Mechanisms in cancer-chemotherapeutic drugs-induced peripheral neuropathy

Effects of protocatechuic acid against cisplatin-induced neurotoxicity in rat brains: an experimental study

Aims/Objectives: Cisplatin (CIS) is widely used in the treatment of various malignant tumors. The aim of study is to determine the potential protective effects of protocatechuic acid (PCA) on the brain in neurotoxicity induced by CIS in rats.Materials and methods: Forty rats were divided into four groups: 1-Control group: 2- PCA group: PCA was administered orally at a dose of 100 mg/kg/day for 5 weeks. 3-CIS group: 5 mg/kg/week of CIS was administered intraperiteonally 4-PCA + CIS group: The rats were given PCA orally daily for 5 weeks and CIS of 5 mg/kg/week. The brain tissues were used for histopathological examinations and for total antioxidant capacity (TAC), total oxidative state (TOS), oxidative stress index (OSI), tumornecrosis factor-alpha (T NF-α), interleukin 6 (IL-6) Interleukin 1 beta (IL-1β), acetylcholinesterase (AChE), glutamate, gamma aminobutyric acid (GABA), dopamine analyzes in ELISA. WBC, RBC, hemoglobin and hematocrit levels were measured.Results: PCA + CIS group compared to CIS group TOS, OSI, T NF-α, IL-6, IL-1β, AChE, glutamate, WBC levels decreased significantly, while TAC and GABA levels increased statistically significant. With this study, P CA corrected the deterioration in the oxidant / antioxidant status, suppressed neuro-inflammation, decreased AChE activity, partially normalized neurotransmitters, and decreased the increased WBC count. Necrosis seen in the CIS group in histopathological examinations was never seen in the PCA + CIS group.Conclusions: PCA may provide therapeutic benefit when used in conjunction with CIS.

The potential neuroprotective effects of cannabinoids against paclitaxel-induced peripheral neuropathy: in vitro study on neurite outgrowth

Introduction: Chemotherapy-induced peripheral neuropathy (CIPN) is a shared burden for 68.1% of oncological patients undergoing chemotherapy with Paclitaxel (PTX). The symptoms are intense and troublesome, patients reporting paresthesia, loss of sensation, and dysesthetic pain. While current medications focus on decreasing the symptom intensity, often ineffective, no medication is yet recommended by the guidelines for the prevention of CIPN. Cannabinoids are an attractive option, as their neuroprotective features have already been demonstrated in neuropathies with other etiologies, by offering the peripheral neurons protection against toxic effects, which promotes analgesia. Methods: We aim to screen several new cannabinoids for their potential use as neuroprotective agents for CIPN by investigating the cellular toxicity profile and by assessing the potential neuroprotective features against PTX using a primary dorsal root ganglion neuronal culture. Results: Our study showed that synthetic cannabinoids JWH-007, AM-694 and MAB-CHMINACA and phytocannabinoids Cannabixir® Medium dried flowers (NC1) and Cannabixir® THC full extract (NC2) preserve the viability of fibroblasts and primary cultured neurons, in most of the tested dosages and time-points. The combination between the cannabinoids and PTX conducted to a cell viability of 70%-89% compared to 40% when PTX was administered alone for 48 h. When assessing the efficacy for neuroprotection, the combination between cannabinoids and PTX led to better preservation of neurite length at all tested time-points compared to controls, highly drug and exposure-time dependent. By comparison, the combination of the cannabinoids and PTX administered for 24 h conducted to axonal shortening between 23% and 44%, as opposed to PTX only, which shortened the axons by 63% compared to their baseline values. Discussion and Conclusion: Cannabinoids could be potential new candidates for the treatment of paclitaxel-induced peripheral neuropathy; however, our findings need to be followed by additional tests to understand the exact mechanism of action, which would support the translation of the cannabinoids in the oncological clinical practice.

Ephrin B/EphB in neuropathic pain: Role and molecular mechanisms

Ephrins are protein ligands that act through the tyrosine kinase receptor family, Eph receptors. The role of ephrin/Eph in the critical processes involved in the development of the nervous system, including axon guidance and cell migration, has been well documented. Moreover, studies have shown an upregulation of ephrin B1/EphB1 and ephrin B2/EphB2 in neuropathic pain of different etiology. The activation of the ephrin B/EphB system in the dorsal root ganglion and dorsal horn of the spinal cord may be essential in initiating and maintaining neuropathic pain. Accordingly, it can be proposed that the pharmacological inhibitors of EphB receptors may be potentially employed to manage the manifestations of pain. One of the primary mechanisms involved in ephrin B/EphB-mediated synaptic plasticity includes phosphorylation and activation of NMDA receptors, which may be secondary to activation of different kinases, including MAP kinases (MAPK), protein kinase C (PKC), and Src family kinases (SFK). The other molecular mechanisms may include activation of inflammatory cytokines in the spinal cord, caspase-3, calpain-1, phosphoinositide 3-kinase (PI3K), protein kinase A (PKA), and cAMP Response Element-Binding Protein (CREB). The present review discusses the role and molecular mechanisms involved in ephrin B/EphB-mediated neuropathic pain of different etiology.

Parkin-mediated mitophagy is a potential treatment for oxaliplatin-induced peripheral neuropathy

Oxaliplatin-induced peripheral nerve pain (OIPNP) is a common chemotherapy-related complication, but the mechanism is complex. Mitochondria are vital for cellular homeostasis and regulating oxidative stress. Parkin-mediated mitophagy is a cellular process that removes damaged mitochondria, exhibiting a protective effect in various diseases; however, its role in OIPNP remains unclear. In this study, we found that Parkin-mediated mitophagy was decreased, and reactive oxygen species (ROS) was upregulated in OIPNP rat dorsal root ganglion (DRG) in vivo and in PC12 cells stimulated with oxaliplatin (OXA) in vitro. Overexpression of Parkin indicated that OXA might cause mitochondrial and cell damage by inhibiting mitophagy. We also showed that salidroside (SAL) upregulated Parkin-mediated mitophagy to eliminate damaged mitochondria and promote PC12 cell survival. Knockdown of Parkin indicated that mitophagy is crucial for apoptosis and mitochondrial homeostasis in PC12 cells. In vivo study also demonstrated that SAL enhances Parkin-mediated mitophagy in the DRG and alleviates peripheral nerve injury and pain. These results suggest that Parkin-mediated mitophagy is involved in the pathogenesis of OIPNP and may be a potential therapeutic target for OIPNP.NEW & NOTEWORTHY This article discusses the effects and mechanisms of Parkin-mediated mitophagy in oxaliplatin-induced peripheral nerve pain (OIPNP) from both in vivo and in vitro. We believe that our study makes a significant contribution to the literature because OIPNP has always been the focus of clinical medicine, and mitochondrial quality regulation mechanisms especially Parkin-mediated mitophagy, have been deeply studied in recent years. We use a variety of molecular biological techniques and animal experiments to support our argument.

The role of gut microbiota and metabolites in cancer chemotherapy

BACKGROUND

The microbiota inhabits the epithelial surfaces of hosts, which influences physiological functions from helping digest food and acquiring nutrition to regulate metabolism and shaping host immunity. With the deep insight into the microbiota, an increasing amount of research reveals that it is also involved in the initiation and progression of cancer. Intriguingly, gut microbiota can mediate the biotransformation of drugs, thereby altering their bioavailability, bioactivity, or toxicity.

AIM OF REVIEW

The review aims to elaborate on the role of gut microbiota and microbial metabolites in the efficacy and adverse effects of chemotherapeutics. Furthermore, we discuss the clinical potential of various ways to harness gut microbiota for cancer chemotherapy.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Recent evidence shows that gut microbiota modulates the efficacy and toxicity of chemotherapy agents, leading to diverse host responses to chemotherapy. Thereinto, targeting the microbiota to improve efficacy and diminish the toxicity of chemotherapeutic drugs may be a promising strategy in tumor treatment.

