Evaluation of efficacy of vitamin E and N-acetyl cysteine in gentamicin-induced nephrotoxicity in rats

Assessment of gentamicin and cisplatin-induced kidney damage mediated via necrotic and apoptosis genes in albino rats

BACKGROUND

Gentamicin (GM) is a low-cost, low-resistance antibiotic commonly used to treat gram-negative bacterial diseases. Cisplatin (Csp) is a platinum-derived anti-neoplastic agent. This experiment aimed to identify the early signs of gentamicin and cisplatin-induced nephrotoxicity in rats. Thirty Wistar rats were divided into three groups of 10: a control group, which received no treatment; a gentamicin group administered by a dose of (100 mg/kg, IP) for 7 consecutive days, and a cisplatin group was administered intraperitoneal in a dose of (1.5 mg/kg body weight) repeated twice a week for 3 weeks.

RESULTS

Both experimental groups exhibited increased levels of creatinine, urea, and uric acid, with the cisplatin-treated group showing higher levels than the gentamicin group. Experimental groups also exhibited significantly increased Malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GSH-Px) with more pronounced effects in the cisplatin-treated group. Further, both experimental groups exhibited significant up-regulation of Tumor Necrosis Factor α (TNF-α), caspase-3, and Bax and down regulation of Bcl-2.

CONCLUSION

These findings confirm the use of necrotic, apoptotic genes as early biomarkers in the detection of tubular kidney damage. Further, cisplatin was shown to have a greater nephrotoxic effect than gentamicin; therefore, its use should be constrained accordingly when co-administered with gentamicin.

The effect of N-Acetyl cysteine on the expression of Fxr (Nr1h4), LXRα (Nr1h3) and Sirt1 genes, oxidative stress, and apoptosis in the liver of rats exposed to different doses of cadmium

The aim of this study was to consider the expression of farnesoid X receptor (Fxr), liver X receptor (LXRα) and sirtuin 1 (Sirt1), oxidative stress, inflammation, apoptosis, and the protective role of N-acetylcysteine (NAC) in the liver of rats treated with cadmium (Cd). 30 Wistar rats were divided into 5 groups: G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd + continuous dose of NAC), and G5 (continuous dose of Cd + continuous dose of NAC). The apoptosis of hepatic cells was measured using the TUNEL assay. Levels of malondialdehyde (MDA), IL-10, TNF-α, and total antioxidant capacity (TAC) were measured by specific kits. The expression of Fxr, LXRα, and Sirt1 genes and ratio of Bax/Bcl2 was considered using RT-PCR. While NAC treatment improved TAC and IL-10 values, it decreased MDA and TNF-α levels in the liver of rats exposed to Cd (P < 0.001). NAC decreased Bax/Bcl2 in the liver of G4 and G5 groups (P < 0.001). Exposure to a continuous dose of Cd decreased Fxr, LXRα, and Sirt1 expression by 36.65- (P < 0.001), 12.52- (P < 0.001) and 11.34-fold (P < 0.001) compared to control, respectively. NAC increased Fxr, LXRα, and Sirt1 expression (P < 0.01) and decreased Cd concentrations in both serum and tissue samples in G4 and G5 groups. Our results suggested that NAC protects liver tissue against Cd toxicity by elevating antioxidant capacity, mitigating oxidative stress, inflammation, apoptosis and up-regulation of FXR, LXR, and SIRT1 genes.

N-acetylcysteine (NAC), an anti-oxidant, does not improve bone mechanical properties in a rat model of progressive chronic kidney disease-mineral bone disorder

Individuals with chronic kidney disease have elevated levels of oxidative stress and are at a significantly higher risk of skeletal fracture. Advanced glycation end products (AGEs), which accumulate in bone and compromise mechanical properties, are known to be driven in part by oxidative stress. The goal of this study was to study effects of N-acetylcysteine (NAC) on reducing oxidative stress and improving various bone parameters, most specifically mechanical properties, in an animal model of progressive CKD. Male Cy/+ (CKD) rats and unaffected littermates were untreated (controls) or treated with NAC (80 mg/kg, IP) from 30 to 35 weeks of age. Endpoint measures included serum biochemistries, assessments of systemic oxidative stress, bone morphology, and mechanical properties, and AGE levels in the bone. CKD rats had the expected phenotype that included low kidney function, elevated parathyroid hormone, higher cortical porosity, and compromised mechanical properties. NAC treatment had mixed effects on oxidative stress markers, significantly reducing TBARS (a measure of lipid peroxidation) while not affecting 8-OHdG (a marker of DNA oxidation) levels. AGE levels in the bone were elevated in CKD animals and were reduced with NAC although this did not translate to a benefit in bone mechanical properties. In conclusion, NAC failed to significantly improve bone architecture/geometry/mechanical properties in our rat model of progressive CKD.

