New Alkoxy- Analogues of Epoxyeicosatrienoic Acids Attenuate Cisplatin Nephrotoxicity In Vitro via Reduction of Mitochondrial Dysfunction, Oxidative Stress, Mitogen-Activated Protein Kinase Signaling, and Caspase Activation.

The usage of cisplatin, a highly potent chemotherapeutic, is limited by its severe nephrotoxicity. Arachidonic acid (ARA)-derived epoxyeicosatrienoic acids (EETs) and soluble epoxide hydrolase (sEH) inhibitors were shown to ameliorate this dose-limiting side effect, but both approaches have some pharmacological limitations. Analogues of EETs are an alternative avenue with unique benefits, but the current series of analogues face concerns regarding their structure and mimetic functionality. Hence, in this study, regioisomeric mixtures of four new ARA alkyl ethers were synthesized, characterized, and assessed as EET analogues against the concentration- and time-dependent toxicities of cisplatin in porcine proximal tubular epithelial cells. All four ether groups displayed bioisostere activity, ranging from marginal for methoxy- (1), good for n-propoxy- (4), and excellent for ethoxy- (2) and i-propoxy- (3). Compounds 2 and 3 displayed cytoprotective effects comparable to that of an EET regioisomeric mixture (5) against high, acute cisplatin exposures but were more potent against low to moderate, chronic exposures. Compounds 2 and 3 (and 5) acted through stabilization of the mitochondrial transmembrane potential and attenuation of reactive oxygen species, leading to reduced phosphorylation of mitogen-activated protein kinases p38 and JNK and decreased activation of caspase-9 and caspase-3. This study demonstrates that alkoxy- groups are potent and more metabolically stable bioisostere alternatives to the epoxide within EETs that enable sEH-independent activity. It also illustrates the potential of ether-based mimics of EETs and other epoxy fatty acids as promising nephroprotective agents to tackle the clinically relevant side effect of cisplatin without compromising its antineoplastic function.

AZD5438-PROTAC: A selective CDK2 degrader that protects against cisplatin- and noise-induced hearing loss.

Cyclin-dependent kinase 2 (CDK2) is a potential therapeutic target for the treatment of hearing loss and cancer. Previously, we identified AZD5438 and AT7519-7 as potent inhibitors of CDK2, however, they also targeted additional kinases, leading to unwanted toxicities. Proteolysis Targeting Chimeras (PROTACs) are a new promising class of small molecules that can effectively direct specific proteins to proteasomal degradation. Herein we report the design, synthesis, and characterization of PROTACs of AT7519-7 and AZD5438 and the identification of PROTAC-8, an AZD5438-PROTAC, that exhibits selective, partial CDK2 degradation. Furthermore, PROTAC-8 protects against cisplatin ototoxicity and kainic acid excitotoxicity in zebrafish. Molecular dynamics simulations reveal the structural requirements for CDK2 degradation. Together, PROTAC-8 is among the first-in-class PROTACs with in vivo therapeutic activities and represents a new lead compound that can be further developed for better efficacy and selectivity for CDK2 degradation against hearing loss and cancer.

Melatonin rescues the mice brain against cisplatin-induced neurodegeneration, an insight into antioxidant and anti-inflammatory effects.

Herein, we evaluated the neuroprotective effect of melatonin against cisplatin-induced oxidative damage, neuroinflammation, and synaptic dysfunction in mice. Cisplatin was administered at a dose of 2 mg/kg for eleven consecutive days to induce symptoms of cognitive impairment and neurodegeneration, while melatonin was administered at a 20 mg/kg dose for thirty consecutive days. We used various experimental techniques such as western blotting, immunofluorescence analysis, and oxidative stress marker assays to support our notion. Moreover, for cognitive impairment, we conducted behavioral analyses such as Morris Water Maze (MWM) and Y-Maze tests. The results indicated that melatonin attenuated oxidative stress by upregulating the expression of NF-E2-related factor-2 (Nrf2) dependent anti-oxidative protein levels. Similarly, melatonin positively modulated the expression of Sirt1 (a member of the sirtuin family), Phospho-AMPKα (Thr172), peroxisome proliferator-activated receptor (PPARγ), PPAR gamma coactivator 1 alpha (PGC-1α) coupled to downregulation of neuroinflammatory mediators and markers such as nuclear factor kappa-B (NF-κB), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß). Moreover, melatonin significantly upregulated the expression of synaptic markers such as postsynaptic density protein -95 (PSD-95), synaptosomal-associated protein 23 (SNAP-23), and synaptophysin compared to the cisplatin alone group. Furthermore, the results of behavior tests suggested that melatonin significantly improved the cognitive functions of the cisplatin injected mice.

