Overview of cisplatin-induced neurotoxicity and ototoxicity, and the protective agents

Berberis lyceum root bark extract attenuates anticancer drugs induced neurotoxicityand cardiotoxicity in rats

Background

Traditionally, Berberis lyceum was extensively used for the treatment of several human diseases.

Objective

This study was undertaken to determine in vivo effects of Berberis lyceum root bark against doxorubicin-induced cardiotoxicity and cisplatin-induced neurotoxicity in Sprague Dawley rats.

Methods

A single dose of doxorubicin (20 mg/ kg i. p) and cisplatin (4mg/kg i.p) was used to induce cardiotoxicity and neurotoxicity, respectively. Berberis lyceum methanolic extract was given orally (200 and 400 mg/ kg) to toxicity-induced rats. The cardiac biomarkers i.e. serum aspartate aminotransferase, alanine transaminase, lactate dehydrogenase, creatine kinase and creatine kinase MB were analyzed in blood collected from cardiotoxic rats. The tissue oxidative stress markers included protein, glutathione s-transferase specific activity, catalase activity, total glutathione, and malondialdehyde levels were measured in cardiac and brain homogenate of the respective groups.

Results

Berberis lyceum methanolic extract has the potential to reduce the doxorubicin-induced cardiotoxicity and cisplatin-induced neurotoxicity significantly (*p<0.05) by reducing the serum markers and oxidative stress parameters. Histopathological analysis exhibited a marked improvement in the morphology of cardiac and brain tissues.

Conclusion

It is concluded that methanolic extract of Berberis lyceum root bark has the potential to protect and reverse anticancer drugs induced cardiotoxicity and neurotoxicity.

Sustainable Release of Propranolol Hydrochloride Laden with Biconjugated-Ufasomes Chitosan Hydrogel Attenuates Cisplatin-Induced Sciatic Nerve Damage in In Vitro/In Vivo Evaluation

Peripheral nerve injuries significantly impact patients’ quality of life and poor functional recovery. Chitosan–ufasomes (CTS–UFAs) exhibit biomimetic features, making them a viable choice for developing novel transdermal delivery for neural repair. This study aimed to investigate the role of CTS–UFAs loaded with the propranolol HCl (PRO) as a model drug in enhancing sciatica in cisplatin-induced sciatic nerve damage in rats. Hence, PRO–UFAs were primed, embedding either span 20 or 60 together with oleic acid and cholesterol using a thin-film hydration process based on full factorial design (24). The influence of formulation factors on UFAs’ physicochemical characteristics and the optimum formulation selection were investigated using Design-Expert® software. Based on the optimal UFA formulation, PRO–CTS–UFAs were constructed and characterized using transmission electron microscopy, stability studies, and ex vivo permeation. In vivo trials on rats with a sciatic nerve injury tested the efficacy of PRO–CTS–UFA and PRO–UFA transdermal hydrogels, PRO solution, compared to normal rats. Additionally, oxidative stress and specific apoptotic biomarkers were assessed, supported by a sciatic nerve histopathological study. PRO–UFAs and PRO–CTS–UFAs disclosed entrapment efficiency of 82.72 ± 2.33% and 85.32 ± 2.65%, a particle size of 317.22 ± 6.43 and 336.12 ± 4.9 nm, ζ potential of −62.06 ± 0.07 and 65.24 ± 0.10 mV, and accumulatively released 70.95 ± 8.14% and 64.03 ± 1.9% PRO within 6 h, respectively. Moreover, PRO–CTS–UFAs significantly restored sciatic nerve structure, inhibited the cisplatin-dependent increase in peripheral myelin 22 gene expression and MDA levels, and further re-established sciatic nerve GSH and CAT content. Furthermore, they elicited MBP re-expression, BCL-2 mild expression, and inhibited TNF-α expression. Briefly, our findings proposed that CTS–UFAs are promising to enhance PRO transdermal delivery to manage sciatic nerve damage.

Repositioning of Lansoprazole as a Protective Agent Against Cisplatin-Induced Ototoxicity

Cisplatin (CDDP) is a well-known chemotherapeutic drug approved for various cancers. However, CDDP accumulates in the inner ear cochlea via organic cation transporter 2 (OCT2) and causes ototoxicity, which is a major clinical limitation. Since lansoprazole (LPZ), a proton pump inhibitor, is known to inhibit OCT2-mediated transport of CDDP, we hypothesized that LPZ might ameliorate CDDP-induced ototoxicity (CIO). To test this hypothesis, we utilized in vivo fluorescence imaging of zebrafish sensory hair cells. The fluorescence signals in hair cells in zebrafish treated with CDDP dose-dependently decreased. Co-treatment with LPZ significantly suppressed the decrease of fluorescence signals in zebrafish treated with CDDP. Knockout of a zebrafish homolog of OCT2 also ameliorated the reduction of fluorescence signals in hair cells in zebrafish treated with CDDP. These in vivo studies suggest that CDDP damages the hair cells of zebrafish through oct2-mediated accumulation and that LPZ protects against CIO, possibly inhibiting the entry of CDDP into the hair cells via oct2. We also evaluated the otoprotective effect of LPZ using a public database containing adverse event reports. The analysis revealed that the incidence rate of CIO was significantly decreased in patients treated with LPZ. We then retrospectively analyzed the medical records of Mie University Hospital to examine the otoprotective effect of LPZ. The incidence rate of ototoxicity was significantly lower in patients co-treated with LPZ compared to those without LPZ. These retrospective findings suggest that LPZ is also protective against CIO in humans. Taken together, co-treatment with LPZ may reduce the risk of CIO.