Inhibition of C5aR1 as a promising approach to treat taxane-induced neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of several antitumor agents resulting in progressive and often irreversible damage of peripheral nerves. In addition to their known anticancer effects, taxanes, including paclitaxel, can also induce peripheral neuropathy by activating microglia and astrocytes, which release pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and chemokine (C-C motif) ligand 2 (CCL-2). All these events contribute to the maintenance of neuropathic or inflammatory response. Complement component 5a (C5a)/C5a receptor 1 (C5aR1) signaling was very recently shown to play a crucial role in paclitaxel-induced peripheral neuropathy. Our recent findings highlighted that taxanes have the previously unreported property of binding and activating C5aR1, and that C5aR1 inhibition by DF3966A is effective in preventing paclitaxel-induced peripheral neuropathy (PIPN) in animal models. Here, we investigated if C5aR1 inhibition maintains efficacy in reducing PIPN in a therapeutic setting. Furthermore, we characterized the role of C5aR1 activation by paclitaxel and the CIPN-associated activation of nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome. Our results clearly show that administration of the C5aR1 inhibitor strongly reduced cold and mechanical allodynia in mice when given both during the onset of PIPN and when neuropathy is well established. C5aR1 activation by paclitaxel was found to be a key event in the induction of inflammatory factors in spinal cord, such as TNF-α, ionized calcium-binding adapter molecule 1 (Iba-1), and glial fibrillary acidic protein (GFAP). In addition, C5aR1 inhibition significantly mitigated paclitaxel-induced inflammation and inflammasome activation by reducing IL-1β and NLRP3 expression at both sciatic and dorsal root ganglia level, confirming the involvement of inflammasome in PIPN. Moreover, paclitaxel-induced upregulation of C5aR1 was significantly reduced by DF3966A treatment in central nervous system. Lastly, the antinociceptive effect of C5aR1 inhibition was confirmed in an in vitro model of sensory neurons in which we focused on receptor channels usually activated upon neuropathy. In conclusion, C5aR1 inhibition is proposed as a therapeutic option with the potential to exert long-term protective effect on PIPN-associated neuropathic pain and inflammation.

The association between sociodemographic, clinical, and potentially preventive therapies with oxaliplatin-induced peripheral neuropathy in colorectal cancer patients

PURPOSE

The purpose of this retrospective cohort study was to evaluate whether several potentially preventive therapies reduced the rate of oxaliplatin-induced peripheral neuropathy (OIPN) in colorectal cancer patients and to assess the relationship of sociodemographic/clinical factors with OIPN diagnosis.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results database combined with Medicare claims. Eligible patients were diagnosed with colorectal cancer between 2007 and 2015, ≥ 66 years of age, and treated with oxaliplatin. Two definitions were used to denote diagnosis of OIPN based on diagnosis codes: OIPN 1 (specific definition, drug-induced polyneuropathy) and OIPN 2 (broader definition, additional codes for peripheral neuropathy). Cox regression was used to obtain hazard ratios (HR) with 95% confidence intervals (CI) for the relative rate of OIPN within 2 years of oxaliplatin initiation.

RESULTS

There were 4792 subjects available for analysis. At 2 years, the unadjusted cumulative incidence of OIPN 1 was 13.1% and 27.1% for OIPN 2. For both outcomes, no therapies reduced the rate of OIPN diagnosis. The anticonvulsants gabapentin and oxcarbazepine/carbamazepine were associated with an increased rate of OIPN (both definitions) as were increasing cycles of oxaliplatin. Compared to younger patients, those 75-84 years of age experienced a 15% decreased rate of OIPN. For OIPN 2, prior peripheral neuropathy and moderate/severe liver disease were also associated with an increased hazard rate. For OIPN 1, state buy-in health insurance coverage was associated with a decreased hazard rate.

CONCLUSION

Additional studies are needed to identify preventive therapeutics for OIPN in cancer patients treated with oxaliplatin.

Trimethoxyflavanone relieves Paclitaxel-induced neuropathic pain via inhibiting expression and activation of P2X7 and production of CGRP in mice

Paclitaxel (PTX) is an anticancer drug used to treat solid tumors, but one of its common adverse effects is chemotherapy-induced peripheral neuropathy (CIPN). Currently, there is limited understanding of neuropathic pain associated with CIPN and effective treatment strategies are inadequate. Previous studies report the analgesic actions of Naringenin, a dihydroflavonoid compound, in pain. Here we observed that the anti-nociceptive action of a Naringenin derivative, Trimethoxyflavanone (Y3), was superior to Naringenin in PTX-induced pain (PIP). An intrathecal injection of Y3 (1 μg) reversed the mechanical and thermal thresholds of PIP and suppressed the PTX-induced hyper-excitability of dorsal root ganglion (DRG) neurons. PTX enhanced the expression of ionotropic purinergic receptor P2X7 (P2X7) in satellite glial cells (SGCs) and neurons in DRGs. The molecular docking simulation predicts possible interactions between Y3 and P2X7. Y3 reduced the PTX-enhanced P2X7 expression in DRGs. Electrophysiological recordings revealed that Y3 directly inhibited P2X7-mediated currents in DRG neurons of PTX-treated mice, suggesting that Y3 suppressed both expression and function of P2X7 in DRGs post-PTX administration. Y3 also reduced the production of calcitonin gene-related peptide (CGRP) in DRGs and at the spinal dorsal horn. Additionally, Y3 suppressed the PTX-enhanced infiltration of Iba1-positive macrophage-like cells in DRGs and overactivation of spinal astrocytes and microglia. Therefore, our results indicate that Y3 attenuates PIP via inhibiting P2X7 function, CGRP production, DRG neuron sensitization, and abnormal spinal glial activation. Our study implies that Y3 could be a promising drug candidate against CIPN-associated pain and neurotoxicity.

Intravenous lidocaine infusion compared to thoracic epidural analgesia in cytoreductive surgery with or without heated intraperitoneal chemotherapy. A retrospective case-cohort study

BACKGROUND

Intravenous (IV) lidocaine is a proven analgesic therapy but has not been evaluated in extensive procedures such as cytoreductive surgery (CRS). Our aim was to assess the effectiveness and safety of IV lidocaine in this setting.

METHODS

This is a retrospective hybrid case-cohort study investigating analgesic effectiveness and complications of perioperative IV lidocaine at 1.5 mg/kg/h for 48 h compared to thoracic epidural anaesthesia (TEA) among patients undergoing CRS in a high-volume centre.

RESULTS

Sixty patients were included, 20 received IV lidocaine and 40 underwent TEA. Pain scores were low (median ≤2) and similar in both groups (p = 0.88). At 72 h, the lidocaine group had a lower median pain score (p = 0.03). Overall opioid consumption in the first 48 h was lower in the lidocaine compared to the TEA group (median 0 (IQR 0-9.5) mg vs. 45.4 (0-62.4) MME respectively, p = 0.001). Opioid consumption was also lower in the lidocaine compared to the TEA group during the whole 5-day period (median 1 (IQR 1-13.5) mg vs. 112 (36.6-137.85) MME respectively, p = 0.000). The incidence of PONV was significantly lower in the lidocaine group (27.5% vs 5%, p = 0.047) with no difference in other complications or length of in-hospital stay.

CONCLUSION

Intravenous lidocaine infusion may be a safe and effective analgesic approach in CRS and is associated with a significant reduction of opioid use and PONV compared to opioid-containing TEA.

COVID-19-Related Neuropathic Pain: A Systematic Review and Meta-Analysis

INTRODUCTION

SARS-CoV-2, responsible for the coronavirus disease (COVID-19) pandemic, may impact other systems apart from the respiratory system, including the nervous system. In this systematic review, we aimed to establish the prevalence and determinants of neuropathic pain amongst COVID-19-infected individuals.

METHODOLOGY

A literature search in the PubMed database was performed and 11 papers were eligible for inclusion in this systematic review and meta-analysis.

