Dose escalation study of intravenous and intra-arterial N-acetylcysteine for the prevention of oto- and nephrotoxicity of cisplatin with a contrast-induced nephropathy model in patients with renal insufficiency

Renogrit selectively protects against cisplatin-induced injury in human renal tubular cells and in Caenorhabditis elegans by harmonizing apoptosis and mitophagy

Cisplatin-induced nephrotoxicity restricts its clinical use against solid tumors. The present study elucidated the pharmacological effects of Renogrit, a plant-derived prescription medicine, using cisplatin-induced human renal proximal tubular (HK-2) cells and Caenorhabditis elegans. Quantification of phytochemicals in Renogrit was performed on HPTLC and UHPLC platforms. Renogrit was assessed in vitro in HK-2 cells post-exposure to clinically relevant concentration of cisplatin. It was observed that renoprotective properties of Renogrit against cisplatin-induced injury stem from its ability to regulate renal injury markers (KIM-1, NAG levels; NGAL mRNA expression), redox imbalance (ROS generation; GST levels), and mitochondrial dysfunction (mitochondrial membrane potential; SKN-1, HSP-60 expression). Renogrit was also found to modulate apoptosis (EGL-1 mRNA expression; protein levels of p-ERK, p-JNK, p-p38, c-PARP1), necroptosis (intracellular calcium accumulation; RIPK1, RIPK3, MLKL mRNA expression), mitophagy (lysosome population; mRNA expression of PINK1, PDR1; protein levels of p-PINK1, LC3B), and inflammation (IL-1β activity; protein levels of LXR-α). More importantly, Renogrit treatment did not hamper normal anti-proliferative effects of cisplatin as observed from cytotoxicity analysis on MCF-7, A549, SiHa, and T24 human cancer cells. Taken together, Renogrit could be a potential clinical candidate to mitigate cisplatin-induced nephrotoxicity without compromising the anti-neoplastic properties of cisplatin.

N-Acetylcysteine Attenuates Cisplatin Toxicity in the Cerebrum and Lung of Young Rats with Artificially Induced Protein Deficiency

Neurotoxicity is a major obstacle in the effectiveness of Cisplatin in cancer chemotherapy. In this process, oxidative stress and inflammation are considered to be the main mechanisms involved in brain and lung toxicity. The aim of the present work was to study the influence of the amount of protein on some oxidative parameters in the brain and lungs of rats treated with Cisplatin (CP) and N-Acetylcysteine (NAC) as neuroprotectors. Four groups of Wistar rats, each containing six animals, were fed with a protein diet at 7% for 15 days. Thereafter, the groups were given either a unique dose of CP® 5 mg/kg or NAC® 5 mg/kg as follows: group 1 (control), NaCl 0.9% vehicle; group 2, CP; group 3, NAC; and group 4, NAC + CP. The animals were sacrificed immediately after the treatments. Blood samples were collected upon sacrifice and used to measure blood triglycerides and glucose. The brain and lungs of each animal were obtained and used to assay lipid peroxidation (TBARS), glutathione (GSH), serotonin metabolite (5-HIAA), catalase, and the activity of Ca+2, and Mg+2 ATPase using validated methods. TBARS, H2O2, and GSH were found to be significantly decreased in the cortex and cerebellum/medulla oblongata of the groups treated with CP and NAC. The total ATPase showed a significant increase in the lung and cerebellum/medulla oblongata, while 5-HIAA showed the same tendency in the cortex of the same group of animals. The increase in 5-HIAA and ATPase during NAC and CP administration resulted in brain protection. This effect could be even more powerful when membrane fluidity is increased, thus proving the efficacy of combined NAC and CP drug therapy, which appears to be a promising strategy for future chemotherapy in malnourished patients.

