Reno-protective role of flunarizine (mitochondrial permeability transition pore inactivator) against gentamicin induced nephrotoxicity in rats

Electric field-directed migration of mesenchymal stem cells enhances their therapeutic potential on cisplatin-induced acute nephrotoxicity in rats

Cisplatin is widely used as an anti-neoplastic agent but is limited by its nephrotoxicity. The use of mesenchymal stem cells (MSCs) for the management of acute kidney injury (AKI) represents a new era in treatment but effective homing of administered cells is needed. This study aimed to investigate the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on cisplatin-induced AKI in rats after directed migration by electric field (EF). Forty-eight adult male albino rats were equally classified into four groups: control, cisplatin-treated, cisplatin plus BM-MSCs, and cisplatin plus BM-MSCs exposed to EF. Serum levels of IL-10 and TNF-α were measured by ELISA. Quantitative real-time PCR analysis for gene expression of Bcl2, Bax, caspase-3, and caspase-8 was measured. Hematoxylin and eosin (H&E) staining, periodic acid Schiff staining, and immunohistochemical analysis were also done. MSC-treated groups showed improvement of kidney function; increased serum levels of IL-10 and decreased levels of TNF-α; and increased mRNA expression of Bcl2 and decreased expression of Bax, caspase-3, and caspase-8 proteins comparable to the cisplatin-injured group. EF application increased MSCs homing with significant decrease in serum urea level and caspase-3 gene expression together with significant increase in Bcl2 expression than occurred in the MSCs group. Restoration of normal kidney histomorphology with significant decrease in immunohistochemical expression of caspase-3 protein was observed in the BM-MSCs plus EF group compared to the BM-MSCs group. EF stimulation enhanced the MSCs homing and improved their therapeutic potential on acute cisplatin nephrotoxicity.

HPLC-ESI/MS profiling, phytoconstituent isolation and evaluation of renal function, oxidative stress and inflammation in gentamicin-induced nephrotoxicity in rats of Ficus spragueana Mildbr. & Burret

Ficus spragueana Mildbr. & Burret (family Moraceae) was reported to have various biological activities. However, its activity in treatment of renal injury has not been investigated yet. The current study aimed to evaluate the effects of F. spragueana leaf extract on nephrotoxicity caused by gentamicin. Gentamicin is an important broad-spectrum antibiotic; nevertheless, it exhibits serious nephrotoxic adverse effects. HPLC-ESI/MS spectrometric analysis of the extract revealed the presence of 37 phenolic compounds. Moreover, five compounds were isolated from the leaf extract, and identified on the basis of spectroscopic analysis. The isolated compounds were syringic acid (1), p-coumaric acid (2), 3',5' O-dicaffeoylquinic acid (3), luteolin-8-C-β-D glucopyranoside (orientin) (4) and 8-methoxy kaempferol-3-O-[α-L-rhamnopyranosyl (1→2) β-D-glucopyranoside] (5). The gentamicin-induced nephrotoxicity model was used to evaluate the protective effect of F. spragueana on renal toxicity biomarkers throughout the development of acute kidney injury. Administration of extract led to improvement in kidney function through inhibition of kidney injury molecule-1, creatinine, blood urea nitrogen and total bilirubin, as well as decreasing the inflammatory markers interlukin1-beta and myeloperoxidase. Furthermore, it reduced the oxidative stress by increasing reduced glutathione and total antioxidant capacity levels while decreasing malondialdehyde and nitric oxide content, and improved renal histopathological injuries.

Nephroprotective Effect of Cilastatin against Gentamicin-Induced Renal Injury In Vitro and In Vivo without Altering Its Bactericidal Efficiency