RESULTS

The pooled prevalence of COVID-19-related neuropathic pain was 6.7% (95% CI: 4.7-9.5%) for hospitalised patients during the acute phase and 34.3% (95% CI: 14.3-62%) for long COVID patients. The identified risk factors for COVID-19-related neuropathic pain development included depression, COVID-19 severity and azithromycin use.

CONCLUSIONS

Neuropathic pain is a very common symptom in long COVID, indicating the urgency for further research in this direction.

Vincristine-induced ptosis in a leukemia patient treated with pyridoxine and pyridostigmine

INTRODUCTION

Blepharoptosis, commonly referred to as ptosis or eyelid sagging, is a condition where the upper eyelid droops over the eye. It can be congenital or acquired and is caused by the weakening of the eyelid muscles.

CASE REPORT

We present a case of a 3-year-old boy with T-cell acute lymphoblastic leukemia who developed bilateral ptosis while on treatment with Berlin-Frankfurt Munster-98 protocol.

MANAGEMENT & OUTCOME

The patient was diagnosed with bilateral ptosis due to vincristine, the primary agent in the induction phase of the protocol. The addition of the neuroregenerative agents and supportive measures led to marked improvement, followed by complete resolution within 3 weeks.

DISCUSSION

Vincristine is an anticancer agent with known neurotoxicity, which has a significant role in treating hematological malignancies and sarcoma. In many studies, the addition of neuroregenerative agents such as pyridoxine and pyridostigmine has been noted to hasten recovery without any documented side effects. Similar findings were also drawn from our research due to India's higher incidence of vincristine-induced neurotoxicity. It is essential to promptly diagnose and manage symptoms at the earliest to prevent the risk of permanent nerve damage and inferior quality of life for the patient.

Serum sodium ions and chloride ions associated with taxane-induced peripheral neuropathy in Chinese patients with early-stage breast cancer: A nation-wide multicenter study

BACKGROUND

Taxane-induced peripheral neuropathy (TIPN) is a debilitating adverse effect of cancer treatments with taxanes which may require a reduction or discontinuation chemotherapy and affect clinical and survival outcomes. A number of factors have contributed to the increasing prevalence of TIPN. Nonetheless, limited knowledge exists of potential prechemotherapy blood-based biochemical factors associated with TIPN development.

METHODS

We recruited breast cancer patients at seven cancer institutions in China. Participants aged 18 years or older with stage I to III breast cancer who scheduled to undergo primary neoadjuvant and adjuvant chemotherapy with taxanes were eligible. Eligible patients underwent patient-reported neuropathy assessments using the EORTC-CIPN20 questionnaire. Patients completed the questionnaire before commencing treatment and after every cycle. For every patient, we selected the highest TIPN toxicity score for analysis since the first cycle. The posttreatment TIPN severity was compared with blood-based biochemical factors within 30 days before commencing treatment. Independent samples t tests, Mann-Whitney U tests and linear regression were used to identify blood-based and clinical associations with TIPN development.

RESULTS

The study included 873 breast cancer participants who received paclitaxel, docetaxel or nanoparticle albumin-bound (nab)-paclitaxel. In the whole cohort, factors associated with higher TIPN toxicity scores were higher cumulative chemotherapy dose (β = 0.005; 95% CI, 0.004 to 0.006; P < .001), lower sodium ions (β = -0.24; 95% CI, -0.39 to -0.09; P = .002) and higher chloride ions (β = 0.30; 95% CI, 0.16 to 0.44; P < .001).

CONCLUSIONS

The findings suggest that breast cancer patients with a higher cumulative chemotherapy dose, lower pretreatment sodium ions, and higher pretreatment chloride ions receiving taxanes should receive closer monitoring to mitigate the development of short-term and long-term TIPN.

Palmitoylethanolamide Mitigates Paclitaxel Toxicity in Primary Dorsal Root Ganglion Neurons

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of several chemotherapeutic agents, such as Paclitaxel. The main symptoms of CIPN are pain and numbness in the hands and feet. Paclitaxel is believed to accumulate in the dorsal root ganglia and free nerve endings. Novel therapeutic agents might help to mitigate or prevent Paclitaxel toxicity on dorsal root ganglion (DRG) neurons. Thus, we used primary DRG neurons as a model to investigate the potential neuroprotective effects of the endocannabinoid-like substance, palmitoylethanolamide (PEA). DRG neurons were isolated from cervical to sacral segments of spinal nerves of Wister rats (6-8 weeks old). After isolation and purification of neuronal cell populations, different concentrations of Paclitaxel (0.01-10 µM) or PEA (0.1-10 µM) or their combination were tested on cell viability by MTT assay at 24 h, 48, and 72 h post-treatment. Furthermore, morphometric analyses of neurite length and soma size for DRG neurons were performed. Adverse Paclitaxel effects on cell viability were apparent at 72 h post-treatment whereas Paclitaxel significantly reduced the neurite length in a concentration-dependent manner nearly at all investigated time points. However, Paclitaxel significantly increased the size of neuronal cell bodies at all time windows. These phenotypic effects were significantly reduced in neurons additionally treated with PEA, indicating the neuroprotective effect of PEA. PEA alone led to a significant increase in neuron viability regardless of PEA concentrations, apparent improvements in neurite outgrowth as well as a significant decrease in soma size of neurons at different investigated time points. Taken together, PEA showed promising protective effects against Paclitaxel-related toxicity on DRG neurons.

Syringaresinol Alleviates Oxaliplatin-Induced Neuropathic Pain Symptoms by Inhibiting the Inflammatory Responses of Spinal Microglia

Oxaliplatin-induced peripheral neuropathy (OIPN) is a serious side effect that impairs the quality of life of patients treated with the chemotherapeutic agent, oxaliplatin. The underlying pathophysiology of OIPN remains unclear, and there are no effective therapeutics. This study aimed to investigate the causal relationship between spinal microglial activation and OIPN and explore the analgesic effects of syringaresinol, a phytochemical from the bark of Cinnamomum cassia, on OIPN symptoms. The causality between microglial activation and OIPN was investigated by assessing cold and mechanical allodynia in mice after intrathecal injection of the serum supernatant from a BV-2 microglial cell line treated with oxaliplatin. The microglial inflammatory response was measured based on inducible nitric oxide synthase (iNOS), phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated nuclear factor-kappa B (p-NF-κB) expression in the spinal dorsal horn. The effects of syringaresinol were tested using behavioral and immunohistochemical assays. We found that oxaliplatin treatment activated the microglia to increase inflammatory responses, leading to the induction of pain. Syringaresinol treatment significantly ameliorated oxaliplatin-induced pain and suppressed microglial expression of inflammatory signaling molecules. Thus, we concluded that the analgesic effects of syringaresinol on OIPN were achieved via the modulation of spinal microglial inflammatory responses.

Supercritical fluid extract of Angelica sinensis promotes the anti-colorectal cancer effect of oxaliplatin

Oxaliplatin-based chemotherapy regimens are recommended for patients with advanced colorectal cancer (CRC). However, oxaliplatin (OXA) can cause toxic side effects at the recommended dosage. Therefore, it is necessary to find new drug candidates that can synergize with OXA and thereby lower the OXA dose while still maintaining its efficacy. Angelica sinensis is a common drug in traditional Chinese medicine and has demonstrated a significant anti-CRC effect in modern pharmacological studies. The active ingredients in Angelica sinensis can be effectively extracted by a supercritical fluid extract. In this study, the supercritical fluid extract of Angelica sinensis (A-SFE) was obtained by a stable extraction process and was chemically characterized by GC/MS. The anti-cancer effect of A-SFE when applied individually was explored in vitro through MTT, scratch, and Transwell assay. The effect of A-SFE on CRC cells under the influence of tumor-associated macrophages (TAMs) was explored by a co-culture model. The results showed that A-SFE could inhibit the viability, metastasis, and invasion of HCT116 cells, especially under the influence of TAMs. When 20–100 μg/ml of A-SFE and 8–64 μg/ml of OXA were used in combination in HCT116 cells, synergistic or additive effects were shown in different concentration combinations. The CT26 syngeneic mouse model was used to explore the anti-CRC effect of OXA combined with A-SFE in vivo. The tumor volume, expression levels of Ki67, MMP9, and CD206 in the OXA + A-SFE group were less than those in the OXA group. In conclusion, A-SFE has the potential to become an adjuvant drug for OXA in the treatment of CRC, which provides new strategies for anti-colorectal cancer research.

