Injection Of Ferric Nitrilotriacetate Research Articles

The Role of Ferric Nitrilotriacetate in Renal Carcinogenesis and Cell Death: From Animal Models to Clinical Implications.

Simple SummaryIron is essential for cellular growth and survival. As a consequence, iron deficiency causes pleiotropic effects on the organism, while iron overload is also deleterious by means of oxidative tissue injury, which causes hepatic cirrhosis, diabetes mellitus, and cardiomyopathy in humans. Non-heme iron comprises ferric ion (Fe(III)), which is much more prominent in the transferrin, ferritin, or labile iron pool than the ferrous ion (Fe(II)); in contrast, ferrous ion yields more reactive oxygen species (ROS) than ferric ion does. In rodents, ferric nitrilotriacetate (Fe-NTA) elicits hepatic and renal oxidized lipids via a glutathione-cycle-dependent iron reduction that eventually causes renal cell carcinoma (RCC). In addition to iron-mediated carcinogenesis, ferroptosis is triggered by the iron-dependent accumulation of lipid peroxidation to lethal levels. Here, the mechanisms of iron- and ROS-mediated RCC and the therapeutic possibility of ferroptosis are discussed.Iron is essential for cellular growth, and various ferroproteins and heme-containing proteins are involved in a myriad of cellular functions, such as DNA synthesis, oxygen transport, and catalytic reactions. As a consequence, iron deficiency causes pleiotropic effects, such as hypochromic microcytic anemia and growth disturbance, while iron overload is also deleterious by oxidative injury. To prevent the generation of iron-mediated reactive oxygen species (ROS), ferritin is synthesized to store excess iron in cells that are consistent with the clinical utility of the serum ferritin concentration to monitor the therapeutic effect of iron-chelation. Among the animal models exploring iron-induced oxidative stress, ferric nitrilotriacetate (Fe-NTA) was shown to initiate hepatic and renal lipid peroxidation and the development of renal cell carcinoma (RCC) after repeated intraperitoneal injections of Fe-NTA. Here, current understanding of Fe-NTA-induced oxidative stress mediated by glutathione-cycle-dependent iron reduction and the molecular mechanisms of renal carcinogenesis are summarized in combination with a summary of the relationship between the pathogenesis of human RCC and iron metabolism. In addition to iron-mediated carcinogenesis, the ferroptosis that is triggered by the iron-dependent accumulation of lipid peroxidation and is implicated in the carcinogenesis is discussed.

Preclinical renal chemo-protective potential of Prunus amygdalus Batsch seed coat via alteration of multiple molecular pathways

Prunus amygdalus Batsch (almond) is a classical nutritive traditional Indian medicine. Along with nutritive with anti-oxidant properties, it is, clinically, used in the treatment of various diseases with underlying anti-oxidant mechanism. This study is an effort to scrutinise the renal protective effect of P. amygdalus Batsch or green almond (GA) seed coat extract and its underlying mechanism in animal model of Ferric nitrilotriacetate (Fe-NTA) induced renal cell carcinoma (RCC). RCC was induced in Swiss Albino Wistar rats by intraperitoneal injection of Fe-NTA. The rats were then treated with ethanolic extract of GA (25, 50 and 100 mg/kg per oral) for 22 weeks. Efficacy of GA administration was evaluated by change in biochemical, renal, macroscopical and histopathological parameters and alterations. Additionally, interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inflammatory mediator including prostaglandin E2 (PGE2), nuclear factor-kappa B (NF-κB) were also observed to explore the possible mechanisms. The oral administration of GA significantly (p < .001) altered the Fe-NTA induced RCC in rats by inhibition of renal nodules, decolourisation of tissues, tumour promoter marker including thymidine 3[H] incorporation, ornithine decarboxylase, renal parameters and anti-oxidant parameters in serum. Additionally, GA treatment significantly (p < .001) down-regulated the IL-6, IL-1β, TNF-α, inflammatory mediators PGE2 and NF-κB in a dose-dependent manner. Histopathology observation supported the renal protective effect of GA by alteration in necrosis, size of Bowman capsules and inflammatory cells. Hence, it can be concluded that GA possesses observable chemo-protective action and effect on Fe-NTA induced RCC via dual inhibition mechanism one by inhibiting free radical generation and second by inhibiting inflammation.

Astaxanthin ameliorates ferric nitrilotriacetate-induced renal oxidative injury in rats.

