Folic acid and melatonin mitigate diabetic nephropathy in rats via inhibition of oxidative stress

The potential protective effect of propolis on diabetic nephropathy induced by streptozotocin in adult albino rats

Diabetes mellitus is a common metabolic disorder. It is associated with serious life-threatening complications if not properly managed. The current study aimed at investigating the possible protective role of propolis on streptozotocin-induced diabetic nephropathy. A diabetic rat model was induced by a single intraperitoneal injection of 55 mg/kg streptozotocin. After 4 days, the diabetic rats received oral propolis (300 mg/kg/day) via gastric gavage for 28 days. Biochemical, histopathological and ultrastructural evaluations were performed. The results showed that: streptozotocin-induced diabetes was associated with a marked decrease in the serum high-density lipoproteins and antioxidant enzymes. However, a significant elevation in the levels of serum creatinine, blood urea nitrogen, uric acid, cholesterol, triglycerides and low-density lipoproteins was detected. Furthermore, streptozotocin treatment induced histopathological alterations of the renal cortex; in the form of distorted glomerular capillaries, widened Bowman's space and signs of epithelial tubular degeneration. Ultra-structurally, thickening and irregularity of the glomerular basement membrane and podocytes foot processes effacement were observed. The tubular epithelial cells showed swollen vacuolated mitochondria, scarce basal infoldings and loss of microvilli. Conversely, propolis partially restored the normal lipid profile, antioxidant biomarkers and renal cortical morphology. Propolis exhibited a sort of renoprotection through hypoglycemic, anti-hyperlipidemic and antioxidant effects.

Effect of melatonin supplementation on cardiometabolic risk factors, oxidative stress and hormonal profile in PCOS patients: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

To investigate whether melatonin supplementation can enhance cardiometabolic risk factors, reduce oxidative stress, and improve hormonal and pregnancy-related factors in patients with PCOS.

METHODS

We conducted a systematic search of PubMed/Medline, Scopus, and the Cochrane Library for articles published in English from inception to March 2023. We included randomized controlled trials (RCTs) on the use of melatonin for patients with polycystic ovary syndrome (PCOS). We performed a meta-analysis using a random-effects model and calculated the standardized mean differences (SMDs) and 95% confidence intervals (CIs).

RESULTS

Six studies met the inclusion criteria. The result of meta-analysis indicated that melatonin intake significantly increase TAC levels (SMD: 0.87, 95% CI: 0.46, 1.28, I2 = 00.00%) and has no effect on FBS, insulin, HOMA-IR, TC, TG, HDL, LDL, MDA, hs-CRP, mFG, SHBG, total testosterone, and pregnancy rate in patients with PCOS compare to controls. The included trials did not report any adverse events.

CONCLUSION

Melatonin is a potential antioxidant that may prevent damage from oxidative stress in patients with PCOS. However, the clear effect of melatonin supplementation on cardiometabolic risk factors, hormonal outcomes, and pregnancy-related outcomes needs to be evaluated further in large populations and long-term RCTs.

Potential therapeutic value of melatonin in diabetic nephropathy: improvement beyond anti-oxidative stress

Diabetic nephropathy (DN) is a common complication of diabetes, and it is also the main cause of chronic renal failure. Physiological/pathological changes mediated by high glucose are the main factors causing injury of DN, including the enhancement of polyol pathway, the accumulation of advanced glycation products (AGEs), and the activation of protein kinase C (PKC) and transforming growth factor-β (TGF-β) signals. In addition, the abnormal activation of renin-angiotensin system (RAS) and oxidative stress are also involved. Melatonin is a physiological hormone mainly secreted by the pineal gland which has been proved to be related to diabetes. Studies have shown that exogenous melatonin intervention can reduce blood glucose and alleviate high glucose mediated pathological damage. At the same time, melatonin also has a strong antioxidant effect, and can inhibit the activation of RAS. Therefore, it is of great significance to explore the therapeutic effect and value of melatonin on DN.

Melatonin attenuates cellular senescence and apoptosis in diabetic nephropathy by regulating STAT3 phosphorylation

AIMS

Melatonin is an endogenous hormone related to the regulation of biorhythm. Previous researchers have found that melatonin can ameliorate diabetic nephropathy (DN), but the mechanism remains to be elucidated. To discover the possible mechanism by which melatonin prevents DN, we investigated the potential effects of melatonin on signal transducer and activator of transcription 3 (STAT3) on the progression of cellular senescence and apoptosis.

MAIN METHODS

Cellular senescence, apoptosis and the underlying mechanism of melatonin were investigated both in vivo and in vitro. C57BL/6 mice were intraperitoneally injected with streptozotocin (STZ) to establish DN. For an in vitro model of DN, human renal cortex proximal epithelial tubule (HK-2) cells were exposed to high glucose conditions.

KEY FINDINGS

Melatonin inhibited the phosphorylation of STAT3, decreased the expression of senescence proteins p53, p21 and p16INK4A. Melatonin also downregulated the expression of apoptotic proteins, including cleaved PARP1, cleaved caspase-9 and -3. Melatonin treatment decreased the positive area of senescence-associated galactosidase (SA-β-gal) staining and the number of TUNEL-positive cells in kidneys of DN mice. In vitro, melatonin inhibited STAT3 phosphorylation and lowered cellular senescence and apoptosis markers, in a manner similar to the STAT3 inhibitor S3I-201. In addition, the inhibition effect of melatonin on cellular senescence and apoptosis in HK-2 cells was reversed by the usage of recombinant IL-6 (rIL-6), which can induce STAT3 phosphorylation.

SIGNIFICANCE

We, for the first time, demonstrate that melatonin inhibits STAT3 phosphorylation, which is involved in alleviating the cellular senescence and apoptosis in DN.

Silver Nanoparticles Decorated with Curcumin Enhance the Efficacy of Metformin in Diabetic Rats via Suppression of Hepatotoxicity

Hepatotoxicity is one of the significant side effects of chronic diabetes mellitus (DM) besides nephrotoxicity and pancreatitis. The management of this disease is much dependent on the restoration of the liver to its maximum functionality, as it is the central metabolic organ that gets severely affected during chronic diabetes. The present study investigates if the silver nanoparticles decorated with curcumin (AgNP-Cur) can enhance the efficacy of metformin (a conventional antidiabetic drug) by countering the drug-induced hepatoxicity. Swiss albino rats were categorized into six treatment groups (n = 6): control (group I without any treatment), the remaining five groups (group II, IV, V, VI) were DM-induced by streptozocin. Group II was untreated diabetic positive control, whereas groups III was administered with AgNP-cur (5 mg/kg). Diabetic group IV treated with metformin while V and VI were treated with metformin in a combination of the two doses of NPs (5 and 10 mg/kg) according to the treatment schedule. Biochemical and histological analysis of blood and liver samples were conducted after the treatment. The groups V and VI treated with the combination exhibited remarkable improvement in fasting glucose, lipid profile (HDL and cholesterol), liver function tests (AST, ALT), toxicity markers (GGT, GST and LDH), and redox markers (GSH, MDA and CAT) in comparison to group II in most of the parameters. Histological evaluation and comet assay further consolidate these biochemical results, pleading the restoration of the cellular structure of the target tissues and their nuclear DNA. Therefore, the present study shows that the NPs can enhance the anti-diabetic action by suppression of the drug-mediated hepatoxicity via relieving from oxidative stress, toxic burden and inflammation.