N-acetyl-l-cysteine exacerbates kidney dysfunction caused by a chronic high-sodium diet in renal ischemia and reperfusion rats

AIMS

To investigate the effect of long-term N-acetyl-l-cysteine (NAC) treatment in Wistar rats subjected to renal ischemia and reperfusion (IR) and a chronic high‑sodium diet (HSD).

MAIN METHODS

Adult male Wistar rats received an HSD (8.0% NaCl) or a normal‑sodium diet (NSD; 1.3% NaCl) and NAC (600 mg/L) or normal drinking water starting at 8 weeks of age. At 11 weeks of age, the rats from both diet and NAC or water treatment groups underwent renal IR or Sham surgery and were followed for 10 weeks. The study consisted of six animal groups: NSD + Sham + water; NSD + IR + water; NSD + IR + NAC; HSD + Sham + water; HSD + IR + water; and HSD + IR + NAC.

KEY FINDINGS

Tail blood pressure (tBP) increased with IR and NAC treatment in the NSD group but not in the HSD group. The serum creatinine level was higher after NAC treatment in both diet groups, and creatinine clearance was decreased in only the HSD + IR + NAC group. Albuminuria increased in the HSD + IR + water group and decreased in the HSD + IR + NAC group. Kidney mass was increased in the HSD + IR group and decreased with NAC treatment. Renal fibrosis was prevented with NAC treatment and cardiac fibrosis was decreased with NAC treatment in the HSD + IR group.

SIGNIFICANCE

NAC treatment promoted structural improvements, such as decreased albuminuria and fibrosis, in the kidney and heart. However, NAC could not recover kidney function or blood pressure from the effects of IR associated with an HSD. Therefore, in general, long-term NAC treatment is not effective and is deleterious to recovery of function after kidney injury.

Neuromodulatory Effect of Thymoquinone in Attenuating Glutamate-Mediated Neurotoxicity Targeting the Amyloidogenic and Apoptotic Pathways

Overexposure of the glutamatergic N-methyl-d-aspartate (NMDA) receptor to the excitatory neurotransmitter l-glutamic acid leads to neuronal cell death by excitotoxicity as a result of increased intracellular Ca²⁺, mitochondrial dysfunction, and apoptosis. Moreover, it was previously reported that prolonged activation of the NMDA receptor increased beta-amyloid (Aβ) levels in the brain. Thymoquinone (TQ), the active constituent of Nigella sativa seeds, has been shown to have potent antioxidant and antiapoptotic effects. The aim of the present study was to explore the neuromodulatory effects of different doses of TQ (2.5 and 10 mg/kg) against apoptotic cell death and Aβ formation resulting from glutamate administration in rats using vitamin E as a positive control. Behavioral changes were assessed using Y-maze and Morris water maze tests for evaluating spatial memory and cognitive functions. Caspase-3, Lactate dehydrogenase, Aβ-42, and cytochrome c gene expression were determined. TQ-treated groups showed significant decreases in the levels of all tested biochemical and behavioral parameters compared with the glutamate-treated group. These findings demonstrated that TQ has a promising neuroprotective activity against glutamate-induced neurotoxicity and this effect is mediated through its anti-amyloidogenic, antioxidant, and antiapoptotic activities.

The role of vitamin E in the prevention of zoledronic acid-induced nephrotoxicity in rats: a light and electron microscopy study

INTRODUCTION

Bisphosphonates are widely used in metastatic cancer such as prostate and breast cancer, and their nephrotoxic effects have been established previously. In this study we aimed to evaluate both the nephrotoxic effects of zoledronic acid (ZA) and the protective effects of vitamin E (Vit-E) on this process under light and electron microscopy.