Daily intake of vegetables can reduce the risk of cancer and lifestyle-related diseases. However, supplementary intake of β-carotene alone has been reported to increase the risk of lung cancer in male cigarette smokers and people who were exposed to asbestos. The mechanism of the antioxidative properties of carotenoids in vivo, especially under oxidative stress conditions, still remains unclear. To investigate the antioxidant properties of dietary compounds, we examined the effects of chemically modified astaxanthin (Ax-C-8) using a rat model of ferric nitrilotriacetate (Fe-NTA)-induced renal oxidative injury. Ax-C-8 demonstrated lethally toxic effects on the rats in a dose-dependent manner. Following supplementation with Ax-C-8 (0.02%, w/w) for 30 days, the rats were euthanized 1, 4 and 24 h after injection of Fe-NTA. After 4 h, Ax-C-8 pretreatment suppressed the elevation of creatinine and blood urea nitrogen and protected the rats from renal tubular necrosis and the formation of 4-hydroxy-2-nonenal-modified proteins. After 24 h, pretreatment with Ax-C-8 maintained the renal antioxidant enzyme levels and renal tubules. Here, we demonstrate the antioxidant effects of Ax-C-8 against Fe-NTA-induced oxidative injury in rats receiving a regular diet. These data suggest that dietary intake of astaxanthin may be useful for the prevention of renal tubular oxidative damage.

301 - Chrysin Suppresses Development of Precancerous Lesions in Kidneys by Regulation of Oxidative Stress, Inflammation, Hyperproliferation and Apoptosis in Murine Model

Chrysin (CH) is a natural compound which belongs to flavonoid family and possesses diverse pharmacological activities like anti-inflammatory, anti-oxidant and anti-cancer. It is found in many plants, honey and propolis. In the present study, we investigated the chemopreventive efficacy of CH against N-nitrosodiethylamine (DEN) initiated and Fe-NTA induced renal carcinogenesis and its role in regulating oxidative injury, histopathological alterations, ultra structural changes, inflammation, hyper proliferation, tumor incidences and apoptosis in the kidneys of Wistar rats. Renal cancer was initiated by single intraperitoneal (i.p.) injection of DEN (200mg/kg b.w) and promoted by twice weekly injection of ferric nitrilotriacetate (Fe-NTA) 9 mg Fe/kg bw for 16 weeks. CH attenuated oxidative injury induced by DEN and Fe-NTA administration. CH supplementation suppressed the development of renal carcinogenesis induced by DEN initiation and Fe-NTA promotion via down regulation of cell proliferation marker like PCNA; tumor incidences and inflammatory mediators like TNF-α, IL-6, NFkB, Cox-2, iNOS. CH up regulated intrinsic apoptotic pathway proteins like bax, bcl-2, caspase-9 and caspase-3 triggering apoptosis. Histopathological and ultra structural alterations further supported our previous findings. Henceforth our results provide a powerful evidence for the chemopreventive efficacy of CH against chemically induced renal carcinogenesis possibly by modulation of multiple molecular pathways.

Inhibition of precancerous lesions development in kidneys by chrysin via regulating hyperproliferation, inflammation and apoptosis at pre clinical stage

Chrysin (CH) is natural, biologically active compound, belongs to flavoniod family and possesses diverse pharmacological activities as anti-inflammatory, anti-oxidant and anti-cancer. It is found in many plants, honey and propolis. In the present study, we investigated the chemopreventive efficacy of CH against N-nitrosodiethylamine (DEN) initiated and Fe-NTA induced precancerous lesions and its role in regulating oxidative injury, hyperproliferation, tumor incidences, histopathological alterations, inflammation, and apoptosis in the kidneys of Wistar rats. Renal cancer was initiated by single intraperitoneal (i.p.) injection of DEN (200 mg/kg bw) and promoted by twice weekly injection of ferric nitrilotriacetate (Fe-NTA) 9 mg Fe/kg bw for 16 weeks. CH attenuated Fe-NTA enhanced renal lipid peroxidation, serum toxicity markers and restored renal anti oxidant armory significantly. CH supplementation suppressed the development of precancerous lesions via down regulation of cell proliferation marker like PCNA; inflammatory mediators like TNF-α, IL-6, NFkB, COX-2, iNOS; tumor incidences. CH up regulated intrinsic apoptotic pathway proteins like bax, caspase-9 and caspase-3 along with down regulation of Bcl-2 triggering apoptosis. Histopathological and ultra structural alterations further confirmed biochemical and immunohistochemical results. These results provide powerful evidence for the chemopreventive efficacy of CH against chemically induced renal carcinogenesis possibly by modulation of multiple molecular pathways.

