Protective effects of irbesartan and alpha lipoic acid in STZ-induced diabetic nephropathy in rats

Alpha-lipoic acid suppresses gibberellic acid nephrotoxicity in Nile tilapia (Oreochromis niloticus) via modulating oxidative stress, inflammation, cytokine production, and apoptosis

Globally, gibberellic acid (GA) is one of the extensively used plant growth regulators in agriculture. Yet, there is limited information about their toxicity to fish. Recently, alpha lipoic acid (ALA) has drawn much interest due to its antioxidant properties. This study was planned to determine whether ALA might protect Nile tilapia's kidneys from the toxic effects of GA and the probable underlying mechanisms. Thus, 240 Oreochromis niloticus fish (average initial weight 30.67 ± 0.57) were allocated into four groups received a basal diet or a basal diet supplemented with 600 mg/kg ALA or a basal diet but exposed to a GA (150 mg/L), or ALA-fortified diet and concurrently exposed to GA as previously described. After 60 days, hematological, oxidative stress, lipid peroxidation, stress indices, selected kidney toxic byproducts, histological investigations, and associated gene expression were assessed. Anemia, leukopenia, hypoproteinemia, and elevated kidney function indicators were noticed in the GA-treated group. Additionally, there were detectable cortisol, glucose, 8-OHdG, and MDA increases. However, there was a considerable drop in Cat, Sod, Gpx, GSH, and AChE levels. Structural damage to the kidneys was also identified. In the kidney of fish treated with GA, pro-inflammatory cytokines (tnfα, il-1β), stress, and apoptotic genes (hsp70, pcna, caspase-3, and p53) genes were markedly up-regulated, while anti-oxidative (cat, sod) gene expression was downregulated. Conversely, adding ALA to the diet abolished the GA-induced changes in most of the markers mentioned above. Conclusively, ALA protects against GA-induced hematotoxicity, oxidative damage, and nephrotoxic effects in Nile tilapia fish.

Inhibitory Effect of Insulin Treatment on Apoptosis of Intervertebral Disc Cells in a Streptozotocin-Induced Diabetic Rat Model

STUDY DESIGN

Experimental study using a streptozotocin (STZ)-induced diabetic rat model.

PURPOSE

This study aims to investigate whether insulin treatment could attenuate disc cell apoptosis and matrix degradation in a STZ-induced diabetic rat model.

OVERVIEW OF LITERATURE

Diabetes is a significant risk factor for disc degeneration due to excessive apoptosis of disc cells and matrix degradation. However, no studies were noted to demonstrate the inhibitory effect of insulin treatment on the apoptosis of disc cells and matrix degradation in diabetic patients.

METHODS

Rats were allocated randomly into one of three groups: control, STZ, and STZ-insulin. Diabetes was induced by a single intraperitoneal injection of STZ (65 mg/kg) in the STZ and STZ-insulin groups. The blood glucose level was consistently above 400 mg/ dL in the STZ and STZ-insulin groups 2 weeks after STZ injection. After 2 weeks of STZ injection, the STZ-insulin group was administered insulin treatment (1.5 unit/100 g) daily for up to 4 weeks. Blood glucose of the STZ-insulin rats significantly decreased to normal levels 4 weeks after insulin treatment. The rats were sacrificed 6 weeks after STZ injection, and disc cells and tissues were harvested to investigate the expression of apoptosis markers and matrix metalloproteinases (MMPs).

RESULTS

Fas and caspase-8, -9, and -3 expressions were significantly increased in the STZ group, along with increased expressions of MMP-2 and -3. On the contrary, insulin treatment significantly decreased the expressions of Fas, caspase-8, -9, and -3 as well as MMP-2 and -3 in the STZ-insulin group.

CONCLUSIONS

The results of the current study demonstrated that insulin treatment attenuates excessive apoptosis of disc cells and matrix degradation in the diabetic rat model. Accordingly, strict blood glucose control should be recommended to prevent disc degeneration in diabetic patients.

Effects of Alpha-lipoic Acid Supplementation on Human Diabetic Nephropathy: A Systematic Review and Meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is kidney dysfunction, which occurs due to elevated urine albumin excretion rate and reduced glomerular filtration rate. Studies on animals have shown that alpha-lipoic acid (ALA) supplementation can reduce the development of DN.

OBJECTIVES

We performed a systematic review and meta-analysis to examine the effects of ALA supplementation on biological indices (albumin, creatinine, etc.) indicative of human DN.

METHODS

The search procedure included PubMed Central, Embase, Cochrane Library (trials), and Web of Science (protocol registration: INPLASY202060095).

RESULTS

We found that ALA supplementation decreased 24h urine albumin excretion rate in patients with diabetes (standardized mean difference=-2.27; confidence interval (CI)=(-4.09)-(-0.45); I²=98%; Z=2.44; p=0.01). A subgroup analysis revealed that the results of studies examining only ALA did not differ from those examined ALA in combination with additional medicines (Chisquared= 0.19; p=0.66; I²=0%), while neither ALA nor ALA plus medication had an effect on 24h urine albumin excretion rate (p>0.05). Also, ALA supplementation decreased urine albumin mg/l (mean difference (MD)=-12.95; CI=(-23.88)-(-2.02); I²=44%; Z=2.32; p=0.02) and urine albumin to creatinine ratio (MD=-26.96; CI=(-35.25)-(-18.67); I²=0%; Z=6.37; p<0.01) in patients with diabetes. When the studies examining ALA plus medication were excluded, it was found that ALA supplementation had no effect on urine albumin mg/l (p>0.05) but did significantly decrease urine albumin to creatinine ratio (MD=-25.88, CI=(34.40-(-17.36), I²=0%, Z=5.95, p<0.00001).

