The effect of L-carnitine on oxidative stress responses of experimental contrast-induced nephropathy in rats

Protective effects of l-carnitine on isoprenaline -induced heart and kidney dysfunctions: Modulation of inflammation and oxidative stress-related gene expression in rats

The aim of this study was to evaluate the effect of l-carnitine (L-CAR) treatment on isoprenaline (ISO) administered kidney and heart impairment in male Long Evans rats. Four groups of rats were engaged in this study such as control, ISO, control + L-CAR, and ISO + L-CAR, where n = 6 in each group. The rats were also provided with chow food and water ad libitum. At the end of the study, all rats were sacrificed, and blood and tissue samples were collected for bio-chemical analysis. Oxidative stress parameters and antioxidant enzyme activities were determined in plasma and tissues. Antioxidant and inflammatory genes expression were analyzed in the kidney cortex, and histopathological studies of kidney tissues were performed. This study showed that creatinine and uric acid in plasma were significantly increased in ISO-administered rats. l-carnitine treatment lowered the uric acid and creatinine level. ISO-administered rats showed increased lipid peroxidation and declined levels of antioxidant enzymes activities in kidneys and heart. l-carnitine treatment restored antioxidant enzymes activities and protect against oxidative stress in kidney and heart. This effect is correlated with the restoration of Nrf-2-HO-1 genes expression followed by increased SOD and catalase genes expression in the kidney. l-carnitine treatment also prevented the TNF-α, IL-6, and NF-кB expression in kidneys of ISO administered rats. Histopathology staining showed that l-carnitine treatment prevented kidney damage and collagen deposition in ISO administered rats. The result of this study exhibited that l-carnitine treatment reduced oxidative stress and increased antioxidant enzyme activities by enhancing antioxidant genes expression in ISO administered rats.

Carnitine, apelin and resveratrol regulate mitochondrial quality control (QC) related proteins and ameliorate acute kidney injury: role of hydrogen peroxide

Mitochondrial impairment is recognised as a prominent feature in kidney diseases. Therefore, we investigated whether the effects of resveratrol, L-carnitine, and apelin in the acute kidney injury model were associated with modulation of mitochondrial quality control (QC) related proteins, intra-renal renin-angiotensin (RAS) activity, adenosine triphosphate (ATP) and Na⁺-K⁺ ATPase gene expression. Rats were randomly assigned to 7 groups: Distilled water injected control group, DMSO injected control group, distilled water injected lipopolysaccharide (LPS) group, DMSO injected LPS group, resveratrol injected LPS group, L-carnitine injected LPS group and apelin 13 injected LPS group. We observed that resveratrol, L-carnitine, and apelin treatments altered mitochondrial (QC) related protein levels (Pink1, Parkin, BNIP-3, Drp1, and PGC1α), decreased intra-renal RAS parameters, increased ATP level and upregulated Na⁺-K⁺ ATPase gene expression in renal tissue. Our results provide new insight into the role of mitochondrial quality control and how different antioxidants exert beneficial effects on acute kidney injury.

Upregulating carnitine palmitoyltransferase 1 attenuates hyperoxia-induced endothelial cell dysfunction and persistent lung injury

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants that may cause long-term lung dysfunction. Accumulating evidence supports the vascular hypothesis of BPD, in which lung endothelial cell dysfunction drives this disease. We recently reported that endothelial carnitine palmitoyltransferase 1a (Cpt1a) is reduced by hyperoxia, and that endothelial cell-specific Cpt1a knockout mice are more susceptible to developing hyperoxia-induced injury than wild type mice. Whether Cpt1a upregulation attenuates hyperoxia-induced endothelial cell dysfunction and lung injury remains unknown. We hypothesized that upregulation of Cpt1a by baicalin or L-carnitine ameliorates hyperoxia-induced endothelial cell dysfunction and persistent lung injury.

METHODS

Lung endothelial cells or newborn mice (< 12 h old) were treated with baicalin or L-carnitine after hyperoxia (50% and 95% O2) followed by air recovery.

