A role for superoxide in gentamicin-mediated nephropathy in rats

Enriched human embryonic stem cells-derived CD133+, CD24+ renal progenitors engraft and restore function in a gentamicin-induced kidney injury in mice

Introduction

Acute kidney injury (AKI) is a common health problem that leads to high morbidity and potential mortality. The failure of conventional treatments to improve forms of this condition highlights the need for innovative and effective treatment approaches. Regenerative therapies with Renal Progenitor Cells (RPCs) have been proposed as a promising new strategy. A growing body of evidence suggests that progenitor cells differentiated from different sources, including human embryonic stem cells (hESCs), can effectively treat AKI.

Methods

Here, we describe a method for generating RPCs and directed human Embryoid Bodies (EBs) towards CD133+CD24+ renal progenitor cells and evaluate their functional activity in alleviating AKI.

Results

The obtained results show that hESCs-derived CD133+CD24+ RPCs can engraft into damaged renal tubules and restore renal function and structure in mice with gentamicin-induced kidney injury, and significantly decrease blood urea nitrogen levels, suppress oxidative stress and inflammation, and attenuate histopathological disturbances, including tubular necrosis, tubular dilation, urinary casts, and interstitial fibrosis.

Conclusion

The results suggest that RPCs have a promising regenerative potential in improving renal disease and can lay the foundation for future cell therapy and disease modeling.

Potential protective effects of Acacia nilotica (L.) against gentamicin - induced nephrotoxicity by suppressing renal redox imbalance, inflammatory stress and caspase-dependent apoptosis in Wistar rats

Gentamicin-induced nephrotoxicity limits its therapeutic use as an effective aminoglycoside. Herbal drugs have a distinct place in the world of pharmaceuticals since they are safe, effective, and cost-efficient. Acacia nilotica (L.) has long been recognized for its antihypertensive, antioxidant, anti-inflammatory, and antiplatelet aggregatory benefits in traditional medicine. Still, the protective effect of Acacia nilotica on gentamicin-induced nephrotoxicity is still unknown. Thus, the goal of this research was to examine the protection of ethanolic extract of Acacia nilotica (ANE) against nephrotoxicity triggered by Gentamicin.

Thirty-six rats were randomly divided into six groups containing six rats in each group. The distilled water were given in control group. The rats in groups two and three were administered metformin and gentamicin respectively. In groups five and six, rats were administered ANE at doses of 100 and 200 mg/kg. Ten days of daily treatments were given. The urea, creatinine, uric acid, and LDH levels were analyzed on serum, whereas histological evaluation, MDA, GSH, SOD, CAT, TNF-α, IL-6, and caspase-3, were performed on kidney tissue on day 11. The gentamicin-treated group exhibited a significantly elevated MDA, and lower levels of antioxidant enzymes. Kidney function markers, inflammatory markers and caspase-3 expression were significantly elevated in the gentamicin-treated group. ANE significantly restored kidney function biomarkers, upregulated biochemical levels, inhibited TNF-α, caspase-3, cytokine expression, and reduced histological lesions.

In conclusion, ANE has the ability to prevent gentamicin-induced nephrotoxicity and reduce nephrotoxic damage. As such, it may represent an effective therapy for patients receiving gentamicin treatment.

Further insights into the impact of rebamipide on gentamicin-induced nephrotoxicity in rats: modulation of SIRT1 and β-catenin/cyclin D1 pathways

Gentamicin (GM) is an effective antibiotic administered to treat acute Gram-negative infections. Nevertheless, its clinical application is limited due to nephrotoxicity. Therefore, our research aimed to investigate the potential renoprotective impact of rebamipide (RBM), a gastroprotective drug, on GM-induced kidney damage in rats, as well as putative nephroprotective pathways. RBM was orally administered (100 mg/kg/d for 14 d) commencing 7 d before the administration of GM (100 mg/kg/d, intraperitoneally). Nephrotoxicity was elucidated, and the silent information regulator 1 (SIRT1) and β-catenin/cyclin D1 pathways were assessed. GM induced a significant elevation in the serum levels of creatinine, blood urea nitrogen (BUN), and kidney injury molecule-1 (KIM-1), as well as the relative kidney index. In addition, GM increased lipid peroxidation and lowered total antioxidant capacity (TAC) level and superoxide dismutase (SOD) activity. GM administration also demonstrated a significant amplification in tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor-κappa B p65 (NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3 kidney levels, as well as B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 ratio. Notably, RBM treatment amended all these changes induced by GM. Furthermore, the potential role of SIRT1 and β-catenin-dependent signaling pathways in GM-induced renal injury was assessed. Our findings showed that GM-treated rats demonstrated a substantial decrease in SIRT1, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) along with an increase in β-catenin, forkhead box O-3a (FOXO-3a), and cyclin D1 protein expressions. RMB treatment markedly attenuated the deterioration caused by GM on these pathways. Additionally, RBM alleviated the GM-induced deleterious kidney tissue histopathology. In conclusion, our findings have verified that RBM can halt GM-induced renal injury by partly modulating SIRT1 and β-catenin pathways.

Mitochondrial Oxidative Metabolism: An Emerging Therapeutic Target to Improve CKD Outcomes

Chronic kidney disease (CKD) predisposes one toward end-stage renal disease (ESRD) and its associated morbidity and mortality. Significant metabolic perturbations in conjunction with alterations in redox status during CKD may induce increased production of reactive oxygen species (ROS), including superoxide (O₂^●-) and hydrogen peroxide (H₂O₂). Increased O₂^●- and H₂O₂ may contribute to the overall progression of renal injury as well as catalyze the onset of comorbidities. In this review, we discuss the role of mitochondrial oxidative metabolism in the pathology of CKD and the recent developments in treating CKD progression specifically targeted to the mitochondria. Recently published results from a Phase 2b clinical trial by our group as well as recently released data from a ROMAN: Phase 3 trial (NCT03689712) suggest avasopasem manganese (AVA) may protect kidneys from cisplatin-induced CKD. Several antioxidants are under investigation to protect normal tissues from cancer-therapy-associated injury. Although many of these antioxidants demonstrate efficacy in pre-clinical models, clinically relevant novel compounds that reduce the severity of AKI and delay the progression to CKD are needed to reduce the burden of kidney disease. In this review, we focus on the various metabolic pathways in the kidney, discuss the role of mitochondrial metabolism in kidney disease, and the general involvement of mitochondrial oxidative metabolism in CKD progression. Furthermore, we present up-to-date literature on utilizing targets of mitochondrial metabolism to delay the pathology of CKD in pre-clinical and clinical models. Finally, we discuss the current clinical trials that target the mitochondria that could potentially be instrumental in advancing the clinical exploration and prevention of CKD.

Curcumin protects rats against gentamicin-induced nephrotoxicity by amelioration of oxidative stress, endoplasmic reticulum stress and apoptosis

CONTEXT

Gentamicin (GM) is an aminoglycoside antibiotic which is commonly used against Gram-negative bacterial infection; however, serious complications including nephrotoxicity could limit its clinical use.