Definition of an Normal Tissue Complication Probability Model for the Inner Ear in Definitive Radiochemotherapy of Nasopharynx Carcinoma

Background: Definitive radiochemotherapy is the treatment of choice for locally advanced nasopharyngeal carcinoma. Due to the vicinity of the nasopharynx to the inner ear and the use of ototoxic platinum-based chemotherapy, there is a risk for irreversible damage to the auditory system. To avoid or minimize these critical side effects, radiation exposure to each inner ear must be balanced between target volume coverage and toxicity. However, normal tissue complication probability (NTCP) models of the inner ear validated by clinical data are rare. Patients and Methods: This retrospective study investigates the inner ear toxicity of 46 patients who received radio(chemo-)therapy for nasopharyngeal carcinoma at our institution from 2004 to 2021 according to CTCAE 5.0 criteria. For each inner ear, the mean (Dmean) and maximum (Dmax) dose in Gray (Gy) was evaluated and correlated with clinical toxicity data. Based on the data, an NTCP model and a cutoff dose logistic regression model (CDLR) were created. Results: In 11 patients (23.9%) hearing impairment and/or tinnitus was observed as a possible therapy-associated toxicity. Dmean was between 15−60 Gy, whereas Dmax was between 30−75 Gy. There was a dose-dependent, sigmoidal relation between inner ear dose and toxicity. A Dmean of 44 Gy and 65 Gy was associated with inner ear damage in 25% and 50% of patients, respectively. The maximum curve slope (m) was found at 50% and is m=0.013. The Dmax values showed a 25% and 50% complication probability at 58 Gy and 69 Gy, respectively, and a maximum slope of the sigmoid curve at 50% with m=0.025. Conclusion: There is a sigmoidal relation between radiation dose and incidence of inner ear toxicities. Dose constraints for the inner ear of <44 Gy (Dmean) or <58 Gy (Dmax) are suggested to limit the probability of inner ear toxicity <25%.

Brain Protection by Methylene Blue and Its Derivative, Azur B, via Activation of the Nrf2/ARE Pathway in Cisplatin-Induced Cognitive Impairment

Cisplatin is a cytotoxic chemotherapeutic drug that leads to DNA damage and is used in the treatment of various types of tumors. However, cisplatin has several serious adverse effects, such as deterioration in cognitive ability. The aim of our work was to study neuroprotectors capable of preventing cisplatin-induced neurotoxicity. Methylene blue (MB) and AzurB (AzB) are able to neutralize the neurotoxicity caused by cisplatin by protecting nerve cells as a result of the activation of the Ntf2 signaling pathway. We have shown that cisplatin impairs learning in the Morris water maze. This is due to an increase in the amount of mtDNA damage, a decrease in the expression of most antioxidant genes, the main determinant of the induction of which is the Nrf2/ARE signaling pathway, and genes involved in mitophagy regulation in the cortex. The expression of genes involved in long-term potentiation was suppressed in the hippocampus of cisplatin-injected mice. MB in most cases prevented cisplatin-induced impairment of learning and decrease of gene expression in the cortex. AzB prevented the cisplatin-induced decrease of genes in the hippocampus. Also, cisplatin induced disbalance in the gut microbiome, decreased levels of Actinotalea and Prevotella, and increased levels of Streptococcus and Veillonella. MB and AzB also prevented cisplatin-induced changes in the bacterial composition of the gut microbiome.

Effects of dihydroartemisinin combined with cisplatin on proliferation, apoptosis and migration of HepG2 cells

Cisplatin (DDP) is a potent and widely applied chemotherapeutic agent. However, its clinical efficacy for the treatment of liver cancer is limited by adverse effects and the development of resistance. Combinatorial therapy may alleviate these issues. Dihydroartemisinin (DHA) is a first-generation derivative of artemisinin. The effects of DDP on liver cancer when applied in combination with DHA have not previously been studied. Therefore, the present study aimed to investigate the effects of DHA combined with DDP on HepG2 cells and their potential underlying molecular mechanisms. HepG2 cells were treated with different concentrations of DHA and/or DDP. Cell Counting Kit-8 assay was used to assess the cell viability. Cell proliferation and apoptosis were quantified using flow cytometry, acridine orange/ethidium bromide (AO/EB) fluorescent dual staining and the colony formation assay. Cell migration was quantified using the Transwell and wound healing assays. The HepG2 cell protein expression levels of Fas, Fas-associated death domain (FADD), procaspase-3, cleaved caspase-3, pro-caspase-8, cleaved caspase-8, Bax, Bcl-2, E-cadherin and N-cadherin, were detected via western blotting. Gelatin zymography was used to assess the levels of MMP-9 secreted by HepG2 cells into the supernatant. Following combined DHA and DDP treatment, the percentage of apoptotic cells was significantly increased, whereas cell proliferation and migration were significantly reduced, compared with cells treated with DDP only. DHA and DPP in combination significantly inhibited the expression of MMP-9, significantly increased the protein expression levels of Fas, FADD, Bax and E-cadherin, significantly increased the ratio of cleaved caspase-3 and cleaved caspase-8 to their precursor proteins and significantly decreased the protein expression levels of Bcl-2 and N-cadherin. The findings of the present study suggested that, DHA may confer synergistic effects with DDP in potentially promoting apoptosis and inhibiting the epithelial-mesenchymal transition for the treatment of liver cancer.

Cisplatin Chemotherapy and Cochlear Damage: Otoprotective and Chemosensitization Properties of Polyphenols

Significance: Cisplatin is an important component of treatment regimens for different cancers. Notwithstanding that therapeutic success often results from partial efficacy or stabilizing the disease, chemotherapy failure is driven by resistance to drug treatment and occurrence of side effects, such as progressive irreversible ototoxicity. Cisplatin's side effects, including ototoxicity, are often dose limiting. Recent Advances: Cisplatin ototoxicity results from several mechanisms, including redox imbalance caused by reactive oxygen species production and lipid peroxidation, activation of inflammation, and p53 and its downstream pathways that culminate in apoptosis. Considerable efforts in research have targeted development of molecular interventions that can be concurrently administered with cisplatin or other chemotherapies to reduce side effect toxicities while preserving or enhancing the antineoplastic effects. Evidence from studies has indicated some polyphenols, such as curcumin, can help to regulate redox signaling and inflammatory effects. Furthermore, polyphenols can exert opposing effects in different types of tissues, that is, normal cells undergoing stressful conditions versus cancer cells. Critical Issues: This review article summarizes evidence of curcumin antioxidant effect against cisplatin-induced ototoxicity that is converted to a pro-oxidant activity in cisplatin-treated cancer cells, thus providing an ideal chemosensitivity combined with otoprotection. Polyphenols can modulate the adaptive responses to stress in the cisplatin-exposed cochlea. These adaptive effects can result from the interaction/cross talk between the cell's defenses, inflammatory molecules, and the key signaling molecules of signal transducers and activators of transcription 3 (STAT-3), nuclear factor κ-B (NF-κB), p53, and nuclear factor erythroid 2-related factor 2 (Nrf-2). Future Directions: We provide molecular evidence for alternative strategies for chemotherapy with cisplatin addressing the otoprotection and chemosensitization properties of polyphenols. Antioxid. Redox Signal. 36, 1229-1245.

