Proteomic characterization of acyclovir-induced nephrotoxicity in a mouse model

Clinical Review of Risk of Nephrotoxicity with Acyclovir Use for Treatment of Herpes Simplex Virus Infections in Neonates and Children

OBJECTIVE

This study aims to clarify the risk of nephrotoxicity with intravenous use of acyclovir (ACV) for the treatment of neonates (ages <3 months) and children (ages ≥3 months to <12 years) with herpes simplex virus (HSV) infections and to identify gaps in knowledge that could be further investigated.

METHODS

Multiple databases were searched to identify studies on risk of nephrotoxicity with ACV use for treatment of invasive HSV infections, defined as any neonatal infection or HSV encephalitis (HSE) in children.

RESULTS

There were 5 and 14 studies that evaluated the risk of ACV-associated nephrotoxicity in neonates and children, respectively. The US Food and Drug Administration (FDA) delayed the approval of high (HD; 60 mg/kg/day) ACV in neonates secondary to risk of toxicity. Based on our review, the risk of ACV-associated nephrotoxicity was lower in the neonatal compared with the pediatric population. Acyclovir dose >1500 mg/m2, older age, and concomitant use of nephrotoxic drugs were identified as variables that increased the risk of ACV nephrotoxicity in children. Although the FDA has approved the use of HD ACV for the treatment of HSE in children, the American Academy of Pediatrics recommends a lower dose to minimize the risk of toxicity. The efficacy and safety of high vs lower doses of ACV for the management of HSE in children has yet to be evaluated.

CONCLUSIONS

The risk of ACV-associated nephrotoxicity was lower among neonates compared with older children. Future studies are needed to identify the optimal dosage that minimizes toxicities and maximizes the efficacy of ACV in children with HSE.

Central Composite Design for Formulation and Optimization of Solid Lipid Nanoparticles to Enhance Oral Bioavailability of Acyclovir

Treatment of herpes simplex infection requires high and frequent doses of oral acyclovir to attain its maximum therapeutic effect. The current therapeutic regimen of acyclovir is known to cause unwarranted dose-related adverse effects, including acute kidney injury. For this reason, a suitable delivery system for acyclovir was developed to improve the pharmacokinetic limitations and ultimately administer the drug at a lower dose and/or less frequently. In this study, solid lipid nanoparticles were designed to improve the oral bioavailability of acyclovir. The central composite design was applied to investigate the influence of the materials on the physicochemical properties of the solid lipid nanoparticles, and the optimized formulation was further characterized. Solid lipid nanoparticles formulated from Compritol 888 ATO resulted in a particle size of 108.67 ± 1.03 nm with an entrapment efficiency of 91.05 ± 0.75%. The analyses showed that the optimum combination of surfactant and solid lipid produced solid lipid nanoparticles of good quality with controlled release property and was stable at refrigerated and room temperature for at least 3 months. A five-fold increase in oral bioavailability of acyclovir-loaded solid lipid nanoparticles was observed in rats compared to commercial acyclovir suspension. This study has presented promising results that solid lipid nanoparticles could potentially be used as an oral drug delivery vehicle for acyclovir due to their excellent properties.

Transdermal Film Loaded with Garlic Oil-Acyclovir Nanoemulsion to Overcome Barriers for Its Use in Alleviating Cold Sore Conditions

The exponentially mounting cases of herpes simplex virus infection or cold sores have become a serious global concern. Acyclovir (ACV) and garlic oil (GO)-loaded lipid nanocarrier could be a promising therapeutic approach in alleviating cold sores, as well as limiting the biopharmaceutical constraints associated with ACV absorption and therapeutic efficacy. Therefore, the objective of the current research study was to formulate an ACV-GO self-nanoemulsifying drug delivery system (ACV-GO-SNEDDS) as transdermal films. The prepared SNEDDS was optimized using an experimental mixture design. The optimized ACV-GO SNEDDS was loaded in transdermal film and was evaluated for ex vivo skin permeation and in vivo pharmacokinetic prospects. An optimized ACV-GO SNEDDs formulation constituted of 10.4% (w/w) of GO, 64.8% (w/w) of surfactant mixture (Tween 20^®-Span 20^®); 24.8%(w/w) of co-surfactant (Propylene glycol^®), and 200mg of ACV, respectively, were prepared and characterized for particle size (Y). The observed globule size of the optimized ACV-GO SNEDDS is 170 ± 13.45 nm. The results of stability studies indicated that the stability index of optimized ACV-GO-SNEDDS was more than 92 ± 3%. This optimized ACV-GO SNEDDS was loaded in hydroxypropyl cellulose transdermal film. The outcome of the ex vivo skin permeation study demonstrated a 2.3-fold augmented permeation of ACV from the optimized ACV-GO SNEDDS HPC transdermal film in comparison to the raw ACV transdermal film. There was a 3-fold increase in the relative bioavailability of the optimized ACV-GO SNEDDS transdermal film compared to the raw ACV-HPC film. The study findings confirmed that the ACV-GO SNEDDS transdermal film exhibited excellent potential to enhance the bioavailability of ACV.