OBJECTIVE

The present study examined the protective effects of curcumin (CUR) on endoplasmic reticulum (ER) stress-mediated apoptosis through its antioxidative property in GM-induced nephrotoxicity in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats (n = 3) were divided into six groups to receive normal saline (control), GM (100 mg/kg/day), co-treatment with GM and CUR (100, 200 and 300 mg/kg/day) and CUR (200 mg/kg/day) alone for 15 days by gavage feeding. Then, the renal function, kidney injury as well as oxidative stress, antioxidative markers and ER stress-mediated apoptosis were evaluated.

RESULTS

Pre-treatment of CUR rescued the nephrotoxicity in GM-treated rats. Several nephrotoxicity hallmarks were reversed in the CUR-pre-treatment group. At the dose of 200 mg/kg/day, it could significantly lower serum creatinine (from 0.95 to 0.50 mg/dL), blood urea nitrogen (from 35.00 to 23.50 mg/dL) and augmented creatinine clearance (from 0.83 to 1.71 mL/min). The normalized expression of oxidative stress marker, malondialdehyde was decreased (from 13.00 to 5.98) in line with the increase of antioxidant molecules including superoxide dismutase (from 5.59 to 14.24) and glutathione (from 5.22 to 12.53). Furthermore, the renal ER stress and apoptotic protein biomarkers were lowered in CUR treatment.

DISCUSSION AND CONCLUSIONS

Our findings pave the way for the application of CUR as a supplement in the prevention of nephrotoxicity and other kidney diseases in the future.

Biochemical interaction of pyrvinium in gentamicin-induced acute kidney injury by modulating calcium dyshomeostasis and mitochondrial dysfunction

Acute kidney injury (AKI) has a poor clinical prognosis and increases the risk of chronic kidney failure (CKD). It is a common complication of organ failure in hospitalised patients (10-15% of all hospitalizations) and in intensive care unit (ICU) patients, with an incidence of up to 50%. Concerning ICU, AKI has a mortality rate ranging from 27% to 35%, rising to 60%-65% when dialysis is needed, with roughly 5%-20% of survivors requiring dialysis on discharge. AKI is believed to cause over 7 million deaths per year worldwide. Currently, there is no treatment for AKI or its progression to CKD. When activated by AKI, numerous pathways have been suggested as possible contributors to CKD progression. Wnt/β-catenin is a crucial regulator of kidney development that increases following the injury. Despite the overwhelming evidence that Wnt/β-catenin promotes AKI, tubulointerstitial fibrosis, a hallmark of CKD progression, is also promoted by this pathway. The therapeutic potential of Wnt/β-catenin in the treatment of AKI and the progression from AKI to CKD is being studied. This hypothesis aims to determine whether the Wnt/β-catenin inhibitor pyrvinium has a beneficial effect on the renal dysfunction and damage caused by Gentamicin.

Dissecting the Crosstalk Between Nrf2 and NF-κB Response Pathways in Drug-Induced Toxicity

Nrf2 and NF-κB are important regulators of the response to oxidative stress and inflammation in the body. Previous pharmacological and genetic studies have confirmed crosstalk between the two. The deficiency of Nrf2 elevates the expression of NF-κB, leading to increased production of inflammatory factors, while NF-κB can affect the expression of downstream target genes by regulating the transcription and activity of Nrf2. At the same time, many therapeutic drug-induced organ toxicities, including hepatotoxicity, nephrotoxicity, cardiotoxicity, pulmonary toxicity, dermal toxicity, and neurotoxicity, have received increasing attention from researchers in clinical practice. Drug-induced organ injury can destroy body function, reduce the patients’ quality of life, and even threaten the lives of patients. Therefore, it is urgent to find protective drugs to ameliorate drug-induced injury. There is substantial evidence that protective medications can alleviate drug-induced organ toxicity by modulating both Nrf2 and NF-κB signaling pathways. Thus, it has become increasingly important to explore the crosstalk mechanism between Nrf2 and NF-κB in drug-induced toxicity. In this review, we summarize the potential molecular mechanisms of Nrf2 and NF-κB pathways and the important effects on adverse effects including toxic reactions and look forward to finding protective drugs that can target the crosstalk between the two.

Renoprotection of Selected Antioxidant-Rich Foods (Water Spinach and Red Grape) and Probiotics in Gentamicin-Induced Nephrotoxicity and Oxidative Stress in Rats

OBJECTIVES

The current study investigated the curative effects of two selected antioxidant-rich foods (water spinach and red grape) and probiotics on the kidney exposed to nephrotoxicity induced by gentamicin.

METHODS

A total of 30 Wistar Albino female rats equally divided into six groups were studied for seven days. Except for the normal control (NC) group, all groups received 80 mg/kg/day gentamicin (GEN) injection intra-peritoneally for seven days. NC and GEN groups received only regular diet. In the water spinach group (GEN + WS) and red grape (GEN + RG) groups, rats were provided with 20 g/rat/day of boiled water spinach and 5 mL/rat/day of red grape juice, respectively. The probiotic (GEN + P₄) and (GEN + P₈) groups received 4 × 10⁹ and 8 × 10⁹ viable bacteria, respectively. On the 8th day, all the rats were sacrificed to collect blood and kidney. Serum creatinine, urea, uric acid, malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD) were analyzed. In addition, kidney histopathology was taken for final observation.

RESULTS

Both antioxidant-rich foods and probiotic (P₄) significantly (p < 0.05) attenuated the GEN-induced oxidative and nitrosative stress and improved kidney function by lowering uremic toxin (serum creatinine, and uric acid) levels. Histopathological findings of kidney tissues of all groups were consistent with the biochemical findings.

CONCLUSION

The current preclinical study suggests that the consumption of antioxidant-rich foods might be a promising fighting option against gentamycin-induced nephrotoxicity and oxidative stress. However, extensive studies and clinical monitoring are immediately required to determine the appropriate probiotic doses and mechanism of action for such effects.

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.

Renoprotective Effect of Fucoidan from Seaweed Sargassum angustifolium C. Agardh 1820 on Gentamicin-Induced Nephrotoxicity: From Marine Resources to Therapeutic Uses

Background: Nephrotoxicity is a major side effect of aminoglycoside antibiotics, caused by oxidative damage and inflammation. Fucoidan, a group of sulfated polysaccharides derived from different species of brown algae, are well recognized for their antioxidant and anti-inflammatory activities. Objectives: In the present study, we aimed to investigate, for the first time, the efficacy of fucoidan extracted from Sargassum angustifolium C. Agardh 1820 against gentamicin-induced nephrotoxicity in rats. Methods: Twenty-eight male Wistar rats were divided into 4 groups of control, gentamicin (100 mg/kg), and gentamicin plus 50- and 100-mg/kg/day fucoidan pretreatment. In the end, all rats were killed, and then urine, blood, and tissue samples were prepared. Kidney weight (KW), body weight (BW), and 24-hour urine volume, as well as serum creatinine (Cr), blood urea nitrogen (BUN), Cr clearance, and malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity, were measured. Kidney samples were also evaluated for histopathological changes. Results: Gentamicin significantly increased KW, KW/BW ratio, 24-hour urine volume, serum Cr, MDA, and BUN levels; however, fucoidan pretreatment, especially at a dose of 50 mg/kg, significantly returned these variables near to the control group values. Gentamicin also decreased BW gain, Cr clearance, SOD activity, and the degree of renal tissue damage compared to the control group, while treatment with fucoidan significantly reversed these alterations. Conclusions: The results show that fucoidan from S. angustifolium C. Agardh 1820 ameliorates gentamicin-induced nephrotoxicity by alleviating oxidative stress and augmenting antioxidant enzymes activity in renal tissue, suggesting the potential use of this fucoidan in a clinical setting.

