocardial lipid hydroperoxide concentration was higher in SHR-DM than SHR and SHR-DM-APO. Glutathione peroxidase activity was lower and catalase higher in SHR-DM than SHR. Apocynin attenuated antioxidant enzyme activity changes in SHR-DM-APO. Advanced glycation end-products and NADPH oxidase activity did not differ between groups.

CONCLUSION

Apocynin reduces oxidative stress independently of NADPH oxidase activity and does not change ventricular or myocardial function in spontaneously hypertensive rats with diabetes mellitus. The apocynin-induced myocardial functional impairment in SHR shows that apocynin actions need to be clarified during sustained chronic pressure overload.

Effect of magnesium sulfate and thyroxine on inflammatory markers in a rat model of hypothyroidism

Inflammation is a major risk factor for cardiovascular complications. Magnesium sulfate (MgSO4) has anti-inflammatory actions. Therefore we investigated the effects of levothyroxine and MgSO4 on inflammatory markers as C-reactive protein (CRP), interleukin-6, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in hypothyroid rats. Sixty male rats were divided into 6 groups; normal, normal + MgSO4, hypothyroidism, hypothyroidism + levothyroxine, hypothyroidism + MgSO4, and hypothyroidism + levothyroxine + MgSO4. Thyroxine, triiodothyronine, and thyroid-stimulating hormone (TSH), CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 were measured in all rats. Hypothyroidism significantly increased TSH, CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 and decreased triiodothronine and thyroxine. Treatment of hypothyroid rats with levothyroxine or MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1. Combined therapy of hypothyroid rats with levothyroxine and MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 compared with hypothyroid rats either untreated or treated with levothyroxine or MgSO4. This study demonstrates that hypothyroid rats have chronic low grade inflammation, which may account for increased risk of cardiovascular diseases. Combined levothyroxine and MgSO4 is better than levothyroxine or MgSO4 alone in alleviating the chronic low grade inflammatory status and therefore reducing the risk of cardiovascular diseases in hypothyroid animals.

Icariside II ameliorates diabetic nephropathy in streptozotocin-induced diabetic rats

Purpose

To investigate the therapeutic effects and potential mechanisms of icariside II (ICA II) on reversing diabetic nephropathy in streptozotocin (STZ)-induced type I diabetic rats.

Methods

Newborn male Sprague Dawley rats were labeled with thymidine analog 5-ethynyl-2-deoxyuridine (EdU) for tracking endogenous label retaining progenitor cells (LRCs). At age of 8 weeks, 48 rats were randomly divided into three groups: normal control group (n=16), diabetes mellitus group (DM; n=16), and diabetes mellitus plus ICA II therapy group (DM+ICA II, n=16). Eight weeks induced for diabetes with STZ, rats in DM group and DM+ICA II group were treated with vehicle or ICA II (5 mg/kg/day) for another 8 weeks, respectively. Then, blood creatinine, 24-hour urine protein, blood urea nitrogen, and glycosylated hemoglobin were measured, as well as the expression of von Willebrand factor, malondialdehyde, transforming growth factor-β/drosophila mothers against decapentaplegic protein/connective tissue growth factor (TGF-β/Smad/CTGF) signaling, marker of proliferation Ki-67, and EdU+ LRCs in renal tissues.

Results

Increased levels of creatinine, 24-hour urine protein, and blood urea nitrogen and remarkably decreased proportion of normal glomeruli and increased proportions of I, IIa, IIb, and III glomeruli were observed in diabetic rats, while ICA II could reverse these changes. Interestingly, ICA II could significantly downregulate the levels of malondialdehyde and TGF-β/Smad/CTGF signaling and increase the expression of von Willebrand factor, Ki-67, and EdU+ LRCs in the kidney.

Conclusion

ICA II treatment could ameliorate diabetic nephropathy in STZ-induced diabetic rats by increasing endothelial cell contents, downregulating TGF-β/Smad/CTGF signaling pathway and oxidative stress level, and promoting cell proliferation both in kidney cortex and medulla. These beneficial effects appear to be mediated by its antioxidant capacity and recruitment of endogenous EdU+ progenitor cells into the kidney tissue.

Effects of curcumin and captopril on the functions of kidney and nerve in streptozotocin-induced diabetic rats: role of angiotensin converting enzyme 1

Oxidative stress and inflammation are involved in the development and progression of diabetes and its complications. The renin-angiotensin system also plays an important role in the pathogenesis of diabetes and its complications. We hypothesized that curcumin and captopril would restore the kidney and nerve functions of diabetic rats through their angiotensin converting enzyme 1 (ACE1) inhibiting activity as well as their antioxidant and anti-inflammatory effects. Diabetes was induced by a single intraperitoneal injection of streptozotocin (100 mg·kg(-1) body weight). One week after induction of diabetes, rats were treated with 100 mg·kg(-1)·day(-1) curcumin or 50 mg·kg(-1)·day(-1) captopril orally for 6 weeks. Compared with diabetic control rats, curcumin- or captopril-treated diabetic rats had significantly improved blood glucose, lipid profile, kidney/body weight ratio, serum creatinine, blood urea nitrogen (BUN), and pain thresholds assessed by Von Frey filaments, hot plate test, and tail-flick test. Diabetic control rats showed increased levels of total peroxide, renal and neural tumor necrosis factor-α and interleukin-10, and renal ACE1 compared with nondiabetic rats. Although treatment with either curcumin or captopril restored the altered variables, captopril was more effective in reducing these variables. ACE1 was positively correlated with BUN and creatinine and negatively correlated with paw withdrawal threshold, hot plate reaction time, and tail-flick latency, suggesting a possible causal relationship. We conclude that curcumin and captopril protect against diabetic nephropathy and neuropathy by inhibiting ACE1 as well as oxidation and inflammation. These findings suggest that curcumin and captopril may have a role in the treatment of diabetic nephropathy and neuropathy.