Chemopreventive efficacy of hesperidin against chemically induced nephrotoxicity and renal carcinogenesis via amelioration of oxidative stress and modulation of multiple molecular pathways

In the present study, chemopreventive efficacy of hesperidin was evaluated against ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and carcinogenesis in wistar rats. Nephrotoxicity was induced by single intraperitoneal injection of Fe-NTA (9mg Fe/kg b.wt). Renal cancer was initiated by the administration of N-nitrosodiethylamine (DEN 200mg/kg b.wt ip) and promoted by Fe-NTA (9mg Fe/kg b.wt ip) twice weekly for 16weeks. Efficacy of hesperidin against Fe-NTA-induced nephrotoxicity was assessed in terms of biochemical estimation of antioxidant enzyme activities viz. reduced renal GSH, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, superoxide dismutase and renal toxicity markers (BUN, Creatinine, KIM-1). Administration of Fe-NTA significantly depleted antioxidant renal armory, enhanced renal lipid peroxidation as well as the levels of BUN, creatinine and KIM-1. However, simultaneous pretreatment of hesperidin restored their levels in a dose dependent manner. Expression of apoptotic markers caspase-3, caspase-9, bax, bcl-2 and proliferative marker PCNA along with inflammatory markers (NFκB, iNOS, TNF-α) were also analysed to assess the chemopreventive potential of hesperidin in two-stage renal carcinogenesis model. Hesperidin was found to induce caspase-3, caspase-9, bax expression and downregulate bcl-2, NFκB, iNOS, TNF-α, PCNA expression. Histopathological findings further revealed hesperidin's chemopreventive efficacy by restoring the renal morphology. Our results provide a powerful evidence suggesting hesperidin to be a potent chemopreventive agent against renal carcinogenesis possibly by virtue of its antioxidant properties and by modulation of multiple molecular pathways.

Oxidation and turnover of renal metallothioneins after an injection of ferric nitrilotriacetate

Metallothioneins (MTs) have demonstrated strong antioxidant properties, however the biological significance of their effect against hydroxyl radical toxicity remains unclear. We investigated the oxidation and turnover of renal MTs in MT-preinduced mice after an injection of ferric nitrilotriacetate (Fe-NTA). Incubation of MTs with Fe-NTA and H2O2 resulted in a loss of their metal-binding properties and a decrease in their thiol concentration independent of binding potential and isoforms. Moreover, in vitro reduction of renal oxidized MT with dithiothreitol (DTT) reversed these oxidative changes. An injection of Fe-NTA oxidized renal preinduced MT in Zn- and Cd-pretreated mice. The metal-binding properties of renal MTs were lost when the Fe-NTA dose was increased. However, analysis of renal MTs using an immunoassay showed that its protein concentration did not decrease 4h after the injection with various Fe-NTA doses. Furthermore, in vitro reduction of renal oxidized MTs with DTT resulted in an increase in the concentration of metals in the MT fraction. These data indicate that radicals produced by Fe-NTA may oxidize MTs in vitro and in vivo. When we investigated the turnover of oxidized MTs in Fe-NTA-treated mice, effects on the concentration of renal 35S-labeled MTs were opposite to those observed in Cd-pretreated mice. The concentration of preinduced 35S-labeled MTs in the kidneys of Cd-pretreated mice showed a significant decrease (p<0.05), whereas that of newly synthesized 35S-labeled MTs showed a considerable increase. These data suggest that degradation of oxidized MTs may be faster than intact MTs. Therefore, the radical scavenging system of MTs may include their induction and degradation during oxidative stress conditions.