Intranasal delivery of Borneol/R8dGR peptide modified PLGA nanoparticles co-loaded with curcumin and cisplatin alleviate hypoxia in pediatric brainstem glioma which improves the synergistic therapy

Cisplatin (cis) is a first-line chemotherapeutic used for the treatment of intractable pediatric brainstem glioma (PBSG). Its therapeutic effect in PBSG is, however, critically challenged by the hypoxic microenvironment of the tumor and the presence of the blood brain barrier (BBB). Herein, we report on the intranasal administration of borneol (Bo)/R8dGR peptide modified PLGA based nanoparticles (NP) co-loaded with curcumin and cisplatin (cur/cis). We observed that borneol modification improved the brain penetration of the nanoparticles by reduction of the expression of ZO-1 and occludin in nasal mucosa, while the R8dGR peptide modification allowed the targeting of the NP through the binding on integrin αvβ3 receptors which are present on PBSG cells. Following intranasal administration, BoR-cur/cis-NP attenuated hypoxia in the PBSG microenvironment and reduced angiogenesis, which prolonged survival of GL261-bearing PBSG mice. Therefore, intranasal administration of BoR-cur/cis-NP, which deeply penetrate PBSG, is an encouraging strategy to attenuate hypoxia which potentiates the efficacy of cisplatin in the treatment of PBSG.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Therapeutic role of N-acetyl cysteine (NAC) for the treatment and/or management of SARS-CoV-2-induced lung damage in hamster model

Oxidative stress by reactive oxygen species (ROS) has been hypothesized to be the major mediator of SARS-CoV-2-induced pathogenesis. During infection, the redox homeostasis of cells is altered as a consequence of virus-induced cellular stress and inflammation. In such scenario, high levels of ROS bring about the production of pro-inflammatory molecules like IL-6, IL-1β, etc. that are believed to be the mediators of severe COVID-19 pathology. Based on the known antioxidant, anti-inflammatory, mucolytic and antiviral properties of NAC, it has been hypothesized that NAC will have beneficial effects in COVID-19 patients. In the current study efforts have been made to evaluate the protective effect of NAC in combination with remdesivir against SARS-CoV-2 induced lung damage in the hamster model. The SARS-CoV-2 infected animals were administered with high (500 mg/kg/day) and low (150 mg/kg/day) doses of NAC intraperitoneally with and without remdesivir. Lung viral load, pathology score and expression of inflammatory molecules were checked by using standard techniques. The findings of this study show that high doses of NAC alone can significantly suppress the SARS-CoV-2 mediated severe lung damage (2 fold), but on the contrary, it fails to restrict viral load. Moreover, high doses of NAC with and without remdesivir significantly suppressed the expression of pro-inflammatory genes including IL-6 (4.16 fold), IL-1β (1.96 fold), and TNF-α (5.55 fold) in lung tissues. Together, results of this study may guide future preclinical and clinical attempts to evaluate the efficacy of different doses and routes of NAC administration with or without other drugs against SARS-CoV-2 infection.

Enhancing the potency of chemotherapeutic agents by combination with bromelain and N-acetylcysteine - an in vitro study with pancreatic and hepatic cancer cells

Current systemic dosages of chemotherapeutic drugs such as gemcitabine, 5-FU, cisplatin, doxorubicin are administered every 7 days over 4 cycles due to systemic toxicity. An increase in potency of the drugs will result in dosage reduction with more frequent administration and efficacy increase. Hence, we investigated how the drugs potency can be increased by combining with bromelain and N-acetylcysteine. Tumour cells (5,000/well) were seeded into a 96 well plate and treated 24 hrs later with either single agents or in combinations at various concentrations. Cell survival was assessed by the sulforhodamine B assay after 72 hours of exposure. LD 50 was determined for each treatment and the Combination Index (CI) was assessed to determine synergy using Tallarida's method. CI indicated that synergy was dependent on the concentration of the agents used and was cell line specific. For bromelain and N-acetylcysteine, certain ratio of the two agents gave very good synergy that was prevalent in almost all cell lines. Gemcitabine and 5-FU and doxorubicin reacted favourably with most concentrations of bromelain and NAC investigated. Cisplatin and oxaliplatin were not very compatible with NAC. A value of CI <0.5 indicated that the current clinical chemotherapeutic dosage can be dramatically reduced. Bromelain with NAC showed synergy in all tumour cell lines and acting synergistically with chemotherapeutic drugs. Synergistic combinations resulting in considerable dosage reduction of chemotherapeutic agents may enable more frequent treatment with higher efficacy.