Melatonin is effective in attenuating cisplatin-induced neurotoxicity

Cisplatin (Cis) is a chemotherapeutic agent that has many side effects. Neurotoxicity is one of the most important of these side effects. Oxidative stress and neuroinflammation are the best-known mechanisms in the pathogenesis of neurotoxicity development. In this study, we aimed to determine whether melatonin (Mel), with antioxidant and anti-inflammatory effects, is effective in preventing Cis-induced neurotoxicity. Forty-eight male Sprague-Dawley rats were divided into six groups (n = 8) as follows: control (0.9% NaCl), vehicle (5% ethanol), Cis (6 mg/kg), Cis (6 mg/kg) + vehicle (5% ethanol), Mel (20 mg/kg), and Cis (6 mg/kg) + Mel (20 mg/kg) groups. Cis was administered as a single dose on the 3rd day of the experiment while Mel was given for 5 days. All administrations were performed via intraperitoneal injection. After injections, T-maze, rotarod, and hot plate tests were performed to evaluate cognitive, motor, and sensory functions, respectively. Following sacrification oxidative stress markers, cholinergic function, and proinflammatory cytokines were studied from brain homogenates. Cis impaired cognitive function and motor performance in the Cis and Cis+Vehicle groups. The drug also increased oxidative stress in the brain. Mel significantly improved brain oxidant/antioxidant status and also decreased the overproduction of proinflammatory cytokines (superoxide dismutase activities in Cis+Vehicle and Cis+Mel groups: 104.55 ± 9.50 µU/mg protein vs. 150.13 ± 4.70 µU/mg protein, respectively, p < 0.05; tumor necrosis factor-α levels in Cis and Cis+Mel groups: 40 pg/ml vs. 20 pg/ml, respectively, p < 0.05). It seems that Mel can improve Cis neurotoxicity. For a more firm conclusion, further studies using Mel at different doses with larger groups should be performed.

Application of Approved Cisplatin Derivatives in Combination Therapy against Different Cancer Diseases

The problems with anticancer therapy are resistance and toxicity. From 3000 Cisplatin derivatives tested as antitumor agents, most of them have been rejected, due to toxicity. The aim of current study is the comparison of therapeutic combinations of the currently applied in clinical practice: Cisplatin, Carboplatin, Oxaliplatin, Nedaplatin, Lobaplatin, Heptaplatin, and Satraplatin. The literature data show that the strategies for the development of platinum anticancer agents and bypassing of resistance to Cisplatin derivatives and their toxicity are: combination therapy, Pt IV prodrugs, the targeted nanocarriers. The very important strategy for the improvement of the antitumor effect against different cancers is synergistic combination of Cisplatin derivatives with: (1) anticancer agents—Fluorouracil, Gemcitabine, Cytarabine, Fludarabine, Pemetrexed, Ifosfamide, Irinotecan, Topotecan, Etoposide, Amrubicin, Doxorubicin, Epirubicin, Vinorelbine, Docetaxel, Paclitaxel, Nab-Paclitaxel; (2) modulators of resistant mechanisms; (3) signaling protein inhibitors—Erlotinib; Bortezomib; Everolimus; (4) and immunotherapeutic drugs—Atezolizumab, Avelumab, Bevacizumab, Cemiplimab, Cetuximab, Durvalumab, Erlotinib, Imatinib, Necitumumab, Nimotuzumab, Nivolumab, Onartuzumab, Panitumumab, Pembrolizumab, Rilotumumab, Trastuzumab, Tremelimumab, and Sintilimab. An important approach for overcoming the drug resistance and reduction of toxicity of Cisplatin derivatives is the application of nanocarriers (polymers and liposomes), which provide improved targeted delivery, increased intracellular penetration, selective accumulation in tumor tissue, and enhanced therapeutic efficacy. The advantages of combination therapy are maximum removal of tumor cells in different phases; prevention of resistance; inhibition of the adaptation of tumor cells and their mutations; and reduction of toxicity.

Targeting the Meningeal Compartment to Resolve Chemobrain and Neuropathy via Nasal Delivery of Functionalized Mitochondria

Cognitive deficits (chemobrain) and peripheral neuropathy occur in ∼75% of patients treated for cancer with chemotherapy and persist long-term in >30% of survivors. Without preventive or curative interventions and with increasing survivorship rates, the population debilitated by these neurotoxicities is rising. Platinum-based chemotherapeutics, including cisplatin, induce neuronal mitochondrial defects leading to chemobrain and neuropathic pain. This study investigates the capacity of nasally administered mesenchymal stem cell-derived mitochondria coated with dextran-triphenylphosphonium polymer (coated mitochondria) to reverse these neurotoxicities. Nasally administered coated mitochondria are rapidly detectable in macrophages in the brain meninges but do not reach the brain parenchyma. The coated mitochondria change expression of >2400 genes regulating immune, neuronal, endocrine and vascular pathways in the meninges of mice treated with cisplatin. Nasal administration of coated mitochondria reverses cisplatin-induced cognitive deficits and resolves neuropathic pain at a >55-times lower dose compared to uncoated mitochondria. Reversal of these neuropathologies is associated with resolution of cisplatin-induced deficits in myelination, synaptosomal mitochondrial integrity and neurogenesis. These findings demonstrate that nasally administered coated mitochondria promote resolution of chemobrain and peripheral neuropathy, thereby identifying a novel facile strategy for clinical application of mitochondrial donation and treating central and peripheral nervous system pathologies by targeting the brain meninges.