Protective effects of p-coumaric acid against gentamicin-induced nephrotoxicity in rats

The most important side effect of gentamicin (GM) is nephrotoxicity. p-Coumaric acid (PCA) is a phenolic compound that scavenges free radicals, reduces fibrosis, and tissue damage. This study investigates the protective effect of PCA on tissue damage and kidney function in gentamicin-induced nephrotoxicity (GIN). Thirty-five rats were separated into five groups and each group contained seven animals: control group, ethanol group, GM group, PCA group, and GM + PCA group. At the end of the seven-day treatment, the rats were sacrificed after blood and kidney tissue samples were taken. While serum urea, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL) levels increased significantly in the GM group compared to the control, they showed a significant decrease in the GM + PCA group compared to the GM. Serum tumor necrosis factor-α (TNF-α) and tissue malondialdehyde (MDA) levels were significantly increased in the GM group compared to the control. While the tissue total oxidant status (TOS) and oxidative stress index (OSI) values of the GM group were significantly higher than the control, they showed a significant decrease in the GM + PCA group compared to the GM. In the histopathological examination, significant tubular necrosis and tubulointerstitial inflammation were detected in the proximal tubules in the GM group compared to the control, while a significant decrease was observed in the severity of these findings in the GM + PCA group compared to the GM. This study shows that PCA has biochemical and histopathological ameliorating effects on GIN in the rat model.

Nephroprotective potential of Anogeissus latifolia Roxb. (Dhava) against gentamicin-induced nephrotoxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Stem bark of Anogeissus latifolia Roxb. (Family: Combretaceae) is used traditionally and ethnomedicinally for correction of kidney disorders.

AIM OF THE STUDY

The present study demonstrates the nephroprotective potential of stem bark of A. latifolia Roxb.

MATERIALS AND METHODS

The HPTLC fingerprint and HPLC analysis were carried out to standardize the ethanolic extract of stem bark of A. latifolia (ALEE) using ellagic acid as a marker. Nephrotoxicity was induced in adult Wistar albino rats by gentamicin (100 mg/kg, intraperitoneally for 8 days) and they were treated with ALEE (100, 200 and 400 mg/kg, orally for 8 days), ellagic acid (10 mg/kg, orally for 8 days) and cystone syrup (5 ml/kg, orally), a standard reference a polyherbal formulation. Urine volume, serum and urine levels of creatinine, urea and uric acid, oxidative stress parameters (lipid peroxidation, catalase, superoxide dismutase and reduced glutathione), inflammatory markers (TNF-α and IL-6) and kidney weight along with its histological changes were studied in experimental animals.

RESULTS

HPTLC, HPLC and LC-MS analysis of ALEE revealed the presence of ellagic acid and other various phytoconstituents. Administration of gentamicin caused significant increase in urine output and kidney weight, elevated biochemical, inflammatory and oxidative stress parameters as well as caused histological damage in the kidney tissue. These parameters were attenuated by the concurrent treatment with ALEE and ellagic acid. The effects were comparable to cystone.

CONCLUSION

Present investigations concluded that ALEE exhibited nephroprotective potential and validated the traditional use of stem bark of A. latifolia in kidney disorders. The nephroprotective effect may be attributed to the antioxidant and anti-inflammatory phytoconstituents in ALEE.

The Mechanism of Drug Nephrotoxicity and the Methods for Preventing Kidney Damage

Acute kidney injury (AKI) is a global health challenge of vast proportions, as approx. 13.3% of people worldwide are affected annually. The pathophysiology of AKI is very complex, but its main causes are sepsis, ischemia, and nephrotoxicity. Nephrotoxicity is mainly associated with the use of drugs. Drug-induced AKI accounts for 19-26% of all hospitalized cases. Drug-induced nephrotoxicity develops according to one of the three mechanisms: (1) proximal tubular injury and acute tubular necrosis (ATN) (a dose-dependent mechanism), where the cause is related to apical contact with drugs or their metabolites, the transport of drugs and their metabolites from the apical surface, and the secretion of drugs from the basolateral surface into the tubular lumen; (2) tubular obstruction by crystals or casts containing drugs and their metabolites (a dose-dependent mechanism); (3) interstitial nephritis induced by drugs and their metabolites (a dose-independent mechanism). In this article, the mechanisms of the individual types of injury will be described. Specific groups of drugs will be linked to specific injuries. Additionally, the risk factors for the development of AKI and the methods for preventing and/or treating the condition will be discussed.

Quercetin-loaded F127 nanomicelles: Antioxidant activity and protection against renal injury induced by gentamicin in rats

Quercetin (Q) is formulated into oil-in-water F127 microemulsions to improve its bioavailability. The size of the Q-loaded microemulsions system was about 8 nm by dynamic light scattering analysis. To compare antioxidant activity of bulk solution and microemulsion of Q, free radical scavenging activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC50 values were 56.77 and 187.68 μM, respectively. The drug in the bulk form released 16.34 times faster than microemulsion form. Although gentamicin (GM) has potent efficacy against gram-negative bacteria, it induces renal toxicity. Poor solubility and low bioavailability of Q as a bioflavonoid with potent antioxidant activity, limit its therapeutic application. We aimed to compare the effect of free Q and nanoencapsulated (NEQ) against GM-induced renal damage in Wistar rats. Forty-two animals were divided into six groups. Control and GM groups received apo-nanomicelles and GM (100 mg/kg) for 10 days. Two groups received Q (50 mg/kg, i.g.) and NEQ (50 mg/kg, i.g.) respectively for 10 days. Remaining two groups received Q and NEQ (50 mg/kg, i.g.) plus GM (100 mg/kg, i.p.) simultaneously for 10 days. After the experiments, serum and kidneys were used for biochemical, molecular and histological examinations. Immunohistochemical analysis was performed to explore kidney injury molecule-1 (KIM-1) expression as a specific protein biomarker of renal injury. Our findings indicated oxidative stress and altered histological features in renal tissue with deviated serum renal biomarkers in GM-treated rats. Although Q treatment in GM group tried to protect against GM-induced nephrotoxicity, but there were still differences compared to control rats. However, NEQ administration corrected elevations in the levels of urea, creatinine, uric acid and decrements in serum total proteins of GM group. Meanwhile, NEQ restored renal oxidative injury in GM rats through attenuation of lipid peroxidation and enhancement of antioxidant defense systems, glutathione, catalase and superoxide dismutase. NEQ could also normalize GM-induced abnormal renal histology features including fibrosis. Furthermore, the result of immunohistochemistry study confirmed these findings by undetecting KIM-1 expression in NEQ treated GM group, meanwhile showing this renal biomarker in GM and Q treated GM groups. Therefore, NEQ seems to be useful in protecting against renal oxidative stress and kidney damage in a rat model of GM nephrotoxicity which deserve further evaluations.