Restoring glomerular filtration rate by sulforaphane modulates ERK1/2/JNK/p38MAPK, IRF3/iNOS, Nrf2/HO-1 signaling pathways against folic acid-induced acute renal injury in rats

BACKGROUND

Folic acid (FA)-induced acute renal injury (AKI) is a commonly and highly reproducible model used to study AKI. The current study aims to evaluate the possible protective effects of sulforaphane (SFN) against FA-induced renal damage and explore the underlying molecular mechanism.

METHODS

The animals were divided into four groups (6 rats/group) as follows: normal group (received vehicle, p.o.), FA group (received 250 mg/kg, i.p.), SFN low dose group (received 15 mg/kg, p.o. plus FA 250 mg/kg, i.p.), SFN high dose group (30 mg/kg, p.o. plus FA 250 mg/kg, i.p.). At the end of the experiment, serum samples and kidney tissues were obtained to perform biochemical, molecular, and histopathological investigations.

RESULTS

The present study showed that FA-caused AKI was confirmed by a significant elevation of kidney function biomarkers serum levels accompanied by an observation of histopathologic changes. Interestingly, SFN-administration significantly improved kidney function, reduced oxidative stress markers; MDA, NADPH oxidase, MPO, iNOS with up-regulation of GSH, GCLM, GPX4, SOD, NQO1, HO-1 and Nrf2 levels. SFN also downregulated proinflammatory markers. The results also demonstrated the anti-apoptotic effect of SFN through its ability to increase the antiapoptotic Bcl-2 protein and to decrease caspase-3. Moreover, SFN significantly decreased the relative expression of JNK, ERK-1/2, IRF3, and p38MAPK as compared to the FA-nephrotoxic group.

CONCLUSION

The present study revealed that SFN possess an antioxidant, anti-inflammatory and antiapoptotic activity by modulating caspase-3, Bcl-2, ERK1/2, JNK, GCLM, NQO1, GPX4, Nrf2, HO-1 and P38 signaling pathways in a dose dependent manner which provides a potential therapeutic strategy for preventing FA-induced AKI.

Regulation of PKC/TLR-4/NF-kB signaling by sulbutiamine improves diabetic nephropathy in rats

One of the serious complications of diabetes mellitus is diabetic nephropathy (DN) which may finally lead to renal failure. The current study aimed to explore the effect of sulbutiamine, a synthetic derivative of vitamin B1, in streptozotocin (STZ)-induced DN and related pathways. Experimental DN was successfully induced 8 weeks after a single low dose of STZ (45 mg/kg, I.P.). Four groups of rats were used in this study and divided randomly into: control group, diabetic group, sulbutiamine control (control + sulbutiamine) group, and sulbutiamine-treated (60 mg/kg) (diabetic + sulbutiamine) group. The fasting blood glucose level (BGL) and the levels of kidney injury molecule-1 (Kim-1), urea, creatinine in serum, and the renal content of malondialdehyde (MDA), protein kinase C (PKC), toll-like receptor-4 (TLR-4) and nuclear factor kappa B (NF-κB) were determined. Additionally, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) contents were evaluated immunohistochemically. Sulbutiamine treatment decreased fasting BGL and improved the kidney function tests compared to diabetic rats. Moreover, TLR-4, NF-κB, MDA and PKC contents were substantially reduced following sulbutiamine treatment compared to the diabetic group. Sulbutiamine managed to obstruct the production of the pro-inflammatory TNF-α and IL-1β and suppressed TGF-β1 level, in addition to attenuating the histopathological changes associated with DN. This study revealed, for the first time, the ability of sulbutiamine to ameliorate STZ-induced diabetic nephropathy in rats. This nephroprotective outcome of sulbutiamine against DN may be attributed to glycemic control in addition to its anti-oxidative, anti-inflammatory and anti-fibrotic effects.

Moringa oleifera impedes protein glycation and exerts reno-protective effects in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Moringa oleifera is a valued plant with wide distribution in tropical and subtropical regions of the world. It is traditionally used for the treatment of fever, infections, rheumatism, cancer, improving cardiac, renal and hepatic functions, and regulating blood glucose level. The plant has been scientifically reported for the anti-inflammatory, antioxidant, renoprotective, and anti-diabetic properties. Diabetic patients are prone to develop end-stage renal diseases due to incidence of diabetes-induced renal dysfunctions. Given that, increased production and accumulation of advanced glycation end-products (AGEs) play a conspicuous role in the development of diabetes-linked renal dysfunctions, nature-based interventions with AGEs inhibitory activity can prevent renal dysfunctions leading to renoprotection.

AIM OF THE STUDY

The study aimed to demonstrate the preventive effects of the ethanolic extract of the leaves of Moringa oleifera (EEMO) on protein glycation and its further assessment for the renoprotective effect in diabetic rats.

MATERIALS AND METHODS

Antiglycation activity of EEMO was assessed in vitro using bovine serum albumin. For reno-protective activity assessment, streptozotocin (STZ)-induced diabetic rats were orally treated with EEMO (100 mg/kg) or standard antiglycation agent aminoguanidine (100 mg/kg) for consecutive 8 weeks. The effects on glucose homeostasis, renal functions, and renal morphology were assessed by clinical biochemistry, molecular and histological examination.

RESULTS

Presence of EEMO efficiently prevented glucose-, fructose- or methylglyoxal-mediated glycation of protein. Under in vivo set-up, compared to diabetic control rats, EEMO treatment effectively improved the glucose tolerance and body weight, and reduced the serum levels of triglycerides and total cholesterol. Additionally, EEMO administration significantly ameliorated renal dysfunctions in diabetic rats characterized by improved levels of creatinine, urea nitrogen, and uric acid in serum, and total protein level in urine, accompanied by improved kidney morphology. The diabetes-associated pro-inflammatory response characterized by upregulated expression of the inducible nitric oxide synthase (iNos), activation of nuclear factor kappa B (NF-κB) and the raised levels of inflammatory factors, interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in renal tissue was significantly attenuated in EEMO-treated rats. Moreover, EEMO treatment diminished renal reactive oxygen species (ROS) levels in diabetic animals.