Gentamicin is a used antibiotic that causes nephrotoxicity in 10-20% of treatment periods, which limits its use considerably. Our results have shown that cilastatin may be a promising therapeutic alternative in toxin-induced acute kidney injury (AKI). Here, we investigated its potential use as a nephroprotector against gentamicin-induced AKI in vitro and in vivo. Porcine renal cells and rats were treated with gentamicin and/or cilastatin. In vivo nephrotoxicity was analyzed by measuring biochemical markers and renal morphology. Different apoptotic, oxidative and inflammatory parameters were studied at cellular and systemic levels. Megalin, mainly responsible for the entry of gentamicin into the cells, was also analyzed. Results show that cilastatin protects cells from gentamicin-induced AKI. Cilastatin decreased creatinine, BUN, kidney injury molecule-1 (KIM-1) and severe morphological changes previously increased by gentamicin in rats. The interference of cilastatin with lipid rafts cycling leads to decreased expression of megalin, and therefore gentamicin uptake and myeloid bodies, resulting in a decrease of apoptotic, oxidative and inflammatory events. Moreover, cilastatin did not prevent bacterial death by gentamicin. Cilastatin reduced gentamicin-induced AKI by preventing key steps in the amplification of the damage, which is associated to the disruption of megalin-gentamicin endocytosis. Therefore, cilastatin might represent a novel therapeutic tool in the prevention and treatment of gentamicin-induced AKI in the clinical setting.

5-aminolaevulinic acid (ALA), enhances heme oxygenase (HO)-1 expression and attenuates tubulointerstitial fibrosis and renal apoptosis in chronic cyclosporine nephropathy

BACKGROUND

Cyclosporine-A (CsA) is an immunosuppressant indicated for various immunological diseases; however, it can induce chronic kidney injury. Oxidative stress and apoptosis play a crucial role in CsA-induced nephrotoxicity. The present study evaluated the protective effect of combining 5-aminolaevulinic acid with iron (5-ALA/SFC), a precursor of heme synthesis, to enhance HO-1 activity against CsA-induced chronic nephrotoxicity.

METHODS

Mice were divided into three groups: the control group (using olive oil as a vehicle), CsA-only group, and CsA+5-ALA/SFC group. After 28 days, the mice were sacrificed, and blood and kidney samples were collected. In addition to histological and biochemical examination, the mRNA expression of proinflammatory and profibrotic cytokines was assessed.

RESULTS

Renal function in the 5-ALA/SFC treatment group as assessed by the serum creatinine and serum urea nitrogen levels was superior to that of the CsA-only treatment group, demonstrating that 5-ALA/SFC significantly attenuated CsA-induced kidney tissue inflammation, fibrosis, apoptosis, and tubular atrophy, as well as reducing the mRNA level of TNF-α, IL-6, TGF-β1, and iNOS while increasing HO-1.

CONCLUSION

The activity of 5-ALA/SFC has important implications for clarifying the mechanism of HO-1 activity in CsA-induced nephrotoxicity and may provide a favorable basis for clinical therapy.

A systematic meta-analysis on the efficacy of pre-clinically tested nephroprotectants at preventing aminoglycoside nephrotoxicity

Nephrotoxicity limits the use of aminoglycoside antibiotics. Kidney damage is produced mainly in the renal tubule due to an inflammatory and oxidative process. At preclinical level, many drugs and natural products have been tested as prospective protectors of aminoglycoside nephrotoxicity. The main objective of this work was to make a systematic literature review of preclinical studies about aminoglycoside nephrotoxicity protection and a statistical analysis based on the meta-analysis methodology. Studies published up to January 2016 were identified. After applying inclusion criteria, 54 studies were chosen. The size of the experimental groups, means and standard deviations of data on renal function (i.e. plasma creatinine and blood urea nitrogen [BUN] concentrations) were extracted and registered in a database. The studies were grouped according to the mechanism of nephroprotection and their route of administration. The Mean Difference (95% confidence interval) was calculated for each study and group. 40 of 54 products tested produced an amelioration of aminoglycoside nephrotoxicity based on creatinine results. Also a dose dependent protective effect was observed (both in creatinine and BUN). Products orally administered were more effective than via i.p. Products with attributed antioxidant activity were the most used and those which proved statistically significant nephroprotection as a class effect. Aminoglycoside tubular reuptake inhibitors, excretion inducers and calcium channel blockers also showed a promising and rather homogeneous class tendency towards nephroprotection, although more research is necessary to obtain solid and conclusive results, based on a larger number of studies.