Antagonistic Interaction between Histone Deacetylase Inhibitor: Cambinol and Cisplatin-An Isobolographic Analysis in Breast Cancer In Vitro Models.

Breast cancer (BC) is the leading cause of death in women all over the world. Currently, combined chemotherapy with two or more agents is considered a promising anti-cancer tool to achieve better therapeutic response and to reduce therapy-related side effects. In our study, we demonstrated an antagonistic effect of cytostatic agent-cisplatin (CDDP) and histone deacetylase inhibitor: cambinol (CAM) for breast cancer cell lines with different phenotypes: estrogen receptor positive (MCF7, T47D) and triple negative (MDA-MB-231, MDA-MB-468). The type of pharmacological interaction was assessed by an isobolographic analysis. Our results showed that both agents used separately induced cell apoptosis; however, applying them in combination ameliorated antiproliferative effect for all BC cell lines indicating antagonistic interaction. Cell cycle analysis showed that CAM abolished cell cycle arrest in S phase, which was induced by CDDP. Additionally, CAM increased cell proliferation compared to CDDP used alone. Our data indicate that CAM and CDDP used in combination produce antagonistic interaction, which could inhibit anti-cancer treatment efficacy, showing importance of preclinical testing.

Design, synthesis and pharmacological screening of novel renoprotective methionine-based peptidomimetics: Amelioration of cisplatin-induced nephrotoxicity.

Cisplatin (CP) is an effective chemotherapeutic agent for treatment of various types of cancer, however efforts are needed to reduce its toxic side effect. Previous studies revealed promising effect of peptides in decreasing CP induced nephrotoxicity. Herein, novel Met-based peptidomimetics were synthesized using N-acylbenzotriazole as acylating agent in high yield. Evaluation of renoprotective effect of the synthesized targets on CP treated kidney cell line (LLC-PK1) revealed that pretreatment with 1/3 IC50 of targets II, IIIa-g attenuated CP induced cell death where the IC50 of CP was raised from 3.28 µM to 9.25-41.1 µM. The most potent compounds IIIg, II and IIIb exhibited antioxidative stress in CP-treated LLC-PK1 cells as confirmed by raising GSH/GSSG ratio and SOD concentration as well as decreasing ROS and MDA. Additionally, in vivo experiments using Sprague Dawley rats showed renoprotective effect of IIIg against CP-induced nephrotoxicity as evidenced by improved results of renal function tests and attenuated CP-induced renal structural injury. Moreover, antioxidant activity of IIIg was demonstrated via its ability to reduce renal MDA level and up-regulate renal antioxidant element GSH level. Further, immunohistochemistry of renal specimens showed the ability of IIIg to restore CP-induced suppression of Nrf2. Interestingly, in vivo and in vitro studies demonstrated that IIIg had no effect on CP antiproliferative activity. An assessment of the ADMET properties revealed that targets IIIg, II and IIIb showed good drug-likeness in terms of their physicochemical, pharmacokinetic properties. The findings presented here showcase that IIIg is a promising renoprotective candidate with antioxidative stress potential.

Ameliorative Effect of Linalool in Cisplatin-Induced Nephrotoxicity: The Role of HMGB1/TLR4/NF-κB and Nrf2/HO1 Pathways.