Mechanistic efficacy assessment of selected novel methanimine derivatives against vincristine induced Neuropathy: In-vivo, Ex-vivo and In-silico correlates

Vincristine induced peripheral neuropathy (VIPN) is a serious untoward side effect suffered by cancer patients, which still lacks an adequate therapeutic approach. This study examined the alleviating potential of novel methanimine derivatives i.e. (E)-N-(4-nitrobenzylidene)-4-chloro-2-iodobenzamine (KB 9) and (E)-N-(2-methylbenzylidene)-4-chloro-2-iodobenzamine (KB 10) in VIPN. Vincristine was injected in BALB/c mice for 10 days to instigate nociceptive neuropathy. Dynamic and static allodynia, thermal (hot and cold) hyperalgesia were evaluated at 0, 5, 10 and 14 days using cotton brush, Von Frey filament application, hot plate test, acetone drop and cold water respectively. Tumour necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), lipid peroxide (LPO), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD) and reactive oxygen species (ROS) assays were performed to assess the efficacy of KB9 and KB10 against neuroinflammation and oxidative stress utilizing ELISA, immunohistochemistry and western blot analysis in brain and sciatic nerve tissues. Computational studies were executed to determine the stable binding conformation of both compounds with respect to COX-2 and NF-κB. Interestingly, both compounds substantially reduced protein expression related to neuroinflammation, oxidative stress (LPO, GST, SOD, CAT) and pain (NF-κB, COX-2, IL-1β and TNF-α). This molecular analysis suggested that the neuroprotective effect of KB9 and KB10 was mediated via regulation of inflammatory signaling pathways. Overall, this study demonstrated that KB9 and KB10 ameliorated vincristine induced neuropathy, through anti-inflammatory, anti-nociceptive and antioxidant mechanisms.

Using Network Pharmacology and Animal Experiment to Investigate the Therapeutic Mechanisms of Polydatin against Vincristine-Induced Neuropathic Pain

Background

Polydatin (PD) is the primary active compound in Polygonum cuspidatum Sieb and has been demonstrated to exert anti-inflammatory and neuroprotective activities. In the present study, we aimed to explore the therapeutic mechanisms of PD against chemotherapy-induced neuropathic pain.

Methods

The putative targets of PD were obtained from the CTD and SwissTargetPrediction databases. Neuropathic pain- and VIN-related targets were collected from the CTD and GeneCards databases. Subsequently, the intersection targets were obtained using the Venn tool, and the protein-protein interaction (PPI) was constructed by the STRING database. GO and KEGG enrichment analyses were performed to investigate the biological functions of the intersection targets. Further, a rat model of VIN-induced neuropathic pain was established to confirm the reliability of the network pharmacology findings.

Results

A total of 46 intersection targets were identified as potential therapeutic targets, mainly related to neuroinflammation. KEGG pathway analysis indicated that the IL-17 signaling pathway was involved in the mechanism of the antinociceptive effect of PD. PPI network analysis indicated that RELA, IL-6, TP53, MAPK3, and MAPK1 were located at crucial nodes in the network. Additionally, PD exerted an antinociceptive effect by increasing the nociceptive threshold. The results of qRT-PCR, western blot, and immunohisochemistry indicated that PD inhibited the IL-6, TP53, and MAPK1 levels in VIN-induced neuropathic pain rats.

Conclusions

Overall, this research provided evidence that suppressing inflammatory signaling pathways might be a potential mechanism action of PD's antinociceptive effect against VIN-induced neuropathic pain.

Roasted cashew (Anacardium occidentale L.) nut-enhanced diet forestalls cisplatin-initiated brain harm in rats

The incessant dose constraining symptom of the chemotherapeutic agent, cisplatin is neurotoxicity. This examination tried to explore the neuroprotective impact of roasted cashew nut-enhanced diet against brain deficits related with treatment with cisplatin. Rats were separated in to six groups: Control, CIS (cisplatin [7 mg/kg body weight, i.p]), CIS +10% CN (cisplatin plus 10% roasted cashew nut), CIS +20% CN (cisplatin plus 20% roasted cashew nut), 10% CN (10% roasted cashew nut) and 20% CN (20% roasted cashew nut) for 28 days. Key enzymes associated with brain function, including cholinesterases (AChE and BChE), monoaminergic enzyme (MAO), arginase, and adenosine deaminase (ADA), were investigated after the treatment. The following oxidative stress indicators were also measured in the rat brain: glutathione-S-transferase (GST), glutathione peroxidase (GPx), total antioxidant capacity (TAC), total thiol (T-SH), non-protein thiol (NPSH), thiobarbituric acid reactive substances (TBARS), reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD). Our outcomes demonstrated that roasted cashew nut enhanced diet showed inhibitory impact on activities of AChE, BChE, ADA, MAO and arginase in cisplatin-induced rats. The roasted cashew nut supplemented diet also boosted redox equilibrium and displayed protection against cispaltin-induced oxidative damage to rats' brains by an increase in SOD, CAT, GST and GPx activities, TAC, T-SH, NPSH and NO levels as well as a considerable drop in ROS and RBARS levels. Roasted cashew nut enhanced diet additionally forestalled neuronal degeneration in rat brain. Thus, roasted cashew nuts could be used as a nutraceutical or functional food to treat cisplatin-induced neurotoxicity.

Practical applications

The results show that increasing roasted cashew nut consumption can significantly improve antioxidant status, reduce lipid peroxidation, and suppress cholinesterase, adenosine deaminase, monoamine oxidase, and arginase activities in the brain under cisplatin-induced circumstances.

Emerging roles of toll-like receptor 4 in chemotherapy-induced neurotoxicity

Chemotherapy-induced neurotoxicity is one of the most prevalent side effects in cancer patients and survivors. Cognitive decline and peripheral neuropathy are the most common chemotherapy-induced neurotoxic symptoms. These symptoms lead not only to the limiting of the dose of chemotherapy given to cancer patients, but also have an impact on the quality of life of cancer survivors. Although the exact mechanisms involved in chemotherapy-induced neurotoxicity are still unclear, neuroinflammation is widely regarded as being one of the major causes involved in chemotherapy-induced neurotoxicity. It is known that Toll-like receptor 4 (TLR4) plays a critical role in the inflammatory process, and it has been recently reported that it is associated with chemotherapy-induced neurotoxicity. In this review, we summarize and discuss all available evidence regarding the activation of the TLR4 signaling pathway in various models of chemotherapy-induced neurotoxicity. This review also emphasizes the evidence pertinent to TLR4 inhibition on chemotherapy-induced neurotoxicity in rodent studies. Understanding the role of the TLR4 signaling pathway behind chemotherapy-induced neurotoxicity is crucial for improving treatments and ensuring the long-term survival of cancer patients.

Bridging the Translational Gap in Chemotherapy-Induced Peripheral Neuropathy with iPSC-Based Modeling

Simple Summary

Chemotherapy-induced peripheral neuropathy (CIPN) remains a clinical challenge with a considerable impact on the effective treatment of cancers and quality of life during and after concluding chemotherapy. Given the limited understanding of CIPN, there are no options for the treatment and prevention of CIPN. Decades of research with the unsuccessful translation of preclinical findings to clinical studies argue for the requirement of human model systems. This review focuses on the translational potential of human induced pluripotent stem cells (iPSCs) in CIPN research. We provide an overview of the current studies and discuss important aspects to improve the translation of in vitro findings. We identified distinct effects on the neurite network and cell viability upon exposure to different classes of chemotherapy. Our study revealed considerable variability between donors and between neurons of the central and peripheral nervous system. Translational success may be improved by including multiple iPSC donors with known clinical data and selecting clinically relevant concentrations.