MATERIAL AND METHODS

A total of 30 male Sprague-Dawley rats were divided into 3 groups. The first group constituted the control group. The second group was given i.v. ZA of 3 mg/kg once every 3 weeks for 12 weeks from the tail vein. The third group received the same dosage of ZA with an additional i.m. injection of 15 mg Vit-E every week for 12 weeks. Tissues were taken 4 days after the last dose of ZA for histopathological and ultrastructural evaluation. Paller score, tubular epithelial thickness and basal membrane thickness were calculated for each group.

RESULTS

For group 2, the p-values are all < 0.001 for Paller score, epitelial thickness, and basal membrane thickness. For group 3 (ZA + Vit. E), the p-values are < 0.001 for Paller score, 0.996 for epitelial thickness, and < 0.001 basal membrane thickness. Significant differences were also observed in ultrastructural changes for group 2. However, adding Vit-E to ZA administration reversed all the histopathological changes to some degree, with statistical significance.

CONCLUSIONS

Administration of ZA had nephrotoxic effects on rat kidney observed under both light and electron microscopy. Concomitant administration of Vit-E significantly reduces toxic histopathological effects of ZA.

Bridging translation for acute kidney injury with better preclinical modeling of human disease

The current lack of effective therapeutics for patients with acute kidney injury (AKI) represents an important and unmet medical need. Given the importance of the clinical problem, it is time for us to take a few steps back and reexamine current practices. The focus of this review is to explore the extent to which failure of therapeutic translation from animal studies to human studies stems from deficiencies in the preclinical models of AKI. We will evaluate whether the preclinical models of AKI that are commonly used recapitulate the known pathophysiologies of AKI that are being modeled in humans, focusing on four common scenarios that are studied in clinical therapeutic intervention trials: cardiac surgery-induced AKI; contrast-induced AKI; cisplatin-induced AKI; and sepsis associated AKI. Based on our observations, we have identified a number of common limitations in current preclinical modeling of AKI that could be addressed. In the long term, we suggest that progress in developing better preclinical models of AKI will depend on developing a better understanding of human AKI. To this this end, we suggest that there is a need to develop greater in-depth molecular analyses of kidney biopsy tissues coupled with improved clinical and molecular classification of patients with AKI.

Amikacin induced renal damage and the role of the antioxidants on neonatal rats

Amikacin (AK) is frequently used on the treatment of Gram-negative infections on neonates, but its usage is restricted because of nephrotoxicity. In this study, on neonatal rats, we aimed to investigate the effects of erythropoietin and vitamin E on AK induced nephrotoxicity. A total of 35 newborn Wistar Albino rats were divided into four groups: (1) injected with saline (serum physiological was administered to placebo controls), (2) injected with AK (1200 mg/kg), (3) injected with AK + vitamin E (150 mg/kg), (4) injected with AK + erythropoietin (EPO) (300 IU/kg/day). In renal tissue, AK levels were significantly high in all groups except the control. Tissue malondialdehyde (MDA) and nitric oxide (NO) levels were statistically higher in AK -treated group than the control. MDA and NO levels were significantly decreased with the administration of vitamin E and EPO. Glutathione peroxidase (GPX) levels were statistically low in AK group compared with the controls. The levels of GPX, in vitamin E group, were increased significantly. However, superoxide dismutase and catalase levels were not significantly different in none of the groups. Insulin-like growth factor-1 values in AK, EPO and vitamin E groups were significantly higher than the control group. Histomorphological changes such as tubular epithelial necrosis were seen in AK treated group. Histopathological improvements observed with EPO and vitamin E administration. AK nephrotoxicity is related to oxidative stress and is supported with biochemical and histopathological findings. Vitamin E and EPO, as antioxidants, can be useful renoprotective agents for ameliorating AK induced nephrotoxicity in neonates.

Enhanced renoprotective effect of IGF-1 modified human umbilical cord-derived mesenchymal stem cells on gentamicin-induced acute kidney injury