BACKGROUND: The monoterpene linalool is a well-known essential oil component produced by several aromatic plants. Cisplatin is a widely used anticancer drug that produces many side effects, particularly nephrotoxicity. Here, we aimed to inspect linalool's protective activity against cisplatin-induced nephrotoxicity and explore part of the underlying mechanisms. METHODS: Male Wistar rats were given linalool (50 and 100 mg/kg/day orally) for 15 days; then challenged with cisplatin (8 mg/kg) on the 12th day. Renal function parameters, oxidative stress, inflammatory and apoptotic markers, and toll-like receptor pathway gene, and protein expressions were investigated. Histopathology, immunohistochemistry, and cell-line mediated cytotoxicity assays were conducted. RESULTS: Linalool ameliorated kidney function after cisplatin challenge and managed all oxidation system parameters including GSH, SOD, CAT, MDA, NADPH, and particularly the Nrf2-mediated pathway markers. Linalool decreased TLR4, MYD88 and TRIF gene and protein expressions; diminished related inflammatory mediators such as TNF-α, IL-1ß, IL-6, and NF-κB; and down-regulated HMBG1. Linalool mitigated cisplatin-induced apoptotic markers such as caspase 3, caspase 9, and Bax expression, and boosted the anti-apoptotic Bcl2 expression. Linalool potentiated the cytotoxic effect of cisplatin when investigated on HeLa and PC3 human cancer cell lines. CONCLUSION: Linalool could protect against cisplatin-induced kidney function and tissue damage.

[6]-Gingerol Ameliorates Cisplatin-Induced Pica by Regulating the TPH/MAO-A/SERT/5-HT/5-HT3 Receptor System in Rats.

PURPOSE: [6]-gingerol is a bioactive compound extracted from ginger, a traditional anti-emetic herb in Chinese medicine. Previous studies have demonstrated that [6]-gingerol can ameliorate chemotherapy-induced pica in rats, although the underlying mechanism has not been elucidated. This study is designed to investigate [6]-gingerol's antiemetic mechanism focusing on the 5-hydroxytryptamine (serotonin, 5-HT) system by evaluating the synthesis, metabolism and reuptake of 5-HT, as well as the mechanism of 5-hydroxytryptamine type 3 receptor (5-HT3 receptor), in a cisplatin-induced pica model of rats. METHODS: Rats were randomly divided into control group (vehicle + saline, Con), [6]-gingerol control group (50 mg/kg [6]-gingerol + saline, G-con), ondansetron control group (2.6 mg/kg ondansetron + saline, O-con), cisplatin model group (vehicle + cisplatin, Model), ondansetron-treated group (2.6 mg/kg ondansetron + cisplatin, O-treated), high dosage of [6]-gingerol-treated group (100 mg/kg [6]-gingerol + cisplatin, GH-treated), and low dosage of [6]-gingerol-treated group (50 mg/kg [6]-gingerol + cisplatin, GL-treated). The rats were administered with [6]-gingerol, ondansetron, and vehicle (3% Tween-80) by gavage twice (7:00 AM and 7:00 PM). One hour after the first treatment (8:00 AM), rats in groups Model, O-treated, GH-treated and GL-treated were injected intraperitoneally (i.p.) with 6 mg/kg cisplatin, and the other groups were injected i.p. with saline of equal volume. The consumption of kaolin of the rats were measured. All the rats were anesthetized by i.p. injection of pentobarbital sodium at 24 h post-cisplatin. After blood samples were taken, medulla oblongata and ileum were removed. The levels of 5-HT and its metabolite 5-HIAA in ileum, medulla oblongata and serum were determined using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The mRNA expression levels of 5-HT3 receptor, tryptophan hydroxylase (TPH), monoamine oxidase A (MAO-A) and serotonin reuptake transporter (SERT) were detected by real-time PCR. The protein expression levels and distribution of 5-HT3 receptor, TPH and MAO-A in the medulla oblongata and ileum were measured by Western blotting and immunohistochemistry, respectively. RESULTS: [6]-gingerol treatment significantly reduced the kaolin ingestion and the increase in 5-HT concentration in rats induced by cisplatin. TPH, MAO-A, SERT, and 5-HT3 receptor are important in 5-HT metabolism, and cisplatin-induced alterations in the associated protein/mRNA levels were restored when treated with [6]-gingerol. CONCLUSION: This suggests that the antiemetic effect of [6]-gingerol against cisplatin-induced emesis may be due to 5-HT attenuation via modulating the TPH/MAO-A/SERT/5-HT/5-HT3 receptor system.

Protective effect of gallic acid and gallic acid-loaded Eudragit-RS 100 nanoparticles on cisplatin-induced mitochondrial dysfunction and inflammation in rat kidney.