RESULTS

We found that incubation with L-carnitine (40 and 80 mg/L) and baicalin (22.5 and 45 mg/L) reduced hyperoxia-induced apoptosis, impaired cell migration and angiogenesis in cultured lung endothelial cells. This was associated with increased Cpt1a gene expression. In mice, neonatal hyperoxia caused persistent alveolar and vascular simplification in a concentration-dependent manner. Treatment with L-carnitine (150 and 300 mg/kg) and baicalin (50 and 100 mg/kg) attenuated neonatal hyperoxia-induced alveolar and vascular simplification in adult mice. These effects were diminished in endothelial cell-specific Cpt1a knockout mice.

CONCLUSIONS

Upregulating Cpt1a by baicalin or L-carnitine ameliorates hyperoxia-induced lung endothelial cell dysfunction, and persistent alveolar and vascular simplification. These findings provide potential therapeutic avenues for using L-carnitine and baicalin as Cpt1a upregulators to prevent persistent lung injury in premature infants with BPD.

L-Carnitine effect on induced hyperlipidemia on premature rats: fertility profile

This study was designed to investigate the effect of hypercholesterolemia on the reproductive performance of premature male rats and to evaluate the influence of L-Carnitine (CAR) in maintaining their fertility. Sixty rats were divided randomly into three groups. Control group (CG n=20 rats), cholesterol feeding group 1 (CFG1 n=20 rats) fed 1.5% cholesterol with diet for one month, and cholesterol feeding group 2 (CFG2 n=20 rats) fed 1.5% cholesterol with diet + CAR 150 mg/kg body weight (B.W.) given by water for one month. Results showed a significant increase in body weight of CFG1 compared with CG and CFG2. The lipid profile of CFG1 after one month of feeding cholesterol showed a significant increase in serum cholesterol and triglyceride compared with CG and with the group that watered by CAR and CFG2. Results of sperms parameters in CGF2 showed a significant increase in sperms count with sperms live percentage and a significant decrease in sperms abnormalities percentage compared with CGF1 and CG. The hormonal profile showed a significant decrease in serum testosterone levels in rats from CFG1 compared with CFG2 and CG. In conclusion, CAR is a powerful antioxidant that can maintain the parameters of sperms of hypercholesterolemic premature rats, which may enhance the fertilizing ability of subfertile rats that may occur due to hyperlipidemia.

L-carnitine alleviated acute lung injuries induced by potassium dichromate in rats: involvement of Nrf2/HO-1 signaling pathway

The activation of the Nrf2/HO-1 signaling pathway regulates cellular antioxidant stress and exerts anti-inflammatory and cytoprotective effects against acute lung injury (ALI). The present study aimed to evaluate the therapeutic role of L-carnitine (LC) against potassium dichromate (PD) - induced acute lung injury in adult male albino rats via modulation of Nrf2/HO-1 signaling pathway. For this purpose, forty rats were randomly allocated into 5 groups (8 rats each). The normal group received intranasal (i.n.) saline, while the ALI group received intranasal instillation of PD as a single dose of 2 mg/kg. The 3d - 5th groups received PD then after 24 h administered L-carnitine (25, 50 and 100 mg/kg; orally) for 3 consecutive days. The therapeutic effect of L-carnitine was evaluated by assessment of serum levels of glutathione (GSH) and malondialdehyde (MDA) along with measurement of lung contents of transforming growth factor β1 (TGFβ1), protein kinase B (AKT), Nuclear factor erythroid-2 related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 enzyme (NQO1) and glutathione cysteine ligase modifier subunit (GCLM) expression. Post-treatment with L-carnitine effectively increased the levels of GSH and AKT, elevated Nrf2 and its target genes and decreased the levels of MDA and TGFβ1 in comparison with PD control rats. Additionally, L-carnitine effectively reduced the number of goblet cell, inhibited the mucus formation in bronchioles and interstitial inflammatory infiltrate as well as alleviated the destruction of alveolar walls, and the congestion of blood vessels in lung tissue induced by PD. Our findings showed that L-carnitine may be a promising therapeutic agent against PD-induced acute lung injury.