The therapeutic action of umbilical cord-derived mesenchymal stem cells (UC-MSCs) against acute kidney injury (AKI) has been demonstrated by several groups. However, how to further enhance the renoprotective effect of UC-MSCs and improve the therapy effect, are still unclear. In this study, we mainly investigated whether insulin-like growth factor-1 (IGF-1)-modified UC-MSCs hold an enhanced protective effect on gentamicin-induced AKI in vivo. Our results indicated that the IGF-1 overexpression could enhance the therapeutic action of human UC-MSCs, and the AKI rats treated with IGF-1-overexpressed UC-MSCs (UC-MSCs-IGF-1) showed better recovery of biochemical variables in serum or urine associated with renal function, histological injury and renal apoptosis, compared with AKI rats treated with normal UC-MSCs. RNA microarray analysis indicated that some key genes in the signal pathways associated with anti-oxidation, anti-inflammatory, and cell migratory capacity were up-regulated in UC-MSCs-IGF-1, and the results were further confirmed with qPCR. Furthermore, a series of detection in vitro and in vivo indicated that the UC-MSCs-IGF-1 hold better anti-oxidation, anti-inflammatory, and cell migratory capacity for IGF-1 overexpression. Thus, our study indicated that enhancement of UC-MSCs bioactivities with IGF-1 overexpression could increase the UC-MSCs therapeutic potential and further developed a new therapeutic strategy for the treatment of AKI.

Chitosan Prevents Gentamicin-Induced Nephrotoxicity via a Carbonyl Stress-Dependent Pathway

Aminoglycosides are widely used to treat infections; however, their applications are limited by nephrotoxicity. With the increase of antibiotic resistance, the use of aminoglycosides is inevitable. Low-molecular-weight chitosan (LMWC) has shown renal protective effects in dialysis patients. However, no study has evaluated LMWC for preventing aminoglycoside-induced nephrotoxicity or determined the mechanisms underlying the renal protective effects. In this study, LMWC (165 or 825 mg/kg/day) or metformin (100 mg/kg/day) was orally administered for 13 days to rats with nephropathy induced by gentamicin (GM), a kind of aminoglycoside (150 mg/kg/day i.p. for 6 days). Both LMCW doses improved renal function. Serum creatinine levels improved in rats treated with 165 and 825 mg/kg/day LMWC (from 2.14 ± 0.74 mg/dL to 1.26 ± 0.46 mg/dL and 0.69 ± 0.12 mg/dL, resp., P < 0.05). Blood urea nitrogen levels were also improved in these rats (from 73.73 ± 21.13 mg/dL to 58.70 ± 22.71 mg/dL and 28.82 ± 3.84 mg/dL, resp., P < 0.05). Additionally, renal tissue morphology improved after LMWC treatment, and accumulation of renal methylglyoxal, a damage factor associated with carbonyl stress, was reversed. These results show that LMWC prevents GM-induced renal toxicity via a carbonyl stress-dependent pathway.

Protective effect of naringenin against gentamicin-induced nephrotoxicity in rats

The protective effect of naringenin, a flavonoid compound isolated from citrus fruits, was investigated against nephrotoxicity induced by gentamicin (80mgkg(-1)/day, i.p., for eight days) in rats. Naringenin treatment (50mgkg(-1)/day, p.o.) was administered for eight days, starting on the same day of gentamicin administration. Gentamicin caused significant elevations of serum creatinine, and kidney tissue levels of malondialdehyde, nitric oxide, and interleukin-8, and a significant decrease in renal glutathione peroxidase activity. Naringenin treatment significantly ameliorated the changes in the measured biochemical parameters resulted from gentamicin administration. Also, naringenin markedly attenuated the histopathological renal tissue injury observed with gentamicin. Immunohistochemical examinations showed that naringenin significantly reduced the gentamicin-induced expression of kidney injury molecule-1, vascular endothelial growth factor, inducible nitric oxide synthase, and caspase-9, and increased survivin expression in the kidney tissue. It was concluded that naringenin, through its antioxidant and anti-inflammatory effects, may represent a therapeutic option to protect against gentamicin nephrotoxicity.

Assessment of nutrient supplement to reduce gentamicin-induced ototoxicity

Gentamicin is an aminoglycoside antibiotic used to treat gram-negative bacterial infections. Treatment with this antibiotic carries the potential for adverse side effects, including ototoxicity and nephrotoxicity. Ototoxic effects are at least in part a consequence of oxidative stress, and various antioxidants have been used to attenuate gentamicin-induced hair cell death and hearing loss. Here, a combination of nutrients previously shown to reduce oxidative stress in the hair cells and attenuate hearing loss after other insults was evaluated for potential protection against gentamicin-induced ototoxicity. Guinea pigs were maintained on a nutritionally complete standard laboratory animal diet or a diet supplemented with β-carotene, vitamins C and E, and magnesium. Three diets with iterative increases in nutrient levels were screened; the final diet selected for study use was one that produced statistically reliable increases in plasma levels of vitamins C and E and magnesium. In two separate studies, significant decreases in gentamicin-induced hearing loss at frequencies including 12 kHz and below were observed, with less benefit at the higher frequencies. Consistent with the functional protection, robust protection of both the inner and outer hair cell populations was observed, with protection largely in the upper half of the cochlea. Protection was independently assessed in two different laboratories, using two different strains of guinea pigs. Additional in vitro tests did not reveal any decrease in antimicrobial activity with nutrient additives. Currently, there are no FDA-approved treatments for the prevention of gentamicin-induced ototoxicity. The current data provide a rationale for continued investigations regarding translation to human patients.

