Reno-protective effect of fenofibrate and febuxostat against vancomycin-induced acute renal injury in rats: Targeting PPARγ/NF-κB/COX-II and AMPK/Nrf2/HO-1 signaling pathways.

BACKGROUND: Vancomycin (VCM) is used clinically to treat serious infections caused by multi-resistant Gram-positive bacteria, although its use is severely constrained by nephrotoxicity. This study investigated the possible nephroprotective effect of febuxostat (FX) and/or fenofibrate (FENO) and their possible underlying mechanisms against VCM-induced nephrotoxicity in a rat model. METHODS: Male Wistar rats were randomly allocated into five groups; Control, VCM, FX, FENO, and combination groups. Nephrotoxicity was evaluated histopathologically and biochemically. The oxidative stress biomarkers (SOD, MDA, GSH, total nitrite, GPx, MPO), the apoptotic marker, renal Bcl-2 associated X protein (Bax), and inflammatory and kidney injury markers (IL-1ß, IL-6, TNF-α, Nrf2, OH-1, kappa-light-chain-enhancer of activated B cells (NF-κB), NADPH oxidase, Kim-1, COX-II, NGAL, Cys-C were also evaluated. RESULTS: VCM resulted in significant elevation in markers of kidney damage, oxidative stress, apoptosis, and inflammatory markers. Co-administration of VCM with either/or FX and FENO significantly mitigated nephrotoxicity and associated oxidative stress, inflammatory and apoptotic markers. In comparison to either treatment alone, a more notable improvement was observed with the FX and FENO combination regimen. CONCLUSION: Our findings show that FX, FENO, and their combination regimen have a nephroprotective impact on VCM-induced kidney injury by suppressing oxidative stress, apoptosis, and the inflammatory response. Renal recovery from VCM-induced injury was accomplished by activation of Nrf2/HO-1 signaling and inhibition of NF-κB expression. This study highlights the importance of FX and FENO as effective therapies for reducing nephrotoxicity in VCM-treated patients.

In Vitro Evaluation of Vancomycin-Induced Toxicity in Human Primary Knee Chondrocytes.

Septic arthritis as a complication of orthopaedic joint surgery can have catastrophic outcomes for patients. To minimise infection risk associated with elective orthopaedics, topical vancomycin during surgery has become increasingly common. Evidence suggests that high concentrations of vancomycin, following direct application of the drug to the joint, are toxic towards various local cell types in the joint, including chondrocytes. However, the mechanism of this vancomycin tissue toxicity is yet to be determined. The aim of this study was to evaluate the toxicity of vancomycin on chondrocytes and the mechanisms of cell death involved. Human primary knee chondrocytes were exposed to vancomycin (1.25-10 mg/mL) for 24 h and their viability assessed using the resazurin reduction assay in vitro. Specific cell death mechanisms and their contributors, including reactive oxygen species (ROS) production and apoptosis, were measured. This study showed that high concentrations of vancomycin (5 and 10 mg/mL) were toxic towards human primary knee chondrocyte cells, while lower concentrations (1.25 and 2.5 mg/mL) were not. Cell death studies found that this occurred through an apoptotic pathway. This study provides additional support that vancomycin in high doses is toxic towards chondrocytes and preliminary evidence that this toxicity occurs via apoptotic cell death mechanisms.

Protective effect of teriparatide against vancomycin-induced cytotoxicity in osteoblasts.

BACKGROUND: Intrawound vancomycin powder is effective in preventing surgical site infection after spine surgery. In a previous study, vancomycin-induced cytotoxicity in osteoblasts was investigated in vitro, and vitamin D3 was verified to be a candidate drug aiding recovery from vancomycin-induced cytotoxicity. The treatment practices involving osteogenesis-promoting drugs vary widely. Teriparatide, an anabolic agent, highly promotes bone formation by inducing osteoblast activation, increasing bone formation and mineral density, and preventing vertebral fractures. Hence, teriparatide may be administered in combination with vancomycin. METHODS: MC3T3-E1 cells were cultured in minimum essential medium supplemented with 10% fetal bovine serum at 37 °C in a humidified incubator containing 5% CO2. The experimental concentrations of vancomycin (2500, 5000, and 7500 µg/mL) were determined based on previous reports and our preliminary experiments. Teriparatide (100 ng/mL) was administered concomitantly to prevent cytotoxicity in osteoblasts, using pulsed vancomycin for 24 h (measured at 1, 3, and 7 days). Cell numbers and morphological changes in cells treated with vancomycin or vancomycin plus 100 ng/mL teriparatide were measured. Osteoblast differentiation was assessed using alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red S staining. RESULTS: Teriparatide showed a recovery effect when vancomycin (7500 µg/mL) was administered only for 24 h. Microscopic examination revealed that teriparatide had a protective effect on osteoblasts exposed to 7500 µg/mL vancomycin. Addition of teriparatide led to the recovery of alkaline phosphatase staining and alizarin red staining. CONCLUSION: Vancomycin-induced cytotoxicity in osteoblasts could be inhibited by administering teriparatide concomitantly with vancomycin.