CONCLUSIONS

Our study demonstrated that EEMO prevented AGEs formation and ameliorated renal dysfunctions in diabetic rats by blocking inflammatory/oxidative pathways. Our observations justify M. oleifera as a potential source of therapeutic interventions for diabetic nephropathy management.

Transplantation of Human Amniotic Mesenchymal Stem Cells Up-Regulates Angiogenic Factor Expression to Attenuate Diabetic Kidney Disease in Rats

BACKGROUND AND AIMS

Diabetic kidney disease (DKD) is a prevalent and intractable microvascular complication of diabetes mellitus (DM), the process of which is closely related to abnormal expression of angiogenesis-regulating factors (ARFs). Stem cell transplantation might be a novel strategy for treating DKD. This study aims to explore the effect of transplantation of human amniotic mesenchymal stem cells (hAMSCs) on renal microangiopathy in a type 1 DKD rat model (T1DRM).

METHODS

Seventy-two rats were randomly divided into three groups, including normal control group, DKD group, and hAMSCs transplantation group. T1DRM was established using a rat tail vein injection of streptozotocin (STZ) (55 mg/kg). hAMSCs were obtained from placental amniotic membranes during cesarean delivery and transplanted at 3 and 4 weeks through penile veins. At 6, 8, and 12 weeks following transplantation, blood glucose levels, renal function, pathological kidney alterations, and the expressions of ARFs' mRNA and protein were analyzed.

RESULTS

In T1DRM, transplanted hAMSCs that were homed at the injured site of kidneys increased ARFs' expression and decreased blood glucose levels. Compared to the DKD group, the levels of 24-h urinary protein, serum creatinine, urea, and kidney injury molecule-1 (KIM-1) were reduced in hAMSCs transplantation group. In terms of renal pathology such as the degree of basement membrane thickening, hAMSCs transplantation was also less severe than the DKD group, thereby alleviating kidney injury.

CONCLUSION

hAMSCs transplantation might ameliorate STZ-induced chronic kidney injury through increasing ARFs' expression in kidneys and lowering blood glucose levels.

A Nutritional Blend Suppresses the Inflammatory Response from Bronchial Epithelial Cells Induced by SARS-CoV-2

Even after virus elimination, numerous sequelae of coronavirus disease 2019 (COVID-19) persist. Based on accumulating evidence, large amounts of proinflammatory cytokines are released to drive COVID-19 progression, severity, and mortality, and their levels remain elevated after the acute phase of COVID-19, playing a central role in the disease' sequelae. In this manner, bronchial epithelial cells are the first cells hyperactivated by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to massive cytokine release, triggering the hyperactivation of leukocytes and other cells, and mediating COVID-19 sequelae. Therefore, proinflammatory cytokine production is initiated by the host. This in vitro study tested the hypothesis that ImmuneRecov™, a nutritional blend, inhibits the SARS-CoV-2-induced hyperactivation of human bronchial epithelial cells (BEAS-2B). BEAS-2B (5x10⁴/mL/well) cells were cocultivated with 1 ml of blood from a SARS-CoV-2-infected patient for 4 h, and the nutritional blend (1 µg/mL) was added in the first minute of coculture. After 4 h, the cells were recovered and used for analyses of cytotoxicity with the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay and the expression of the IL-1β, IL-6, and IL-10 mRNAs. The supernatant was collected to measure cytokine levels. SARS-CoV-2 incubation resulted in increased levels of IL-1β and IL-6 in BEAS-2B cells (p < 0.001). Treatment with the nutritional blend resulted in reduced levels of the proinflammatory cytokines IL-1β and IL-6 (p < 0.001) and increased levels of the anti-inflammatory cytokine IL-10 (p < 0.001). Additionally, the nutritional blend reduced the expression of the IL-1β and IL-6 mRNAs in SARS-CoV-2-stimulated cells and increased the expression of the IL-10 and IFN-γ mRNAs. In conclusion, the nutritional blend exerts important anti-inflammatory effects on cells in the context of SARS-CoV-2 infection.

A natural products solution to diabetic nephropathy therapy

Diabetic nephropathy is one of the most common complications in diabetes. It has been shown to be the leading cause of end-stage renal disease. However, due to their complex pathological mechanisms, effective therapeutic drugs other than angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which have been used for 20 years, have not been developed so far. Recent studies have shown that diabetic nephropathy is characterized by multiple signalling pathways and multiple targets, including inflammation, apoptosis, pyroptosis, autophagy, oxidative stress, endoplasmic reticulum stress and their interactions. It definitely exacerbates the difficulty of therapy, but at the same time it also brings out the chance for natural products treatment. In the most recent two decades, a large number of natural products have displayed their potential in preclinical studies and a few compounds are under invetigation in clinical trials. Hence, many compounds targeting these singals have been emerged as a comprehensive blueprint for treating strategy of diabetic nephropathy. This review focuses on the cellular and molecular mechanisms of natural prouducts that alleviate this condition, including preclinical studies and clinical trials, which will provide new insights into the treatment of diabetic nephropathy and suggest novel ideas for new drug development.

The Relationship Between Serum Folate Level and Residual Renal Function in CAPD Patients

Objective

To investigate the relationship between serum folate (FA) levels and residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD) patients.

Methods

Clinical data were collected from 180 hospitalized patients who received CAPD regularly. Patients were divided into the FA deficiency group and the FA non-deficiency group according to serum FA level. Data on age, sex, PD vintage, hemoglobin, mean corpuscular volume, serum FA, total Kt/V, residual kidney Kt/V, peritoneum Kt/V, creatinine clearance (Ccr), ultrafiltration volume, cystatin C (cytC), serum creatinine (Scr), urea nitrogen, retinol-binding protein and the primary disease were gathered from 2 groups. Statistical methods were used to analyze the relationship between serum FA level and RRF.

Results

Peritoneal Kt/V, cytC, Scr were higher, and residual kidney Kt/V was lower in FA deficiency group than in non-deficiency group. Univariate correlation showed the peritoneal Kt/V, cytC, Scr negatively correlated with serum FA while residual kidney Kt/V positively correlated with serum FA, and there was a simple linear regression relationship between serum FA and residual kidney Kt/V. Differences were statistically significant (P<0.05).

Conclusion

There is a relationship between serum FA and RRF in CAPD patients. Prospective studies or trials should be performed to clarify the importance of FA supplementation on RRF during peritoneal dialysis.

