Leea macrophylla root extract upregulates the mRNA expression for antioxidative enzymes and repairs the necrosis of pancreatic ß-cell and kidney tissues in fructose-fed Type 2 diabetic rats.

This research investigated the functional food effect of Leea macrophylla (Roxb.) ex Hornem root extract on pancreatic necrosis in Streptozotocin-induced type-2 diabetes. Prior to animal intervention, Leea macrophylla root extract (LMR) was subjected to GC-MS analysis. Across a three-week intervention of fructose-fed albino model with LMR50, LMR100 and LMR200, the fluid & food intake, body weight changes, weekly blood glucose concentrations and oral glucose tolerance (OGT) were recorded. The animals were sacrificed after intervention and serum was analyzed for insulin, ALT, AST, LDH, CK-MB, creatinine, uric acid and lipid profile and liver section was used for glycogen estimation. Changes of pancreas and kidney architecture were evaluated by histopathology. Relative mRNA for superoxide dismutase 1 (SOD1), glutathione peroxidase (GPx) and catalase (CAT) were quantitated using assay kits. Results showed that fluid and food intake, weekly blood glucose level, ALT, AST, LDH, CK-MB level were significantly (p < 0.05) decreased in LMR50 group. Conversely, the glucose tolerance ability, liver glycogen level, serum insulin, organ weight and pancreatic morphology were improved significantly in this group. Diameter of islet of Langerhans (µm), area occupied by ß-cell/ islet of Langerhans (µm2) and number of ß-cells/islet of Langerhans were amazingly improved to the NC animals. Expressions of mRNA for SOD1 and CAT from liver tissue have been found to be increased multifold while GPx was remained unchanged. The data suggests that L. macrophylla root extract could be very potential as functional food to modulate pancreatic action.

Gelofusine Ameliorates Colistin-Induced Nephrotoxicity.

Colistin therapy is used as the last line of defense against life-threatening Gram-negative infections. Nephrotoxicity is the major dose-limiting side effect that impedes optimal dosing of patients. This study aims to examine the nephroprotective effect of the plasma volume expander gelofusine against colistin-induced nephrotoxicity. Renal protection was assessed in mice that were subcutaneously injected with colistin sulfate (14 mg/kg of body weight × 6 doses every 2 h; accumulated dose, 84 mg/kg) and simultaneously injected in the intraperitoneal region with gelofusine (75, 150, 300, or 600 mg/kg × 6). At 2 and 20 h after the last colistin dose, mice were euthanized, and the severity of renal alteration was examined histologically. Histological findings in mice revealed that colistin-induced nephrotoxicity was ameliorated by gelofusine in a dose-dependent manner, whereas significant histological abnormalities were detected in the kidneys of mice in the colistin-only group. The impact of coadministered gelofusine on colistin pharmacokinetics was investigated in rats. Rats were administered a single intravenous dose of gelofusine at 400 mg/kg 15 min prior to the intravenous administration of colistin (1 mg/kg). Gelofusine codosing did not alter the pharmacokinetics of colistin in rats; however, gelofusine did significantly lower the accumulation of colistin in the kidney tissue of mice. This is the first study demonstrating the protective effect of gelofusine against colistin-induced nephrotoxicity. These findings highlight the clinical potential of gelofusine as a safe adjunct for ameliorating the nephrotoxicity and increasing the therapeutic index of polymyxins.

Nephroprotective and antioxidant activities of Salacia oblonga on acetaminophen-induced toxicity in rats.

Salacia oblonga, a woody climbing plant belonging to the family Celastaceae, is widely distributed in India and other southeast Asian countries. The genus Salacia have been used particularly for the treatment of diabetes, obesity, gonorrhoea, rheumatism, pruritus and asthma. Acetaminophen (APAP), used as an analgesic drug, produces liver and kidney necrosis in mammals at high doses. The aim of this study was to investigate the nephroprotective and antioxidant activities of the ethanol extract of Salacia oblonga (EESO) at the two dose levels of 250 and 500 mg/kg bw on APAP-induced toxicity in rats. The results showed that APAP significantly increases the levels of serum urea, creatinine, and reduces levels of uric acid concentration. The EESO reduces these by increasing anti-oxidative responses as assessed by biochemical and histopathological parameters. In conclusion, our results suggest that the EESO possesses nephroprotective and antioxidant effects against APAP-induced nephrotoxicity in rats.

Antioxidation and anti-inflammation by haem oxygenase-1 contribute to protection by tetramethylpyrazine against gentamicin-induced apoptosis in murine renal tubular cells.