Protective effects of vitamin D3 (cholecalciferol) on vancomycin-induced oxidative nephrotoxic damage in rats.

CONTEXT: Vancomycin (VCM), an important antibiotic against refractory infections, has been used to treat secondary infections in severe COVID-19 patients. Regrettably, VCM treatment has been associated with nephrotoxicity. Vitamin D3 can prevent nephrotoxicity through its antioxidant effect. OBJECTIVE: This study tests the antioxidant effect of vitamin D3 in the prevention of VCM-induced nephrotoxicity. MATERIALS AND METHODS: Wistar Albino rats (21) were randomly divided into 3 groups: (A) control; (B) VCM 300 mg/kg daily for 1 week; and (C) VCM plus vitamin D3 500 IU/kg daily for 2 weeks. All the rats were sacrificed and serum was separated to determine kidney function parameters. Their kidneys were also dissected for histological examination and for oxidative stress markers. RESULTS: Lipid peroxidation, creatinine, and urea levels decreased significantly (p < 0.0001) in the vitamin D3-treated group (14.46, 84.11, 36.17%, respectively) compared to the VCM group that was given VCM (MIC<2 µg/mL) only. A significant increase was observed in superoxide dismutase levels in the vitamin D3-treated group (p < 0.05) compared to rats without treatment. Furthermore, kidney histopathology of the rats treated with vitamin D3 showed that dilatation, vacuolization and necrosis tubules decreased significantly (p < 0.05) compared with those in the VCM group. Glomerular injury, hyaline dystrophy, and inflammation improved significantly in the vitamin D3 group (p < 0.001, p < 0.05, p < 0.05, respectively) compared with the VCM group. DISCUSSION AND CONCLUSIONS: Vitamin D3 can prevent VCM nephrotoxicity. Therefore, the appropriate dose of this vitamin must be determined, especially for those infected with COVID-19 and receiving VCM, to manage their secondary infections.

Detection of vancomycin-resistant Enterococcus faecium hospital-adapted lineages in municipal wastewater treatment plants indicates widespread distribution and release into the environment.

Vancomycin-resistant Enterococcus faecium (VREfm) is a leading cause of healthcare-associated infection. Reservoirs of VREfm are largely assumed to be nosocomial although there is a paucity of data on alternative sources. Here, we describe an integrated epidemiological and genomic analysis of E. faecium associated with bloodstream infection and isolated from wastewater. Treated and untreated wastewater from 20 municipal treatment plants in the East of England, United Kingdom was obtained and cultured to isolate E. faecium, ampicillin-resistant E. faecium (AREfm), and VREfm. VREfm was isolated from all 20 treatment plants and was released into the environment by 17/20 plants, the exceptions using terminal ultraviolet light disinfection. Median log10 counts of AREfm and VREfm in untreated wastewater from 10 plants in direct receipt of hospital sewage were significantly higher than 10 plants that were not. We sequenced and compared the genomes of 423 isolates from wastewater with 187 isolates associated with bloodstream infection at five hospitals in the East of England. Among 481 E. faecium isolates belonging to the hospital-adapted clade, we observed genetic intermixing between wastewater and bloodstream infection, with highly related isolates shared between a major teaching hospital in the East of England and 9/20 plants. We detected 28 antibiotic resistance genes in the hospital-adapted clade, of which 23 were represented in bloodstream, hospital sewage, and municipal wastewater isolates. We conclude that our findings are consistent with widespread distribution of hospital-adapted VREfm beyond acute healthcare settings with extensive release of VREfm into the environment in the East of England.

Vancomycin-Associated Acute Kidney Injury: A Narrative Review from Pathophysiology to Clinical Application.