Regulation of ACSL4-Catalyzed Lipid Peroxidation Process Resists Cisplatin Ototoxicity

Cisplatin-induced ototoxicity is one of the common side effects during its treatment and there are no effective measures to prevent it. Our study aimed to investigate the effect of ACSL4-catalyzed lipid peroxidation on cisplatin-induced hearing loss and its possible protective mechanisms. We used a variety of cisplatin ototoxicity models, including HEI-OC1 cell line, cochlear explants, and ET4 GFP+ zebrafish. After measuring the experimental concentrations of cisplatin by CCK8 assay and immunofluorescence, respectively, we examined the levels of lipid peroxidation by MDA content, 4-HNE content, and C11-BODIPY (581/591) probe. Then, we used two ferroptosis inhibitors, FER-1, and Vit-E to protect hair cells. We found that cisplatin significantly increased the levels of lipid peroxidation and that this process can be resisted by the ferroptosis inhibitors. Afterwards, we performed metabolomic assays on the cisplatin-treated hair cells. The metabolite levels were significantly altered in the experimental group compared to the control group, and the highest degree of change was observed in the glutathione metabolic pathway and the arachidonic acid metabolic pathway. Therefore, we screened the key enzymes on the arachidonic acid metabolic pathway in the hair cells after cisplatin treatment and found that ACSL4 had the greatest regulatory value. Further, we reduced the level of lipid peroxide in hair cells by specifically inhibiting the expression of ACSL4, which protected hair cells from cisplatin damage at source. In conclusion, the lipid peroxidation process regulated by ACSL4 may be an important factor contributing to the sensitivity of hair cells to cisplatin. Inhibition of ACSL4 expression may be an effective preventive measure against cisplatin ototoxicity.

Is Autophagy Always a Barrier to Cisplatin Therapy?

Cisplatin has long been a first-line chemotherapeutic agent in the treatment of cancer, largely for solid tumors. During the course of the past two decades, autophagy has been identified in response to cancer treatments and almost uniformly detected in studies involving cisplatin. There has been increasing recognition of autophagy as a critical factor affecting tumor cell death and tumor chemoresistance. In this review and commentary, we introduce four mechanisms of resistance to cisplatin followed by a discussion of the factors that affect the role of autophagy in cisplatin-sensitive and resistant cells and explore the two-sided outcomes that occur when autophagy inhibitors are combined with cisplatin. Our goal is to analyze the potential for the combinatorial use of cisplatin and autophagy inhibitors in the clinic.

Progressive Sensorineural Hearing Loss in Vibrant Soundbridge Users Requiring Cochlear Implantation

Less than 20% of patients with sensorineural hearing loss (HL) provided with the Vibrant Soundbridge (VSB) experience a progressive HL and warrant cochlear implantation (CI). The aim of this study was to identify possible predictors of progressive HL prior to VSB implantation. This retrospective study included all consecutive ears with sensorineural HL provided with the VSB between 1998 and 2016. The patient cohort was divided in a study group comprising patients who underwent CI (CI group) after years of VSB usage and those who did not require VSB replacement during the observational time (control group). Pre- and postoperative pure-tone audiometry thresholds were compared among the two groups. Fifteen out of 81 VSB devices (18.5%) required a CI. The CI group had higher preoperative air-conduction (AC) thresholds than the control group (64.3 ± 8.9 dB vs. 56.3 ± 12.9 dB; p = 0.007) at the time of the VSB implantation. On average, the CI group was significantly younger (39.1 ± 12.3 years vs. 52.6 ± 16.2 years; p = 0.003). In conclusion, VSB users with higher preoperative AC thresholds and younger age at the time of VSB implantation might be at risk for progressive HL within the upcoming eight years and need a further CI surgery. Preoperative counseling is particularly advisable in this patient group.

Metabolic Impact of Anticancer Drugs Pd2Spermine and Cisplatin on the Brain of Healthy Mice

The new palladium agent Pd2Spermine (Spm) has been reported to exhibit promising cytotoxic properties, while potentially circumventing the known disadvantages associated to cisplatin therapeutics, namely acquired resistance and high toxicity. This work presents a nuclear magnetic resonance (NMR) metabolomics study of brain extracts obtained from healthy mice, to assess the metabolic impacts of the new Pd2Spm complex in comparison to that of cisplatin. The proton NMR spectra of both polar and nonpolar brain extracts were analyzed by multivariate and univariate statistics, unveiling several metabolite variations during the time course of exposition to each drug (1–48 h). The distinct time-course dependence of such changes revealed useful information on the drug-induced dynamics of metabolic disturbances and recovery periods, namely regarding amino acids, nucleotides, fatty acids, and membrane precursors and phospholipids. Putative biochemical explanations were proposed, based on existing pharmacokinetics data and previously reported metabolic responses elicited by the same metal complexes in the liver of the same animals. Generally, results suggest a more effective response of brain metabolism towards the possible detrimental effects of Pd2Spm, with more rapid recovery back to metabolites’ control levels and, thus, indicating that the palladium drug may exert a more beneficial role than cDDP in relation to brain toxicity.

trans-Dichloro(triphenylarsino)(N,N-dialkylamino)platinum(II) Complexes: In Search of New Scaffolds to Circumvent Cisplatin Resistance

The high incidence of the resistance phenomenon represents one of the most important limitations to the clinical usefulness of cisplatin as an anticancer drug. Notwithstanding the considerable efforts to solve this problem, the circumvention of cisplatin resistance remains a challenge in the treatment of cancer. In this work, the synthesis and characterization of two trans-dichloro(triphenylarsino)(N,N-dialkylamino)platinum(II) complexes (1 and 2) were described. The trypan blue exclusion assay demonstrated an interesting antiproliferative effect for complex 1 in ovarian carcinoma-resistant cells, A2780cis. Quantitative analysis performed by ICP-AES demonstrated a scarce ability to platinate DNA, and a significant intracellular accumulation. The investigation of the mechanism of action highlighted the ability of 1 to inhibit the relaxation of supercoiled plasmid DNA mediated by topoisomerase II and to stabilize the cleavable complex. Cytofluorimetric analyses indicated the activation of the apoptotic pathway and the mitochondrial membrane depolarization. Therefore, topoisomerase II and mitochondria could represent possible intracellular targets. The biological properties of 1 and 2 were compared to those of the related trans-dichloro(triphenylphosphino)(N,N-dialkylamino)platinum(II) complexes in order to draw structure–activity relationships useful to face the resistance phenotype.