Nephroprotective Effects of Zataria multiflora Boiss. Hydroalcoholic Extract, Carvacrol, and Thymol on Kidney Toxicity Induced by Cisplatin in Rats

Background

Cisplatin (Cis) is an anticancer drug; however, it has dose-dependent renal toxicity. The current study aims to investigate the protective effects of Zataria multiflora Boiss. hydroalcoholic extract (Z.M.B), carvacrol, and thymol on cisplatin-induced nephrotoxicity in rats.

Materials and Methods

Forty-two Wistar male rats were randomly allocated into six groups (n = 7). Group I received normal saline; group II received Cis (7 mg/kg. ip); group III received the Z.M.B extract only (500 mg/kg/d, po); group IV received Z.M.B extract (500 mg/kg/d, po) + Cis; group V received carvacrol (50 mg/kg/d, po) + Cis; and group VI received thymol (50 mg/kg/d, po) + Cis. The levels of biochemical markers, oxidative stress parameters, and histopathological staining were determined in serum and renal tissues. Also, the chemical compositions (carvacrol and thymol) of the Z.M.B extract were assayed by HPLC analysis.

Result

The results revealed that Z.M.B extract, carvacrol, and thymol markedly decreased the renal index as compared with the Cis-only group. Also, carvacrol and thymol significantly reduced the blood urea nitrogen level as compared with the Cis-only group. Furthermore, Z.M.B extract, carvacrol, and thymol significantly attenuated the Cis-induced increase in malondialdehyde and nitric oxide metabolite. Additionally, histopathological examination showed that Z.M.B extract, carvacrol, and thymol markedly ameliorated Cis-induced renal tubular necrosis.

Conclusion

The results showed renoprotective effects of Z.M.B extract, carvacrol, and thymol in Cis-induced nephrotoxicity in rats. Therefore, Z.M.B extract can be considered as a potential candidate for the protection of nephrotoxicity induced by Cis.

Catalytic Antioxidants in the Kidney

Reactive oxygen species and reactive nitrogen species are highly implicated in kidney injuries that include acute kidney injury, chronic kidney disease, hypertensive nephropathy, and diabetic nephropathy. Therefore, antioxidant agents are promising therapeutic strategies for kidney diseases. Catalytic antioxidants are defined as small molecular mimics of antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and some of them function as potent detoxifiers of lipid peroxides and peroxynitrite. Several catalytic antioxidants have been demonstrated to be effective in a variety of in vitro and in vivo disease models that are associated with oxidative stress, including kidney diseases. This review summarizes the evidence for the role of antioxidant enzymes in kidney diseases, the classifications of catalytic antioxidants, and their current applications to kidney diseases.

The Role of Mitochondria in Drug-Induced Kidney Injury

The kidneys utilize roughly 10% of the body’s oxygen supply to produce the energy required for accomplishing their primary function: the regulation of body fluid composition through secreting, filtering, and reabsorbing metabolites and nutrients. To ensure an adequate ATP supply, the kidneys are particularly enriched in mitochondria, having the second highest mitochondrial content and thus oxygen consumption of our body. The bulk of the ATP generated in the kidneys is consumed to move solutes toward (reabsorption) or from (secretion) the peritubular capillaries through the concerted action of an array of ATP-binding cassette (ABC) pumps and transporters. ABC pumps function upon direct ATP hydrolysis. Transporters are driven by the ion electrochemical gradients and the membrane potential generated by the asymmetric transport of ions across the plasma membrane mediated by the ATPase pumps. Some of these transporters, namely the polyspecific organic anion transporters (OATs), the organic anion transporting polypeptides (OATPs), and the organic cation transporters (OCTs) are highly expressed on the proximal tubular cell membranes and happen to also transport drugs whose levels in the proximal tubular cells can rapidly rise, thereby damaging the mitochondria and resulting in cell death and kidney injury. Drug-induced kidney injury (DIKI) is a growing public health concern and a major cause of drug attrition in drug development and post-marketing approval. As part of the article collection “Mitochondria in Renal Health and Disease,” here, we provide a critical overview of the main molecular mechanisms underlying the mitochondrial damage caused by drugs inducing nephrotoxicity.

Ursodeoxycholic acid abrogates gentamicin-induced hepatotoxicity in rats: Role of NF-κB-p65/TNF-α, Bax/Bcl-xl/Caspase-3, and eNOS/iNOS pathways

AIM

The present study focused on the possible underlying protective mechanisms of UDCA against GNT-induced hepatic injury.

METHODS

For achieving this goal, adult male rats were allocated into 4 groups: normal control (received vehicle), GNT (100 mg/kg, i.p. for 8 days), UDCA (60 mg/kg, P.O. for 15 days), and GNT + UDCA (received UDCA for 15 days and GNT started from the 7th day and lasted for 8 days).

RESULTS

The results revealed that UDCA significantly improved GNT-induced hepatic injury, oxidative stress, apoptosis, and inflammatory response. Interestingly, UDCA inhibited apoptosis by marked down-regulation of the Bax gene, Caspase-3, and cleaved Caspase-3 protein expressions while the level of Bcl-xL gene significantly increased. Moreover, UDCA strongly inhibited the inflammatory response through the down-regulation of both NF-κB-p65 and TNF-α accompanied by IL-10 elevation. Furthermore, the obtained results ended with the restored of mitochondria function that confirmed by electron microscopy. Histological analysis showed that UDCA remarkably ameliorated the histopathological changes induced by GNT.

SIGNIFICANCE

UDCA may be a promising agent that can be used to prevent hepatotoxicity observed in GNT treatment. This effect could be attributed to, at least in part, the ability of UDCA to modulate NF-κB-p65/TNF-α, Bax/Bcl-xl/Caspase-3, and eNOS/iNOS signaling pathways.

Renoprotective effect of irbesartan in a rat model of gentamicin-induced nephrotoxicity: Role of oxidative stress

BACKGROUND:

The renin–angiotensin system (RAS) is essential in renal physiology; however, disturbance of the RAS is one of the chief pathways involved in renal injury. Dysregulation of RAS may result in both glomerular and tubulointerstitial injuries through direct effects of angiotensin II (Ang II) type 1 receptor. Irbesartan and other Ang II blockers have renoprotective effect through reduction of on renal inflammations. Therefore, the aim of the present study was to demonstrate the renoprotective effect of irbesartan on gentamicin-induced nephrotoxicity in rats concerning the oxidative stress.