Abstract

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially serious adverse effect of a wide range of chemotherapeutics. The lack of understanding of the molecular mechanisms underlying CIPN limits the efficacy of chemotherapy and development of therapeutics for treatment and prevention of CIPN. Human induced pluripotent stem cells (iPSCs) have become an important tool to generate the cell types associated with CIPN symptoms in cancer patients. We reviewed the literature for iPSC-derived models that assessed neurotoxicity among chemotherapeutics associated with CIPN. Furthermore, we discuss the gaps in our current knowledge and provide guidance for selecting clinically relevant concentrations of chemotherapy for in vitro studies. Studies in iPSC-derived neurons revealed differential sensitivity towards mechanistically diverse chemotherapeutics associated with CIPN. Additionally, the sensitivity to chemotherapy was determined by donor background and whether the neurons had a central or peripheral nervous system identity. We propose to utilize clinically relevant concentrations that reflect the free, unbound fraction of chemotherapeutics in plasma in future studies. In conclusion, iPSC-derived sensory neurons are a valuable model to assess CIPN; however, studies in Schwann cells and motor neurons are warranted. The inclusion of multiple iPSC donors and concentrations of chemotherapy known to be achievable in patients can potentially improve translational success.

Sulindac acetohydrazide derivative attenuates against cisplatin induced organ damage by modulation of antioxidant and inflammatory signaling pathways

This study aimed to explore the mechanisms of action of a sulindac acetohydrazide derivative, N'-(4-dimethylaminobenzylidene)-2-1-(4-(methylsulfinyl) benzylidene)-5-fluoro-2-methyl-1H-inden-3-yl) acetohydrazide, against anticancer drug cisplatin induced organ damage. Using a rodent model, various markers of organ function and signaling pathways were examined and validated by molecular docking studies. The study involves five groups of animals: control, DMSO, CDDP, CDDP + DMFM, and DMFM. Biochemical enzyme activity, histopathology, tissue antioxidant, and oxidative stress markers were examined. RT-PCR and western blot analyses were conducted for the expression of inducible cyclooxygenase enzyme (COX-2), nuclear factor kappa beta (NF-κB), p65, IL-1, TNF-α, and inducible nitric oxide synthase (iNOS). Flow cytometry analysis of CD4 + TNF-α, CD4 + COX-2, and CD4 + STAT-3 cells in whole blood was performed. Structural and dynamic behavior of DMFM upon binding with receptor molecule molecular docking and dynamic simulations were performed using bioinformatics tools and software. Treatment with DMFM reversed cisplatin-induced malondialdehyde (MDA) and nitric oxide (NO) induction, whereas the activity of glutathione peroxidase (GPx), and superoxide dismutase (SOD) in the kidney, heart, liver, and brain tissues were increased. DMFM administration normalized plasma levels of biochemical enzymes. We observed a marked decline in CD4 + STAT3, TNF-α, and COX2 cell populations in whole blood after treatment with DMFM. DMFM downregulated the expression factors related to inflammation at the mRNA and protein levels, i.e., IL-1, TNF-α, iNOS, NF-κB, STAT-3, and COX-2. Dynamic simulations and in silico docking data supports the experimental findings. Our experimental and in silico results illustrated that DMFM may affect protective action against cisplatin-induced brain, heart, liver, and kidney damage via reduction of inflammation and ROS.

Glioblastoma: Current Status, Emerging Targets, and Recent Advances

Glioblastoma (GBM) is a highly malignant brain tumor characterized by a heterogeneous population of genetically unstable and highly infiltrative cells that are resistant to chemotherapy. Although substantial efforts have been invested in the field of anti-GBM drug discovery in the past decade, success has primarily been confined to the preclinical level, and clinical studies have often been hampered due to efficacy-, selectivity-, or physicochemical property-related issues. Thus, expansion of the list of molecular targets coupled with a pragmatic design of new small-molecule inhibitors with central nervous system (CNS)-penetrating ability is required to steer the wheels of anti-GBM drug discovery endeavors. This Perspective presents various aspects of drug discovery (challenges in GBM drug discovery and delivery, therapeutic targets, and agents under clinical investigation). The comprehensively covered sections include the recent medicinal chemistry campaigns embarked upon to validate the potential of numerous enzymes/proteins/receptors as therapeutic targets in GBM.

Shaoyao Gancao Decoction Ameliorates Paclitaxel-Induced Peripheral Neuropathy via Suppressing TRPV1 and TLR4 Signaling Expression in Rats

Purpose

Paclitaxel-induced peripheral neuropathy (PIPN) is increasingly becoming one of the most widespread adverse effects in the treatment of cancer patients, and further precipitate neuroinflammation in the nervous system. Interestingly, Shaoyao Gancao Decoction (SGD), a traditional Chinese analgesic prescription, has emerged as a primary adjuvant to chemotherapy in relieving side effects, especially in the case of PIPN. However, the underlying mechanism of SGD functioning in PIPN remains elusive. Accordingly, the current study set out to explore the potential axis implicated in the functioning of SGD in PIPN.

Methods

First, network pharmacology was adopted to predict the role of the transient receptor potential vanilloid type 1 (TRPV1) protein in treating PIPN with SGD. Subsequently, the effects of SGD treatment on mechanical allodynia and thermal hyperalgesia were evaluated in rat PIPN models. Based on the bioinformatics information and current literature, paclitaxel activates toll-like receptor 4 (TLR4) induces the sensitization of TRPV1 mechanistically. Thereafter, TLR4-myeloid-differentiation response gene 88 (MyD88) signaling and TRPV1 expression patterns in dorsal root ganglias (DRGs) were measured by means of Western blotting, qPCR and immunofluorescence.

Results

Initial bioinformatics reared a total of 105 bioactive compounds and 1075 target genes from SGD. In addition, 40 target genes intersected with PIPN were considered as potential therapeutic genes. Based on the network analysis, SGD was found to exert its analgesic effect by reducing the expression of TRPV1. Further experimentation validated that SGD exerted an analgesic effect on thermal hyperalgesia in PIPN models, such that this protective effect was associated with the suppression of TRPV1 and TLR4-MyD88 Signaling over-expression.

Conclusion

Collectively, our findings indicated that SGD ameliorates PIPN by inhibiting the over-expression of TLR4-MyD88 Signaling and TRPV1, and further highlights the use of SGD as a potential alternative treatment for PIPN.

Neuronal and non-neuronal TRPA1 as therapeutic targets for pain and headache relief

The transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily of channels, has a major role in different types of pain. TRPA1 is primarily localized to a subpopulation of primary sensory neurons of the trigeminal, vagal, and dorsal root ganglia. This subset of nociceptors produces and releases the neuropeptide substance P (SP) and calcitonin gene-related peptide (CGRP), which mediate neurogenic inflammation. TRPA1 is characterized by unique sensitivity for an unprecedented number of reactive byproducts of oxidative, nitrative, and carbonylic stress and to be activated by several chemically heterogenous, exogenous, and endogenous compounds. Recent preclinical evidence has revealed that expression of TRPA1 is not limited to neurons, but its functional role has been reported in central and peripheral glial cells. In particular, Schwann cell TRPA1 was recently implicated in sustaining mechanical and thermal (cold) hypersensitivity in mouse models of macrophage-dependent and macrophage-independent inflammatory, neuropathic, cancer, and migraine pain. Some analgesics and herbal medicines/natural products widely used for the acute treatment of pain and headache have shown some inhibitory action at TRPA1. A series of high affinity and selective TRPA1 antagonists have been developed and are currently being tested in phase I and phase II clinical trials for different diseases with a prominent pain component. Abbreviations: 4-HNE, 4-hydroxynonenal; ADH-2, alcohol dehydrogenase-2; AITC, allyl isothiocyanate; ANKTD, ankyrin-like protein with transmembrane domains protein 1; B2 receptor, bradykinin 2 receptor; CIPN, chemotherapeutic-induced peripheral neuropathy; CGRP, calcitonin gene related peptide; CRISPR, clustered regularly interspaced short palindromic repeats; CNS, central nervous system; COOH, carboxylic terminal; CpG, C-phosphate-G; DRG, dorsal root ganglia; EP, prostaglandins; GPCR, G-protein-coupled receptors; GTN, glyceryl trinitrate; MAPK, mitogen-activated protein kinase; M-CSF, macrophage-colony stimulating factor; NAPQI, N-Acetyl parabenzoquinone-imine; NGF, nerve growth factor; NH2, amino terminal; NKA, neurokinin A; NO, nitric oxide; NRS, numerical rating scale; PAR2, protease-activated receptor 2; PMA, periorbital mechanical allodynia; PLC, phospholipase C; PKC, protein kinase C; pSNL, partial sciatic nerve ligation; RCS, reactive carbonyl species; ROS, reactive oxygen species; RNS, nitrogen oxygen species; SP, substance P; TG, trigeminal ganglion; THC, Δ9-tetrahydrocannabinol; TrkA, neurotrophic receptor tyrosine kinase A; TRP, transient receptor potential; TRPC, TRP canonical; TRPM, TRP melastatin; TRPP, TRP polycystin; TRPM, TRP mucolipin; TRPA, TRP ankyrin; TRPV, TRP vanilloid; VG, vagal ganglion.