Protective effect of berberine chloride against cisplatin-induced ototoxicity

Background

Cisplatin (CP) is an effective anticancer drug broadly used for various types of cancers, but it has shown ototoxicity that results from oxidative stress. Berberine has been reported for its anti-oxidative stress suggesting its therapeutic potential for many diseases such as colitis, diabetes, and vascular dementia.

Objective

Organ of Corti of postnatal day 3 mouse cochlear explants were used to compare hair cells after the treatment with cisplatin alone or with berberine chloride (BC) followed by CP.

Methods

We investigated the potential of the anti-oxidative effect of BC against the cisplatin-induced ototoxicity. We observed a reduced aberrant bundle of stereocilia in hair cells in CP with BC pre-treated group. Caspase-3 immunofluorescence and TUNEL assay supported the hypothesis that BC attenuates the apoptotic signals induced by CP. Reactive oxygen species level in the mitochondria were investigated by MitoSOX Red staining and the mitochondrial membrane potentials were compared by JC-1 assay.

Results

BC decreased ROS generation with preserved mitochondrial membrane potentials in mitochondria as well as reduced DNA fragmentation in hair cells. In summary, our data indicate that BC might act as antioxidant against CP by reducing the stress in mitochondria resulting in cell survival.

Conclusion

Our result suggests the therapeutic potential of BC for prevention of the detrimental effect of CP-induced ototoxicity.

Experimental animal models of drug-induced sensorineural hearing loss: a narrative review

Objective

This narrative review describes experimental animal models of sensorineural hearing loss (SNHL) caused by ototoxic agents.

Background

SNHL primarily results from damage to the sensory organ within the inner ear or the vestibulocochlear nerve (cranial nerve VIII). The main etiology of SNHL includes genetic diseases, presbycusis, ototoxic agents, infection, and noise exposure. Animal models with functional and anatomic damage to the sensory organ within the inner ear or the vestibulocochlear nerve mimicking the damage seen in humans are employed to explore the mechanism and potential treatment of SNHL. These animal models of SNHL are commonly established using ototoxic agents.

Methods

A literature search of PubMed, Embase, and Web of Science was performed for research articles on hearing loss and ototoxic agents in animal models of hearing loss.

Conclusions

Common ototoxic medications such as aminoglycoside antibiotics (AABs) and platinum antitumor drugs are extensively used to induce SNHL in experimental animals. The effect of ototoxic agents in vivo is influenced by the chemical mechanisms of the ototoxic agents, the species of animal, routes of administration of the ototoxic agents, and the dosage of ototoxic agents. Animal models of drug-induced SNHL contribute to understanding the hearing mechanism and reveal the function of different parts of the auditory system in humans.

Coupling EGFR-Antagonistic Affibody Enhanced Therapeutic Effects of Cisplatin Liposomes in EGFR-expressing Tumor Models

Epidermal growth factor receptor (EGFR) is an efficient target for cancer therapy. In this study, a high-affinity EGFR-antagonistic affibody (Z_EGFR) molecule coupled with cisplatin-loaded PEGylated liposomes (LS-DDP) was applied to actively target EGFR⁺ A431 tumor cells in vitro and in vivo. The LS-DDP coupled with Z_EGFR (AS-DDP) had an average size of 140.01 ± 0.84 nm, low polydispersity, a zeta potential of -13.40 ± 0.8 mV, an acceptable encapsulation efficiency of 17.30 ± 1.35%, and released cisplatin in a slow-controlled manner. In vitro, AS-DDP demonstrated a higher amount of platinum intracellular uptake by A431 cells than LS-DDP. The IC50 value of AS-DDP (9.02 ± 1.55 μg/ml) was much lower than that of LS-DDP (16.44 ± 0.87 μg/ml), indicating that the anti-tumor effects of AS-DDP were remarkable due to the modification of Z_EGFR. In vivo, the concentration of AS-DDP in the tumor site increased more than 1.76-fold, while an increase in apoptotic cells at 48 h compared to the LS-DDP was also observed, illustrating that AS-DDP possessed excellent tumor-targeting efficiency. As a result, the targeted nano-liposomes achieved greater tumor suppression. Therefore, selective targeting of LS-DDP coupled with Z_EGFR enhanced the anti-tumor effects and appeared to be a promising strategy for the treatment of EGFR⁺ tumors.

Autophagy Promotes the Survival of Adipose Mesenchymal Stem/Stromal Cells and Enhances Their Therapeutic Effects in Cisplatin-Induced Liver Injury via Modulating TGF-β1/Smad and PI3K/AKT Signaling Pathways

Autophagy is a key metabolic process where cells can recycle its proteins and organelles to regenerate its own cellular building blocks. Chemotherapy is indispensable for cancer treatment but associated with various side-effects, including organ damage. Stem cell-based therapy is a promising approach for reducing chemotherapeutic side effects, however, one of its main culprits is the poor survival of transplanted stem cells in damaged tissues. Here, we aimed to test the effects of activating autophagy in adipose-derived mesenchymal stem/stromal cells (ADSCs) on the survival of ADSCs, and their therapeutic value in cisplatin-induced liver injury model. Autophagy was activated in ADSCs by rapamycin (50 nM/L) for two hours before transplantation and were compared to non-preconditioned ADSCs. Rapamycin preconditioning resulted in activated autophagy and improved survival of ADSCs achieved by increased autophagosomes, upregulated autophagy-specific LC3-II gene, decreased protein degradation/ubiquitination by downregulated p62 gene, downregulated mTOR gene, and finally, upregulated antiapoptotic BCL-2 gene. In addition, autophagic ADSCs transplantation in the cisplatin liver injury model, liver biochemical parameters (AST, ALT and albumin), lipid peroxidation (MDA), antioxidant profile (SOD and GPX) and histopathological picture were improved, approaching near-normal conditions. These promising autophagic ADSCs effects were achieved by modulation of components in TGF-β1/Smad and PI3K-AKT signaling pathways, besides reducing NF-κB gene expression (marker for inflammation), reducing TGF-β1 levels (marker for fibrosis) and increasing SDF-1 levels (liver regeneration marker) in liver. Therefore, current results highlight the importance of autophagy in augmenting the therapeutic potential of stem cell therapy in alleviating cisplatin-associated liver damage and opens the path for improved cell-based therapies, in general, and with chemotherapeutics, in particular.