Vancomycin is the most frequently used antibiotic, accounting for up to 35% of hospitalized patients with infection, because of its optimal bactericidal effectiveness and relatively low price. Vancomycin-associated AKI (VA-AKI) is a clinically relevant but not yet clearly understood entity in critically ill patients. The current review comprehensively summarizes the pathophysiological mechanisms of, biomarkers for, preventive strategies for, and some crucial issues with VA-AKI. The pathological manifestations of VA-AKI include acute tubular necrosis, acute tubulointerstitial nephritis (ATIN), and intratubular crystal obstruction. The proposed pathological mechanisms of VA-AKI include oxidative stress and allergic reactions induced by vancomycin and vancomycin-associated tubular casts. Concomitant administration with other nephrotoxic antibiotics, such as piperacillin-tazobactam, high vancomycin doses, and intermittent infusion strategies compared to the continuous infusion are associated with a higher risk of VA-AKI. Several biomarkers could be applied to predict and diagnose VA-AKI. To date, no promising therapy is available. Oral steroids could be considered for patients with ATIN, whereas hemodialysis might be applied to remove vancomycin from the patient. In the future, disclosing more promising biomarkers that could precisely identify populations susceptible to VA-AKI and detect VA-AKI occurrence early on, and developing pharmacological agents that could prevent or treat VA-AKI, are the keys to improve the prognoses of patients with severe infection who probably need vancomycin therapy.

Precision dosing of vancomycin: in defence of AUC-guided therapy in children.

In 2020, new vancomycin guidelines were released, recommending the transition from trough-based to AUC24 monitoring for adult and paediatric patients. Given the resources required to achieve this transition, there has been debate about the costs and benefits of AUC24-based monitoring. A recent narrative review of vancomycin therapeutic drug monitoring in paediatrics claims to have uncovered the methodological weaknesses of the data that informed the guidelines and advises against premature adoption of AUC24-guided monitoring. In this article, we present supporting arguments for AUC24-guided monitoring in children, which include that: (i) troughs alone are inadequate surrogates for AUC24; (ii) vancomycin-associated nephrotoxicity has significant consequences that warrant optimization of dosing; (iii) a substantial portion of children receiving vancomycin are at high risk for poor outcomes and deserve targeted monitoring; and (iv) limited efficacy data in support of AUC24 is not a justification to revert to a less supported monitoring approach.

Comparative evaluation of phosphatidylcholine and phosphatidylserine with different fatty acids on nephrotoxicity in vancomycin-induced mice.

Phospholipids reportedly alleviate drug-induced acute kidney injury. However, no study has compared the effect of phospholipids with different fatty acids and polar heads on drug-induced nephrotoxicity. In the present study, we aimed to compare the possible nephroprotection afforded by phosphatidylcholine and phosphatidylserine with different fatty acids in a mouse model of vancomycin-induced nephrotoxicity. Pretreatment with phospholipids rich in docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) doubled the survival time when compared with the model group. Moreover, phospholipids rich in DHA/EPA significantly reduced the serum levels of renal function biomarkers and ameliorated kidney pathologies. In terms of alleviating renal damage, no significant differences were observed between different polar heads in DHA-enriched phospholipids, while phosphatidylserine from soybean was better than phosphatidylcholine in mitigating renal injury. Furthermore, DHA/EPA-enriched phospholipids inhibited vancomycin-induced nephrotoxicity mainly by inhibiting apoptosis and oxidative stress. These results provide a scientific basis for phospholipids as potential ingredients to prevent acute kidney injury.

Comparison of trough concentration and area under the curve of vancomycin associated with the incidence of nephrotoxicity and predictors of a high trough level.

PURPOSE: A high vancomycin trough concentration during therapy is associated with increased nephrotoxicity, and the recent guidelines for therapeutic monitoring of vancomycin recommend target of the ratio of area under the curve (AUC) to minimum inhibitory concentration. We aimed to determine vancomycin trough concentration and AUC that induce nephrotoxicity and evaluate predictive factors associated with a high serum vancomycin trough level according to the initial dosing strategy. METHODS: We conducted a retrospective cohort study in patients administered intravenous vancomycin from June 2013 to February 2017. Totally, 346 patients were included. RESULTS: 38 experienced nephrotoxicity during therapy. The both trough level and AUC were significant risk factors for the occurrence of vancomycin induced-nephrotoxicity (p < 0.001, p = 0.001). The exposure-response analysis revealed that the trough level of 15 µg/mL was associated with 12.0% nephrotoxicity incidence and AUC of 600 was associated with 12.9% nephrotoxicity incidence. During the treatment, 90 patients had an initial trough concentration of ≥15 µg/mL, and 124 patients had AUC of ≥600 µg h/mL. The multiple logistic regression analysis revealed body weight (p = 0.001), serum creatinine level (p = 0.028), daily vancomycin dose (p = 0.001), and ICU (p = 0.015) were independent predictive factors for a high trough concentration. And same factors were selected for the high AUC. CONCLUSION: The risk factors for vancomycin induced nephrotoxicity were comparable in both trough concentration and AUC. The incidence of nephrotoxicity can be reduced by controlling vancomycin trough concentration similarly AUC and promoting antimicrobial stewardship.

Vancomycin is toxic to human chondrocytes in vitro.