Induction of apoptotic change in the rat hippocampus caused by ferric nitrilotriacetate

Iron, a source of oxidative stress, plays a major role in the pathology of neurodegenerative disease. In Alzheimer's disease, the hippocampus is vulnerable to oxidative stress, leading to impairment in memory formation. In our previous study, a brain oxidative reaction was induced after intraperitoneal injection of ferric nitrilotriacetate (Fe-NTA). However, since only a small amount of iron reached the brain in the previous study, Fe-NTA was administered into the hippocampus using an osmotic pump in this study.After continuous injection of Fe-NTA for 2 weeks, a high level of apoptotic change was induced in the hippocampus, in accordance with the iron localization. After injection for 4 weeks, the hippocampus was totally destroyed. A small amount of iron infiltrated into the cerebral cortex and the striatum, and deposition was observed at the choroid plexus and ependymal cells. However, no apoptotic reaction or clear tissue injury was observed in these areas. In addition, muscarinic acetylcholine receptors (M1, M2, and M4) were decreased in both the cortex and hippocampus while it increased in the striatum. Thus, the hippocampus is likely vulnerable to oxidative stress from Fe-NTA, and the oxidative stress is considered to bring the disturbance in the muscarinic acetylcholine receptors.

Oxidative changes in the rat brain by intraperitoneal injection of ferric nitrilotriacetate

Iron is known to be involved in neuronal diseases such as neurodegenerative diseases, brain ischemia and epilepsy. However, it is unclear if a high level of peripheral iron induces these pathological conditions. Since ferric nitrilotriacetate (Fe-NTA), a low molecule iron chelate, causes kidney carcinoma and diabetes in animals due to its strong and unique oxidative stress, it is also considered to cause pathological conditions in the brain. Therefore, we studied brain changes after intraperitoneal (i.p.) injection of Fe-NTA. We investigated iron distribution in the brain and evaluated heme oxygenase (HO)-1 mRNA, IL-6 mRNA and 4-hydroxy-2-nonenal (4-HNE) quantitatively. In addition, changes in muscarinic acetylcholine receptor mRNAs were measured. It was found that iron was localized in the cortex and the hypothalamus, but not in other areas of the brain. HO-1 was induced in both the cortex and hypothalamus, and the levels of IL-6 and 4-HNE were raised in the hypothalamus, but not in the cortex. In the cortex, expression in M1 and M2 mAChRs were suppressed. In conclusion, iron reached the brain parenchyma after i.p. injection of Fe-NTA, and Fe-NTA caused oxidative reactions and suppression of mAChRs in the brain.

Hepatoprotective potential of crocin and curcumin against iron overload-induced biochemical alterations in rat.

The present study was undertaken to evaluate the possible ameliorating effect of crocin and curcumin on certain biochemical alterations associated with iron overload-induced liver injury in rats. 5 groups of rats were used, a normal control group received daily i.p. injections of saline and 4 groups received daily i.p. injections of ferric nitrilotriacetate (FeNTA) for 8 successive days, the dose of iron was increased during the experimental period (from 6 to 15 mg Fe/kg). The first iron overloaded group kept without further treatment and served as a positive control group. The second iron overloaded group received daily i.p injections of crocin (200 mg/kg ) in saline. The 3rd and the 4th iron overloaded groups received orally either 0.5% carboxy methyl cellulose (CMC) or curcumin (100 mg/kg) in CMC respectively. Treatment started 3 days before and concurrently with iron administration for 8 days. Results revealed that iron-induced liver injury was reflected by significant changes in the liver function indices, hyperammonemia and reduced serum urea level. A significant deposition of iron in liver was associated with enhanced oxidative and nitrosative stress status. Moreover, iron overloaded rats exhibited significant alterations in liver energy metabolism together withdiminished ureogenesis and a decline in dimethylarginine dimethylaminohydrolaseactivity. Supplementation with either crocin or curcumin ameliorated most of the biochemical changes induced by iron overload in rat liver. A function that may be beneficial for populations at risk for iron overload. Key words: Iron overload, liver, rat, oxidative stress, energy metabolism, ureogenesis, crocin, curcumin.