The Role of Melatonin in Chronic Kidney Disease and Its Associated Risk Factors: A New Tool in Our Arsenal?

BACKGROUND

The increasing incidence of chronic kidney disease (CKD), as a consequence of the high prevalence of arterial hypertension and type 2 diabetes mellitus (T2DM), warrants the need for developing effective treatment approaches. In this regard, the pineal gland-derived hormone melatonin may represent an appealing treatment approach of CKD and its associated risk factors.

SUMMARY

Targeting the adverse pathophysiology surrounding CKD and its associated risk factors has been the concept of pharmacologic treatment developed for its management. This review article aimed to present the role of melatonin in this direction, by providing an overview of melatonin's physiology followed by its effect as a therapeutic agent in arterial hypertension and T2DM.

KEY MESSAGES

Melatonin, the primary darkness hormone, possesses pleiotropic mechanisms of action which may have important implications in various pathologic states since its receptors are situated across various organ systems. As a treatment tool in arterial hypertension, melatonin may be efficacious in reducing both daytime and nocturnal blood pressure by influencing endothelial function, oxidative stress, the autonomic nervous system, and the renin-angiotensin system. Melatonin may also increase insulin sensitivity and β-cell function. However, late meal intake may be detrimental in glucose regulation, as consumption close to melatonin peak concentrations may induce hyperglycemia and insulin resistance. This finding may explain the inconsistent glycose regulation achieved with melatonin in clinical trials and meta-analyses. Additionally, the presence of genetic variants to melatonin receptor 2 may predispose to T2DM development. Finally, we present the available preclinical evidence supporting melatonin's efficacy in ameliorating CKD's pathophysiology since melatonin supplementation has not been adequately explored in patients with CKD. The combined use of stem cells with melatonin is an appealing therapeutic approach which ought to be assessed further.

Proteomic Analysis of Mouse Kidney Tissue Associates Peroxisomal Dysfunction with Early Diabetic Kidney Disease

Background: The absence of efficient inhibitors for diabetic kidney disease (DKD) progression reflects the gaps in our understanding of DKD molecular pathogenesis. Methods: A comprehensive proteomic analysis was performed on the glomeruli and kidney cortex of diabetic mice with the subsequent validation of findings in human biopsies and omics datasets, aiming to better understand the underlying molecular biology of early DKD development and progression. Results: LC–MS/MS was employed to analyze the kidney proteome of 2 DKD models: Ins2Akita (early and late DKD) and db/db mice (late DKD). The abundance of detected proteins was defined. Pathway analysis of differentially expressed proteins in the early and late DKD versus the respective controls predicted dysregulation in DKD hallmarks (peroxisomal lipid metabolism and β-oxidation), supporting the functional relevance of the findings. Comparing the observed protein changes in early and late DKD, the consistent upregulation of 21 and downregulation of 18 proteins was detected. Among these were downregulated peroxisomal and upregulated mitochondrial proteins. Tissue sections from 16 DKD patients were analyzed by IHC confirming our results. Conclusion: Our study shows an extensive differential expression of peroxisomal proteins in the early stages of DKD that persists regardless of the disease severity, providing new perspectives and potential markers of diabetic kidney dysfunction.

Renal Protective Effects of Melatonin in Animal Models of Diabetes Mellitus-Related Kidney Damage: A Systematic Review and Meta-Analysis

Diabetic nephropathy (DN)-chronic kidney damage caused by hyperglycemia-eventually develops into end-stage renal disease (ESRD). Melatonin is a powerful antioxidant that has a wide range of biological activities. Potentially helpful effects of melatonin on diabetic kidney disease have been found in several studies. However, its protective mechanisms are not clear and remain to be explored. In this review (CRD42021285429), we conducted a meta-analysis to estimate the effects and relevant mechanisms of melatonin for diminishing renal injuries in diabetes mellitus models. The Cochrane Library, PubMed, and EMBASE databases up to September 2021 were used. Random- or fixed-effects models were used for calculating the standardized mean difference (SMD) or 90% confidence interval (CI). The risk of bias was estimated using the SYRCLE's RoB tool. Statistical analysis was conducted with RevMan. A total of 15 studies including 224 animals were included in the analysis. The experimental group showed a remarkable decrease in serum creatinine (P = 0.002), blood urea nitrogen (P = 0.02), and urinary albumin excretion rate (UAER) (P < 0.00001) compared with the control group, while the oxidative stress index improved. The experimental group also showed a remarkable increase in superoxide dismutase (P = 0.21), glutathione (P < 0.0001), and catalase (P = 0.04) and a remarkable decrease in MDA (P < 0.00001) content compared with the control group. We concluded that melatonin plays a role in renal protection in diabetic animals by inhibiting oxidative stress. Moreover, it should be noted that fasting blood glucose was reduced in the experimental group compared with the control group. The kidney and body weights of the animals were not decreased in the diabetic animal model compared with the control group.

Hematological and renoprotective effects of folic acid and lentil extract in diclofenac sodium exposed rats

Excessive intake of non-steroidal anti-inflammatory drugs such as, diclofenac sodium (DS) may lead to toxicity in the rats. In this work, we aimed to examine the protective impact of lentil extract (LE) and folic acid (FA) on the hematological markers, the kidney tissue oxidative stress and the renal function against diclofenac sodium (DS) in male albino rats. The rats (120-150 g) were divided into four equal groups randomly, the first group kept as the untreated control. The second group was administrated with DS (11.6 mg/kg b.wt. orally once/day). The third group was received DS+FA (11.6 mg/kg b.wt.+76.9 microgram/kg b.wt.) orally once/day. The fourth group was treated with DS+LE (11.6 mg/kg b.wt.+500 mg/kg b.wt.) orally once/day. After four weeks, the results revealed that DS produced a significant decrease in the values of red blood cells (RBCs), hemoglobin concentration (Hb), hematocrit (HCT) and white blood cells (WBCs). On the other hand, there was a significant increase in the platelets count. Also, DS induced a renal deterioration; this was evidenced by the significant increase in the serum levels of urea, creatinine, uric acid, Na, Ca, Mg as well as the nitric oxide (NO) level in the kidney tissue. Also, there were a significant reduction in the serum levels of potassium (K) and reduced glutathione (GSH) in the kidney homogenates. Moreover, the findings in the rats treated by DS+LE or DS+FA showed a potential protection on the hematological markers, oxidative stress in the kidney tissue and the renal function disturbed by DS. LE and FA could play a potent role for the prevention the adverse hematological, the kidney tissue oxidative stress and the renal dysfunction caused by DS via their anti-oxidative and bioactive phytochemicals.