MATERIALS AND METHODS:

Thirty Sprague-Dawley Male rats divided into three groups, Group I (10 rats) treated with distilled water, Group II (10 rats) treated with gentamicin, and Group III (10 rats) treated with gentamicin plus irbesartan for 12 days. Blood urea, serum creatinine, serum malondialdehyde (MDA), superoxide dismutase (SOD), glutathione reductase (GSH), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecules (KIM-1), and cystatin-c were measured in each group.

RESULTS:

Irbesartan significantly reduced blood urea, serum creatinine, serum MDA, NGAL, KIM-1, and cystatin-c P < 0.05. Irbesartan significantly increases SOD P < 0.05 without significant effect in elevation of GSH serum levels.

CONCLUSION:

Irbesartan has renoprotective effect in attenuation of acute nephrotoxicity through modulation of oxidative stress and antioxidant capacity in rats.

Development of a Novel Pharmaceutical Formula of Nanoparticle Lipid Carriers of Gentamicin/α-Tocopherol and In Vivo Assessment of the Antioxidant Protective Effect of α-Tocopherol in Gentamicin-Induced Nephrotoxicity

Gentamicin is a potent antibiotic with a nephrotoxicity drawback which limits its use. D-α-tocopherol polyethylene glycol succinate (α-tocopherol) is widely used as a surfactant and have potent antioxidant properties. This study aimed to assess the protective effect of α-tocopherol on gentamicin-induced nephrotoxicity by loading gentamicin on nanostructured lipid carriers (NLC). In vivo, the product was administered intravenously to three groups of rabbits (control, gentamicin and gentamicin/α-tocopherol NLC) for 10 consecutive days. Blood was collected on days 1, 5 and 10 to assess renal function. A significant difference in all plasma parameters related to kidney function were observed in the gentamicin group compared to the control by day 5 and 10, confirming the nephrotoxicity effect. On the other hand, the same parameter levels of the NLC group were significantly different compared to the gentamicin group, confirming the protective effect on kidney function. Gentamicin also caused significant decreases in plasma levels of glutathione sulfhydryl (GSH) and superoxide dismutase (SOD) activity. However, gentamicin-α-tocopherol NLC significantly elevates both plasma levels of GSH as well as SOD activity. The present work indicates that, loading of gentamicin on NLC by using α-tocopherol, is an innovative strategy to protect against aminoglycoside-induced nephrotoxicity due to its antioxidant activity.

Antioxidant, anti-inflammatory, and antiapoptotic effects of virgin coconut oil against antibiotic drug gentamicin-induced nephrotoxicity via the suppression of oxidative stress and modulation of iNOS/NF-ĸB/caspase-3 signaling pathway in Wistar rats

Gentamicin is an effective antibiotic against severe infections; however, its major side effect is oxidative nephrotoxicity. We explored whether virgin coconut oil (VCO) could mitigate gentamicin-induced nephrotoxicity. Rats were fed with VCO-supplemented diet for 16 days against renal toxicity induced by gentamicin (100 mg/kg bw, ip) from Day 11 to 16. Gentamicin caused marked elevated serum urea, uric acid, and creatinine levels, followed by considerable depletion in renal antioxidant enzymes, glutathione (GSH), while the malondialdehyde (MDA) level increased significantly. It significantly increased renal cytokines and nitric oxide (NO) levels, confirmed by renal histopathology. The expression of inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-ĸB), and caspase-3 was prominently increased. VCO-supplemented diet significantly modulated the levels of biochemical indices, downregulated the expression of NO, iNOS, NF-ĸB, caspase-3, cytokines, and alleviated histopathological lesions. VCO protects against gentamicin-induced nephrotoxicity; thus, it could be a promising dietary supplement for patients undergoing gentamicin treatment. PRACTICAL APPLICATIONS: Gentamicin is an efficacious clinical antibiotic used against severe infections; however, the robust body of evidence indicates that the nephrotoxic side effect constrained its use. Virgin coconut oil (VCO) is an edible oil with growing human consumption and pharmacological effects. Our study has reported herein, for the first time, that VCO diet prevented the nephrotoxicity of gentamicin. Dietary supplementation of this oil could be beneficial in alleviating the nephrotoxic side effect of gentamicin in patients.

Renoprotective effects of stevia (Stevia rebaudiana Bertoni), amlodipine, valsartan, and losartan in gentamycin-induced nephrotoxicity in the rat model: Biochemical, hematological and histological approaches

The current study investigated the renoprotective effects of stevia, angiotensin-II type 1 receptor (AT1) blocker and calcium (Ca2+) channel blocker in gentamycin-induced nephrotoxicity in rat models. Six groups of male Sprague-Dawley rats of eight weeks old were taken for the experiment: sham control, nephrotoxicity, treatment with amlodipine (4 mg/kg/day); stevia (200 mg/kg/day); losartan (15 mg/kg/day) and valsartan (5 mg/kg/day), accordingly. The blood sample was taken for the assessment of renal and hepatic-functional variables like serum creatinine, blood urea, BUN and SGPT, SGOT, and total serum bilirubin. Hematological parameters were also examined. Histological examination has been done on kidneys and liver. Alterations of the body weight and the organ's weight were documented. Treatment with stevia and valsartan significantly decreased serum creatinine levels. A reduction of liver enzymes, and total serum bilirubin levels were observed in all the treatment groups. Treatment with valsartan and amlodipine, remarkably and stevia, mildly reduced the renal tissue damage, inflammation, and tubular necrosis. However, the present study demonstrated that losartan treatment aggravated kidney damage by increasing protein cast, calcification, tubular necrosis, and injury. This comparison indicated that both stevia and valsartan have beneficial renoprotective effect and valsartan offers a better treatment option in renal damage over losartan.

Rutin inhibits carfilzomib-induced oxidative stress and inflammation via the NOS-mediated NF-κB signaling pathway

BACKGROUND

Carfilzomib (CFZ), a proteasome inhibitor approved by the FDA to treat multiple myeloma, may cause nephrotoxicity.

HYPOTHESIS

Rutin is a bioflavonoid with antioxidant properties. We aimed to examine whether rutin protects the kidney from CFZ-induced nephrotoxicity.

STUDY DESIGN

This study aimed to demonstrate the effect of rutin on CFZ-induced renal injury via the inhibition of oxidative stress and inflammation.