The Physiological Significance of Metallothionein in Oxidative Stress

Metallothionein (MT), a ubiquitous family of low-molecular weight metal-binding proteins, comprises 30% cysteine residues. Although all of the thiol residues in MT are bound to metals, it still remains active to reactive oxygen species. Each cysteine residue in MT is more effective at protecting DNA from hydroxyl radical attack than the glutathione cysteine in vitro. Prooxidative agents such as paraquat and carbon tetrachloride induce MT synthesis mediated by some responsive elements. MT demonstrates strong antioxidant properties, yet the physiological relevance of its antioxidant action is not clear. An injection of ferric nitrilotriacetate (Fe-NTA), which produces reactive oxygen species, caused transcriptional induction of MT synthesis in the liver and kidney. Pretreatment of mice with Zn attenuated nephrotoxicity induced by Fe-NTA. After a Fe-NTA injection, a loss of Cd-binding properties of preinduced MT was observed only in kidneys of Zn-pretreated mice but not in liver. MT-enriched hepatocytes are resistant to Fe-NTA toxicity, oxidative DNA, and cell damage during conditions of glutathione depletion. In glutathione-depleted cells, but not in non-treated cells, Cd-binding properties of cellular MT decreased with increasing concentration of Fe-NTA. Moreover, Cd released from MT after an injection of Fe-NTA induced new MT protein again. Thus MT may act as a secondary antioxidant in cellular protection system against oxidative stress.

Estimation of hydroxyl radical generation by salicylate hydroxylation method in kidney of mice exposed to ferric nitrilotriacetate and potassium bromate

Hydroxyl radical (·OH) generation in the kidney of mice treated with ferric nitrilotriacetate (Fe-NTA) or potassium bromate (KBrO3) in vivo was estimated by the salicylate hydroxylation method, using the optimal experimental conditions we recently reported. Induction of DNA lesions and lipid peroxidation in the kidney by these nephrotoxic compounds was also examined. The salicylate hydroxylation method revealed significant increases in the ·OH generation after injection of Fe-NTA or KBrO3 in the kidneys. A significant increase in 8-hydroxy-2′-deoxyguanosine in nuclei of the kidney was detected only in the KBrO3 treated mice, while the comet assay showed that the Fe-NTA and KBrO3 treatments both resulted in significant increases in DNA breakage in the kidney. With respect to lipid peroxidation, the Fe-NTA treatment enhanced lipid peroxidation and ESR signals of the alkylperoxy radical adduct. These DNA breaks and lipid peroxidation mediated by ·OH were diminished by pre-treatment with salicylate in vivo. These results clearly demonstrated the usefulness of the salicylate hydroxylation method as well as the comet assay in estimating the involvement of ·OH generation in cellular injury induced by chemicals in vivo.

Oxidative Stress Induces Phosphoenolpyruvate Carboxykinase Expression in H4IIE Cells

Oxidative stress is closely associated with diabetes and is a major cause of insulin resistance. Impairment of hepatic insulin action is thought to be responsible for perturbations in hepatic glucose metabolism. In this study, we found that oxidative stress is involved in the dysregulation of gene expression of phosphoenolpyruvate carboxykinase (PEPCK), a key gluconeogenic enzyme, by a mechanism independent of insulin. Elevation of oxidative stress by injection of ferric nitrilotriacetate in rats increased the expression of hepatic PEPCK mRNA. To examine the direct action of oxidative stress on PEPCK expression, we treated H4IIE hepatoma cells with buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis. BSO increased intracellular oxidative stress and the expression of PEPCK mRNA. Inhibition of p38 mitogen-activated protein kinase (p38 MAP kinase), which mediates responses to oxidative stress, suppressed the induction of PEPCK mRNA by BSO. These results suggest that oxidative stress dysregulates hepatic PEPCK expression by an insulin-independent mechanism.

α-Tocopherol induces calnexin in renal tubular cells: Another protective mechanism against free radical-induced cellular damage

Pre-administration of α-tocopherol is protective against oxidative renal tubular damage and subsequent carcinogenesis by ferric nitrilotriacetate (Fe-NTA) in rats. We searched for mechanisms other than the scavenging effect of α-tocopherol with microarray analyses, which implicated calnexin, a chaperone for glycoproteins. Renal mRNA levels of calnexin significantly increased 3 h after an injection of Fe-NTA in rats fed a standard diet whereas those fed an α-tocopherol-supplemented diet showed an increase prior to injection, but after injection showed a decrease in renal calnexin mRNA levels, with unaltered protein levels. In experiments using LLC-PK1 cells, addition of α-tocopherol was protective against oxidative stress by H 2O 2, concomitant with calnexin induction. Knockdown of calnexin by siRNA significantly reduced this protection. Furthermore, COS-7 cells transfected with the calnexin gene were more resistant to H 2O 2. Together with the fact that α-tocopherol induced N-acetylglucosaminyltransferase 3, our data suggest that α-tocopherol modifies glycoprotein metabolism partially by conferring mild ER stress. This adds another molecular mechanism of α-tocopherol toward cancer prevention.