Folic Acid Alleviates High Glucose and Fat-Induced Pyroptosis via Inhibition of the Hippo Signal Pathway on H9C2 Cells

Diabetic cardiomyopathy (DCM) is the leading cause of death in diabetic patients. Folic acid has a protective effect on diabetes-induced cardiomyocyte damage. The aim of this study was to explore the effects of folic acid on cardiomyocytes cultured under high glucose and fat (HGF) conditions and type 2 diabetes mellitus (T2DM) mice, and elucidate the underlying mechanisms. Bioinformatics analysis was used to identify the potential drugs through the Drug-Gene Interaction database. H9C2 cardiomyocytes were cultured with 30 mM glucose and 500 nM palmitic acid in the presence or absence of folic acid or YAP1 inhibitor (verteporfin) or YAP1 siRNA. The cell viability and lactate dehydrogenase (LDH) release were measured using specific assay kits. Pyroptosis was detected by flow cytometry. The concentrations of IL-1β and IL-18 in the supernatants were measured by ELISA. The NLRP3, ASC and caspase-1 mRNA levels were detected by qRT-PCR and that the proteins expression of NLRP3, ASC, cleaved caspase-1 (p10), caspase-1, YAP1, p-YAP1, LATS1 and P-LATS1 were detected by Western blotting. C57BL/6 mice were fed with high fat diet (HFD) combined with streptozotocin (STZ) intraperitoneally to establish a T2DM model, folic acid or PBS treatment for 8 weeks by oral gavage, blood glucose and body weight were measured every 4 weeks, mouse heart tissue was used to detect pyroptosis and hippo signaling pathway related protein expression. We identified 427 differentially expressed genes in the cardiac tissues of high fat diet + streptozotocin mice, among the 30 most significantly DEGs, folic acid was predicted to be the most likely therapeutic drug. Folic acid alleviated HGF-induced cell damage in vitro and in vivo by decreasing activation of the Hippo pathway, as indicated by lower LDH release and increased cell viability, and decreased expression of NLRP3, ASC, cleaved caspase-1, IL-1β, IL-18, p-YAP and p-LATS. Verteporfin or YAP1 siRNA neutralized the protective effect of folic acid by reversing YAP1-induced pyroptosis. Folic acid reduced NLRP3 inflammasome-mediated pyroptosis by down-regulating the Hippo signaling pathway, thereby effectively reducing T2DM-induced damage in H9C2 cells and animals.

Folic Acid Attenuates Contrast-Induced Nephropathy in Patients With Hyperhomocysteinemia Undergoing Coronary Catheterization: A Randomized Controlled Trial

Background: Hyperhomocysteinemia is a risk factor for contrast-induced nephropathy. Folic acid can attenuate such nephropathies in rats. The protective effect of folic acid against contrast-induced nephropathy has not been studied in humans. We aimed to investigate the effect of folic acid on the incidence of contrast-induced nephropathy (CIN) after coronary catheterization in patients with hyperhomocysteinemia.

Methods: This was a single-center, prospective, double-blind, randomized controlled trial (ClinicalTrials.gov, NCT02444013). In total, 412 patients (mean age: 65 ± 12 years, 268 male) with plasma homocysteine ≥15 μM, who underwent coronary arteriography (CAG) or percutaneous coronary intervention (PCI) from May 2015 to August 2018, were enrolled. Patients were randomly assigned to two groups: a treatment group (n = 203), taking 5 mg of folic acid (orally, three times/day) immediately after enrollment and for 72 h after operation, and a control group (n = 209), taking placebo. Contrast-induced nephropathy was defined as an increase in serum creatinine of >25% or 44 μM within 48 or 72 h after contrast medium administration.

Results: In total, 50 (12%) patients developed CIN after 48 h after catheterization, including 16 (8%) in the treatment group and 34 (16%) in the control group (P = 0.009). Meanwhile, 53 (13%) patients developed CIN after 72 h of CAG/PCI, including 18 (9%) in the treatment group and 35 (17%) in the control group (P = 0.017). The incidence of contrast-induced nephropathy in the treatment group was lower than that in the control group (P = 0.017). Logistic regression analysis confirmed that administration of folic acid was a protective factor against contrast-induced nephropathy (RD = 0.0788, 95%CI: 0.0105–0.1469, P = 0.019). We found no serious adverse events associated with folic acid. No death or hemodialysis occurred in either group.

Conclusions: Perioperative administration of folic acid attenuates the incidence of contrast-induced nephropathy after coronary catheterization in patients with hyperhomocysteinemia.

Clinical Trial Registration:ClinicalTrials.gov, identifier [NCT02444013].

Bupi Yishen formula attenuates kidney injury in 5/6 nephrectomized rats via the tryptophan-kynurenic acid-aryl hydrocarbon receptor pathway

BACKGROUND

Bupi Yishen Formula (BYF), a patent traditional Chinese medicine (TCM) formulation, has been used in the clinical treatment of chronic kidney disease (CKD). However, the mechanism of action of BYF has not been fully elucidated.

METHOD

To investigate the variation in the metabolic profile in response to BYF treatment in a rat model of 5/6 nephrectomy (Nx), rats in the treatment groups received low- or high-dose BYF. At the end of the study, serum and kidney samples were collected for biochemical, pathological, and western blotting analysis. Metabolic changes in serum were analyzed by liquid chromatography-tandem mass spectrometry.

RESULTS

The results showed that BYF treatment could reduce kidney injury, inhibit inflammation and improve renal function in a dose-dependent manner. In total, 405 and 195 metabolites were identified in negative and positive ion modes, respectively. Metabolic pathway enrichment analysis of differential metabolites based on the Kyoto Encyclopedia of Genes and Genomes database identified 35 metabolic pathways, 3 of which were related to tryptophan metabolism. High-dose BYF reduced the level of kynurenic acid (KA) by more than 50%, while increasing melatonin 25-fold and indole-3-acetic acid twofold. Expression levels of aryl hydrocarbon receptor (AhR), Cyp1A1, and CyP1B1 were significantly reduced in the kidney tissue of rats with high-dose BYF, compared to 5/6 Nx rats.

CONCLUSION

BYF has a reno-protective effect against 5/6 Nx-induced CKD, which may be mediated via inhibition of the tryptophan-KA-AhR pathway.

Effects of paired associated stimulation with different stimulation position on motor cortex excitability and upper limb motor function in patients with cerebral infarction

OBJECTIVE

To investigate the effects of paired associated stimulation (PAS) with different stimulation position on motor cortex excitability and upper limb motor function in patients with cerebral infarction.