Cisplatin is used as a chemotherapy drug in the treatment of various types of cancer. Mitochondrial dysfunction, oxidative stress and inflammation have been identified as major mechanisms of cisplatin nephrotoxicity. The present study investigated the protective effects of pure gallic acid and nanoparticle gallic acid nanoparticles (nano-gallic acid) on cisplatin induced nephrotoxicity. Nano-gallic acid was prepared by double emulsions-solvent evaporation technique using Eudragit RS 100 polymer and polyvinyl alcohol as carrier. Then, the physicochemical characterization of the nanoparticles was examined. In the present study, renal mitochondria were isolated using different centrifugal methods. Our data indicated that the doses of 50 and 100 mg/kg gallic acid and 10 mg/kg nano-gallic acid significantly decreased mitochondrial reactive oxygen species (ROS) formation, mitochondrial membrane damage (ΔΨm), mitochondrial malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and significantly increased mitochondrial glutathione (GSH), mitochondrial superoxide dismutase (MnSOD), mitochondrial glutathione peroxidase (GPX) and mitochondrial catalase compared to the cisplatin treated group. Histopathological studies also confirmed biochemical tests. Finally, our results confirmed that the pure gallic acid and its nanoparticle improved renal oxidative stress, inflammation and mitochondrial dysfunction in acute nephrotoxicity induced by cisplatin in rat. Nano-gallic acid (10 mg/kg) was selected as the most effective dose. The findings of this study showed the superiority of nano-gallic acid against pure gallic acid. In conclusion, nano-gallic acid-loaded Eudragit-RS 100 as a novel antioxidant can be considered in the treatment of renal complications of cisplatin.

Mitochondria targeted peptide SS-31 prevent on cisplatin-induced acute kidney injury via regulating mitochondrial ROS-NLRP3 pathway.

OBJECTIVE: This study aimed to assess the effect and mechanism of SS31 on cisplatin-induced acute kidney injury (CP-AKI) both in vivo and in vitro. METHOD: Male mices and HK-2 cells were treated using cisplatin to establish models of CP-AKI. 32 C57BL/6 mices were randomly divided into four groups (control group, CP group, CP + normal saline group, CP + SS-31 group). Cisplatin was intraperitoneally injected once to the mice (25 mg/kg). SS31 was administrated for 10 days at dosages of 10 mg/kg per day. Kidney histological changes and level of reactive oxygen species(ROS) were detected. In vitro studies, HK-2 cells were incubated with cisplatin (50 u M) or combimed with SS-31(100 u M), the level of mitochondrial ROS, apoptosis rate and the the expression of NLRP3, Caspase-1 and IL-1ß were tested. RESULTS: Renal tubulointerstitial apoptosis and oxidative stress were significantly increased in CP-AKI mice. Cisplatin caused elevation of serum creatinine (Scr), blood urea nitrogen (BUN) levels and enhanced IL-1ß, caspase1 and NLRP3 expression, the electron microscopy examination showed mitochondria cristae swelling, mitochondrial spheres and partial ridge breakdown in renal tubular cell of CP-AKI mice. SS31 treatment could effectively suppress mitochondrial ROS, ameliorate these lesions and decrease the expression of NLRP3, IL-1ß and Caspase1. In vitro studies, SS31 could restored the level of mitochondrial ROS and downregulate apoptosis rate in HK-2 cells, moreover, the elevated expression of NLRP3, IL-1ß and Caspase-1were restored. CONCLUSION: SS31 could protect CP-AKI in mices, which might be due to an anti-oxidative and anti-apoptotic action via regulating mitochondrial ROS-NLRP3 pathway. NLRP3 inflammasome might be considered as a novel therapeutic target of CP-AKI.

Tert-butylhydroquinone preserve testicular steroidogenesis and spermatogenesis in cisplatin-intoxicated rats by targeting oxidative stress, inflammation and apoptosis.