METHODS

Wistar albino rats were divided into six groups (n = 6): Group 1 (normal control; NC) was administered normal saline for 3 weeks; Group 2 (CFZ/toxic group) received CFZ [4 mg/kg, intraperitoneal (i.p.) injection] twice weekly for 3 weeks; Group 3 (standard treatment group) was administered CFZ (4 mg/kg, i.p.) and olmesartan (2 mg/kg, p.o.) for 3 weeks; Group 4 was administered CFZ (4 mg/kg, i.p.) and rutin (10 mg/kg, p.o.) for 3 weeks; Group 5 was administered CFZ (4 mg/kg, i.p.) and rutin (20 mg/kg, p.o.) for 3 weeks; and Group 6 was administered CFZ (4 mg/kg, i.p.) and rutin (40 mg/kg, p.o.) for 3 weeks. We carried out haematological and biochemical analyses, determined oxidative stress, caspase-3 activity, and protein levels, and performed a histopathological evaluation to confirm CFZ-induced nephrotoxicity and its prevention by rutin administration.

RESULTS

Exposure to only CFZ significantly (p < 0.05) increased white blood cell (WBC) count, Hb%, and HTC% concentration; however, these features were significantly decreased (p < 0.05) when olmesartan and rutin were administered. CFZ administration significantly decreased (p < 0.0001) the level of antioxidant enzymes; whereas, administration of olmesartan and rutin significantly reversed (p < 0.05) their levels toward the normal range. The levels of caspase-3 enzyme significantly increased (p < 0.001) in the CFZ group and were reduced toward the normal values by olmesartan and rutin administration. Furthermore, the results of NOS-2, NF-κB, IkBa, and IL-17 protein estimation and the histopathological evaluation strengthened our findings that rutin exhibits a protective effect against CFZ-induced nephrotoxicity.

CONCLUSION

These findings clearly demonstrate that rutin ameliorates CFZ-induced oxidative stress and inflammation in nephrotoxicity via the NOS-mediated NF-κB signaling pathway.

Nephroprotective properties of the methanol stem extract of Abrus precatorius on gentamicin-induced renal damage in rats

Background The use of plants for the treatment and prevention of diseases in man and his animals has led to a renewed scientific interest in the use of medicinal plants for therapeutic purposes. The nephroprotective properties of methanol stem bark extract of Abrus precatorius against gentamicin-induced renal damage in rats was evaluated in this study. Methods Thirty male Wistar rats were divided into five equal groups. Group A was the negative control group while B was the positive control group which received gentamicin 100 mg/kg intra-peritoneally for 6 days. Group C were pretreated with 100 mg/kg extract for the 3 days and then concurrently with gentamicin 100 mg/kg for 3 days and group D were pretreated with 200 mg/kg extract for 3 days and then concurrently with gentamicin 100 mg/kg for 3 days. Group E received gentamicin intraperitoneally for 6 days followed by administration of 200 mg/kg of the extract for 3 days. Blood samples, kidneys and kidney homogenates were collected for haematological, biochemical, histopathological and immunohistochemical analysis. Results The results showed that no significant haematological changes were noted. The groups treated with extract exhibited significant increase in body weight gain. While group B significantly exhibited focal areas of inflammation, fatty degeneration, congestion of vessels, tubular necrosis and glomerular atrophy, the lesions were mild with the treated groups. Treated groups exhibited a dose dependent significant decrease in serum creatinine, urea, XO, NO and Myeloperoxidase, AOPP, Protein carbonyl, H2O2 generated and MDA levels when compared with group B. There were significant dose dependent improvements in SOD, GST, GSH, Protein thiol, and non-protein thiol levels in the treated groups when compared with group B. In immunohistochemistry, Group B exhibited over expression of CRP and NF-κB levels, and marked reduction in expression of Bcl-2 while the reverse was seen in the groups treated with methanol extracts of Abrus precatorius. Conclusion The methanol extract of Abrus precatorius plays a vital role against gentamicin induced renal damage by reducing levels of renal markers of oxidative stress, inflammation and apoptosis, enhancing enzymatic and non enzymatic renal antioxidant system, alongside an increase in Bcl-2 and a decrease in NF-κB and CRP expressions.

Protective and antioxidant effects of copper-nicotinate complex against glycerol-induced nephrotoxicity in rats

Copper-nicotinate complex (CNC) has antioxidant activities through scavenging of free radicals formed inside the body. CNC also has anti-tumor and anti-inflammatory activities. The current study was designed to determine the effect of glycerol on rat kidney function and oxidative stress as well as, the potential nephroprotective effects of CNC. Forty male Wistar rats were randomly allocated into four equal groups. The groups of rats were as follows: GI was kept under normal control conditions; GII was orally given CNC at a dose of 0.043 mg kg^-1 body weight (BW), three times/week for 4 weeks; GIII was administered glycerol (topical application) at a dose of 3.15 ml kg^-1 BW daily for 4 weeks; and GIV was given CNC and glycerol with the same dose and route. The results revealed that CNC improves the renal dysfunctions induced by glycerol by recovering the levels of urea and creatinine to normal, as well as through the antioxidant status manifested by the normalization of catalase, superoxide dismutase, reduced glutathione, and malondialdehyde levels. Moreover, by its effect as an anti-oxidant, CNC reduces the effect of glycerol on the kidney by decreasing the fibrosis, degenerative changes and necrotic changes in the renal tubules. In conclusion, CNC could alleviate the side effects that might be caused by glycerol.

Troxerutin down-regulates KIM-1, modulates p38 MAPK signaling, and enhances renal regenerative capacity in a rat model of gentamycin-induced acute kidney injury

Troxerutin enhances renal tissue regeneration, improves renal function, and decreases renal tissue injury in gentamycin-treated rats.

Kolaviron attenuates ischemia/reperfusion injury in the stomach of rats

Kolaviron (KV), an active complex of at least 3 compounds in Garcinia kola seed, which is known for its antioxidant and anti-inflammatory activity, was investigated for its gastro-protective effect in the stomach of rats subjected to ischemia/reperfusion-induced gastric ulceration. Male adult Wistar rats (180-210 g) were randomized into 6 groups (n = 15) as follows: (i) control, (ii) ulcerated untreated (UU), (iii) KV alone (KVA), (iv) KV + ulcer (KVU), (v) ulcer + KV (UKV), and (vi) ulcer + omeprazole (20 mg/kg). Ulcer was induced through ischemia/reperfusion method after 2 weeks of daily oral KV (100 mg/kg). Rats were weighed daily, and gastric acid secretion, ulcer scores, hematological, biochemical, and histological variables were assessed 1 h after induction at 3 and 7 days post-ulceration. Body weight decreased in KVA (179.1 ± 1.6 g), and KVU (170.1 ± 2.2 g) compared with UU (199.0 ± 1.4 g). Gastric acid secretion decreased significantly in KVU after 1 h and 3 days post-ulceration (0.27 ± 0.03 mEq/L; 0.49 ± 0.02 mEq/L) compared with UU (0.60 ± 0.06 mEq/L; 0.85 ± 0.29 mEq/L), respectively. There was significant reduction in neutrophil/lymphocyte ratio of KVA (0.29 ± 0.06) and KVU (0.35 ± 0.02) compared with UU (0.54 ± 0.04). Malondialdehyde level decreased significantly with concomitant increase in anti-oxidative activities and nitric oxide level in the KV treated groups (KVA, KVU, UKV) compared with UU. In conclusion, treatment with KV protects the stomach by reducing gastric acid secretion, promoting antioxidant activity and suppressing action of reactive oxygen species.