A Dose-Dependent Effect of Carnipure® Tartrate Supplementation on Endurance Capacity, Recovery, and Body Composition in an Exercise Rat Model

The objective of this work is to investigate the effects of Carnipure^® Tartrate (CT) supplementation with or without exercise on endurance capacity, recovery, and fatigue by assessing time to exhaustion as well as body weight and composition in rats. In addition, antioxidant capacity has been evaluated by measuring malondialdehyde (MDA) levels and antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT; glutathioneperoxidase; GSHPx) activities. Fifty-six male Wistar rats were divided into eight groups including seven rats each. A control group did not receive CT nor exercise. Another control group received 200 mg/kg CT without exercise. The other six groups of rats went through an exercise regimen consisting of a 5-day training period with incremental exercise capacity, which was followed by 6 weeks of the run at 25 m/min for 45 min every day. CT was supplemented at 0, 25, 50, 100, 200, and 400 mg/kg per day during the 6 weeks. Rats submitted to exercise and supplemented with CT had a significant and dose-dependent increase in time to exhaustion and this effect seems to be independent of exercise (p < 0.05). Additionally, recovery and fatigue were improved, as shown by a significant and dose-dependent decrease in myoglobin and lactic acid plasma levels, which are two markers of muscle recovery. CT supplementation led to a dose-response decrease in body weight and visceral fat. These effects become significant at 200 and 400 mg/kg doses (p < 0.05). Additionally, the antioxidant capacity was improved, as shown by a significant and dose-dependent increase in SOD, CAT, and GSHPx. Serum MDA concentrations decreased in exercising rats with CT supplementation. CT supplementation led to a decrease in serum glucose, triglycerides, and total cholesterol concentrations with the lowest levels observed at 400 mg/kg dose (p < 0.05). These effects correlated with a significant dose-dependent increase in serum total L-carnitine, free L-carnitine, and acetyl-carnitine, which linked the observed efficacy to CT supplementation. These results demonstrate that CT supplementation during exercise provides benefits on exercise performance, recovery, and fatigue as well as improved the lipid profile and antioxidant capacity. The lowest dose leads to some of these effects seen in rats where 25 mg/kg corresponds to 250 mg/day as a human equivalent.

The Nutraceutical Value of Carnitine and Its Use in Dietary Supplements

Carnitine can be considered a conditionally essential nutrient for its importance in human physiology. This paper provides an updated picture of the main features of carnitine outlining its interest and possible use. Particular attention has been addressed to its beneficial properties, exploiting carnitine's properties and possible use by considering the main in vitro, in animal, and human studies. Moreover, the main aspects of carnitine-based dietary supplements have been indicated and defined with reference to their possible beneficial health properties.

Fatty Acid Oxidation Protects against Hyperoxia-induced Endothelial Cell Apoptosis and Lung Injury in Neonatal Mice

In neonates, hyperoxia or positive pressure ventilation causes continued lung injury characterized by simplified vascularization and alveolarization, which are the hallmarks of bronchopulmonary dysplasia. Although endothelial cells (ECs) have metabolic flexibility to maintain cell function under stress, it is unknown whether hyperoxia causes metabolic dysregulation in ECs, leading to lung injury. We hypothesized that hyperoxia alters EC metabolism, which causes EC dysfunction and lung injury. To test this hypothesis, we exposed lung ECs to hyperoxia (95% O₂/5% CO₂) followed by air recovery (O₂/rec). We found that O₂/rec reduced mitochondrial oxidative phosphorylation without affecting mitochondrial DNA copy number or mitochondrial mass and that it specifically decreased fatty acid oxidation (FAO) in ECs. This was associated with increased ceramide synthesis and apoptosis. Genetic deletion of carnitine palmitoyltransferase 1a (Cpt1a), a rate-limiting enzyme for carnitine shuttle, further augmented O₂/rec-induced apoptosis. O₂/rec-induced ceramide synthesis and apoptosis were attenuated when the FAO was enhanced by l-carnitine. Newborn mice were exposed to hyperoxia (>95% O₂) between Postnatal Days 1 and 4 and were administered l-carnitine (150 and 300 mg/kg, i.p.) or etomoxir, a specific Cpt1 inhibitor (30 mg/kg, i.p.), daily between Postnatal Days 10 and 14. Etomoxir aggravated O₂/rec-induced apoptosis and simplified alveolarization and vascularization in mouse lungs. Similarly, arrested alveolarization and reduced vessel numbers were further augmented in EC-specific Cpt1a-knockout mice compared with wild-type littermates in response to O₂/rec. Treatment with l-carnitine (300 mg/kg) attenuated O₂/rec-induced lung injury, including simplified alveolarization and decreased vessel numbers. Altogether, enhancing FAO protects against hyperoxia-induced EC apoptosis and lung injury in neonates.