Impact of cisplatin administration on cerebellar cortical structure and locomotor activity of infantile and juvenile albino rats: the role of oxidative stress

The central neurotoxicity of cisplatin (CisPt) has always raised questions especially during development, but few studies are available. Hence, this work was designed to assess the CisPt's impacts on the postnatal rat cerebellum via evaluation of locomotor activity, histological and immunohistochemical studies, and to focus on cerebellar oxidative stress-related alterations. Eighty newborn pups were divided into 2 equal experimental groups: the control group was kept without any treatment and CisPt-treated group received a single subcutaneous injection of CisPt (5 μg /g b.w.) in their nape at PD10. Ten rats at PD11, PD17, and PD30 ages were weighed, then deeply anesthetized and sacrificed. For locomotor assessment, 20 pups were divided equally into control and CisPt-treated groups and tested at PD11-13, PD15-17, and PD28-30 ages. CisPt-treated rats suffered from decreased motor activity and showed decreased body and cerebellar weights, reduced levels of enzymatic antioxidants (SOD and CAT), and non-enzymatic antioxidant defense (GSH), and increase of lipid peroxidation marker (MDA). Histopathologically, CisPt sowed deleterious changes within cerebellar cortical layers in the form of vacuolations, decreased thickness, and hemorrhage (in PD17), while Purkinje cells exhibited profound degenerative changes in the form of swelling, disrupted arrangement, distortion, and nuclear shrinkage. In CisPt-treated rats, GFAP demonstrated upregulated, hypertrophied, and branched Bergmann glial fibers and reactive astrogliosis. Immuno-localization of Ki-67-positive cells revealed defective migration associated with decreased proliferation in early ages in addition to glial proliferation in PD30. In conclusion, CisPt causes oxidative stress-related deleterious effects on structure of developing cerebellar cortex and affects locomotor activity.

Development of a multi-target anticancer Sn(ii) pyridine-2-carboxaldehyde thiosemicarbazone complex

In this study, we proposed to design effective multi-target anticancer agents based on the chelation of nontoxic metals with ligands that possess anticancer activity. In total, five Sn(ii) pyridine-2-carboxaldehyde thiosemicarbazone complexes are synthesized and their activities are tested. Among these complexes, C5 is found to show the highest cytotoxicity on investigating their structure-activity relationships. In addition, C5 not only exhibits an effective inhibitory effect against tumor growth in vivo, but also suppresses angiogenesis and restricts the metastasis of cancer cells in vitro. Multiple mechanisms underlie the antitumor effect of C5, and they include acting against DNA, inducing apoptosis, and inhibiting the activities of anti-apoptotic Bcl-xL protein, metalloproteinase MMP2 and topoisomerase II.

Autophagy-dependent ferroptosis contributes to cisplatin-induced hearing loss

Cisplatin-induced hearing loss is a common side effect of cisplatin chemotherapy, for which clinical therapy remains unavailable. Apoptosis of hair cells is considered the primary cause of cisplatin-induced ototoxicity; however, inhibiting apoptosis can only partially restore cisplatin-induced hearing loss. Therefore, auditory cell death caused by cisplatin damage requires further study. Ferroptosis, a novel form of regulated cell death, has been shown to play a role in the mechanism of cisplatin toxicity. In this study, we observed proferroptotic alterations (lipid peroxidation and impaired antioxidant capacity) in the cochleae of C57BL/6 mice after cisplatin damage, verifying the induction of ferroptosis. Using the HEI-OC1 cell line, we observed that cisplatin induced proferroptotic alterations and activated ferritinophagy (specific autophagy pathway). Employing chloroquine, we confirmed that the blockage of autophagy remarkably alleviated cisplatin-induced ferroptosis in HEI-OC1 cells; therefore, the induction of ferroptosis in cisplatin-treated auditory cells was dependent on the activation of autophagy. In addition, the ferroptosis inhibitor ferrostatin-1 and iron chelator deferoxamine significantly attenuated cisplatin-induced cytotoxicity in HEI-OC1 cells and cochlear explants. Moreover, pharmacologically inhibiting ferroptosis using ferrostatin-1 significantly decreased the auditory cell loss and, notably, attenuated hearing loss in C57BL/6 mice after cisplatin damage. Collectively, these findings indicate that autophagy-dependent ferroptosis plays an integrated role in the mechanism of cisplatin-induced hearing loss.

Cisplatin and phenanthriplatin modulate long-noncoding RNA expression in A549 and IMR90 cells revealing regulation of microRNAs, Wnt/β-catenin and TGF-β signaling

The monofunctional platinum(II) complex, phenanthriplatin, acts by blocking transcription, but its regulatory effects on long-noncoding RNAs (lncRNAs) have not been elucidated relative to traditional platinum-based chemotherapeutics, e.g., cisplatin. Here, we treated A549 non-small cell lung cancer and IMR90 lung fibroblast cells for 24 h with either cisplatin, phenanthriplatin or a solvent control, and then performed microarray analysis to identify regulated lncRNAs. RNA22 v2 microRNA software was subsequently used to identify microRNAs (miRNAs) that might be suppressed by the most regulated lncRNAs. We found that miR-25-5p, -30a-3p, -138-5p, -149-3p, -185-5p, -378j, -608, -650, -708-5p, -1253, -1254, -4458, and -4516, were predicted to target the cisplatin upregulated lncRNAs, IMMP2L-1, CBR3-1 and ATAD2B-5, and the phenanthriplatin downregulated lncRNAs, AGO2-1, COX7A1-2 and SLC26A3-1. Then, we used qRT-PCR to measure the expression of miR-25-5p, -378j, -4516 (A549) and miR-149-3p, -608, and -4458 (IMR90) to identify distinct signaling effects associated with cisplatin and phenanthriplatin. The signaling pathways associated with these miRNAs suggests that phenanthriplatin may modulate Wnt/β-catenin and TGF-β signaling through the MAPK/ERK and PTEN/AKT pathways differently than cisplatin. Further, as some of these miRNAs may be subject to dissimilar lncRNA targeting in A549 and IMR90 cells, the monofunctional complex may not cause toxicity in normal lung compared to cancer cells by acting through distinct lncRNA and miRNA networks.