N-Acetylcysteine to Combat COVID-19: An Evidence Review

The novel coronavirus disease (COVID-19) is caused by a virus (SARS-Cov-2) and is known for inducing multisystem organ dysfunction associated with significant morbidity and mortality. Current therapeutic strategies for COVID-19 have failed to effectively reduce mortality rate, especially for elderly patients. A newly developed vaccine against SARS-Cov-2 has been reported to induce the production of neutralizing antibodies in young volunteers. However, the vaccine has shown limited benefit in the elderly, suggesting an age-dependent immune response. As a result, exploring new applications of existing medications could potentially provide valuable treatments for COVID-19. N-acetylcysteine (NAC) has been used in clinical practice to treat critically ill septic patients, and more recently for COVID-19 patients. NAC has antioxidant, anti-inflammatory and immune-modulating characteristics that may prove beneficial in the treatment and prevention of SARS-Cov-2. This review offers a thorough analysis of NAC and discusses its potential use for treatment of COVID-19.

N-Acetyl-L-cysteine Protects Human Retinal Pigment Epithelial Cells from Oxidative Damage: Implications for Age-Related Macular Degeneration

Age-related macular degeneration (AMD) involves the loss of retinal pigment epithelium (RPE) and photoreceptors and is one of the leading causes of blindness in the elderly. Oxidative damage to proteins, lipids, and DNA has been associated with RPE dysfunction and AMD. In this study, we evaluated oxidative stress in AMD and the efficacy of antioxidant, N-acetyl-L-cysteine (NAC), in protecting RPE from oxidative damage. To test this idea, primary cultures of RPE from human donors with AMD (n = 32) or without AMD (No AMD, n = 21) were examined for expression of NADPH oxidase (NOX) genes, a source of reactive oxygen species (ROS). Additionally, the cells were pretreated with NAC for 2 hours and then treated with either hydrogen peroxide (H₂O₂) or tert-butyl hydroperoxide (t-BHP) to induce cellular oxidation. Twenty-four hours after treatment, ROS production, cell survival, the content of glutathione (GSH) and adenosine triphosphate (ATP), and cellular bioenergetics were measured. We found increased expression of p22phox, a NOX regulator, in AMD cells compared to No AMD cells (p = 0.02). In both AMD and No AMD cells, NAC pretreatment reduced t-BHP-induced ROS production and protected from H₂O₂-induced cell death and ATP depletion. In the absence of oxidation, NAC treatment improved mitochondrial function in both groups (p < 0.01). Conversely, the protective response exhibited by NAC was disease-dependent for some parameters. In the absence of oxidation, NAC significantly reduced ROS production (p < 0.001) and increased GSH content (p = 0.02) only in RPE from AMD donors. Additionally, NAC-mediated protection from H₂O₂-induced GSH depletion (p = 0.04) and mitochondrial dysfunction (p < 0.05) was more pronounced in AMD cells compared with No AMD cells. These results demonstrate the therapeutic benefit of NAC by mitigating oxidative damage in RPE. Additionally, the favorable outcomes observed for AMD RPE support NAC's relevance and the potential therapeutic value in treating AMD.

N-acetylcysteine tiherapeutically protects against pulmonary fibrosis in a mouse model of silicosis

Silicosis is a lethal pneumoconiosis disease characterized by chronic lung inflammation and fibrosis. The present study was to explore the effect of against crystalline silica (CS)-induced pulmonary fibrosis. A total of 138 wild-type C57BL/6J mice were divided into control and experimental groups, and killed on month 0, 1, 2, 3, 4, and 5. Different doses of N-acetylcysteine (NAC) were gavaged to the mice after CS instillation to observe the effect of NAC on CS induced pulmonary fibrosis and inflammation. The pulmonary injury was evaluated with Hematoxylin and eosin/Masson staining. Reactive oxygen species level was analyzed by DCFH-DA labeling. Commercial ELISA kits were used to determine antioxidant activity (T-AOC, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) and cytokines (TNF-α, IL-1β, IL-4, and IL-6). The expression of oxidising enzymes (NOX2, iNOS, SOD2, and XO) were detected by real time PCR. Immunohistochemistry (IHC) staining was performed to examine epithelial-mesenchymal transition-related markers. The mice treated with NAC presented markedly reduced CS-induced pulmonary injury and ameliorated CS-induced pulmonary fibrosis and inflammation. The level of malondialdehyde was reduced, while the activities of GSH-PX, SOD, and T-AOC were markedly enhanced by NAC. We also found the down-regulation of oxidising enzymes (NOX2, iNOS, SOD2, and XO) after NAC treatment. Moreover, E-cadherin expression was increased while vimentin and Cytochrome C expressions were decreased by NAC. These encouraging findings suggest that NAC exerts pulmonary protective effects in CS-induced pulmonary fibrosis and might be considered as a promising agent for the treatment of silicosis.