Neuroprotective efficacy of nano-CoQ against propionic acid toxicity in rats: Role of BDNF and CREB protein expressions

Propionic acid (PRA) is used as a food preservative. This study was aimed to investigate the neuroprotective effect of acetyl-l-carnitine (ALC) and nano-Coenzyme Q (N-CoQ) on brain intoxication induced by PRA in rats. Rats were divided into five groups: group I: control; group II: received PRA; group III: received ALC; group IV: received N-CoQ; and group V: received ALC and N-CoQ for 5 days. The antioxidants in question markedly ameliorated serum interleukin-1β and tumor necrosis factor-α, and brain NO, lipid peroxide, glutathione, and superoxide dismutase levels as well as protein expression of brain-derived neurotrophic factor (BDNF) and P-cyclic-AMP response element-binding protein (CREB) that were altered by a toxic dose of PRA, as well as histopathological alterations, including improvement of the cerebellum architecture. Interestingly, the combination therapy of ALC and N-CoQ achieved the most neuroprotective effect compared with monotherapies. The current study established that N-CoQ is considered as a useful tool to prevent brain injury induced by PRA. BDNF and CREB proteins are involved in both PRA neurotoxicity and treatment.

Characterization of Polysaccharides Extracted from Sargassum fusiforme and Its Effective Prevention of Contrast-Induced Nephropathy via Enhancing Antioxidant Capacity

Contrast-induced nephropathy (CIN) is a common complication in patients with coronary arteriography, and oxidative stress is involved in the CIN pathogenesis. Sargassum fusiforme (SF) is a brown seaweed with medicinal value, and its polysaccharides have good antioxidant activity. In this study, the crude polysaccharides (cSFP-C) were extracted by cold water, precipitated by ethanol, purified by CaCl2, and detected with high contents of sulfate radical and fucose. cSFP-C is composed of glucose, glucuronic acid, xylose, rhamnose, mannose, galactose, and fucose with a molar ratio of 1.0 : 0.4 : 5.6 : 1.2 : 1.7 : 12.3 : 56.1. The cSFP-C has the typical absorption of polysaccharides. Antioxidation assays in vitro showed that cSFP-C exhibited superoxide radical scavenging activity which was better than the hot water-extracted crude polysaccharides (cSFP-H). 20 rats were divided into 4 groups (n=5): sham group; CIN group; CIN+cSFP-C group, and cSFP-C group. The CIN+cSFP-C group and cSFP-C group were pretreated intragastrically with cSFP-C at a dose of 9.45 g/kg twice daily for 5 consecutive days. Then, the CIN group and CIN+cSFP-C group were given indomethacin to develop CIN. The in vivo results showed that cSFP-C could decrease blood creatinine and urea nitrogen, inhibiting pathological injury in the renal tissues. The MDA content of renal tissues was decreased, while the activity of SOD was increased. The crude sulfated polysaccharides extracted from S. fusiforme have a renoprotective effect on oxidative stress to alleviate the kidney injury in CIN rats.

Effects of probucol on contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention

OBJECTIVE

This study was performed to explore the effects of probucol on contrast-induced acute kidney injury (CIAKI) in patients with coronary heart disease undergoing percutaneous coronary intervention (PCI).

METHODS

In total, 220 patients undergoing PCI were randomly assigned to either the control group (hydration from 12 hours before to 12 hours after contrast administration; n = 110) or the probucol group (hydration plus probucol 500 mg twice daily 1 day before and 3 days after the operation; n = 110). The primary endpoint was the occurrence of serum creatinine (Scr)-based CIAKI, defined as an absolute increase in Scr by 0.5 mg/dl (44.2 μmol/L) or a relative 25% increase from baseline within 48 to 72 hours after exposure to contrast medium. The secondary outcomes were composite variations in Scr, blood urea nitrogen (BUN), creatinine clearance rate (Ccr) within 48 to 72 hours, and major adverse events during hospitalization or the 7-day follow-up period after PCI.