Endoplasmic Reticulum Stress-Activated PERK-eIF2α-ATF4 Signaling Pathway is Involved in the Ameliorative Effects of Ginseng Polysaccharides against Cisplatin-Induced Nephrotoxicity in Mice

Although previous studies have reported that saponins (ginsenosides, the major active and most representative ingredients in Panax ginseng C.A. Meyer) exerted a good ameliorative effect on cisplatin (CP)-induced acute kidney injury in animal models, little attention has been paid to a large number of polysaccharides isolated and purified from ginseng. This work aimed to investigate the protective effect and the possible molecular mechanism of ginseng polysaccharide (WGP) on CP-induced kidney toxicology in mice. The results from biomarker analysis including serum creatinine (CRE) and blood urea nitrogen (BUN) confirmed the protective effect of WGP at 200 and 400 mg/kg on CP-induced renal-toxicology. We found that WGP reduces the apoptosis of kidney cells by inhibiting endoplasmic reticulum (ER) stress caused by CP, which is manifested by increased phosphorylation of PERK. In addition, the apoptosis-associated with caspase 3 activation in renal cells induced by CP was inhibited after administration of WGP, and the phosphorylation levels of PI3K and AKT were also reduced significantly. We also demonstrated that after exposure to CP, the unfolded protein response signaling pathway PERK-eIF2α-ATF4 axis was significantly activated, manifested by increased phosphorylation of eIF2α and increased expression of ATF4 and CHOP. Interestingly, the WGP administration improves this situation. Furthermore, the supplement of WGP inhibited the overexpression of nuclear factor-kappa B p65 (NF-κB p65) and tumor necrosis factor-α (TNF-α) caused by CP exposure. In short, for the first time, our findings indicated that WGP could effectively prevent CP-induced ER stress, inflammation, and apoptosis in renal cells, in part, by regulating the PI3K/AKT and PERK-eIF2α-ATF4 signaling pathways.

Synthesis and anticancer activity of mixed ligand 3d metal complexes

Our previously reported copper-based complexes of tropolone show nice antitumor effects, but with high cytotoxicity to normal cells, which is presumably caused by copper ions. Here, we managed to achieve this challenge by using other 3D metals to replace copper ions. We thus prepared four mononuclear 3D metal complexes [M(phen)L2] (M = Mn, Co, Ni, and Zn for 1-4, respectively). Complexes 1 and 4 show selectivity on different cancer cell lines with much lower cytotoxicity to normal cells than cisplatin. The anticancer effects for complexes 2 and 3 on the tested cancer cell lines are very poor. It revealed a tuning effect of different metal ions on the anticancer activities with those for Mn(II) and Zn(II) being much higher than those for Co(II) and Ni(II) in this system. Among them, complex 1 presents a best anticancer effect on HeLa cells comparable to cisplatin. It overcame the afore-mentioned shortage of high cytotoxicity to normal cells for the reported Cu(II) complexes. It revealed from the mechanistic studies that complex 1 mainly induces apoptosis through the mitochondrial pathway by increasing intracellular reactive oxygen species, releasing Ca2+, and activating Caspase 9 and proapoptotic gene Bax.

U0126 pretreatment inhibits cisplatin-induced apoptosis and autophagy in HEI-OC1 cells and cochlear hair cells

Deafness is the most common sensory disorder in the world. Ototoxic drugs are common inducing factors of sensorineural hearing loss, and cochlear hair cell (HC) damage is the main concern of the present studies. Cisplatin is a widely used, highly effective antitumor drug, but some patients have experienced irreversible hearing loss as a result of its application. This hearing loss is closely related to HC apoptosis and autophagy. U0126 is a specific inhibitor of the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) signaling pathway and has neuroprotective effects. For example, the neuroprotective effect of U0126 on ischemic stroke has been widely recognized. In neural cells, U0126 can prevent death due to excess glutamate, dopamine, or zinc ions. However, no studies of U0126 and ototoxic drug-induced injury have been reported to date. In the present study, we found that U0126 pretreatment significantly reduced the apoptosis and autophagy of HCs in auditory House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and cochlear HCs. In addition, U0126 reduced the cisplatin-induced production of reactive oxygen species as well as the cisplatin-induced decrease in the mitochondrial membrane potential. These findings suggest that U0126 may be a potential therapeutic candidate for the prevention of cisplatin-induced ototoxicity.

Knockdown of sorcin increases HEI-OC1 cell damage induced by cisplatin in vitro

Hearing loss caused by ototoxic drugs is a kind of acquired hearing loss. Cisplatin is one of the most commonly used drugs and its main action sites are hair cells (HCs). Sorcin is a drug-resistant calcium-binding protein belonging to the small penta-EF-hand protein family. Sorcin is highly expressed in many tissues, including bone, heart, brain, lung, and skin tissues. Single-cell RNA sequencing showed that sorcin was expressed in the outer HCs of mice, but its role remained unknown. We also found that sorcin was highly expressed in the cytoplasm of cochlear HCs and HEI-OC1 cells. After cisplatin injury, the expression of sorcin in HCs and HEI-OC1 cells decreased significantly. SiRNA transfection technology was used to knock down the expression of sorcin. The results showed that the number of apoptotic cells, the expression of cleaved caspased-3, and the expression of Bax increased while the anti-apoptotic factor Bcl-2 decreased in the siRNA-Sorcin + CIS group. The observed increase in apoptosis was related to the increase of reactive oxygen species (ROS) and the destruction of the mitochondrial membrane potential (MMP). Finally, we found that the downregulated sorcin worked by activating the P-ERK1/2 signaling pathway. Overall, this study showed that sorcin can be used as a new target to prevent the ototoxicity of platinum drugs.