Protective effect of rutin supplementation against cisplatin-induced Nephrotoxicity in rats

Background

Cisplatin (CP) is commonly used in the treatment of different types of cancer but nephrotoxicity has been a major limiting factor. Therefore, the present study aimed to study the possible protective effect of rutin against nephrotoxicity induced by cisplatin in rats.

Methods

Forty male Wistar albino rats were randomly divided into 4 groups. Rats of group 1 control group intraperitoneal (i.p.) received 2.5 ml/kg, group 2 CP group received single dose 5 mg/kg cisplatin i.p. group 3 rutin group orally received 30 mg/kg rutin group 4 (CP plus rutin) received CP and rutin as in group 2 and 3. Kidneys were harvested for histopathology and for the study the gene expression of c-Jun N-terminal kinases (JNK), Mitogen-activated protein kinase 4 (MKK4), MKK7, P38 mitogen-activated protein kinases (P38), tumor necrosis factors alpha (TNF-α), TNF Receptor-Associated Factor 2 (TRAF2), and interleukin-1 alpha (IL-1-α).

Results

The cisplatin single dose administration to rats induced nephrotoxicity associated with a significant increase in blood urea nitrogen (BUN) and serum creatinine and significantly increase Malondialdehyde (MDA) in kidney tissues by 230 ± 5.5 nmol/g compared to control group. The animal treated with cisplatin showed a significant increase in the expression levels of the IL-1α (260%), TRFA2 (491%), P38 (410%), MKK4 (263%), MKK7 (412%), JNK (680%) and TNF-α (300%) genes compared to control group. Additionally, histopathological examination showed that cisplatin-induced interstitial congestion, focal mononuclear cell inflammatory, cell infiltrate, acute tubular injury with reactive atypia and apoptotic cells. Rutin administration attenuated cisplatin-induced alteration in gene expression and structural and functional changes in the kidney. Additionally, histopathological examination of kidney tissues confirmed gene expression data.

Conclusion

The present study suggested that the anti-oxidant and anti-inflammatory effect of rutin may prevent CP-induced nephrotoxicity via decreasing the oxidative stress, inhibiting the interconnected ROS/JNK/TNF/P38 MAPK signaling pathways, and repairing the histopathological changes against cisplatin administration.

Key role of oxidative stress in animal models of aminoglycoside nephrotoxicity revealed by a systematic analysis of the antioxidant-to-nephroprotective correlation

The clinical utility of aminoglycoside antibiotics is partly limited by their nephrotoxicity. Co-administration of a variety of candidate nephroprotectants has been tested at the preclinical level. According to a recent meta-analytic study, antioxidants are the only family of compounds with enough preclinical documentation to draw solid conclusions on their class nephroprotective capacity in animal models. In this study a systematic analysis of the relation between the level of antioxidation and the level of nephroprotection was performed. A regression model is presented which crosses the y-axis (i.e. the axis representing the level of nephroprotection) very nearly the zero value, meaning that maximal prevention of the oxidative stress induced by aminoglycosides results in almost maximal nephroprotection. This indicates that oxidative stress plays a central role in the hierarchy of pathophysiological mechanisms underlying aminoglycoside nephrotoxicity. In addition, this model may potentially serve: i) as a standard to evaluate the role of the antioxidant effect of candidate nephroprotectants; ii) to reveal additional, antioxidant-independent effects among those compounds providing more nephroprotection than that expected from its antioxidant activity; and thus iii) to discriminate and focus most effective nephroprotectants on clinical usage.

Nephroprotective effect of Rudgea viburnoides (Cham.) Benth leaves on gentamicin-induced nephrotoxicity in rats

RELEVANCE

Rudgea viburnoides, popularly known as "congonha-de-bugre" or "erva de bugre", is used in folk medicine as hypotensive, blood depurative, anti-rheumatic, diuretic and in the treatment of kidney and bladder pain.

AIM

Based on the popularly acclaimed nephron-protective effect of R. viburnoides, we investigated, using rats, the protective effect of this plant extract on gentamicin-induced kidney injury.

MATERIAL AND METHODS

Urinary volume, water and food intakes were assessed in adult male Wistar rats (naive or gentamicin-induced model of nephrotoxicity) treated with R. viburnoides extract. Also blood and kidney samples were collected for further laboratory and histological analyses.

RESULTS

R. viburnoides leaves extract improved renal function. It also improved the renal function impairments caused by gentamicin-induced nephrotoxicity, as revealed by glomerular filtration rate, urine output and proteinuria.

CONCLUSION

R. viburnoides exert renoprotective effect, which may support its popular use for renal diseases treatment.

Gentamicin nephrotoxicity in animals: Current knowledge and future perspectives

Due to high relative blood flow the kidney is prone to drug-induced damage. Aminoglycoside type antibiotic gentamicin is one of the leading cause of drug-induced nephrotoxicity. In recent years gentamicin nephrotoxicity is significantly reduced by shifting to once daily dosage as well as by eliminating known risk factors. Application of gentamicin is still related to serious side effects which are reported more often compared to other antibiotics. Because gentamicin is still heavily used and is highly efficient in treating infections, it is important to find mechanisms to reduce its nephrotoxicity. This aim can only be achieved through better understanding of kidney metabolism of gentamicin. This problem has been extensively researched in the last 20 years. The experimental results have provided evidence for almost complete understanding of mechanisms responsible for gentamicin nephrotoxicity. We now have well described morphological, biochemical and functional changes in kidney due to gentamicin application. During the years, this model has become so popular that now it is used as an experimental model for nephrotoxicity per se. This situation can mislead an ordinary reader of scientific literature that we know everything about it and there is nothing new to discover here. But quite opposite is true. The precise and complete mechanism of gentamicin nephrotoxicity is still point of speculation and an unfinished story. With emerge of new and versatile technics in biomedicine we have an opportunity to reexamine old beliefs and discover new facts. This review focuses on current knowledge in this area and gives some future perspectives.

Riceberry bran extract prevents renal dysfunction and impaired renal organic anion transporter 3 (Oat3) function by modulating the PKC/Nrf2 pathway in gentamicin-induced nephrotoxicity in rats

PURPOSE

This study investigated the protective effects of Riceberry bran extract (RBBE) on renal function, and the function and expression of renal organic anion transporter 3 (Oat3) in gentamicin-induced nephrotoxicity in rats and explored the mechanisms for its protective effects.

MATERIAL AND METHODS

Male Sprague Dawley rats (n= 42) were divided into six groups to receive normal saline, gentamicin (100mg/kg), co-treatment of gentamicin and RBBE (at dose of 250, 500 and 1000mg/kg), and RBBE (at dose of 1000mg/kg) only, for consecutive fifteen days. Renal function, oxidative and antioxidative markers, the function and expression of Oat3 and histological changes in the kidney were evaluated.