RESULTS

The overall incidence of Scr-based CIAKI was 7.3% (16/220): 5.5% (6/110) in the control group and 9.1% (10/110) in the probucol group (χ = 1.078, P = .298). There were no significant differences in the occurrence rate of major adverse events during hospitalization or the 7-day follow-up period after PCI between the groups. Multivariate logistic regression analysis showed that probucol was not an independent protective factor for CIAKI (odds ratio, 1.825; 95% confidence interval, 0.639-5.212; P = .261). However, hydration was an independent protective factor (odds ratio, 0.997; 95% confidence interval, 0.995-0.999; P = .004).

CONCLUSION

Probucol cannot effectively reduce the incidence of CIAKI through its anti-inflammatory and antioxidative stress effects.

Sirtuin 3 deficiency aggravates contrast-induced acute kidney injury

Background

Sirtuin 3 (Sirt3) is a key regulator of energy metabolism and oxidative stress. To investigate the role of Sirt3 in contrast-induced acute kidney injury (CIAKI), we established the model both in vivo and in vitro to explore the potential mechanisms.

Methods

In vivo, we established CIAKI models in wild-type (WT) and Sirt3-knockout (Sirt3-KO) mice. Blood urea nitrogen (BUN) and serum creatinine (Scr) were detected by enzyme-linked immunosorbent assay, Glomerular Filtration Rate (GFR) and creatinine clearance were also investigated. We detected the production of reactive oxygen species (ROS) via 2′7′-dichlorodihydro-fluorescein diacetate. The expressions of Sirt3, oxidative stress and apoptosis related markers (MnSOD, Catalase, Acetyl-MnSOD K68, Nox4, Bax, Bcl-2 and Caspase3) were measured and analyzed. In addition, we observed the effect of nicotinamide riboside (NR) on CIAKI in WT and Sirt3-KO mice. In vitro, Sirt3 was knocked out by siRNA transfection method in HK-2 cells. Sirt3, ROS, oxidative stress and apoptosis markers in HK-2 cells were also measured.

Results

Our data demonstrated that the levels of Scr and BUN in Sirt3-KO mice were increased while the levels of the GFR and creatinine clearance were decreased in CIAKI mice. In Sirt3-KO or siRNA groups, the activities of MnSOD and Catalase were markedly down-regulated. Also, the expression of Caspase3 were markedly increased and the ratio of Bcl-2/Bax was decreased, while the ROS level was increased in Sirt3 deficiency groups. NR ameliorated CIAKI in WT mice but not in Sirt3-KO mice.

Conclusion

Our results suggest that Sirt3 deficiency aggravates contrast-induced acute kidney injury. Sirt3 is critical in NR-mediated renoprotection in CIAKI.

Possible involvement of tetrahydrobiopterin in the disturbance of redox homeostasis in sepsis - Induced brain dysfunction

BACKGROUND AND AIM

Tetrahydrobiopterin (BH4) is an essential co-factor that regulates nitric oxide (NO) and reactive oxygen species (ROS) production by nitric oxide synthases (NOS). In this study, we evaluated the effects of sepsis on BH4 level and redox status in the brain by using the rat model of sepsis-induced by cecal ligation and puncture (CLP) and examined whether BH4 and/or acetyl-L-carnitine (ALC) could prevent the neuronal apoptosis and neurological changes induced by sepsis.

MATERIAL AND METHOD

Male albino rats were randomly and blindly divided into 8 groups: sham, sham + BH4, sham + ALC, sham +BH4+ ALC, CLP, CLP + BH4, CLP + ALC, and CLP+BH4+ ALC. We measured neurological indicators, brain levels of BH4, guanosine triphosphate cyclohydrolase (GTPCH), sepiapterin reductase (SR) and dihydropteridine reductase (DHPR) genes expression (Essential enzymes in BH4 biosynthesis and recycling pathways). We investigated also brain redox status and both endothelial and inducible NOS expressions.

RESULTS

Brain of septic rats demonstrated a reduced BH4 bioavailability, downregulation of BH4 synthetic enzymes, increased production of hydrogen peroxide and impaired antioxidant enzymes activities. Treatments with BH4 and/or ALC increased BH4 level, upregulated BH4 synthetic enzymes expressions, and attenuated oxidative-induced neuronal apoptosis.

CONCLUSION

Our results suggest that BH4 and/or ALC might protect the brain against oxidative stress induced neuronal apoptosis by restoring bioavailability of BH4 and upregulating of BH4 synthetic enzymes in the brain during sepsis.