METHOD

A total of 120 volunteers with cerebral infarction were randomly divided into four groups. Based on conventional rehabilitation treatment, the PAS stimulation group was given the corresponding position of PAS treatment once a day for 28 consecutive days. The MEP amplitude and RMT of both hemispheres were assessed before and after treatment, and a simple upper limb Function Examination Scale (STEF) score, simplified upper limb Fugl-Meyer score (FMA), and improved Barthel Index (MBI) were used to assess upper limb motor function in the four groups.

RESULTS

Following PAS, the MEP amplitude decreased, and the RMT of abductor pollicis brevis (APB) increased on the contralesional side, while the MEP amplitude increased and the RMT of APB decreased on the ipsilesional side. After 28 consecutive days the scores of STEF, FMA, and MBI in the bilateral stimulation group were significantly better than those in the ipsilesional stimulation group and the contralesional stimulation group, but there was no significant difference in the scores of STEF, FMA, and MBI between the ipsilesional stimulation group and the contralesional stimulation group.

CONCLUSION

The excitability of the motor cortex can be changed when the contralesional side or the ipsilesional side was given the corresponding PAS stimulation, while the bilateral PAS stimulation can more easily cause a change of excitability of the motor cortex, resulting in better recovery of the upper limb function.

Glycoprotein levels and oxidative lung injury in experimental diabetes: effect of oxovanadium(IV) complex based on thiosemicarbazone

Diabetes mellitus (DM) is chronic and metabolic disorder, which is mainly attributed by hyperglycemia. Vanadium salts and their oxo-complexes have been shown to possess insulin-mimetic and anti-diabetic activities in animal models and diabetic patients. The main goal of this study was to investigate the protective effect of oxovanadium(IV) complex based on thiosemicarbazone (VOL) [L: (N(1)-2,4-dihydroxybenzylidene-N-(4)-2-hydroxybenzylidene-S-methyl-isothiosemicarbazidato-oxovanadium(IV)] on glycoprotein components levels and oxidative lung injury of streptozotocin (STZ)-induced diabetic rats. Male Swiss albino rats were separated into four groups. Group I (n = 5): Control (normal) animals, Group II (n = 5): Control animals administered with VOL, Group III (n = 6): STZ-induced diabetic animals, and Group IV (n = 5): STZ-induced diabetic rats treated with VOL. VOL was given to the experimental animals by gavage at a dose of 0.2 mM/kg body weight every day for 12 days. Diabetes was induced by single intraperitoneal injection of STZ (65 mg/kg body weight). On the 12th day, lung tissue samples were taken. Glycoprotein components, advanced oxidation protein products, protein carbonyl, hydroxyproline levels, and prolidase, arginase, xanthine oxidase, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and adenosine deaminase activities significantly increased whereas aryl esterase, paraoxonase-1, carbonic anhydrase, Na⁺/K⁺-ATPase activities remarkably decreased in lung tissue of diabetic rats. Treatment with VOL reversed these effects showing a beneficial effect. The present study shows that VOL has a protective effect against diabetes-induced lung damage as well as on abnormal glycoprotein component levels.

Melatonin Alleviated Potassium Dichromate-Induced Oxidative Stress and Reprotoxicity in Male Rats

Melatonin (ML) is a potent antioxidant that reduces oxidative stress. This study was designed to examine the protective effect of melatonin on potassium dichromate- (PDC-) induced male reproductive toxicity. Forty rats were divided into five groups: the control group, rats administered PDC orally (10 mg/kg body weight) for eight weeks, rats administered ML intraperitoneally at doses of either 2.5 or 5 mg/kg followed by the administration of PDC, and rats administered 5 mg/kg ML only. The treatment of rats with PDC led to a decrease in the levels of plasma sex hormones, glutathione, superoxide dismutase, catalase, carnitine, sperm count, and motility. Testicular malondialdehyde levels, nitric oxide concentrations, and abnormalities increased significantly in the PDC group. Melatonin administration to the PDC-treated rats reduced the increase of malondialdehyde and restored the activity of antioxidant enzymes (superoxide dismutase and catalase), glutathione, and sex hormone levels. Moreover, ML attenuated PDC-induced increase in levels of tumor necrosis factor-alpha or interleukin-6. ML alleviated histopathological changes and an increase of p53-positive immune reaction due to PDC. Furthermore, ML inhibited PDC-induced decrease in the DNA content of spermatogenic cells. This study proposed that melatonin may be useful in mitigating oxidative stress-induced testicular damage due to potassium dichromate toxicity.

Piperazine ferulate attenuates high glucose‑induced mesangial cell injury via the regulation of p66Shc

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes. Hyperglycemia-induced glomerular mesangial cells injury is associated with microvascular damage, which is an important step in the development of DN. Piperazine ferulate (PF) has been reported to exert protective effects against the progression of DN. However, whether PF prevents high glucose (HG)-induced mesangial cell injury remains unknown. The aim of the present study was to investigate the effects of PF on HG-induced mesangial cell injury and to elucidate the underlying mechanisms. Protein and mRNA expression levels were determined via western blot analysis and reverse transcription-quantitative PCR, respectively. IL-6 and TNF-α levels were measured using ELISA. Reactive oxygen species levels and NF-κB p65 nuclear translation were determined via immunofluorescence analysis. Apoptosis was assessed by measuring lactate dehydrogenase (LDH) release, as well as using MTT and flow cytometric assays. The mitochondrial membrane potential of mesangial cells was determined using the JC-1 kit. The results revealed that LDH release were increased; however, cell viability and mitochondrial membrane potential were decreased in the HG group compared with the control group. These changes were inhibited after the mesangial cells were treated with PF. Moreover, PF significantly inhibited the HG-induced production of inflammatory cytokines and the activation of NF-κB in mesangial cells. PF also attenuated the HG-induced upregulation of the expression levels of fibronectin and collagen 4A1. Furthermore, the overexpression of p66^{Src homology/collagen (Shc)} abolished the protective effect of PF on HG-induced mesangial cell injury. In vivo experiments revealed that PF inhibited the activation of inflammatory signaling pathways, glomerular cell apoptosis and mesangial matrix expansion in diabetic mice. Collectively, the present findings demonstrated that PF attenuated HG-induced mesangial cells injury by inhibiting p66^Shc.