INTRODUCTION: Vancomycin powder (VP) is a well-established topical antibiotic used in spinal surgery to prevent surgical site infections. More recently its extension to hip and knee arthroplasty was introduced. The aim of this study was to examine toxic effects of VP on the viability of human chondrocytes. Our hypothesis was that VP damages human chondrocytes in vitro with increasing concentration and length of exposure. MATERIAL AND METHODS: Primary human chondrocytes were isolated and cultured from donated human knee joints. VP was added to these cultures with increasing concentrations (0-50 mg/ml) and length of exposure (0-336 h). Toxicity and viability were analyzed using LDH und XTT Elisa assays. Cell structure and determination of vital versus dead cells were visualized using light microscopy and fluorescence microscopy. RESULTS: Light microscopy and fluorescence microscopy visualized defect cell structures and cell death proportional to increasing dose and length of exposure to VP. The analysis of LDH activity data showed toxic effects on chondrocytes as early as 2,5 min after exposure to VP. XTT activity data revealed a significant toxic threshold of a VP concentration above 12.5 mg/ml. CONCLUSIONS: These results show that exposure to high VP concentrations yields to a damage of human chondrocytes in vitro. Chondrotoxicity is an immediate effect that is proportional to VP concentration. Therefore, the intraarticular use of high concentrations of vancomycin powder in the presence of native cartilage tissue must be considered critically.

Evaluation of risk factors for nephrotoxicity associated with high-dose vancomycin in Japanese patients.

Introduction: Considering the physique of the Japanese population, the standard daily vancomycin dose of 2 g/day and doses ≥ 3 g/day are high in terms of dose per body weight. Studies have reported that administering high-dose vancomycin to achieve a high target trough concentration has been associated with nephrotoxicity. The risk of high-dose vancomycin-associated nephrotoxicity is believed to be exceptionally high for Japanese patients because of their relatively low body weights, but data on the population is lacking. In this retrospective study, we aimed to evaluate risk factors associated with nephrotoxicity in Japanese patients treated with vancomycin. Methods: We examined the medical records of 107 Japanese patients who received vancomycin (3 to 4 g/day). They were divided into two groups based on the presence or absence of nephrotoxicity, and their demographics and clinical characteristics were compared. Results : The incidence of nephrotoxicity in patients receiving high-dose vancomycin was 13%. Age (≥ 60 years) and concurrent use of piperacillin/tazobactam were independent risk factors for vancomycin-associated nephrotoxicity (P = 0.027 and 0.017, respectively). Conclusions : We conclude that the nephrotoxicity risk of high-dose vancomycin in Japanese patients is not excessively high when administered within the confines of a therapeutic drug-monitoring program. However, special care must be taken with patients who are older or on concurrent piperacillin/tazobactam therapy.

Lack of synergistic nephrotoxicity between vancomycin and piperacillin/tazobactam in a rat model and a confirmatory cellular model.

BACKGROUND: Vancomycin and piperacillin/tazobactam are reported in clinical studies to increase acute kidney injury (AKI). However, no clinical study has demonstrated synergistic toxicity, only that serum creatinine increases. OBJECTIVES: To clarify the potential for synergistic toxicity between vancomycin, piperacillin/tazobactam and vancomycin + piperacillin/tazobactam treatments by quantifying kidney injury in a translational rat model of AKI and using cell studies. METHODS: (i) Male Sprague-Dawley rats (n = 32) received saline, vancomycin 150 mg/kg/day intravenously, piperacillin/tazobactam 1400 mg/kg/day intraperitoneally or vancomycin + piperacillin/tazobactam for 3 days. Urinary biomarkers and histopathology were analysed. (ii) Cellular injury was assessed in NRK-52E cells using alamarBlue®. RESULTS: Urinary output increased from Day -1 to Day 1 with vancomycin but only after Day 2 for vancomycin + piperacillin/tazobactam-treated rats. Plasma creatinine was elevated from baseline with vancomycin by Day 2 and only by Day 4 for vancomycin + piperacillin/tazobactam. Urinary KIM-1 and clusterin were increased with vancomycin from Day 1 versus controls (P < 0.001) and only on Day 3 with vancomycin + piperacillin/tazobactam (P < 0.001, KIM-1; P < 0.05, clusterin). The histopathology injury score was elevated only in the vancomycin group when compared with piperacillin/tazobactam as a control (P = 0.04) and generally not so with vancomycin + piperacillin/tazobactam. In NRK-52E cells, vancomycin induced cell death with high doses (IC50 48.76 mg/mL) but piperacillin/tazobactam did not, and vancomycin + piperacillin/tazobactam was similar to vancomycin. CONCLUSIONS: All groups treated with vancomycin demonstrated AKI; however, vancomycin + piperacillin/tazobactam was not worse than vancomycin. Histopathology suggested that piperacillin/tazobactam did not worsen vancomycin-induced AKI and may even be protective.