Identification of Novel Biomarkers for Predicting Kidney Injury Due to Drugs Using "Omic" Strategies

Drug-induced kidney injury accounts for 20% of community- and hospital-acquired cases of acute kidney injury (AKI). The incidence is higher among older individuals, who often have co-existing morbidities and are exposed to more diagnostic procedures and therapies. While demographic and clinical components have been identified as risk factors, the proposed cellular mechanisms of drug-induced kidney injury are numerous and complicated. There are also limitations recognized in the use of traditional biomarkers, such as serum creatinine and blood urea nitrogen, to provide high sensitivity, specificity, and timeliness to identification of drug-induced kidney injury. Therefore, novel biomarkers are currently being investigated, identified, developed, and validated for their performance over the traditional biomarkers. This review will provide an overview of drug-induced kidney injury and will discuss what is known regarding "omic" (proteomic, genomic, transcriptomic, and metabolomic) biomarker strategies for drugs known to induce nephrotoxicity.

Acyclovir-Loaded Solid Lipid Nanoparticles: Optimization, Characterization and Evaluation of Its Pharmacokinetic Profile

Acyclovir is an antiviral drug used for the treatment of herpes simplex virus infection. Its oral bioavailability is low; therefore, frequent and high doses are prescribed for optimum therapeutic efficacy. Moreover, the current therapeutic regimen of acyclovir is associated with unwarranted adverse effects, hence prompting the need for a suitable drug carrier to overcome these limitations. This study aimed to develop solid lipid nanoparticles (SLNs) as acyclovir carriers and evaluate their in vivo pharmacokinetic parameters to prove the study hypothesis. During the SLN development process, response surface methodology was exploited to optimize the composition of solid lipid and surfactant. Optimum combination of Biogapress Vegetal 297 ATO and Tween 80 was found essential to produce SLNs of 134 nm. The oral bioavailability study showed that acyclovir-loaded SLNs possessed superior oral bioavailability when compared with the commercial acyclovir suspension. The plasma concentration of acyclovir-loaded SLNs was four-fold higher than the commercial suspension. Thus, this investigation presented promising results that the method developed for encapsulation of acyclovir offers potential as an alternative pathway to enhance the drug’s bioavailability. In conclusion, this study exhibited the feasibility of SLNs as an oral delivery vehicle for acyclovir and therefore represents a new promising therapeutic concept of acyclovir treatment via a nanoparticulate drug delivery system.

The combination of acyclovir and dexamethasone protects against Alzheimer's disease-related cognitive impairments in mice

Alzheimer's disease (AD) is the most common neurodegenerative disease. However, effective drugs for this disease have not yet been developed. The analysis of big data indicated that childhood herpes virus infection may be associated with the incidence of AD, suggesting that anti-herpetic drugs, such as acyclovir, may have preventive and suppressive effects in AD therapy. Moreover, short-term use of dexamethasone (DXMT), a clinical used synthetic corticosteroid, could effectively inhibit AD-related neuroinflammation. In this study, we have found that the combination of acyclovir and DXMT, but not acyclovir or DXMT alone, could protect against AD causing β-amyloid (Aβ) oligomer-induced spatial cognitive impairments. Moreover, acyclovir and DXMT could prevent Aβ oligomer-induced over-activation of microglia and astrocytes, and over-expression of pro-inflammatory cytokines, indicating that anti-AD effects of drug combination might be at least partially via neuroinflammation inhibition and immunomodulation. Furthermore, Aβ oligomer-induced decrease of PSD-95 and increase of pTau expression was prevented by the combination of acyclovir and DXMT, suggesting the involvement of synaptic protective effects of the drug combination. Taken together, our studies indicated that the combination of acyclovir and DXMT might be an alternative therapy for the treatment of AD.

Leflunomide increased the renal exposure of acyclovir by inhibiting OAT1/3 and MRP2