BACKGROUND: Gentamicin, a widely used antibiotic for the treatment of bacterial infection, can cause nephrotoxicity. Tetramethylpyrazine (TMP) is a compound purified from the rhizome of Ligusticum wallichi (called chuanxiong in Chinese). Besides its protection against ischaemia-reperfusion injury and nephritis in mice, we previously reported that TMP reverses gentamicin-induced apoptosis in rat kidneys. Haem oxygenase-1 (HO-1) induction by TMP has also been shown to attenuate myocardial ischaemia/reperfusion injury in rats. METHODS: We used rat renal tubular (NRK-52E) cells, transformed cells with HO-1 overexpression or knockdown, and an adenovirus carrying the HO-1 gene (Adv-HO-1) as gene therapy targeting murine kidneys to explore the role of HO-1 in protection by TMP against gentamicin-induced toxicity both in vitro and in vivo. We evaluated the protective effects of HO-1 on several apoptotic parameters induced by gentamicin: cleaved caspases-3 and -9, cycloxygenase-2 (Cox-2) and subcellular localization of nuclear factor kappa B-p65 (NF-kappaB-p65), Bcl-xl and HS-1-associated protein (Hax-1) in NRK-52E cells. RESULTS: NRK-52E cells treated with TMP exhibited transcriptional upregulation of the HO-1 protein by approximately twofold. Overexpression of HO-1 in NRK-52E cells significantly increased mitochondrial protein levels of the antiapoptotic molecules, Bcl-xL and Hax-1, and markedly decreased the NADPH oxidase activity and proinflammatory molecules, NF-kappaB-p65 and Cox-2, which might decrease gentamicin-induced activation of caspases-9 and -3. Conversely, NRK-52E cells with HO-1 knockdown significantly exacerbated gentamicin-induced tubular cell apoptosis. Additionally, the concomitant HO-1 induction by TMP was also evident in vivo, and HO-1 therapy markedly attenuated gentamicin-induced renal apoptosis to a similar extent as TMP pretreatment. CONCLUSIONS: Collectively, we suggest that HO-1 induced by TMP might, at least in part, protect against gentamicin-induced nephrotoxicity through antiapoptotic and anti-inflammatory mechanisms, and that it may have therapeutic potential for patients with renal disease. This is also the first demonstration that HO-1 increases Hax-1 mitochondrial localization.

Enterococcal endocarditis associated with crescentic glomerulonephritis.

Glomerulonephritis secondary to infective endocarditis (IE) is an uncommon diagnosis and is usually associated with cardiac valvular infection by blood-culture-positive bacteria. We report a case of necrotizing glomerulonephritis associated with culture-positive endocarditis caused by Enterococcus faecalis. The patient presented with renal abnormalities and was further investigated by renal biopsy. He had immune complex-mediated necrotizing and crescentic glomerulonephritis with mesengial and capillary deposition of immunoglobulin M (Ig M), Ig G, and complement 3 (C3). He was treated with antibiotics, including ampicillin and gentamicin. In addition, steroid and cyclophosphamide were administered. The patient died of renal failure 48 days after hospital admission. In conclusion, glomerulonephritis caused by Enterococcus faecalis endocarditis is an immune-complex-mediated disease characterized by necrotizing and crescentic glomerular lesions that can be fatal despite aggressive antimicrobial and immunosuppressive therapy.

Endocytic delivery of lipocalin-siderophore-iron complex rescues the kidney from ischemia-reperfusion injury.

Neutrophil gelatinase-associated lipocalin (Ngal), also known as siderocalin, forms a complex with iron-binding siderophores (Ngal:siderophore:Fe). This complex converts renal progenitors into epithelial tubules. In this study, we tested the hypothesis that Ngal:siderophore:Fe protects adult kidney epithelial cells or accelerates their recovery from damage. Using a mouse model of severe renal failure, ischemia-reperfusion injury, we show that a single dose of Ngal (10 microg), introduced during the initial phase of the disease, dramatically protects the kidney and mitigates azotemia. Ngal activity depends on delivery of the protein and its siderophore to the proximal tubule. Iron must also be delivered, since blockade of the siderophore with gallium inhibits the rescue from ischemia. The Ngal:siderophore:Fe complex upregulates heme oxygenase-1, a protective enzyme, preserves proximal tubule N-cadherin, and inhibits cell death. Because mouse urine contains an Ngal-dependent siderophore-like activity, endogenous Ngal might also play a protective role. Indeed, Ngal is highly accumulated in the human kidney cortical tubules and in the blood and urine after nephrotoxic and ischemic injury. We reveal what we believe to be a novel pathway of iron traffic that is activated in human and mouse renal diseases, and it provides a unique method for their treatment.

Haemolytic-uraemic syndrome treated with heparin.

Three children with the haemolytic-uraemic syndrome were treated with intravenous heparin. Peritoneal dialysis was required for two of them, one of whom died after 26 days of therapy. Renal biopsy specimens from the two survivors showed widespread glomerular disease, which appeared permanent in one case, but only occasional thrombi. It is suggested that heparin therapy, by preventing further intrarenal thrombosis, allowed the normal fibrinolytic mechanisms to remove previously formed thrombi.