Toxicity Profile and Pharmacokinetic Study of Antibiotic Mixtures, Gentamicin and Vancomycin, in Rat Plasma by Ecofriendly Liquid Chromatography Coupled Tandem Mass Spectrometry.

The global burden of bacterial infection and antimicrobial resistance increases the demand to associate more than one antibiotic to fight life-threatening bacteria. Therefore, there is a great necessity to develop simple and sensitive methods for routine analysis of clinical samples. Therapeutic drug monitoring, bioequivalence, and pharmacokinetic studies are essential to ensure drug efficiency and safety. Herein, therefore, the first ecofriendly liquid chromatography -tandem mass spectrometry (LC-MS/MS) method was developed and fully validated for simultaneous determination of a commonly combined antibiotic for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin (VCM) and gentamicin (GTM), in rat plasma after parenteral administration. VCM and GTM were extracted from plasma sample using acetonitrile (ACN)/0.1% TFA-induced protein precipitation followed by the separation on an Agilent Eclipse Plus ODS (3 mm × 100 mm, 3.5 µm) column using water-enriched mobile phase consisting of water containing 0.1% THF/ACN (85:15, v/v%) at flow rates of 0.30 mL min-1. The mass spectrometry parameters were optimized, and multiple reaction monitoring (MRM) in positive ion mode of two transitions was utilized for quantification of precursor to product ion at m/z 725.5 → 144 and 100.1 for VCM as [M + 2H]2+, 478.3 → 322.2 and 156.9 for GTM, and 586.3 → 162.9 and 425.3 for amikacin (AMK) internal standard, as [M + H]+. The current method has been validated as per U.S. FDA bioanalytical guidelines in terms of linearity, accuracy, precision, selectivity, recovery, matrix effects, and stability. The method was linear in the range of 1-2000 ng mL-1 and 1-1000 ng mL-1 with detection limits (S/N of 3) of 0.18 and 0.09 ng mL-1 for VCM and GTM, respectively. The selectivity and high sensitivity allow the current method to succeed in the study of pharmacokinetic parameters and drug-drug interaction between VCM and GTM after single-dose administration. VCM increased plasma clearance and elimination rate constant of GTM when coadministered and GTM also too. The change of serum chemistry analysis and significant elevation of creatinine and BUN indicate an alteration in kidney function in group III in those given the combined antibiotics. Our finding illustrated the nephrotoxicity of the two drugs when associated. The ecofriendly, simplicity, and rapidity of the current study made it a promising method for high-throughput biomonitoring in clinical samples.

Atg7 mediates renal tubular cell apoptosis in vancomycin nephrotoxicity through activation of PKC-δ.

Recent studies have shown that autophagy exhibits a renoprotective role in various models of acute kidney injury (AKI). However, its role in vancomycin (Van)-induced AKI remains largely unclarified. This study was the first to indicate that autophagy was rapidly activated in both human kidney-2 cells and renal tissues, and mammalian target of rapamycin (mTOR) was inactivated via the suppression of ERK1/2 and mTOR during Van treatment. Interestingly, for both in vitro and in vivo experiments, the suppression of autophagy via chloroquine and PT-Atg7-KO significantly ameliorated Van-induced kidney injury and renal tubular cell apoptosis. Global gene expression analysis indicated that the expression levels of 6159 genes were induced by Van treatment in the kidney cortical tissues of PT-Atg7 wild-type mice, and 18 of them were notably suppressed in PT-Atg7-KO mice. These 18 genes were further classified as programmed cell death, protein binding, signal transduction, E3 ubiquitin ligase, nucleoside diphosphate kinase activity, and E1-like activating enzyme. Unexpectedly, following Van treatment, PKC-δ expression was found to be highest among the 4 genes related to cell death, which was remarkably suppressed in vitro and in PT-Atg7-KO mice. In addition, Atg7 could induce renal cell apoptosis during Van treatment via binding to PKC-δ. Likewise, the inhibition of PKCδ ameliorated Van-induced apoptosis in human kidney-2 cells and kidney tissues. Furthermore, the data showed that PT-Atg7-KO exerted a renoprotective effect against Van-induced nephrotoxicity, but this effect was lost after injection with myc-tagged PKCδ. Taken altogether, these results indicate that Van induces autophagy by suppressing the activation of the ERK1/2 and mTOR signaling pathway. In addition, Atg7 mediates Van-induced AKI through the activation of PKCδ. In sum, autophagy inhibition may serve as a novel therapeutic target for treating nephrotoxic AKI induced by Van.-Xu, X., Pan, J., Li, H., Li, X., Fang, F., Wu, D., Zhou, Y., Zheng, P., Xiong, L., Zhang, D. Atg7 mediates renal tubular cell apoptosis in vancomycin nephrotoxicity through activation of PKC-δ.