Rheumatoid arthritis patients can be prescribed a combination of immunosuppressive drug leflunomide (LEF) and the antiviral drug acyclovir to reduce the high risk of infection. Acyclovir is a substrate of organic anion transporter (OAT) 1/3 and multidrug resistance-associated protein (MRP) 2. Considering the extraordinarily long half-life of LEF's active metabolite teriflunomide (TER) and the kidney injury risk of acyclovir, it is necessary to elucidate the potential impact of LEF on the disposition of acyclovir. Here we used a specific MRP inhibitor MK571 and probenecid (OAT1/3 and MRP2 inhibitor) to assess the effects of MRP2 and OAT1/3 on the pharmacokinetics and tissue distribution of acyclovir in rats. We showed that LEF and probenecid, but not MK571 significantly increased the plasma concentration of acyclovir. However, kidney and liver exposures of acyclovir were increased when coadministered with LEF, probenecid or MK571. The kidney/plasma ratio of acyclovir was increased to approximately 2-fold by LEF or probenecid, whereas it was increased to as much as 14.5-fold by MK571. Consistently, these drugs markedly decreased the urinary excretion of acyclovir. TER (0.5-100 μmol/L) dose-dependently increased the accumulation of acyclovir in MRP2-MDCK cells with an IC₅₀ value of 4.91 μmol/L. TER (5 μmol/L) significantly inhibited the uptake of acyclovir in hOAT1/3-HEK293 cells. These results suggest that LEF/TER increased the kidney accumulation of acyclovir by inhibiting the efflux transporter MRP2, which increased its kidney/plasma ratio and renal injury risk. However, the inhibitory effects of LEF/TER on OAT1/3 reduced the tubular cells' uptake of acyclovir and increased the plasma concentration.

Determination of acyclovir in renal microdialysis fluid and confirmation of renal function index

Acyclovir (ACV) is a nucleoside antivirus-free agent that was developed and marketed by Burroughs Well-come of the United States. Renal damage from ACV has been a major factor limiting its clinical application. Thus, the renal toxicity mechanism of ACV requires systematic study. In our previous study, we speculated that the nephrotoxicity of ACV may be associated with oxidative stress. In addition to the study of ACV's toxic effect in vivo, it is also necessary to explore the absorption and distribution of ACV in the body to further investigate the changes to ACV in the body. In this study, the toxicokinetics ACV in the kidney of the rat were explored using microdialysis, and the renal function of rats was measured. The results showed that high-dose ACV is associated with renal toxicity after a single intravenous injection or successive administration.

A metabolic profiling analysis of the nephrotoxicity of acyclovir in rats using ultra performance liquid chromatography/mass spectrometry

Acyclovir (ACV) exposure is a common cause of acute kidney injury (AKI). The toxicity mechanism of ACV has always been a matter of debate. The present study investigated into the time-effect relationship and dose-effect relationship of ACV-induced nephrotoxicity in rats using metabonomics. Twenty-four rats were randomly divided into four groups: a 0.9% NaCl solution group, and 100, 300, and 600mg/kg ACV-treated groups; the ACV or vehicle solution was administered with a single intravenous injection. Urine was collected at different time periods (12h before administration, and 0-6h, 7-12h, and 13-24h after administration). Routine urinalysis was conducted by a urine automatic analyzer. Renal markers, including urine urea nitrogen, urine creatinine, and urinary N-acetyl-β-d-glucosaminidase (NAG) activity, were determined using established protocols. Urinary metabolites were evaluated using ultra performance liquid chromatography/mass spectrometry (UPLC/MS). In the ACV-treated rats, increased levels of protein (PRO), occult blood (BLD), white blood cell (WBC), and NAG activity in urine were observed, while the urine creatinine and urea nitrogen levels showed a decrease compared with the control. Moreover, urine metabolites significantly changed after the treatment with ACV, and all the effects induced by ACV were dose-time dependent. Finally, 4 metabolites (guanine, 4-guanidinobutyric acid, creatinine, and urea) were identified, which can be used for further research on the mechanism of ACV-induced nephrotoxicity.

Proteomic identification of mitochondrial targets involved in andrographolide sodium bisulfite-induced nephrotoxicity in a rat model

Our previous works have indicated that the mitochondrion is the primary target of nephrotoxicity induced by andrographolide sodium bisulfate (ASB), but the mechanisms of ASB-induced nephrotoxicity have remained largely unknown. In this study, proteomic analysis was used to explore the changes in the renal mitochondrial proteome in SD rats after treatment with ASB. SD rats were intraperitoneally administered with ASB (100, 600mg/kg/d) for 7 days. Renal impairment was evaluated by pathological observation. Two-dimensional gel electrophoresis (2-DE), as well as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS), was applied for the identification of mitochondrial protein and was validated by Western blotting. Protein-protein interactions were analyzed using a Web-based bioinformatics tool (STRING, version 9.1). Rat kidneys exhibited histopathological changes after treatment with ASB, and 13 proteins were significantly changed, including ES1 protein homolog, heat shock cognate 71kDa protein, peroxiredoxin-1 (Prdx1), cytochrome C oxidase subunit 5B (COX5B), prohibitin (PHB), threonine-tRNA ligase, pyruvate dehydrogenase E1 component subunit beta (PDH-β), voltage-dependent anion-selective channel protein 2 (VDAC2), voltage-dependent anion-selective channel protein 1 (VDAC1), adenylate kinase 2 (KAD2) and others. These data demonstrated that the expression levels of several proteins significantly changed in the mitochondria, and these proteins could be candidate biomarkers for ASB-induced nephrotoxicity.