Preliminary study of astragaloside IV on oxaliplatin-induced peripheral neurotoxicity in rats

Objective: As an effective component of Astragalus membranaceus, astragaloside IV (AS-IV) has a history of thousands of years in China. Many evidences have indicated that AS-IV has a potential neuroprotective effect. In this study, we aimed to preliminarily study the effects of AS-IV on oxaliplatin-induced peripheral neurotoxicity (OIPN) in rats.

Methods: Intraperitoneal injection of oxaliplatin for 4 weeks (4 mg/kg, twice a week) was used to establish peripheral neurotoxicity in rats. 40 Sprague Dawley rats were randomly divided into five groups, eight rats in each group, including control group, model group, and three AS-IV treated groups. Different doses of AS-IV (5 mg/kg, 10 mg/kg, and 20 mg/kg, daily) were orally administrated to OIPN rats once a day for 4 weeks at beginning of oxaliplatin administration. Behaviors and histologic evaluation of sciatic nerve and dorsal root ganglia (DRG) were performed to assess the changes of peripheral neurotoxicity through mechanical allodynia and cold allodynia, immunofluorescence, H&E staining, myelin staining, and Nissl staining.

Results: AS-IV treatments were able to significantly reduce oxaliplatin induced mechanical and cold allodynia. Moreover, AS-IV administration could increase the levels of NGF, but decrease the levels of TNF-α and IL-6 in oxaliplatin induced rats. AS-IV suppressed the activation of Iba-1 in anterior horn of spinal cord of OIPN rats. The myelin sheath degenerations in the sciatic nerve of OIPN rats were repaired after AS-IV administration. Through observation of sciatic nerves and DRG, AS-IV treatments improved the oxaliplatin induced pathologic injuries in a dose-dependent.

Conclusion: AS-IV administration was able to attenuate the oxaliplatin-induced peripheral neurotoxicity in rats.

Memantine ameliorates oxaliplatin-induced neurotoxicity via mitochondrial protection

Oxaliplatin is an effective chemotherapeutic agent for the treatment of malignant tumors. However, severe oxaliplatin-induced neurotoxicity has been well documented. Memantine is a drug for the management of Alzheimer's Disease (AD) due to its promising neuroprotective properties. We hypothesize that Memantine possesses a beneficial role against chemotherapy-induced neuronal damages. In this study, we established an oxaliplatin-induced neurotoxicity assay model in human SHSY-5Y neuronal cells and investigated the protective effect of Memantine. We showed that Memantine treatment ameliorated oxaliplatin-elevated intracellular production of reactive oxygen species (ROS), lipid product malondialdehyde (MDA), and NOX-2 expression. Memantine alleviated impairment of the mitochondrial membrane potential and ATP production by oxaliplatin. As a result, Memantine showed a protective role against oxaliplatin-induced cytotoxicity. Moreover, the terminal deoxynucleotidyl Transferase-mediated dUTP nick end labeling (TUNEL) apoptosis assay revealed that Memantine protected oxaliplatin-induced apoptosis through mitigating the ratio of Bax/Bcl-2 and Caspase-3 cleavage. We concluded Memantine ameliorated the neurotoxicity of oxaliplatin in a mitochondrial-dependent pathway.

2-Aminoethoxydiphenyl borate ameliorates functional and structural abnormalities in cisplatin-induced peripheral neuropathy

AIM OF THE STUDY

Cisplatin is a platinum-derived chemotherapeutic agent commonly used in the treatment of various tumors. Ototoxicity, nephrotoxicity, and peripheral neuropathy are the most common side effects of this drug. 2-Aminoethoxydiphenyl borate (2-APB), boron- containing compound, has some protective effects against various tissue damage. The present study aimed to investigate the potential protective effects of 2-APB on in vitro and in vivo cisplatin-induced neurotoxicity.

MATERIALS AND METHODS

MTT assay was used to determine cell viability in DRG cells. Peripheral neuropathy was induced in forty male Sprague-Dawley rats (200-250g) by administering cisplatin (3 mg/kg/week) intraperitoneally (i.p) for five weeks. 2-APB (2, 4, and 8 mg/kg, i.p) was administered. Mechanical allodynia, thermal hyperalgesia, cold allodynia, mechanical stimuli, motor coordination, and locomotor activity tests were performed. DRG cells and sciatic nerves were analyzed histologically. NGF, BDNF, TNF-α, GSH, MDA, and LDH levels were investigated in rat DRG tissue homogenates.

RESULTS

Our results revealed that 2-APB ameliorated cisplatin-induced neurotoxicity by improving mechanical and cold allodynia and motor coordination impairment. It also reduced cisplatin-induced structural toxicity in peripheral tissues.

CONCLUSION

These findings demonstrated that 2-APB could be considered as a potential therapeutic strategy for the treatment of cisplatin-induced peripheral neuropathy.

Feasibility and effectiveness of opioid-free anesthesia in cytoreductive surgery with or without heated intraperitoneal chemotherapy

BACKGROUND

Opioid-free anesthesia (OFA) provides analgesia minimizing opioids. OFA has not been evaluated in cytoreductive surgery (CRS) with or without heated intraperitoneal chemotherapy. We aim to evaluate OFA feasibility and effectiveness in CRS.

METHODS

Retrospective cohort study of adult patients (84) undergoing CRS in a tertiary center from May 2020 until June 2021. Predefined protocols for either opioid-based anesthesia (OBA) or OFA were followed.

RESULTS

OFA protocol patients (41) had better mean pain scores (1 ± 0.8 vs. 2 ± 1; p = 0.00) despite the avoidance of intravenous and epidural fentanyl intraoperatively (220 ± 104 and 194 ± 73 µg, respectively, in OBA vs. 0; p = 0.00). Postoperative epidural levobupivacaine was also lower in the OFA group (575 ± 192 vs. 706 ± 346 mg; p = 0.034) despite the lack of epidural fentanyl without difference in duration (4.3 ± 1.2 vs. 4 ± 1.2 days; p = 0.22). Morphine consumption was very low (4.1 ± 10 vs. 1.7 ± 5 mg; p = 0.16). Intraoperative hypertensive events and postoperative nausea and vomiting (PONV) were higher for OBA (43) (30.2% vs. 7.3%; p = 0.01% and 69.8% vs. 34.1%; p = 0.001, respectively). Postoperative epidural fentanyl was independently associated with PONV (p = 0.004). There was no difference in total complications or length of stay.

CONCLUSION

OFA is feasible, safe, and offers optimal pain control while minimizing the use of opioids in CRS.