Does oral vancomycin use necessitate therapeutic drug monitoring?

PURPOSE: Oral vancomycin use has generally increased as a consequence of the need to treat and/or prevent Clostridium (Clostridiodes) difficile-associated disease (CDAD). This review examines the cumulative scientific evidence that guides therapeutic monitoring of oral vancomycin therapy. METHODS: The existing publications were reviewed from the time of the drug's inception to July 2019. This review utilized access as available in PubMed, EMBASE, CINAHL Plus, and the Cochrane Library. RESULTS: Case reports and small patient series have documented anecdotal-associated elevations in serum levels. Correlation of absorbed vancomycin with subsequent toxicity is difficult to determine, but serum levels approaching those obtained after parenteral administration have raised concern. Prolonged usage and total dosing over 500 mg/day among adult age ranges have been associated with accumulation. In addition, risk factors for vancomycin accumulation systemically after oral dosing include renal compromise, combined oral and other enteral therapy, severe CDAD, other intercurrent bowel inflammation, polypharmacy, and increased patient complexity/morbidity. CONCLUSION: Until systemic toxicity from oral vancomycin absorption is better understood, individual considerations should be made for therapeutic serum monitoring during oral vancomycin treatment. Therapeutic drug monitoring is suggested for several high-risk situations in which high blood levels may be anticipated.

Silybum marianum (milk thistle) improves vancomycin induced nephrotoxicity by downregulating apoptosis.

Increased use of vancomycin for treating infections, and the associated risk of causing nephrotoxicity lead to the present study. The antioxidant and anti-apoptotic potential of Silybum marianum is used along with vancomycin to reduce adverse effects on the kidney. Vero cells (monkey kidney cells) and mice were used to test S. marianum extract on vancomycin induced nephrotoxicity. Vero cells were treated with different concentrations of vancomycin and S. marianum for 24 h for determination of cytotoxic potential and mRNA levels of apoptotic genes p53 , p21, and cyt-c were measured. For in-vivo studies mice were divided into five groups; G1 control (untreated), G2 vehicle (olive oil), G3 vancomycin treated (300 mg/kg body weight), G4 (S. marianum; 400 mg/kg bodyweight and vancomycin 300 mg/kg bodyweight simultaneously) and G5 (S. marianum 400 mg/kg bodyweight and vancomycin 300 mg/kg bodyweight treatment started after day 4 of S. marianum treatment). After 10 days histopathological analysis of mice kidneys was performed, serum urea and creatinine were analysed and mRNA expression of p53 , p21, and cyt-c was evaluated. Expression of p53, p21, and cyt-c in Vero cells was elevated in response to vancomycin treatment, whereas after S. marianum administration expression of these genes reduced. Vancomycin showed apoptosis in cells at the concentration of 6 mg/ml (LC50). Urea and creatinine levels in mice were increased in response to vancomycin administration and kidney histology showed an abnormality in functional units. The apoptotic cells were very visible in kidney structure in vancomycin treated group. These symptoms were however relieved in groups where treatment of S. marianum extract was given. mRNA expression of p53 , p21, and cyt-c also reduced in S. marianum treated groups of mice. S. marianum extract has protective effects against renal damage from vancomycin induced oxidative stress and relieves symptoms may be by downregulating apoptotic genes.

New insights into the vancomycin-induced nephrotoxicity using in vitro metabolomics combined with physiologically based pharmacokinetic modeling.

Vancomycin is a first-line treatment for invasive infections caused by multidrug-resistant gram-positive bacteria. However, vancomycin-induced nephrotoxicity is an increasing burden, particularly in patients with complex life-threatening conditions. Vancomycin-induced nephrotoxicity associated with clinically relevant exposure on the target site has not been well defined. This study aimed to acquire the concentration of vancomycin in the renal tubules and kidneys in humans using physiologically based pharmacokinetic (PBPK) modeling and simulation. Based upon the exposure of vancomycin in the renal tubule, the toxicity of vancomycin in human renal proximal tubular epithelial cells was examined with the XTT assay and in vitro metabolomics analysis. A rat PBPK model predicting plasma and kidney concentration-time profiles of vancomycin matched the observed behavior after a single administration of 10 mg/kg. The concentration of vancomycin in renal tubules was about 40-50 times higher than that in plasma. The human PBPK model transferred from the rat model predicted renal tubule concentrations of vancomycin as 316.1-2136.6 µg/mL at 500 mg every 6 hours, and 199.0-3932.5 µg/mL at 1000 mg every 12 hours. Vancomycin showed significant nephrotoxicity at 4 mg/mL in XTT assessment. In total, 11 lysophosphatidylcholines and one lysophosphatidylethanolamine were identified by metabolomics analysis. The concentration-dependent increase was evident in the release of lysophospholipids after vancomycin treatment (0.125-4 mg/mL) for 24 hours. Our study revealed the relationship between the exposure of vancomycin in the kidney and toxicity of vancomycin at clinically relevant concentrations achieved from a mechanical PBPK model. A series of lysophospholipids as potential metabolic markers of renal toxicity were identified.