Effect of finasteride particle size reduction on its pharmacokinetic, tissue distribution and cellular permeation

Finasteride (FSD), a specific competitive inhibitor of the steroid type-II 5α-reductase enzyme, is used in treatment of benign prostate hyperplasia (BPH) and male pattern baldness. The drug is of limited solubility that affect its dissolution and bioavailability. The aim was to study the effect of FSD particle size reduction on the pharmacokinetic, tissue distribution and cellular permeation. An optimized drug micro- and nano-particles were developed, characterized, administered to group of rats, and systemic pharmacokinetic and tissue distribution within target and not-target organs were determined using near-infrared (NIR) spectroscopy technique. Moreover, the cellular permeation of the prepared formulations through normal prostate epithelial cells was assessed and compared to pure FSD. The developed micro- and nano-particles were of 930 and 645 nm, respectively. Plasma maximum drug levels (C_max) and overall exposure (AUC) of both formulations were not significantly higher than unformulated drug. However, micronized FSD achieved significant higher concentration within the target tissue (prostate) within the current study compared to pure drug and nano-sized formulation as well. Yet, this is explained by the higher sequestration ability of spleen tissue to the nano-sized formula compared to micro-sized FSD. At the cellular level, permeation of nano-sized FSD through prostate epithelial cells was superior to the unformulated FSD as well as the micro-sized drug formulation. FSD particle size reduction significantly influences its cellular permeation and to a lesser extend affect its systemic pharmacokinetics and tissue distribution after oral administration.

Assessment of Renal and Hepatic Tissue-Protective Effects of N-Acetylcysteine via Ammonia Metabolism: A Prospective Randomized Study

Background

The present study sought to assess the renal and liver protective effect of N-acetylcysteine through NH3 and urea metabolism in patients with chronic obstructive pulmonary disease who were scheduled for coronary artery bypass grafting surgery.

Material/Methods

Patients with chronic obstructive pulmonary disease (COPD) who were scheduled for coronary artery bypass grafting were divided into 2 groups so as to receive (Group 1, n=35) or not receive (Group 2, n=35) 900 mg/day of n-acetylcysteine for 7 days before the operation starting from their admission to the service by a pulmonologist with the purpose of treating COPD until the day of surgery. Both groups were subjected to the same anesthesia protocol. Blood samples were taken preoperatively, within the first 15^th minute following cessation of the cardiopulmonary bypass, at postoperative 24^th hour, and at postoperative 48^th hour. Blood tests included ammonia (NH3), lactate, blood urea nitrogen, creatinine, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), troponin I (Tn I), and creatinine kinase-muscle brain (CKMB).

Results

There was a significant difference between the groups’ NH3 and lactate levels after cardiopulmonary bypass, postoperative 24^th hour, and postoperative 48^th hour (respectively, NH3: 39.0±8.8 vs. 55.4±19.6 and 40.1±8.4 vs. 53.2±20.2 mcg/dl, lactate: 1.7±0.9 vs. 2.1±1.2 and 1.2±0.5 vs. 1.8±1.4 mmol/L; p<0.01). Creatinine and BUN levels in Group 2 were found to be significantly higher at the postoperative 48^th hour compared to the levels of Group 1 (P<0.05).

Conclusions

N-acetylcysteine pretreatment appears to improve renal and hepatic functions through regulation of ammonia and nitrogen metabolism and reduction of lactate in patients with chronic obstructive pulmonary disease who undergo coronary artery bypass grafting surgery. We found that N-acetylcysteine improved kidney and/or liver functions.

Progress in brain barriers and brain fluid research in 2017

The past year, 2017, has seen many important papers published in the fields covered by Fluids and Barriers of the CNS. This article from the Editors highlights some.