Cisplatin (Cis) is an effective chemotherapeutic intervention against many cancer types. However, the oxidative stress-related toxicities associated with cancer cell resistance-induced dose scaling has limited its long-term use. In the present study, we explored the benefits of the antioxidant, tert-butylhydroquinone (tBHQ; 50 mg/kg b.w./day, for 14 days) against Cis single dose injection (7 mg/kg b.w., i.p on Day 8), on testicular toxicity of male Wistar rats. Cis triggered testicular and epididymal oxidative stress, testicular inflammation (upregulated NF-κB, TNF-α and IL-1ß mRNA levels, and downregulated IL-10 mRNA level), increased testicular apoptosis (increased Bax/Bcl2 and caspase-3 mRNA levels) and decreased testicular germ cells proliferation. Further, Cis decreased testicular steroidogenesis (decreased expression of StAR, CYP11A1, 3ß-HSD and 17ß-HSD mRNA and proteins) and decreased follicle stimulating hormone, luteinizing hormone and testosterone levels. Cis also decreased sperm count, motility, viability, normal morphology and Johnsen score. However, intervention with tBHQ significantly decreased oxidative stress by upregulating Nrf2 gene, suppressed inflammation, apoptosis and increased testicular germ cells proliferation. tBHQ also increased steroidogenesis and improved sperm parameters. Taken together, tBHQ improves steroidogenesis and spermatogenesis in Cis-intoxicated rats by improving antioxidant status, dampening inflammation and apoptosis, thus improving the proliferative capacity of spermatogenic cells.

Modulatory effects of perindopril on cisplatin-induced nephrotoxicity in mice: Implication of inflammatory cytokines and caspase-3 mediated apoptosis.

Cisplatin-induced nephrotoxicity limits its anticancer effectiveness, thus this study's aim was to assess the potential modulatory effect of perindopril on cisplatin-induced nephrotoxicity and to elucidate the possible underlying mechanisms. Renal dysfunction was induced in mice by a single injection of cisplatin (10 mg kg-1, i.p.) and perindopril was administered orally (2 mg kg-1, once daily) for 5 days. Perindopril remarkably ameliorated cisplatin-induced perturbations in renal histology, renal levels of tumor necrosis factor-alpha, interleukin-6 and interleukin-10, apoptosis-regulating protein expressions (Bax and Bcl2), and partially normalized Bax to Bcl2 ratio and active caspase 3 protein expression. Conversely, perindopril had no significant effect on cisplatin-induced elevations in serum creatinine and urea, microalbuminuria, kidney to body weight ratio, lipid peroxidation marker, superoxide dismutase and catalase activities and reduced glutathione content. In conclusion, perindopril may be safely used with cisplatin in mice since it ameliorated cisplatin-induced histopathological changes, inflammation and apoptosis without affecting renal biomarkers or oxidative stress.

Protective effect of ginsenoside Rk1, a major rare saponin from black ginseng, on cisplatin-induced nephrotoxicity in HEK-293 cells.

Cisplatin, as one of the most effective chemotherapeutic agents, its clinical use is limited by serious side effect of nephrotoxicity. Cisplatin-induced nephrotoxicity is closely related to apoptosis induction and activation of caspase. The present study aimed to explore the potential protective effect of ginsenoside Rk1 (Rk1), a rare ginsenoside generated during steaming ginseng, on cisplatin-induced nephrotoxicity and the underlying mechanisms in human embryonic kidney 293 (HEK-293) cells. Our results showed that the reduced cell viability induced by cisplatin could significantly recover by Rk1. Furthermore, glutathione (GSH) as an oxidative index, was elevated and the lipid peroxidation product malondialdehyde (MDA) was significantly decreased after Rk1 treatment compared to the cisplatin group. Additionally, Rk1 can also decrease the ROS fluorescence expression and increase the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) compared to the cisplatin group, which suggested a suppression of oxidative response. More importantly, the cisplatin-induced elevated protein levels of Bax, cleaved caspase-3, cleaved caspase-9, and decreased protein level of Bcl-2 were reversed after treatment with Rk1. Our results elucidated the possible protective mechanism of Rk1 for the first time, which may involve in its anti-oxidation and anti-apoptosis effects.

Modulatory effect of zingerone against cisplatin or γ-irradiation induced hepatotoxicity by molecular targeting regulation.