Does Vitamin D3 Prevent the Inhibitory Effect of Vancomycin on Osteoblasts?

BACKGROUND: The utility of vancomycin powder to prevent surgical site infection, mainly in spinal surgery, has been widely examined, and the local administration of vancomycin powder to wounds has been reported to be effective in preventing surgical site infections after spine surgery. However, in vitro studies have shown that high local concentrations of vancomycin may inhibit osteogenesis, although it remains unclear how these high concentrations influence osteoblasts. No candidate drug has been reported to recover cytotoxicity with high concentrations of vancomycin, but we suggest that vitamin D3, which induces osteoblast proliferation, may be administrated concomitantly with vancomycin in these situations. QUESTIONS/PURPOSES: (1) Does a high concentration of vancomycin reduce viable osteoblast numbers in cell culture compared with controls? (2) Does vitamin D3 administration confer a protective effect on osteoblasts when administered with continuous vancomycin? (3) Does vitamin D3 administration confer a protective effect on osteoblasts when administered with pulsed vancomycin (24 hours of administration)? (4) Does vitamin D3 administration confer alkaline phosphatase, mineralization, and gene expression when administered with pulsed vancomycin? METHODS: MC3T3-E1 cells were cultured at 37° C in an α-minimum essential medium supplemented with 10% fetal bovine serum in a humidified incubator containing 5% CO2. The experimental concentrations of vancomycin (2500 µg/mL, 5000 µg/mL, and 7500 µg/mL) were determined based on previous reports and preliminary experiments. We concomitantly administered vitamin D3 (0.01 nM) to prevent cytotoxicity in osteoblasts, using two different treatments: continuous vancomycin administration (measured at 6 hours, 12 hours, 24 hours, and 72 hours) and pulsed vancomycin for 24 hours (measured at 1 days, 3 days, and 7 days). We analyzed cell numbers and morphologic changes in cells treated with vancomycin or vancomycin plus 0.01 nM vitamin D3. Osteoblast differentiation was assessed with alkaline phosphatase staining, alkaline phosphatase activity, and Alizarin red S staining. RESULTS: The number of cells was reduced at 6 hours, 24 hours, 48 hours, and 72 hours in response to continuous vancomycin administration at 7500 µg/mL (at 72 hours, control 14.6 × 10 cells/mL ± 0.260 × 10 cells/mL, vancomycin at 0.917 × 10 cells/mL ± 0.288 × 10 cells/mL, mean difference -13.7 × 10 cells/mL ± 0.388 × 10 cells/mL [95% CI -14.5 to -12.9]; p < 0.001). Vitamin D3 did not have a protective effect when vancomycin was administered continuously at 7500 µg/mL (at 72 hours, vancomycin alone 0.917 × 10 cells/mL ± 0.288 × 10 cells/mL, vancomycin + vitamin D3 1.67 × 10 cells/mL ± 0.310 × 10 cells/mL, mean difference 0.75 × 10 cells/mL ± 0.423 × 10 cells/mL [95% CI -0.127 to 1.63]; p = 0.09).With pulsed administration for only the first 24 hours, the number of cells was reduced at 1 day, 3 days, and 7 days at 7500 µg/mL (at 7 days, control 18.6 × 10 cells/mL ± 1.29 × 10 cells/mL, vancomycin at 3.46 × 10 cells/mL ± 0.292 × 10 cells/mL, mean difference -15.1 × 10 cells/mL ±1.33 × 10 cells/mL [95% CI -17.9 to -12.4]; p < 0.001 for all). However, vitamin D3 had a recovery effect when vancomycin was administered only for 24 hours (cell number with 7500 µg/mL, day 7: vancomycin alone 3.46 × 10 cells/mL ± 0.292 × 10 cells/mL, vancomycin +vitamin D3 10.6 × 10 cells/mL ± 0.900 × 10 cells/mL, mean difference 7.13 × 10 cells/mL ± 0.946 × 10 cells/mL [95% CI 5.16 to 9.09]; p < 0.001).With the addition of vitamin D3, we observed recovery of alkaline phosphatase staining and Alizarin red staining (evidence of calcification) but no difference in the gene expression of Type I collagen (vancomycin alone 0.319 ± 0.0730, vancomycin + vitamin D3 0.511 ± 0.139, mean difference 0.192 ± 0.157 [95% CI -0.483 to 0.867]; p = 0.345), alkaline phosphatase (vancomycin alone 0.532 ± 0.0210, vancomycin + vitamin D3 0.785 ± 0.0590, mean difference 0.253 ± 0.0620 [95% CI -0.0150 to 0.521]; p = 0.0550), and cathelicidin antimicrobial peptide (vancomycin alone 0.885 ± 0.0520, vancomycin + vitamin D3 1.24 ± 0.125, mean difference 0.355 ± 0.135 [95% CI -0.0200 to 0.730]; p = 0.0580). CONCLUSION: We found that 7500 µg/mL of vancomycin is cytotoxic to osteoblasts. Cytotoxicity could be prevented by administering vitamin D3 in combination with vancomycin. CLINICAL RELEVANCE: The high concentrations of vancomycin routinely used clinically raises concerns related to osteoblast cytotoxicity, which may contribute to pseudoarthrosis after spinal surgery. Thus, vitamin D3, which is frequently used to treat osteoporosis, may have efficacy as a concomitantly administered drug by inducing the proliferation of osteoblasts. These results indicate that a combination therapy of vancomycin and vitamin D3 may prevent adverse events such as osteoblast cytotoxicity.