Effect of Cliothosa aurivilli on Paclitaxel-induced Peripheral Neuropathy in Experimental Animals

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious complication leading to painful episodes of parasthesia and numbness in hands and feet. The present drugs that have been used for symptomatic treatment yield inconclusive results in trials and assorted side effects. Thus, there is a pressing demand for development of therapeutically efficacious strategy to combat CIPN. The present study investigates about the effect of a marine sponge; Cliothosa aurivilli (CA) on paclitaxel (PT)-induced peripheral neuropathy in mice. Peripheral neuropathy was induced by intoxication with chemotherapeutic drug PT (2 mg/kg; i.p.) for 5 days consequently. Subsequent treatment with aqueous extract of CA (100 and 200 mg/kg) and standard drug methylcobalamin (MCA) (5 mg/kg) was done and results compared statistically. Neuropathic pain sensations were assessed using various behavioural and locomotory models and evaluated on 0^th, 7^th and 14^th days. Kinovea software was used for video path-tracking of animals and total distance travelled calculated. The results indicated clear signs of improvement post 10 days of PT intoxication in CA-treated groups when compared PT challenged group. A significant reduction in pain behaviours in mechanical allodynia, cold chemical allodynia and thermal hyperalgesia models, improvement in sensory motor coordination, locomotor activity, and distance travelled in closed field model reveals that CA possesses potential ameliorating effect against PT-induced neuropathic pain symptoms. The extract notably improved the movement of the PT challenged animals which was shown by the video path-tracking software and total distance travelled by those animals.

Systems Pharmacology Modeling Identifies a Novel Treatment Strategy for Bortezomib-Induced Neuropathic Pain

Chemotherapy-induced peripheral neurotoxicity is a common dose-limiting side effect of several cancer chemotherapeutic agents, and no effective therapies exist. Here we constructed a systems pharmacology model of intracellular signaling in peripheral neurons to identify novel drug targets for preventing peripheral neuropathy associated with proteasome inhibitors. Model predictions suggested the combinatorial inhibition of TNFα, NMDA receptors, and reactive oxygen species should prevent proteasome inhibitor-induced neuronal apoptosis. Dexanabinol, an inhibitor of all three targets, partially restored bortezomib-induced reduction of proximal action potential amplitude and distal nerve conduction velocity in vitro and prevented bortezomib-induced mechanical allodynia and thermal hyperalgesia in rats, including a partial recovery of intraepidermal nerve fiber density. Dexanabinol failed to restore bortezomib-induced decreases in electrophysiological endpoints in rats, and it did not compromise bortezomib anti-cancer effects in U266 multiple myeloma cells and a murine xenograft model. Owing to its favorable safety profile in humans and preclinical efficacy, dexanabinol might represent a treatment option for bortezomib-induced neuropathic pain.

The role of TRP ion channels in migraine and headache

Migraine afflicts more than 10% of the general population. Although its mechanism is poorly understood, recent preclinical and clinical evidence has identified calcitonin gene related peptide (CGRP) as a major mediator of migraine pain. CGRP, which is predominantly expressed in a subset of primary sensory neurons, including trigeminal afferents, when released from peripheral terminals of nociceptors, elicits arteriolar vasodilation and mechanical allodynia, a hallmark of migraine attack. Transient receptor potential (TRP) channels include several cationic channels with pleiotropic functions and ubiquitous distribution in various cells and tissues. Some members of the TRP channel family, such as the ankyrin 1 (TRPA1), vanilloid 1 and 4 (TRPV1 and TRPV4, respectively), and TRPM3, are abundantly expressed in primary sensory neurons and are recognized as sensors of chemical-, heat- and mechanical-induced pain, and play a primary role in several models of pain diseases, including inflammatory, neuropathic cancer pain, and migraine pain. In addition, TRP channel stimulation results in CGRP release, which can be activated or sensitized by various endogenous and exogenous stimuli, some of which have been proven to trigger or worsen migraine attacks. Moreover, some antimigraine medications seem to act through TRPA1 antagonism. Here we review the preclinical and clinical evidence that highlights the role of TRP channels, and mainly TRPA1, in migraine pathophysiology and may be proposed as new targets for its treatment.

The Cannabidiol Analog PECS-101 Prevents Chemotherapy-Induced Neuropathic Pain via PPARγ Receptors

Chemotherapy-induced peripheral neuropathy (CIPN) is the main dose-limiting adverse effect of chemotherapy drugs such as paclitaxel (PTX). PTX causes marked molecular and cellular damage, mainly in the peripheral nervous system, including sensory neurons in the dorsal root ganglia (DRG). Several studies have shown the therapeutic potential of cannabinoids, including cannabidiol (CBD), the major non-psychotomimetic compound found in the Cannabis plant, to treat peripheral neuropathies. Here, we investigated the efficacy of PECS-101 (former HUF-101), a CBD fluorinated analog, on PTX-induced neuropathic pain in mice. PECS-101, administered after the end of treatment with PTX, did not reverse mechanical allodynia. However, PECS-101 (1 mg/kg) administered along with PTX treatment caused a long-lasting relief of the mechanical and cold allodynia. These effects were blocked by a PPARγ, but not CB1 and CB2 receptor antagonists. Notably, the effects of PECS-101 on the relief of PTX-induced mechanical and cold allodynia were not found in macrophage-specific PPARγ-deficient mice. PECS-101 also decreased PTX-induced increase in Tnf, Il6, and Aif1 (Iba-1) gene expression in the DRGs and the loss of intra-epidermal nerve fibers. PECS-101 did not alter motor coordination, produce tolerance, or show abuse potential. In addition, PECS-101 did not interfere with the chemotherapeutic effects of PTX. Thus, PECS-101, a new fluorinated CBD analog, could represent a novel therapeutic alternative to prevent mechanical and cold allodynia induced by PTX potentially through the activation of PPARγ in macrophages.

Quality Control Mechanisms of Mitochondria: Another Important Target for Treatment of Peripheral Neuropathy

Mitochondria provide energy for various cellular activities and are involved in the regulating of several physiological and pathological processes. Mitochondria constitute a dynamic network regulated by numerous quality control mechanisms; for example, division is necessary for mitochondria to develop, and fusion dilutes toxins produced by the mitochondria. Mitophagy removes damaged mitochondria. The etiologies of peripheral neuropathy include congenital and acquired diseases, and the pathogenesis varies; however, oxidative stress caused by mitochondrial damage is the accepted pathogenesis of peripheral neuropathy. Regulation and control of mitochondrial quality might point the way toward potential treatments for peripheral neuropathy. This article will review mitochondrial quality control mechanisms, their involvement in peripheral nerve diseases, and their potential therapeutic role.

Oncology clinic nurses' attitudes and perceptions regarding implementation of routine fall assessment and fall risk screening: A survey study

Falls in older adults with cancer are often under-recognized and under-reported. The objective of this study was to explore oncology clinic nurses' willingness and perceived barriers to implement routine falls assessment and falls screening in their practice. Nurses working in outpatient oncology clinics were invited to complete an online survey. Data were analyzed using descriptive statistics and sorted into thematic categories. The majority of respondents indicated willingness to routinely ask older patients about falls (85.7%) and screen for fall risks (73.5%). The main reasons for unwillingness included: belief that patients report falls on their own, lack of time, and lack of support staff. Findings from this study show many oncology nurses believe in the importance of routine fall assessment and screening and are willing to implement them routinely, although falls are not routinely asked about or assessed. Future work should explore strategies to address barriers nurses face given the implications of falls amongst this vulnerable population.