Zingerone (ZO) is an ingredient of ginger (Zingiber officinale) which has different pharmacological properties. The objective of this research was to evaluate the protective effect of ZO against Cisplatin (Cis) or γ-Irradiation (IR)-induced hepatotoxicity in rats. ZO was given orally for consecutive 14 days prior to the treatment with Cis or exposure to IR at 15th day. Animals were sacrificed at the 23rd day. Cis or IR induced a marked increase in MAPK signal transduction as evidenced by increased p38 MAPK, JNK and ErK1/2. CYP2E1 and NADPH oxidase were significantly up-regulated. Inflammatory markers (TLR4, iNOS, COX-2 and MPO) and liver enzymes (AST, ALT and ALP) activities were also increased. Administration of ZO significantly ameliorated the above mentioned parameters.

Glucosamine Protects Rat Bone Marrow Cells Against Cisplatin-induced Genotoxicity and Cytotoxicity.

BACKGROUND AND OBJECTIVE: Glucosamine is a widely prescribed dietary supplement used in the treatment of osteoarthritis. In the present study, the chemoprotectant ability of glucosamine was evaluated against cisplatin-induced genotoxicity and cytotoxicity in rat bone marrow cells. METHODS: Glucosamine was orally administrated to rats at doses of 75 and 150 mg/kg body weight for seven consecutive days. On the seventh day, the rats were treated with a single injection of cisplatin (5 mg/kg, i.p.) at 1h after the last oral administration. The cisplatin antagonistic potential of glucosamine was assessed by micronucleus assay, Reactive Oxygen Species (ROS) level analysis, hematological analysis, and flow cytometry. RESULTS: Glucosamine administration to cisplatin-treated rats significantly decreased the frequencies of Micronucleated Polychromatic Erythrocytes (MnPCEs) and Micronucleated Normchromatic Erythrocytes (MnNCEs), and also increased PCE/(PCE+NCE) ratio in bone marrow cells. Furthermore, treatment of rats with glucosamine before cisplatin significantly inhibited apoptosis, necrosis and ROS generation in bone marrow cells, and also increased red blood cells count in peripheral blood. CONCLUSION: This study shows glucosamine to be a new effective chemoprotector against cisplatin-induced DNA damage and apoptosis in rat bone marrow cells. The results of this study may be helpful in reducing the harmful effects of cisplatin-based chemotherapy in the future.

GMDTC Chelating Agent Attenuates Cisplatin-Induced Systemic Toxicity without Affecting Antitumor Efficacy.

Cisplatin is a platinum-based chemotherapeutic drug widely used in the treatment of various cancers such as testicular, ovarian, lung, bladder, and cervical cancers. However, its use and the dosage range applied have been limited by severe side effects (e.g., nephrotoxicity and ototoxicity) and by the development of resistance to cisplatin in patients during treatment. Metal chelators have shown promising potential in overcoming these problems often associated with platinum drugs. Previously, a new chelating agent, sodium (S)-2-(dithiocarboxylato((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)-4(methylthio)butanoate (GMDTC), was developed. In this study, we examined the effect of GMDTC in modifying cisplatin-induced toxicities following in vitro and in vivo exposures. GMDTC treatment dramatically reduced cisplatin-induced apoptosis and cytotoxicity in HK2 cells by decreasing the amount of intracellular platinum. In the 4T1 breast cancer mouse model, GMDTC reduced cisplatin-induced nephrotoxicity by reducing cisplatin deposition in the kidney. GMDTC attenuated cisplatin-induced elevations in blood urea nitrogen and plasma creatinine, ameliorated renal tubular dilation and vacuolation, and prevented necrosis of glomeruli and renal tubular cells. GMDTC also inhibited cisplatin-induced ototoxicity as shown by improved hearing loss which was assessed using the auditory brainstem response test. Furthermore, GMDTC attenuated cisplatin-induced hematotoxicity and hepatotoxicity. Importantly, co-treatment of cisplatin with GMDTC did not affect cisplatin antitumor efficacy. Tumor growth, size, and metastasis were all comparable between the cisplatin only and cisplatin-GMDTC co-treatment groups. In conclusion, the current study suggests that GMDTC reduces cisplatin-induced systemic toxicity by preventing the accumulation and assisting in the removal of intracellular cisplatin, without compromising cisplatin therapeutic activity. These results support the development of GMDTC as a chemotherapy protector and rescue agent to overcome the toxicity of and resistance to platinum-based antineoplastic drugs.