Carfilzomib-related acute kidney injury may be prevented by N-acetyl-L-cysteine

Carfilzomib is a second-generation epoxyketone proteasome inhibitor that is approved for treatment of relapsed and refractory multiple myeloma. Phase 2 trials have reported that 25% of treated patients have renal adverse effects. Pre-renal/vasoconstriction-related insult from this chemotherapy agent has been documented. We describe a case of a 78-year-old man with refractory multiple myeloma with acute kidney injury associated with carfilzomib treatment. We show that use of N-acetyl-l-cysteine in our patient partially mitigated the renal injury upon re-challenge. This case report hypothesizes that acute renal injury from carfilzomib is caused by vasoconstriction of the renal vessels, which may be prevented by N-acetyl-l-cysteine.

Time-series pattern of gene expression profile in gentamycin-induced nephrotoxicity

There have been many studies investigating the genomic biomarker and/or molecular mechanism of nephrotoxicity using microarray. However, most of these researches were carried out by studying gene expression changes at one specific time point. As gene expression varies with time and disease stage, the current study investigated the time-series pattern of gene expression in a rat model using a typical nephrotoxic compound. Rats were administrated with 80 mg/kg gentamycin or saline by intramuscular injection for 14 consecutive days followed by a 28-d recovery. Rats were scarified on D2, D4, D8, D15 and Recovery Day (R29), when kidneys were obtained for whole-genome microarray analysis and histological examination. Urine was collected at each necropsy for kidney injury molecular-1 (KIM-1) analysis. The KIM-1 detection and histological examination confirmed the nephrotoxicity. After differentially expression genes (DEGs) identification, there were 4360 and 4323 regulated genes for females and males, respectively. However, few overlapping expression genes co-regluated at each time point were found. By principle component analysis (PCA) and hierarchical cluster, the gene expression patterns were observed to be apparently associated with the disease stage. GO Annotation showed (1) immune response and related process, response to wounding, cell locomotion on D2; (2) cell death and apoptosis was also noted on D4; (3) processes of organic acid or carboxylic acid, apoptosis or cell death on D8 and D15; (4) processes of cell cycle, mitosis, division cell cycle on R29. In conclusion, the authors mapped the time-series gene expression patterns at the initiation, development and recovery stage of gentamycin-induced nephrotoxicity.

Signalling mechanisms involved in renal pathological changes during cisplatin-induced nephropathy

CONTEXT

Cisplatin, a coordination platinum complex, is used as a potential anti-neoplastic agent, having well recognized DNA-damaging property that triggers cell-cycle arrest and cell death in cancer therapy. Beneficial chemotherapeutic actions of cisplatin can be detrimental for kidneys.

BACKGROUND

Unbound cisplatin gets accumulated in renal tubular cells, leading to cell injury and death. This liable action of cisplatin on kidneys is mediated by altered intracellular signalling pathways such as mitogen-activated protein kinase (MAPK), extracellular regulated kinase (ERK), or C- Jun N terminal kinase/stress-activated protein kinase (JNK/SAPK). Further, these signalling alterations are responsible for release and activation of tumour necrosis factor (TNF-α), mitochondrial dysfunction, and apoptosis, which ultimately cause the renal pathogenic process. Cisplatin itself enhances the generation of reactive oxygen species (ROS) and activation of nuclear factor-κB (NF-κB), inflammation, and mitochondrial dysfunction, which further leads to renal apoptosis. Cisplatin-induced nephropathy is also mediated through the p53 and protein kinase-Cδ (PKCδ) signalling pathways.

OBJECTIVE

This review explores these signalling alterations and their possible role in the pathogenesis of cisplatin-induced renal injury.