Melatonin Improves Endoplasmic Reticulum Stress-Mediated IRE1α Pathway in Zücker Diabetic Fatty Rat

Obesity and diabetes are linked to an increased prevalence of kidney disease. Endoplasmic reticulum stress has recently gained growing importance in the pathogenesis of obesity and diabetes-related kidney disease. Melatonin, is an important anti-obesogenic natural bioactive compound. Previously, our research group showed that the renoprotective effect of melatonin administration was associated with restoring mitochondrial fission/fusion balance and function in a rat model of diabesity-induced kidney injury. This study was carried out to further investigate whether melatonin could suppress renal endoplasmic reticulum (ER) stress response and the downstream unfolded protein response activation under obese and diabetic conditions. Zücker diabetic fatty (ZDF) rats and lean littermates (ZL) were orally supplemented either with melatonin (10 mg/kg body weight (BW)/day) (M-ZDF and M-ZL) or vehicle (C-ZDF and C-ZL) for 17 weeks. Western blot analysis of ER stress-related markers and renal morphology were assessed. Compared to C-ZL rats, higher ER stress response associated with impaired renal morphology was observed in C-ZDF rats. Melatonin supplementation alleviated renal ER stress response in ZDF rats, by decreasing glucose-regulated protein 78 (GRP78), phosphoinositol-requiring enzyme1α (IRE1α), and ATF6 levels but had no effect on phospho-protein kinase RNA-like endoplasmic reticulum kinase (PERK) level. In addition, melatonin supplementation also restrained the ER stress-mediated apoptotic pathway, as indicated by decreased pro-apoptotic proteins phospho-c-jun amino terminal kinase (JNK), Bax, and cleaved caspase-3, as well as by upregulation of B cell lymphoma (Bcl)-2 protein. These improvements were associated with renal structural recovery. Taken together, our findings revealed that melatonin play a renoprotective role, at least in part, by suppressing ER stress and related pro-apoptotic IRE1α/JNK signaling pathway.

An updated pharmacological insight of resveratrol in the treatment of diabetic nephropathy

As one of the most common complications of diabetes, nephropathy develops in approximately 40% of diabetic individuals. Although end stage kidney disease is known as one of the most consequences of diabetic nephropathy, the majority of diabetic individuals might die from cardiovascular diseases and infections before renal replacement treatment. Moreover, the routine medical treatments for diabetes hold undesirable side effects. The explosive prevalence of diabetes urges clinicians and scientists to investigate the complementary or alternative therapies. Phytochemicals are emerging as alternatives with a wide range of therapeutic effects on various pathologies, including diabetic kidney disease. Of those phytochemicals, resveratrol, a natural polyphenolic stilbene, has been found to exert a broad spectrum of health benefits via various signaling molecules. In particular, resveratrol has gained a great deal of attention because of its anti-oxidative, anti-inflammatory, anti-diabetic, anti-obesity, cardiovascular-protective, and anti-tumor properties. In the renal system, emerging evidence shows that resveratrol has already been used to ameliorate chronic or acute kidney injury. This review critically summarizes the current findings and molecular mechanisms of resveratrol in diabetic renal damage. In addition, we will discuss the adverse and inconsistent effects of resveratrol in diabetic nephropathy. Although there is increasing evidence that resveratrol affords great potential in diabetic nephropathy therapy, these results should be treated with caution before its clinical translation. In addition, the unfavorable pharmacokinetics and/or pharmacodynamics profiles, such as poor bioavailability, may limit its extensive clinical applications. It is clear that further research is needed to unravel these limitations and improve its efficacy against diabetic nephropathy. Increasing investigation of resveratrol in diabetic kidney disease will not only help us better understand its pharmacological actions, but also provide novel potential targets for therapeutic intervention.

Administration of mesenchymal stem cells in diabetic kidney disease: a systematic review and meta-analysis

BACKGROUND

Mesenchymal stem cell (MSC) therapy shows great promise for diabetic kidney disease (DKD) patients. Research has been carried out on this topic in recent years. The main goals of this paper are to evaluate the therapeutic effects of MSCs on DKD through a meta-analysis and address the mechanism through a systematic review of the literature.

METHOD

An electronic search of the Embase, Cochrane Library, ISI Web of Science, PubMed, and US National Library of Medicine (NLM) databases was performed for all articles about MSC therapy for DKD, without species limitations, up to January 2020. Data were pooled for analysis with Stata SE 12.

RESULT

The MSC-treated group showed a large and statistically significant hypoglycemic effect at 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, and 6 months. Total hypoglycemic effect was observed (SMD = - 1.954, 95%CI - 2.389 to - 1.519, p < 0.001; I² = 85.1%). The overall effects on serum creatinine (SCr) and blood urea nitrogen (BUN) were analyzed, suggesting that MSC decreased SCr and BUN and mitigated the impairment of renal function (SCr: SMD = - 4.838, 95%CI - 6.789 to - 2.887, p < 0.001; I² = 90.8%; BUN: SMD = - 4.912, 95%CI - 6.402 to - 3.422, p < 0.001; I² = 89.3%). Furthermore, MSC therapy decreased the excretion of urinary albumin. Fibrosis indicators were assessed, and the results showed that transforming growth factor-β, collagen I, fibronectin, and α-smooth muscle actin were significantly decreased in the MSC-treated group compared to the control group.

CONCLUSION

MSCs might improve glycemic control and reduce SCr, BUN, and urinary protein. MSCs can also alleviate renal fibrosis. MSC therapy might be a potential treatment for DKD.

Curcumin reverses diabetic nephropathy in streptozotocin-induced diabetes in rats by inhibition of PKCβ/p66Shc axis and activation of FOXO-3a

This study investigated if the nephroprotective effect of Curcumin in streptozotocin-induced type 1 diabetes mellitus (DM) in rats involves downregulation/inhibition of p66Shc and examined the underlying mechanisms. Rats were divided into 4 groups (n = 12/group) as control, control + Curcumin (100 mg/kg), T1DM, and T1DM + Curcumin. Curcumin was administered orally to control or diabetic rats for 12 weeks daily. As compared to diabetic rats, Curcumin didn't affect either plasma glucose or insulin levels but significantly reduced serum levels of urea, blood urea nitrogen, and creatinine, and concurrently reduced albumin/protein urea and increased creatinine clearance. It also prevented the damage in renal tubules and mitochondria, mesangial cell expansion, the thickness of the basement membrane. Mechanistically, Curcumin reduced mRNA and protein levels of collagen I/III and transforming growth factor- β-1 (TGF-β1), reduced inflammatory cytokines levels, improved markers of mitochondrial function, and suppressed the release of cytochrome-c and the activation of caspase-3. In the kidneys of both control and diabetic rats, Curcumin reduced the levels of reactive oxygen species (ROS), increased mRNA levels of manganese superoxide dismutase (MnSOD) and gamma-glutamyl ligase, increased glutathione (GSH) and protein levels of Bcl-2 and MnSOD, and increased the nuclear levels of nuclear factor2 (Nrf2) and FOXO-3a. Besides, Curcumin reduced the nuclear activity of the nuclear factor-kappa B (NF-κB), downregulated protein kinase CβII (PKCβII), NADPH oxidase, and p66Shc, and decreased the activation of p66Shc. In conclusion, Curcumin prevents kidney damage in diabetic rats by activating Nrf2, inhibiting Nf-κB, suppressing NADPH oxidase, and downregulating/inhibiting PKCβII/p66Shc axis.