RESULTS

Elevation of BUN, serum creatinine levels and reduction in urine creatinine and creatinine clearance indicated decreased renal function in the gentamicin-treated rats. The decrease of [³H]ES uptake in the renal cortical slices of these rats, reflecting the attenuation of Oat3 transport function that was accompanied by decreased expression of Oat3. Moreover, increased MDA level and reduced superoxide dismutase (SOD) and glutathione (GSH) activities were found in gentamicin-treated rats compared to the control group. These changes were associated with the upregulated PKCα, Nrf-2, Keap 1, NQO-1 and HO-1 expressions in kidneys. RBBE treatment improved the renal function and Oat3 transport function and expression in gentamicin-treated rats. The oxidative status was also restored by RBBE treatment.

CONCLUSION

RBBE protects kidney injury by its antioxidant effect, subsequently leading to modulation of the PKC/Nrf2 antioxidant defense pathway.

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.

Protective effects of kolaviron and gallic acid against cobalt-chloride-induced cardiorenal dysfunction via suppression of oxidative stress and activation of the ERK signaling pathway

Cobalt (Co) toxicity is a potential public health problem due to recent renewed use of Co in orthopedic implants, dietary supplements, and blood doping in athletes and horses. We investigated the protective roles of kolaviron (KV), a bi-flavonoid of Garcinia kola, and gallic acid (GA) on cobalt chloride (CoCl2)-induced cardiorenal damage in rats. CoCl2 caused significant increases (p < 0.05) in serum creatine kinase–myocardial band (CK-MB), lactate dehydrogenase (LDH), aspartate transaminase (AST), xanthine oxidase (XO), urea, creatinine, malondialdehyde, H2O2, nitric oxide, as well as C-reactive protein expression, along with significant (p < 0.05) reduction in cardiac and renal expression of extracellular signal regulated kinase (ERK) and the activities of superoxide dismutase, catalase, and glutathione S-transferase. KV and GA prevented the toxic effects of CoCl2 by stimulating ERK expression and reversing Co-induced biochemical changes. Administration of CoCl2 alone did not significantly alter ECG patterns in the rats, although co-treatment with KV (200 mg/kg) produced QT-segment prolongation and also appeared to potentiate Co hypotension. Histopathology of the heart and kidneys of rats treated with KV and GA confirmed the biochemical data. KV and GA thus protected against cardiac and renal damage in Co intoxication via antioxidant and (or) cell survival mechanisms, possibly involving ERK activation.

Chemopreventive role of Coriandrum sativum against gentamicin-induced renal histopathological damage in rats

Drug induced nephrotoxicity is one of the most common causes of renal failure. Gentamicin belongs to aminoglycosides, which elicit nephrotoxic potential. Natural antioxidants from plants demonstrate a number of biotherapeutic activities. Coriander is an important medicinal plant known for its hepatoprotective, diuretic, carminative, digestive and antihelminthic potential. This study was designed to investigate whether the extract of Coriandrum sativum ameliorates the nephrotoxicity induced by gentamicin in rats. Dried coriander powder was coarsely grinded and subjected to defatting by petroleum ether and further with ethyl acetate. The extract was filtered and subjected to phytochemical and phytoanalytical studies.

Acute toxicity in Wistar rats was determined by the OECD Guideline (423). Animals were divided into four groups. The first group served as positive control, while the second group was toxic control (gentamicin treated). The third and fourth group were treated with the extract (200 and 400 mg/kg gentamicin). After 8 days, the animals were sacrificed and biochemical and histopathological studies were carried out. Phytochemical screening of the extract demonstrated Coriandrum sativum to be rich in flavonoids, polyphenolics and alkaloids. Results of acute toxicity suggested the use of 200 mg/kg and 400 mg/kg for Coriandrum sativum in the study. Coriandrum sativum extract at the dose of 400 mg/kg significantly (p<0.01) decreased creatinine levels in the animals, along with a decrease in serum urea and blood urea nitrogen. Treatment with Coriandrum sativum extract ameliorated renal histological lesions. It is concluded that Coriandrum sativum is a potential source of nephroprotective phytochemical activity, with flavonoids and polyphenols as the major components.

Time dependent effect of gentamicin on enzymes of carbohydrate metabolism and terminal digestion in rat intestine

Gentamicin (GM) is an aminoglycoside antibiotic commonly used against life threatening gram negative bacterial infections, however, nephrotoxicity remains the major concern for its long term use. Although its effects on kidney are well characterized but there have been no studies regarding its effects on intestine. We hypothesize that GM causes adaptive coordinated effect on enzymes of carbohydrate metabolism and terminal digestion/ absorption in rat intestine. Rats were administerd a nephrotoxic dose of GM (80 mg /kg body weight) daily for 15 days and a time dependent effect was observed on various enzyme activities. Activities of lactate (LDH), malate (MDH) and isocitrate (ICDH) dehydrogenases, significantly increased and peaked at different time intervals of GM treatment. Whereas LDH activity remained higher, MDH and ICDH activity slowly declined from their peak values. Activities of fructose-1,6-bisphosphatase, glucose-6-phosphatase and glucose-6-phosphate dehydrogenase increased but malic enzyme decreased in a time dependent manner. Activity of alkaline phosphatase and sucrase significantly increased but γ-glutamyl transpeptidase activity decreased. GM administration increased lipid peroxidation, glutathione peroxidase but decreased superoxide dismutase and catalase activities. The results indicate that GM treatment selectively upregulated certain enzymes of carbohydrate metabolism and terminal digestion/absorption and perturbed antioxidant defenses. Human & Experimental Taxicology, ( 2007) 26, 587—593.

Protective effect of the methanolic leaf extract of Eclipta alba (L.) Hassk. (Asteraceae) against gentamicin-induced nephrotoxicity in Sprague Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Eclipta alba, also known as Eclipta prostrata, is a weed of the family Asteraceae found in tropical and subtropical regions widely used in herbal medicine, including treatment of renal diseases.

AIM OF THE STUDY

This study aims to evaluate the protective effect of the methanolic leaf extract of Eclipta alba on gentamicin-induced nephrotoxicity in rats.

MATERIALS AND METHODS

Nephrotoxicity was induced in rats by subcutaneous injection of gentamicin (80mg/kg/day for seven days). Quercetin was used as a positive control. The nephroprotective activity was evaluated by determining blood urea nitrogen, serum creatinine, urinary microprotein, renal catalase and malondialdehyde levels.

RESULTS

The extract protected the rat kidneys against gentamicin-induced renal tubular alterations and rises in blood urea nitrogen, serum creatinine, and microprotein levels. Lipid peroxidation and decrement in catalase levels were also ameliorated.

CONCLUSION

The study revealed the protective effect of the methanolic leaf extract of E. alba and suggests that the probable mechanism for the nephroprotection by the extract may be due to its good radical scavenging activity and Fe(3+) ion-reducing ability.