Contrast-induced nephropathy: Basic concepts, pathophysiological implications and prevention strategies

Contrast-induced nephropathy (CIN) is reversible acute renal failure observed following administration of iodinated contrast media (CM) during angiographic or other medical procedures such as urography. There are various mechanisms through which CM develop their nephrotoxic effects, including oxidative stress and apoptosis. CIN is a real-life, albeit not very rare, entity. Exact pathophysiology remains obscure and no standard diagnostic criteria apply. The Acute Kidney Injury Network criteria was recently employed but its incidence/clinical significance warrants further clarification based on recent methodological advancements, because most published studies to date were contaminated by bias. The current study is a comprehensive review conducted to provide an overview of the basic concepts of CIN and summarize recent knowledge on its pathophysiology and the evidence supporting potential prevention strategies. CIN is expected to increase morbidity, hospital stay and mortality, while all patients scheduled to receive CM should undergo risk assessment for CIN and high-risk patients may be considered candidates for prevention strategies. The value of using compounds with antioxidant properties other than sodium bicarbonate, remains controversial, warranting further clinical investigation.

Nephroprotective Effects of L-Carnitine against Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention: A Randomized Open-Labeled Clinical Trial

Background: L-carnitine may prevent the incidence of AKI by its antioxidant effects and improving circulation in ischemic conditions. The goal of this trial was to evaluate the impact of L-carnitine on contrast-induced nephropathy in patients undergoing elective PCI. Methods: Totally, the patients were randomly allocated to 2 groups. The treatment group received 1 g of L-carnitine orally 3 times a day, 24 hours before the procedure (3 g before PCI) and 2 g after PCI, whereas the control group did not receive L-carnitine. In both groups, the plasma level of neutrophil gelatinase-associated lipocalin (NGAL) was measured at baseline and 12 hours after PCI. Results: Our study was conducted on 202 patients (including 91 vs. 111 patients in the treatment and the control group; 31 (34.1%) vs 33 (29.7%) female in carnitine and control group; and ages include 62.0 ± 9.0 vs 57.0 ± 11.2 years). The median plasma levels of NGAL were not different between the carnitine and control groups at baseline (57 [IQR: 22 - 255] vs. 54 [IQR: 29 - 324]; p value = 0.155) and 12 hours after PCI (71 [IQR: 52 - 129] vs. 70 [IQR: 46 - 153]; p value = 0.925), but the changes in the plasma NGAL from baseline to 12 hours after PCI were different between the 2 groups (5 [IQR:-147 - 30] vs. 17 [IQR: -21 - 41]; p value = 0.010). Conclusion: Our results showed that oral L-carnitine was able to prevent an increase in NGAL following contrast medium administration in patients undergoing PCI. More studies should be performed to fully elucidate the nephroprotective effects of L-carnitine.

Contribution of platelets indices in the development of contrast-induced nephropathy

Contrast-induced nephropathy (CIN) accounts for 10% of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor clinical outcome. The underlying mechanism of the CIN development remains unclear and seems to be multifactorial. The potential link between platelet indices such as mean platelet volume (MPV) and platelet distribution width (PDW) with CIN is unknown. Herein, we aimed to investigate the correlation between MPV and PDW levels with the development of CIN. The incidence of CIN (20.5%) was prospectively evaluated in 430 patients with diagnosis of acute coronary syndrome. Initial creatinine (1.13 ± 0.25 vs. 1.05 ± 0.27 mg/dl, P = 0.01) and PDW (40.1 ± 20.2 vs. 34.5 ± 19.9%, P = 0.02) levels and the total volume of contrast media used (121 ± 61 vs. 94 ± 42 ml, P = 0.01) were higher in patients who developed CIN. MPV was similar between the two groups (P = 0.80). In a univariate regression analysis, age, increased creatinine, uric acid, phosphate, PDW levels and higher total volume of contrast media used were significantly correlated with CIN incidence. However, in a multivariate analysis, only total volume of CM used [odds ratio (OR) 1.011, 95% confidence interval (CI) 1.006-1.016; P = 0.01], increased age (OR 1.026, 95% CI 1.00-1.052; P = 0.05) and increased PDW levels (OR 1.009, 95% CI 1.00-1.022; P = 0.04) remained as the independent predictors of CIN. Among platelet indices, PDW, but not MPV, was associated with CIN development. The clinical significance of such link remains unclear, but may indicate involvement of platelet activation in CIN pathogenesis.