CONCLUSION

The available evidence suggests that ALA supplementation does not improve biological indices that reflect DN in humans. Overall, we identified limited evidence, and therefore, the outcomes should be considered with caution.

Ameliorative effect of hesperidin on streptozotocin-diabetes mellitus-induced testicular DNA damage and sperm quality degradation in Sprague-Dawley rats

This study aimed to investigate the effect of hesperidin on reproductive damage caused by diabetes mellitus. A total of 24 adult male rats were divided into four groups: control group, hesperidin group, diabetes mellitus group, and diabetes mellitus + hesperidin group. The study was conducted for 4 weeks. At the end of the study, the rats were sacrificed and testicular oxidative stress markers (MDA, GSH, GSH-Px, SOD, and CAT), DNA damage in testes (8-OHdG), and routine sperm parameters were evaluated. According to the results of the study, most of the parameters were similar in the control and hesperidin groups but CAT activity in the hesperidin group was statistically higher than the control group. Also, diabetes mellitus (DM) significantly increased MDA levels and decreased enzymatic antioxidant (GSH-Px, SOD, CAT) activities and nonenzymatic (GSH) antioxidant levels. On the other hand, hesperidin supplementation significantly decreased oxidative stress and increased enzymatic antioxidant activities and nonenzymatic antioxidant levels due to the antioxidant effect. Also, DM increased DNA damage levels in testicular tissue and hesperidin supplementation significantly decreased DNA damage levels in testes of diabetic male rats. Besides, sperm motility significantly decreased while abnormal sperm rate and dead sperm rate were significantly increased in diabetic rats. Hesperidin supplementation significantly reduced these side effects in diabetic rats. In conclusion, hesperidin supplementation could be beneficial for decreasing the side effects on the male reproductive system caused by DM in rats. PRACTICAL APPLICATIONS: Diabetes is an important metabolic disease, affecting quality of life and fertility. Hesperidin has an antioxidant effect and has a potential protective effect on reproductive toxicity in diabetic male rats. Hesperidin decreased oxidative stress, and DNA damage in testis resulted from hyperglycemia and improved sperm quality in diabetic rats. The hesperidin supplementation could be a good strategy to protect male fertility in diabetic patients.

Protective effect of L-glutamine against diabetes-induced nephropathy in experimental animal: Role of KIM-1, NGAL, TGF-β1, and collagen-1

Diabetic nephropathy is a serious microvascular complication and one of the main causes of end-stage renal disease. L-Glutamine (LG) is naturally occurring amino acids with antidiabetic and antioxidant potential. The aim of present investigation was to evaluate the potential of LG against streptozotocin (STZ)-induced diabetic nephropathy (DN) in laboratory rats. DN was induced in male Wistar rats (200-220 g) by intraperitoneal administration of STZ (55 mg/kg). Animals were treated orally with either distilled water (10 mg/kg) or LG (250, 500, and 1000 mg/kg) or Sitagliptin (5 mg/kg). Various biochemical, molecular, and histological (hematoxylin-eosin and Masson's trichrome stain) parameters were assessed. Administration of LG (500 and 1000 mg/kg) significantly inhibited (p < .05) STZ-induced alterations in serum and urine biochemistry (urine creatinine, uric acid, albumin, and BUN). It also significantly increased creatinine clearance rate. STZ induced increase in renal oxidonitrosative stress was significantly decreased (p < .05) by LG (500 and 1000 mg/kg) treatment. Upregulated renal KIM-1, NGAL, TGF-β1, and collagen-1 mRNA expression after STZ administration was significantly inhibited (p < .05) by LG (500 and 1000 mg/kg) treatment. Correlation analysis also revealed that antidiabetic potential of LG attenuates STZ-induced elevated renal KIM-1, NGAL, TGF-β1, and collagen-1 mRNA expression. Histopathological alteration induced by STZ in renal tissue was ameliorated by LG treatment. In conclusion, results of present investigation suggest that treatment with LG ameliorated STZ-induced DN via the inhibition of oxidonitrosative stress as well as downregulation of KIM-1, NGAL, TGF-β1, and collagen-1 mRNA expressions.

Role of alpha-lipoic acid in the management of anemia in patients with chronic renal failure undergoing hemodialysis

Introduction

Anemia associated with chronic kidney disease is a serious complication necessitating expenditure of huge medical efforts and resources. This study investigates the role of alpha-lipoic acid (ALA) in end stage renal disease patients undergoing hemodialysis. By the virtue of its antioxidative effects, ALA is expected to act as an erythropoietin (EPO) adjuvant, and also has extended beneficial effects on endothelial dysfunction.

Methods

Forty-four patients undergoing hemodialysis and receiving EPO were randomized into two groups: the first group received ALA 600 mg once daily for 3 months; while the other group represented the control group. Parameters measured at baseline and at end of study were hemoglobin, EPO doses, EPO resistance index (ERI), iron store indices, malondialdehyde, oxidized low-density lipoprotein (ox-LDL), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and asymmetric dimethylarginine (ADMA), as well as routine laboratory follow-up.

Results

EPO doses and ERI were significantly decreased in the treatment group, while they did not change in the control group. Hemoglobin, iron store indices, malondialdehyde, oxidized ox-LDL, IL-6, TNF-α, and ADMA were similar in both treatment and control groups at baseline, and did not change by the end of study period. Likewise, routine laboratory measures were not affected by the treatment.

Conclusion

ALA could be used in hemodialysis patients to reduce requirements for EPO. However, larger and longer term studies are required to clarify the exact role of ALA in hemodialysis as well as in pre-hemodialysis patients.