Tissue Prx I in the protection against Fe-NTA and the reduction of nitroxyl radicals

Peroxiredoxin I (Prx I) is a key cytoplasmic peroxidase that reduces intracellular hydroperoxides in concert with thioredoxin. To study the role of tissue Prx I in protection from oxidative stress, we generated Prx I −/− mice by gene trapping. We then evaluated the acute-phase tissue damage caused by ferric-nitrilotriacetate (Fe-NTA). Increases in serum aspartate aminotransferase and alanine aminotransferase levels were significantly greater in Prx I −/− than wild-type mice, 4 and 12 h after the injection of Fe-NTA. Using real-time EPR imaging, we examined the reduction of the stable paramagnetic nitroxyl radical 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl in vivo, and found that the half-life of this spin probe in the liver and kidney was significantly prolonged in the Prx I −/− mice. These results demonstrate that Prx I −/− mice have less reducing activity and are more susceptible to the damage mediated by reactive oxygen species in vivo than wild-type mice.

TOCOTRIENOL OFFERS BETTER PROTECTION THAN TOCOPHEROL FROM FREE RADICAL‐INDUCED DAMAGE OF RAT BONE

1. Free radicals generated by ferric nitrilotriacetate (FeNTA) can activate osteoclastic activity and this is associated with elevation of the bone resorbing cytokines interleukin (IL)-1 and IL-6. In the present study, we investigated the effects of 2 mg/kg FeNTA (2 mg iron/kg) on the levels of serum IL-1 and IL-6 with or without supplementation with a palm oil tocotrienol mixture or alpha-tocopherol acetate in Wistar rats. 2. The FeNTA was found to elevate levels of IL-1 and IL-6. Only the palm oil tocotrienol mixture at doses of 60 and 100 mg/kg was able to prevent FeNTA-induced increases in IL-1 (P < 0.01). Both the palm oil tocotrienol mixture and alpha-tocopherol acetate, at doses of 30, 60 and 100 mg/kg, were able to reduce FeNTA-induced increases in IL-6 (P < 0.05). Therefore, the palm oil tocotrienol mixture was better than pure alpha-tocopherol acetate in protecting bone against FeNTA (free radical)-induced elevation of bone-resorbing cytokines. 3. Supplementation with the palm oil tocotrienol mixture or alpha-tocopherol acetate at 100 mg/kg restored the reduction in serum osteocalcin levels due to ageing, as seen in the saline (control) group (P < 0.05). All doses of the palm oil tocotrienol mixture decreased urine deoxypyridinoline cross-link (DPD) significantly compared with the control group, whereas a trend for decreased urine DPD was only seen for doses of 60 mg/kg onwards of alpha-tocopherol acetate (P < 0.05). 4. Bone histomorphometric analyses have shown that FeNTA injections significantly lowered mean osteoblast number (P < 0.001) and the bone formation rate (P < 0.001), but raised osteoclast number (P < 0.05) and the ratio of eroded surface/bone surface (P < 0.001) compared with the saline (control) group. Supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent all these FeNTA-induced changes, but a similar dose of alpha-tocopherol acetate was found to be effective only for mean osteoclast number. Injections of FeNTA were also shown to reduce trabecular bone volume (P < 0.001) and trabecular thickness (P < 0.05), whereas only supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent these FeNTA-induced changes.

Protective effect of naringin, a bioflavonoid on ferric nitrilotriacetate-induced oxidative renal damage in rat kidney.

An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces acute proximal tubular necrosis as a consequence of lipid peroxidation and oxidative tissue damage that eventually leads to high incidence of renal adenocarcinomas in rodents. This study was designed to investigate the effect of Naringin, a bioflavonoid with anti-oxidant potential, on Fe-NTA-induced nephrotoxicity in rats. One hour after a single intra-peritoneal (i.p.) injection of Fe-NTA (8 mg iron/kg body weight), a marked deterioration of renal architecture and renal function was observed. Fe-NTA induced a significant renal oxidative stress, demonstrated by elevated thiobarbituric acid reacting substances (TBARS) and reduction in activities of renal catalase, superoxide dismutase, and glutathione reductase. Pre-treatment of animals with Naringin, 60 min before Fe-NTA administration, markedly attenuated renal dysfunction, morphological alterations, reduced elevated TBARS, and restored the depleted renal anti-oxidant enzymes. These results clearly demonstrate the role of oxidative stress and its relation to renal dysfunction and suggest a protective effect of Naringin on Fe-NTA-induced nephrotoxicity in rats.