Potential protective effects of naringenin against vancomycin-induced nephrotoxicity via reduction on apoptotic and oxidative stress markers in rats.

Vancomycin (VCM), a glycopeptide antibiotic, is a drug widely used in severe infections. However, VCM induce notable nephrotoxic side effects. Naringenin (NAR) is a natural of flavonoid and are known as strongly antioxidant, nefroprotective, antiapoptotic, and anti-inflammatory. The purpose of this study was to determine the potential protective effects of NAR against VCM-induced nephrotoxicity by measuring apoptotic and oxidative stress markers and evaluating histopathological alterations in rats. For this purpose, we used male Wistar albino rats that divided into seven groups: (i) Control [saline, intraperitoneally (i.p.)], (ii) carboxymethyl cellulose (0.5% CMC, orally), (iii) VCM (400 mg/kg, i.p.), (iv) NAR100 (100 mg/kg, orally), (v) VCM + NAR25 (25 mg/kg, orally), (vi) VCM + NAR50 (50 mg/kg, orally), and (vii) VCM + NAR100 (100 mg/kg, orally) groups. VCM administration was started one day after the first treatment of NAR and continued across 7-day. Caspase-3, -8, and-9 activities and malondialdehyde (MDA) and nitric oxide (NO) levels were measured by colorimetric methods in the kidney tissues, creatinine, and blood urea nitrogen (BUN) levels were analyzed based on ELISA in serum. Caspase-3 and -8 activities, NO levels, serum creatinine and BUN levels were significantly higher in VCM group in comparison with VCM + NAR (25, 50, and 100) groups (p < 0.05). Caspase-9 activity and MDA were significantly higher in VCM group compared to VCM + NAR (25 and 50) groups (p < 0.05). Histopathological alterations in VCM group were significantly diminished by administration of NAR, especially NAR 25. In conclusion, NAR 25 and 50 mg have more potent protective effects on VCM-induced nephrotoxicity compared to NAR 100 mg.

Rutin Attenuates Vancomycin-Induced Nephrotoxicity by Ameliorating Oxidative Stress, Apoptosis, and Inflammation in Rats.

Nephrotoxicity is the major limiting factor for the clinical use of vancomycin (VCM) for treatment of serious infections caused by multiresistant Gram-positive bacteria. This study investigated the renal protective activity of rutin in a rat model of VCM-induced kidney injury in male Wistar rats. VCM administered intraperitoneally at 200 mg/kg twice daily for 7 successive days resulted in significant elevation of blood urea nitrogen and creatinine, as well as urinary N-acetyl-ß-D-glucosaminidase. Coadministration of VCM with oral rutin at 150 mg/kg significantly reduced these markers of kidney damage. Rutin also significantly attenuated VCM-induced oxidative stress, inflammatory cell infiltration, apoptosis, and decreased interleukin-1ß and tumor necrosis factor alpha levels (all P < 0.05 or 0.01) in kidneys. Renal recovery from VCM injury was achieved by rutin through increases in Nrf2 and HO-1 and a decrease in NF-κB expression. Our results demonstrated a protective effect of rutin on VCM-induced kidney injury through suppression of oxidative stress, apoptosis, and downregulation of the inflammatory response. This study highlights a role for oral rutin as an effective intervention to ameliorate nephrotoxicity in patients undergoing VCM therapy.