Chemopreventive effect of riboflavin on the potassium bromate-induced renal toxicity in vivo

Potassium bromate (PB) is a general food additive, flavor enhancer, a by-product of water disinfection, and a class 2 carcinogen. It exerts various toxic effects in a dose- and time-dependent manner in vivo. This study is to explore the chemopreventive efficacy of vitamin B2 (riboflavin, RF) in PB-administered Swiss albino rats. The rats were distributed into five groups: control (group 1), PB alone (group 2, 150 mg/kg), RF alone (group 3, 2 mg/kg), PB + RF1 (group 4, 150 and 2 mg/kg), and PB + RF2 (group 5, 150 and 4 mg/kg). All the rodents were sacrificed after the completion of the treatment cycle. Then, blood and kidney samples were subjected to biochemical analysis. Group 2 demonstrated vivid signs of renal toxicities evidenced by altered renal function markers (urea, creatinine, albumin, glutathione-S-transferase) and redox status parameters (superoxide dismutase, catalase, glutathione reductase, reduced glutathione, lipid, and protein oxidation products). However, group 3 exhibited a slight alteration in many of the parameters while groups 4 and 5 demonstrated dose-dependent chemopreventive efficiency of RF against PB-induced alterations. Besides, RF seemed to facilitate apoptosis as well as inhibition of the necrosis in the PB-pre-challenged groups, as demonstrated by the cleaved PARP and lactate dehydrogenase activity. Also, the histopathological analysis and comet assay validate the biochemical results of the treatment groups significantly. All these results plead that RF has a significant chemopreventive property against PB-induced toxicity in vivo. Therefore, RF is a suitable agent in preventing the PB-induced toxicities at the clinical and industrial levels.

Melatonin improves periodontitis-induced kidney damage by decreasing inflammatory stress and apoptosis in rats

BACKGROUND

Two main aims of this animal study were to inspect the possible effects of periodontitis on the structure and functions of the kidneys and the therapeutic effectiveness of melatonin.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Periodontitis was induced by placing 3.0-silk sutures sub-paramarginally around the cervix of right-left mandibular first molars and maintaining the sutures for 5 weeks. Then melatonin (10 mg/kg body weight/day, 14 days), and the vehicle was administered intraperitonally. Mandibular and kidney tissue samples were obtained following the euthanasia. Periodontal bone loss was measured via histological and microcomputed tomographic slices. On right kidney histopathological and immunohistochemical, and on the left kidney biochemical (malonyl-aldehyde [MDA], glutathione, oxidative stress [OSI], tumor necrosis factor [TNF]-α, interleukin [IL]-1β, matrix metalloproteinase [MMP]-8, MMP-9, and cathepsin D levels) evaluations were performed. Renal functional status was analyzed by levels of serum creatinine, urea, cystatin-C, and urea creatinine.

RESULTS

Melatonin significantly restricted ligature-induced periodontal bone loss (P <0 .01) and suppressed the levels of proinflammatory cytokines (TNF-α and IL-1β), oxidative stress (MDA and OSI), and proteases (MMP-8, MMP-9, and CtD) that was significantly higher in the kidneys of the rats with periodontitis (P <0.05). In addition, periodontitis-related histological damages and apoptotic activity were also significantly lower in the Ep-Mel group (P <0.05). However, the markers of renal function of the Ep group were detected slightly impaired in comparison with the control group (P >0.05); and the therapeutic activity of melatonin was limited (P >0.05).

CONCLUSION

Melatonin restricts the periodontitis-induced inflammatory stress, apoptosis, and structural but not functional impairments.

Comprehensive epigenetic analysis of m6A modification in the hippocampal injury of diabetic rats

Aim: To study RNA N6-methyladenosine (m6A) modification in the diabetic hippocampus. Methods: Behavioral tests and staining were performed to evaluate the damage to the diabetic hippocampus in model rats. Western blotting was performed to investigate the expression of methylation-related enzymes, and flow cytometry was used to demonstrate HT22 cell apoptosis. M6A and RNA sequencing analyses were conducted to profile m6A-tagged transcripts in the diabetic hippocampus. Results: The rat models of diabetes mellitus suffered from cognitive disorders and hippocampal neuron damage. High glucose levels altered the expression of methylation-related enzymes. A total of 4890 differentially methylated m6A peaks and 63 differentially expressed genes and differentially methylated m6A sites were identified. Conclusion: The findings suggest that m6A modification is altered in the diabetic hippocampus and provide new insight into diabetic hippocampal injury.

Melatonin suppresses the brain injury after cerebral ischemia/reperfusion in hyperglycaemic rats

Background and purpose

Diabetes mellitus is a disorder accompanied by oxidative and inflammatory responses, that might exacerbate vascular complications. The purpose of this study was to investigate the potential antioxidant and anti-inflammatory effects of melatonin (MLN) on streptozotocin (STZ)-induced diabetic rats subjected to middle cerebral artery occlusion followed by reperfusion (MCAO/Re).

Experimental approach

Diabetes was induced in rats by a single injection of STZ (55 mg/kg; i.p.). The cerebral injury was then induced by MCAO/Re after six weeks. After 24 h of MCAO/Re the MLN (10 mg/kg) was administered orally for 14 days. Serum and tissue samples were extracted to determine malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), interleukin-1β (IL-1β), and the tumor necrosis factor- α (TNF-α). Part of the brain tissue was kept in formalin for pathological and immunohistochemical studies to determine nuclear factor kappa B (NF-kB) and cyclooxygenase-2 (COX-2) immune reactivity.

Findings/Results

MCAO/Re in STZ-induced hyperglycaemic rats caused a decrease in brain GSH, an increase in brain MDA, and NO was increased in both serum and brain tissue. Rats showed a prominent increase in the serum and brain inflammatory markers viz. IL-1β and TNF-α. Oral treatment with MLN (10 mg/kg) for two weeks reduced the brain levels of MDA, NO, IL-1β, and TNF-α. Impressive amelioration in pathological findings, as well as a significant decrease in NF-kB and COX2 immune stained cells of the cerebral cortex, hippocampus, and cerebellum, occurred after treatment with MLN. It also succeeded to suppress the exacerbation of damage in the brain of hyperglycaemic rats.

Conclusion and implications

Daily intake of MLN attenuates the exacerbation of cerebral ischemic injury in a diabetic state.