The first copper(I) complex of anthrahydrazone with potential ROS scavenging activity showed significant in vitro anticancer activity by inducing apoptosis and autophagy

Based on the anticancer pharmacophore of anthrahydrazone and quinoline, a new quinolylanthrahydrazone ligand, 9-AQH (anthracene-9-quinolylhydrazone), was synthesized to further afford four metal complexes, [Co^II(9-AQH)(NO₃)₂(H₂O)] (1), [Ni^II(9-AQH)₂(H₂O)₂]·2NO₃ (2), [Cu^I(9-AQH)₂]·NO₃ (3), [Zn^II(9-AQH)₂(NO₃)]·NO₃ (4), determined by X-ray single crystal diffraction analysis. The reaction of Cu(NO₃)₂ with 9-AQH formed the stable and repeatable copper(I) complex 3. In vitro screening demonstrated only 3 showed significant and broad-spectrum anticancer activity, indicating that Cu(I) played a key role in exerting the anticancer activity. In solution, Cu(I) was not naturally oxidized to Cu(II) suggested by ¹H-NMR (Nuclear Magnetic Resonance) and EPR (Electron Paramagnetic Resonance) analysis. The presence of 3 could also catalyze the H₂O₂ system to give hydroxyl free radicals, suggested by further EPR and electrophoresis assay. At the cellular level, although no obvious Cu(II) signals were detected and the total ROS (Reactive Oxygen Species) scavenging in the tumor cells treated with 3, the potential redox property between Cu(I)/Cu(II), as a key role, should not be denied for the significant anticancer activity of 3, considering the much complicated circumstance and other reductive substances in cells. The anticancer mechanism of 3 on the most sensitive MGC-803 cells pointed to significant cell apoptosis through mitochondrial pathway, rather than cell cycle arrest. While the autophagy observed in tumor cells treated by 3 suggested its complicated anticancer mechanism, and whether there was an intrinsic correlation still needed to be further investigated.

Attenuated cytarabine, etoposide, dexamethasone plus rituximab (R-Mini-CYVE) regimen for patients with relapsed or refractory B-cell non-Hodgkin's lymphoma not eligible for intensive chemotherapy

OBJECTIVES

To evaluate the efficacy and tolerability of an attenuated immunochemotherapy regimen based on cytarabine, etoposide and dexamethasone plus rituximab (R-mini-CYVE) in patients with relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL).

METHODS

We included pretreated adult patients with B-cell NHL who were ineligible for high-dose immunochemotherapy (HDT). Cytarabine and etoposide were given at four different dose levels, depending on the patient's frailty. Up to 8 cycles were administered.

RESULTS

Between 2013 and 2019, 56 patients with diffuse large B-cell lymphoma (n = 45, 80%) and indolent B-cell lymphoma (n = 11, 20%) were included. Median age was 75 (range: 36-88). Nineteen patients (35%) had a performance status ≥2. Patients received a median of 4 cycles of R-mini-CYVE. The objective response and the complete response rates were 50% and 33%, respectively. Median progression-free survival and overall survival times were 5.7 (95% CI: 0.5-10.9) and 14.7 (95% CI: 3.5-25.9) months, respectively. Grade ≥3 anaemia, thrombocytopenia and neutropenia occurred in 44%, 55% and 60% of the patients, respectively. The most frequent non-haematological grade ≥3 adverse events were sepsis (21%), fatigue (13%) and cytarabine-related neurotoxicity (5%).

CONCLUSION

R-mini-CYVE demonstrated a meaningful antitumour efficacy and an acceptable safety profile in patients with relapsed/refractory B-cell NHL who were ineligible for HDT.

Strategies to reduce the risk of platinum containing antineoplastic drug-induced ototoxicity

INTRODUCTION

Cisplatin is a highly effective chemotherapeutic agent against a variety of solid tumors in adults and in children. Unfortunately, a large percentage of patients suffer permanent sensorineural hearing loss. Up to 60% of children and at least 50% of adults suffer this complication that seriously compromises their quality of life. Hearing loss is due to damage to the sensory cells in the inner ear. The mechanisms of cochlear damage are still being investigated. However, it appears that inner ear damage is triggered by reactive oxygen species (ROS) formation and inflammation 34.

AREAS COVERED

We discuss a number of potential therapeutic targets that can be addressed to provide hearing protection. These strategies include enhancing the endogenous antioxidant pathways, heat shock proteins, G protein coupled receptors and counteracting ROS and reactive nitrogen species, and blocking pathways that produce inflammation, including TRPV1 and STAT1 36.

EXPERT OPINION

Numerous potential protective agents show promise in animal models by systemic or local administration. However, clinical trials have not shown much efficacy to date with the exception of sodium thiosulfate. There is an urgent need to discover safe and effective protective agents that do not interfere with the efficacy of cisplatin against tumors yet preserve hearing 151.

Beta-Blockers and Cancer: Where Are We?

Cancer is one of the leading causes of death worldwide. After diagnosis, cancer treatment may involve radiotherapy, chemotherapy, and surgery. Several of the approaches used to treat cancer also attack normal cells and, thus, there is the need for more effective treatments that decrease the toxicity to normal cells and increase the success rates of treatment. The use of beta-blockers in cancer has been studied for their antagonist action on the adrenergic system through inhibition of beta-adrenergic receptors. Besides regulating processes such as blood pressure, heart rate, and airway strength or reactivity, beta-blockers block mechanisms that trigger tumorigenesis, angiogenesis, and tumor metastasis. This study presents a literature review of the available studies addressing cancer treatments and beta-blockers. Overall, data suggest that propranolol may be used as a complement for the treatment of several types of cancer due to its ability to improve cancer outcomes by decreasing cancer cell proliferation rates. Nonetheless, additional in vitro studies should be performed to fully understand the protective role of BBs in cancer patients.

Pharmacotherapy of Tinnitus

Tinnitus is a common symptom for which there is in most cases no causal therapy. The search for an improvement of tinnitus through pharmacological interventions has a long tradition. The observation that tinnitus can be transiently suppressed by the use of lidocaine has shown that the symptom is susceptible to pharmacotherapy. So far, however, no medication has been found for either acute or chronic subjective tinnitus that reliably leads to a long-term reduction or even complete disappearance of the symptom for the majority of tinnitus sufferers. Nevertheless, in everyday clinical life, drugs are frequently used, usually off-label, to relieve tinnitus or tinnitus-associated symptoms (e.g. sleep disturbance, depression, anxiety disorder or hearing loss). This chapter shows the different approaches to acute and chronic subjective tinnitus by means of pharmacotherapeutic interventions. Furthermore, this review reports on the scientific studies carried out in this area in recent years and explains the difficulties in finding a suitable medication for most forms of tinnitus. In addition, it reports on the pharmacotherapeutic options for objective tinnitus and describes the development of tinnitus as a side effect of certain drugs. Finally, possible target structures are mentioned, which should possibly be addressed in pharmacological studies in the near future.