Nephroprotective potential of carnitine against glycerol and contrast-induced kidney injury in rats through modulation of oxidative stress, proinflammatory cytokines, and apoptosis

OBJECTIVE

Contrast media (CM) are a major cause of nephropathy in high-risk patients. The aim of this study was to examine the effects of carnitine (CAR) in advanced nephrotoxicity due to CM administration in rats with glycerol-induced renal functional disorder.

METHODS

40 rats were divided randomly into five groups (n = 8): (1) healthy group; (2) glycerol only (GLY); (3) glycerol and CM (GLY + CM); (4) glycerol, CM and 200 mg kg(-1) carnitine (CAR200, Carnitene(®); Sigma-tau/Santa Farma, Istanbul, Turkey); and (5) glycerol, CM and 400 mg kg(-1) carnitine (CAR400). Kidney injury was induced with a single-dose, intramuscular injection of 10 ml kg(-1) body weight (b.w.) of GLY. CAR was administered intraperitoneally. CM (8 ml kg(-1) b.w. iohexol, Omnipaque™; Opakim Medical Products, Istanbul, Turkey) was infused via the tail vein to the rats in Groups 3-5.

RESULTS

l-carnitine administration significantly decreased serum creatinine and blood urea nitrogen levels. Superoxide dismutase and glutathione activity increased significantly in the treatment groups compared with the nephrotoxic groups. CAR400 significantly reduced malondialdehyde levels to healthy levels. In the treatment groups, tumour necrosis factor (TNF)-α, transforming growth factor 1β, interleukin 1β and caspase-3 gene expression decreased compared with the nephrotoxic groups. TNF-α and nuclear factor kappa-beta (NF-κB) protein expression increased after CM and CAR administration reduced both TNF-α and NF-κB expressions. Histopathologically, hyaline and haemorrhagic casts and necrosis in proximal tubules increased in the nephrotoxicity groups and decreased in the CAR groups.

CONCLUSION

The results reveal that l-carnitine protects the oxidant/antioxidant balance and decreases proinflammatory cytokines and apoptosis in CM-induced nephrotoxicity in rats with underlying pathology.

ADVANCES IN KNOWLEDGE

Depending on the underlying kidney pathologies, the incidence of CM-induced nephropathy (CIN) increases. Therefore, this is the best model to represent clinically observed CIN.

Benefical effects of lycopene against contrast medium-induced oxidative stress, inflammation, autophagy, and apoptosis in rat kidney

Currently, the number of imaging and interventional procedures that use contrast agents (CAs) is gradually increasing. Contrast-induced nephropathy (CIN) is the most important CA-related complication. Oxidative stress plays a significant role in its pathophysiology. Lycopene (LPN) is a natural substance with strong antioxidant capacity. The present study aimed to investigate the potential preventive effects of LPN against CIN. In total, 28 male Wistar albino rats were divided into 4 groups with 7 rats in each group; the groups include normal control group, LPN only group at a dose of 4 mg/kg/day for 10 days, CIN group by administering 10 mg/kg furosemide IM + 10 mg/kg indomethacin IP + 10 ml/kg iomeprol IV following 24-h dehydration, and CIN + LPN group. There were statistically significant increase in urea, creatinine, and malondialdehyde levels (p < 0.001, for all) but a significant decrease in glutathione, superoxide dismutase, catalase, and glutathione peroxidase levels (p < 0.001, for all) in the CIN group compared with the control group. On histological examination, a significant increase of infiltrated inflammatory cells and necrotic degenerative changes were observed in the CIN group and the immunohistochemical examination revealed a significant increase in inflammation (inducible nitric oxide synthase), autophagy (LC3/B), and apoptosis (cleaved caspase 3) in the CIN group compared with the control group (p < 0.05, for all). Significant improvements in these unfavorable parameters were observed with CIN + LPN group compared with the CIN only group. In conclusion, the favorable effects of LPN as an anti-inflammatory, antiautophagic, and antiapoptotic agent in an experimental model of CIN have been demonstrated.