3-deazaneplanocin A protects against cisplatin-induced renal tubular cell apoptosis and acute kidney injury by restoration of E-cadherin expression.

3-deazaneplanocin A (3-DZNeP) has been used as an inhibitor of enhancer of zeste homolog 2 (EZH2). Here, we explore the role and underlying mechanisms action of 3-DZNeP in abrogating cisplatin nephrotoxicity. Exposure of cultured mouse renal proximal tubular epithelial cells (mTECs) to cisplatin resulted in dose and time-dependent cleavage of caspase-3, decrease of cell viability, and increase of histone H3 lysine 27 trimethylation (H3K27me3), whereas expression levels of EZH2, a major methyltransferase of H3K27me3, were not affected. Treatment with 3-DZNeP significantly inhibited cisplatin-induced activation of caspase-3, apoptosis, loss of cell viability but did not alter levels of EZH2 and H3K27me3 in cultured mTECs. 3-DZNeP treatment did not affect activation of extracellular signal-regulated kinase (ERK) 1/2, p38 or c-Jun N-terminal kinases (JNK) 1/2, which contribute to renal epithelial cell death, but caused dose-dependent restoration of E-cadherin in mTECs exposed to cisplatin. Silencing of E-cadherin expression by siRNA abolished the cytoprotective effects of 3-DZNeP. In contrast, 3-DZNeP treatment potentiated the cytotoxic effect of cisplatin in H1299, a non-small cell lung cancer cell line that expresses lower E-cadherin levels. Finally, administration of 3-DZNeP attenuated renal dysfunction, morphological damage, and renal tubular cell death, which was accompanied by E-cadherin preservation, in a mouse model of cisplatin nephrotoxicity. Overall, these data indicate that 3-DZNeP suppresses cisplatin-induced tubular epithelial cell apoptosis and acute kidney injury via an E-cadherin-dependent mechanism, and suggest that combined application of 3-DZNeP with cisplatin would be a novel chemotherapeutic strategy that enhances the anti-tumor effect of cisplatin and reduces its nephrotoxicity.

Neuroprotective effect of N-acetylcysteine against cisplatin-induced toxicity in rat brain by modulation of oxidative stress and inflammation.

BACKGROUND: Neurotoxicity is a major obstacle to the effectiveness of cisplatin (CDDP) in cancer chemotherapy. Oxidative stress and inflammation are considered to be the major mechanisms involved in CDDP-induced neurotoxicity. The rationale of our study was to investigate the efficacy of N-acetylcysteine (NAC) at two different doses in the management of CDDP-induced toxicity in rat brain by monitoring its antioxidant and anti-inflammatory effects. METHODS: Thirty-five male rats were divided into five groups (n=7) as follows: control group (0.5 mL saline), NAC100 group (100 mg/kg), CDDP group (8 mg/kg), NAC50-CDDP group (50 mg/kg NAC and 8 mg/kg CDDP), and NAC100-CDDP group (100 mg/kg NAC and 8 mg/kg CDDP). NAC was administered for 20 consecutive days, while CDDP was injected once on day 15 of the treatment protocol. RESULTS: The neurotoxicity of CDDP was evidenced by a marked increase in acetylcholinesterase and monoamine oxidase activities. It also induced oxidative stress as indicated by increased levels of lipid peroxidation, nitric oxide, and protein carbonyl with a concomitant decline in reduced glutathione, glutathione peroxidase, glutathione S-transferase, superoxide dismutase, and catalase in the brain. Moreover, CDDP enhanced the synthesis of pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1ß, and interleukin-6. Treatment with NAC at the two selected doses significantly attenuated CDDP-induced changes in the brain cholinergic function, improved the brain oxidant/antioxidant status, and also reversed the overproduction of pro-inflammatory cytokines in brain and serum. CONCLUSION: NAC could serve as an appropriate and safe complementary therapeutic agent to attenuate the toxicity of CDDP in the brain and therefore improve its outcomes in chemotherapy.

ß-Hydroxybutyrate, a ketone body, reduces the cytotoxic effect of cisplatin via activation of HDAC5 in human renal cortical epithelial cells.