Curcumin Attenuates Gentamicin-Induced Kidney Mitochondrial Alterations: Possible Role of a Mitochondrial Biogenesis Mechanism

It has been shown that curcumin (CUR), a polyphenol derived from Curcuma longa, exerts a protective effect against gentamicin- (GM-) induced nephrotoxicity in rats, associated with a preservation of the antioxidant status. Although mitochondrial dysfunction is a hallmark in the GM-induced renal injury, the role of CUR in mitochondrial protection has not been studied. In this work, LLC-PK1 cells were preincubated 24 h with CUR and then coincubated 48 h with CUR and 8 mM GM. Treatment with CUR attenuated GM-induced drop in cell viability and led to an increase in nuclear factor (erythroid-2)-related factor 2 (Nrf2) nuclear accumulation and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) cell expression attenuating GM-induced losses in these proteins. In vivo, Wistar rats were injected subcutaneously with GM (75 mg/Kg/12 h) during 7 days to develop kidney mitochondrial alterations. CUR (400 mg/Kg/day) was administered orally 5 days before and during the GM exposure. The GM-induced mitochondrial alterations in ultrastructure and bioenergetics as well as decrease in activities of respiratory complexes I and IV and induction of calcium-dependent permeability transition were mostly attenuated by CUR. Protection of CUR against GM-induced nephrotoxicity could be in part mediated by maintenance of mitochondrial functions and biogenesis with some participation of the nuclear factor Nrf2.

Therapeutic potential of 7,8-dimethoxycoumarin on cisplatin- and ischemia/reperfusion injury-induced acute renal failure in rats

This study was designed to investigate the role of 7,8-dimethoxycoumarin on cisplatin- and ischemia/reperfusion (I/R)-induced acute renal failure in rats. Acute renal failure was induced in rats by administration of a single dose of cisplatin (CP) (6 mg/kg, intraperitoneally on day 6) and occlusion of the left renal artery for 45 min (I) and opened for the next 24 h (R). The drug samples of 7,8-dimethoxycoumarin (DMC, 50, 75, and 100 mg/kg) and cyclosporin A (50 μM/kg) were administered orally for six consecutive days. Administration of a single dose of cisplatin and I/R event has significantly raised blood urea nitrogen and creatinine, N-acetyl beta-D: -glucosaminidase, and thiobarbituric acid reactive substances but decreased FrNa, creatinine clearance, reduced glutathione (GSH), mitochondrial cytochrome c oxidase, and adenosine triphosphate levels. Further, pretreatment of DMC (50, 75, and 100 mg/kg, p.o., for six consecutive days) has ameliorated the CP- and I/R-induced biochemical and histopathological changes in a dose-dependent manner. Furthermore, 75 and 100 mg/kg of 7,8-dimethoxycoumarin has shown to possess the significant renoprotective effect similar to that of the cyclosporin A-treated group which served as positive control. Based on the results of the present study, it has been concluded that 7,8-dimethoxycoumarin protects the kidney against the CP and I/R injury via antioxidant, anti-inflammatory, and inactivation of mitochondrial permeability transition pore opening.

Mitochondrial dependent apoptosis: ameliorative effect of flunarizine on ischemia-reperfusion of celiac artery-induced gastric lesions in the rat

OBJECTIVES

Ischemia-reperfusion is a major event for induction of cellular apoptosis. Apoptosis is due to the activation of death receptor and/or mitochondrial pathways. Mitochondrial permeability transition pore opening is the cause of apoptosis. In our present study, we tried to evaluate the role of flunarizine in ischemia and reperfusion of celiac artery-induced gastric lesion in the rat.

METHODS

The therapeutic potential of flunarizine was assessed by measuring the changes in gastric lesion index, biomarker (i.e., thiobarbituric acid reactive substance, reduced glutathione, superoxide dismutase, myeloperoxidase, and total calcium and protein content), and mitochondrial damage (i.e., adenosine triphosphate and deoxyribonucleic acid fragmentation content) in ischemia and reperfusion-induced gastric lesion model.

RESULTS

Medium and higher doses of flunarizine produced a significant (P<0.05) ameliorative effect which was observed from the assessment of all the above-mentioned parameters (i.e., increase in reduced glutathione, superoxide dismutase and decrease in thiobarbituric acid reactive substance, myeloperoxidase, and total calcium content). Similar results were also obtained from omeprazole and cyclosporine. In the pre-treated group, deoxyribonucleic acid fragmentation pattern has also indicated that a mitochondria-associated anti-apoptotic effect of flunarizine was responsible to prevent the ischemia and reperfusion of celiac artery-induced gastric lesion.

CONCLUSION

The gastroprotective effect of flunarizine may be produced due to its inactivation potential of mitochondrial permeability transition pore opening associated with anti-oxidative, calcium regulation along with its anti-apoptotic effect.