Nephrotoxicity and its prevention by catechin in ferric nitrilotriacetate promoted oxidative stress in rats.

Intraperitoneal injection of ferric nitrilotriacetate (Fe-NTA) to rats and mice results in iron-induced free radical injury and cancer in kidneys. This study was designed to investigate the effect of catechin, a bioflavonoid with antioxidant potential, on Fe-NTA-induced nephrotoxicity in rats. Four groups were employed in the present study. Group I served as control group, Group II animals received Fe-NTA (8 mg iron/kg body weight i.p.), Group III animals were given 40 mg/kg catechin p.o. twice a day for 4 days and on the 5th day Fe-NTA was challenged, and Group IV animals received catechin alone for 4 days. Renal function was assessed by measuring plasma creatinine and blood urea nitrogen. The oxidative stress was measured by renal malondialdehyde levels, reduced glutathione levels and by enzymatic activity of catalase, glutathione reductase and superoxide dismutase. One hour after a single intraperitoneal (i.p.) injection of Fe-NTA (8 mg iron/kg), a marked deterioration of renal architecture, renal function and severe oxidative stress was observed. Pretreatment of animals with catechin markedly attenuated renal dysfunction, reduced elevated thiobarbituric acid reacting substances (TBARS), restored the depleted renal antioxidant enzymes and normalized the renal morphological alterations. These results clearly demonstrate the role of oxidative stress and its relation to renal dysfunction, and suggest a protective effect of catechin on Fe-NTA-induced nephrotoxicity in rats.

Carvedilol and trimetazidine attenuates ferric nitrilotriacetate-induced oxidative renal injury in rats.

Intraperitoneal (i.p.) injection of ferric nitrilotriacetate (Fe-NTA) induces acute proximal tubular necrosis as a consequence of lipid peroxidation and oxidative tissue damage, which eventually leads to high incidence of renal adenocarcinoma in rodents. This study was designed to investigate the effect of carvedilol, an antihypertensive and trimetazidine, an antiischemic, both the drugs with additional antioxidative potentials, on Fe-NTA induced nephrotoxicity in rats. One hour after a single i.p. injection of Fe-NTA (8 mg iron per kg), a marked deterioration of renal architecture and renal function as evidenced by a sharp increase in blood urea nitrogen (BUN) and serum creatinine was observed. Fe-NTA induced a significant renal oxidative stress demonstrated by elevated thiobarbituric acid reacting substances (TBARS) and reduction in activities of renal catalase, superoxide dismutase (SOD) and glutathione reductase (GR). Pretreatment of animals with carvedilol (2 mg/kg, i.p.) as well as with trimetazidine (3 mg/kg, i.p.), 30 min before Fe-NTA administration markedly attenuated renal dysfunction, reduced elevated TBARS, restored the depleted renal antioxidant enzymes and normalised the renal morphological alterations. These results clearly demonstrate the role of oxidative stress and its relation to renal dysfunction, and suggest a protective effect of carvedilol and trimetazidine on Fe-NTA-induced nephrotoxicity in rats.

Ceroid accumulation in rat kidneys caused by uptake of ferric nitrilotriacetate

Ceroid accumulation in kidneys caused by lipid peroxidation in vivo was studied during intraperitoneal (i.p.) injections of ferric nitrilotriacetate (Fe 3+-NTA) solution, which is a weak iron chelate compound and generates free radicals in the presence of oxygen. Fe 3+-NTA solution (0.5–0.75 mg/100 g body weight) was injected into rats ( n=6) for 4 days a week. After 2 weeks of Fe 3+-NTA loading, the rats were not treated for 1 month as a rest interval, and then the iron loading was repeated for 35 weeks including the rest intervals. Two rats in each group, Fe 3+-NTA loading and control, were sacrificed at 19 and 40 weeks of age, and portions of a kidney and the liver of each rat were fixed in 10% formalin buffered to pH 7.0 for the histological studies. We found ceroid accumulates in greater amounts and more quickly within macrophages and epithelial cells of proximal convoluted tubules of the kidney and Kupffer cells of the liver in iron-loaded rats.