AIMS: ß-Hydroxybutyrate (ßOHB) is a metabolic intermediate that constitutes about 70% of ketone bodies produced in liver from oxidation of fatty acids released from adipose tissue. A recent study showed that ßOHB inhibits HDAC1, 3 and 4 (classes I and IIa) in human embryonic kidney 293 (HEK293) cells. Therefore, ßOHB could regulate epigenetics via modulating HDACs. However, little is known about the protective effect of ßOHB on renal cells through epigenetics. The aim of this study is to investigate whether ßOHB reduces cisplatin-induced nephrotoxicity in human renal cortical epithelial (HRCE) cells by modulating HDACs. MAIN METHODS: In this study, we used human renal cortical epithelial (HRCE) cells. The anti-apoptotic effect of ßOHB was evaluated using flow cytometry analysis. The expression of apoptosis-related proteins and HDACs was evaluated by western immunoblot. KEY FINDINGS: The results showed that ßOHB significantly reduced cisplatin-induced apoptosis in HRCE cells. Furthermore, ßOHB significantly reduced cisplatin-induced cleavage of caspase-3, acetylation of histone H3, and phosphorylation of AMP-activated kinase. This anti-apoptotic effect of ßOHB was markedly attenuated by an inhibitor of HDAC4/5, and ßOHB-mediated suppression of cleavage of caspase3 was significantly blocked by siRNA-induced gene silencing of HDAC5. SIGNIFICANCE: ßOHB attenuates cisplatin-induced apoptosis by activation of HDAC5 in HRCE cells, suggesting that ßOHB may be a new therapeutic agent for cisplatin nephropathy.

Alterations of colonic sensitivity and gastric dysmotility after acute cisplatin and granisetron.

BACKGROUND: Cisplatin is a highly emetogenic antineoplastic drug and induces peripheral neuropathy when given in cycles. Granisetron, a 5-HT3 antagonist, is clinically used to prevent chemotherapy-induced nausea/emesis and abdominal pain in irritable bowel syndrome. The effects of cisplatin on visceral sensitivity and those of granisetron in the context of cancer chemotherapy are not well known. METHODS: Adult male Wistar rats received two intraperitoneal injections 30 minutes apart: granisetron (1 mg kg-1 )/vehicle and cisplatin (6 mg kg-1 )/vehicle. Thereafter, nausea-like behavior was measured as bedding intake for 4 hours, and gastric dysmotility was measured radiographically for 8 hours. Gastric weight and size were determined ex vivo and samples of the forestomach, corpus, ileum, and colon were obtained for histological analysis at 4 and 30 hours after cisplatin/vehicle. Visceral sensitivity was measured as abdominal contractions in response to mechanical intracolonic stimulation 2 hours after cisplatin/vehicle. KEY RESULTS: Cisplatin-induced bedding intake and gastric dysmotility, and granisetron blocked these effects, which occurred in the absence of frank mucositis. Visceral sensitivity was reduced to a similar extent by both drugs alone or in combination. CONCLUSIONS AND INFERENCES: Cisplatin-induced bedding intake and gastric dysmotility were blocked by granisetron, confirming the involvement of serotonin acting on 5-HT3 receptors. Unexpectedly, visceral sensitivity to colonic distension was reduced, to the same extent, by cisplatin, granisetron, and their combination, suggesting important mechanistic differences with nausea and gastric dysmotility that warrant further investigation.

The Role of the Reactive Oxygen Species Scavenger Agent, Astaxanthin, in the Protection of Cisplatin-Treated Patients Against Hearing Loss.

Emerging evidence of significant hearing loss occurring shortly after cisplatin administration in cancer patients has stimulated research into the causes and treatment of this side effect. Although the aetiology of cisplatin-induced hearing loss (CIHL) remains unknown, an increasing body of research suggests that it is associated with excessive generation of intracellular reactive oxygen species (ROS) in the cochlea. Astaxanthin, a xanthophyll carotenoid, has powerful anti-oxidant, anti-inflammatory, and anti-apoptotic properties based on its unique cell membrane function, diverse biological activities, and ability to permeate the blood-brain barrier. In this review, we summarize the role of ROS in CIHL and the effect of astaxanthin on inhibiting ROS production. We focus on investigating the mechanism of action of astaxanthin in suppressing excessive production of ROS.