Évaluation systématique des chutes et du risque de chutes : Sondage sur l’attitude et les perceptions des infirmières cliniques en oncologie

Chez les personnes âgées atteintes de cancer, les chutes sont un problème souvent sous-estimé et peu rapporté. La présente étude visait à explorer la volonté des infirmières cliniques en oncologie à évaluer et à dépister systématiquement les chutes dans leur pratique; l’étude examinait également les obstacles perçus à l’évaluation et au dépistage systématique. Les infirmières ont donc été invitées à remplir un sondage en ligne. Les données ont été analysées à l’aide de statistiques descriptives. La majorité des infirmières ayant répondu ont dit qu’elles accepteraient de poser systématiquement des questions sur les chutes (85,7 %) et de dépister les risques de chutes (73,5 %) chez les personnes âgées. Voici les principales raisons des réticences : conviction que les patients signalent les chutes d’euxmêmes, manque de temps, pénurie de personnel de soutien. Selon les résultats de l’étude, beaucoup d’infirmières en oncologie trouvent important d’évaluer et de dépister systématiquement les chutes, et sont d’accord pour l’intégrer à leur pratique bien que, d’habitude, les chutes ne fassent pas automatiquement l’objet de questions ou d’une évaluation. Étant donné les conséquences des chutes sur ces patients vulnérables, la recherche à venir devra explorer les stratégies permettant de surmonter les obstacles auxquels se butent les infirmières.

Involvement of the Sodium Channel Nav1.7 in Paclitaxel-induced Peripheral Neuropathy through ERK1/2 Signaling in Rats

BACKGROUND

Paclitaxel treatment is a major cause of chemotherapy-induced peripheral neuropathy. The sodium channel Nav1.7 plays a critical role in pain perception. However, whether Nav1.7 in the dorsal root ganglion (DRG) is involved in paclitaxel-induced peripheral neuropathy remains unclear. Thus, our study aimed to evaluate whether Nav1.7 participates in the pathogenesis of paclitaxel-induced neuropathy.

METHODS

Paclitaxel-induced peripheral neuropathy was generated by intraperitoneal administration of paclitaxel on four alternate days.

RESULTS

The results showed that DRG mRNA and protein expression levels of Nav1.7 were upregulated between days 7 and 21 after the administration of paclitaxel. Besides, paclitaxel upregulated extracellular signal-regulated kinase (ERK1/2) phosphorylation in DRG. Intrathecal injection of U0126 (a MEK inhibitor) blocking ERK1/2 phosphorylation blunted up-regulation of Nav1.7 in the DRG and correspondingly attenuated hyperalgesia.

CONCLUSION

These results indicated that the sodium channel Nav1.7 in the DRG exerted an important function in paclitaxel-induced neuropathy, which was associated with ERK phosphorylation in neurons.

Pathomechanisms of Paclitaxel-Induced Peripheral Neuropathy

Peripheral neuropathy is one of the most common side effects of chemotherapy, affecting up to 60% of all cancer patients receiving chemotherapy. Moreover, paclitaxel induces neuropathy in up to 97% of all gynecological and urological cancer patients. In cancer cells, paclitaxel induces cell death via microtubule stabilization interrupting cell mitosis. However, paclitaxel also affects cells of the central and peripheral nervous system. The main symptoms are pain and numbness in hands and feet due to paclitaxel accumulation in the dorsal root ganglia. This review describes in detail the pathomechanisms of paclitaxel in the peripheral nervous system. Symptoms occur due to a length-dependent axonal sensory neuropathy, where axons are symmetrically damaged and die back. Due to microtubule stabilization, axonal transport is disrupted, leading to ATP undersupply and oxidative stress. Moreover, mitochondria morphology is altered during paclitaxel treatment. A key player in pain sensation and axonal damage is the paclitaxel-induced inflammation in the spinal cord as well as the dorsal root ganglia. An increased expression of chemokines and cytokines such as IL-1β, IL-8, and TNF-α, but also CXCR4, RAGE, CXCL1, CXCL12, CX3CL1, and C3 promote glial activation and accumulation, and pain sensation. These findings are further elucidated in this review.

Redox-sensitive TRP channels: a promising pharmacological target in chemotherapy-induced peripheral neuropathy

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN) and its related pain is a major side effect of certain chemotherapeutic agents used in cancer treatment. Available analgesics are mostly symptomatic, and on prolonged treatment, patients become refractive to them. Hence, the development of improved therapeutics that act on novel therapeutic targets is necessary. Potential targets include the redox-sensitive TRP channels [e.g. TRPA1, TRPC5, TRPC6, TRPM2, TRPM8, TRPV1, TRPV2, and TRPV4] which are activated under oxidative stress associated with CIPN.

AREAS COVERED

We have examined numerous neuropathy-inducing cancer chemotherapeutics and their pathophysiological mechanisms. Oxidative stress and its downstream targets, the redox-sensitive TRP channels, together with their potential pharmacological modulators, are discussed. Finally, we reflect upon the barriers to getting new therapeutic approaches into the clinic. The literature search was conducted in PubMed upto and including April 2021.

EXPERT OPINION

Redox-sensitive TRP channels are a promising target in CIPN. Pharmacological modulators of these channels have reduced pain in preclinical models and in clinical studies. Clinical scrutiny suggests that TRPA1, TRPM8, and TRPV1 are the most promising targets because of their pain-relieving potential. In addition to the analgesic effect, TRPV1 agonist-Capsaicin possesses a disease-modifying effect in CIPN through its restorative property in damaged sensory nerves.

Punicalagin and ellagic acid containing Punica granatum L. fruit rind extract prevents vincristine-induced neuropathic pain in rats: an in silico and in vivo evidence of GABAergic action and cytokine inhibition

Objectives: We aimed to investigate the protective potential of Punica granatum L. fruit rind extract (PFE) containing punicalagin (10.3% W/W), ellagic acid (EA) (2.7%W/W) in vincristine (75 µg/kg i.p.)- induced neuropathic pain in Wistar rats.Methods: Docking simulation studies were done on the three-dimensional (3D) structure of the GABA_A and PPAR γ receptor for the binding of EA as well as punicalagin docking studies on TNF-α, and IL-6. The Present Study conceptualized a test battery to evaluate the behavioral, biochemical and histological changes.Results: Vincristine -induced significant cold allodynia, mechanical hyperalgesia, and functional deficit on 12th and 21st days. It also increased in the levels of TNF-α (Tumor necrosis factor-α), IL-6 (Interleukin-6), and MPO (Myeloperoxidase). Administration of PFE (100 and 300 mg/kg, p.o.), EA (50 mg/kg), and gabapentin (100 mg/kg) attenuated Vincristine-induced behavioral and biochemical changes significantly (P < .05). PFE showed better antinociceptive activity to EA. The histopathological evaluation also revealed the protective effects of PFE. Pretreatment of bicuculline (selective antagonist of GABAA receptors) reversed antinociceptive action of PFE, but administration of γ aminobutyric acid potentiated the action of PFE. PPAR-γ antagonist BADGE did not modify the effect of PFE. Docking results revealed that EA properly positioned into GABA and PPARγ binding site and acts as a partial agonist. Docking score of Punicalagin found to be - 9.02 kcal/mol and - 8.32 kcal/mol on IL-6 and TNFα respectively.Discussion: Conclusively, the attenuating effect of PFE may be attributed to the GABAergic system, cytokine inhibition, and anti-inflammatory activities.

Gastrodia elata Blume Polysaccharides Attenuate Vincristine-Evoked Neuropathic Pain through the Inhibition of Neuroinflammation

Vincristine (Vin) is a well-known antitumor agent that frequently evokes neuropathic pain and decreases the quality of life of patients. Polysaccharides (GBP) extracted from Gastrodia elata Blume have been demonstrated to possess anti-inflammatory and neuroprotective effects in vivo; however, the effects of GBP on Vin-induced neuropathic pain remain unknown. The present study is aimed at exploring the alleviative potential of GBP against chemotherapy-evoked peripheral neuropathy to better understand and extend its pharmacological application. Vin was administered intraperitoneally to evoke neuropathic pain. GBP was orally administered for 21 days. The mechanical allodynia and thermal hyperalgesia were assessed using the Von Frey test and hot-plate test. Histopathological changes were assessed by hematoxylin and eosin staining. ELISA kits were used to measure the levels of inflammatory cytokines in the sciatic nerve, spinal cord, and dorsal root ganglion (DRG). qRT-PCR was employed to examine the expression of inflammatory cytokines and Sirtuin1 (SIRT1) in the sciatic nerve, spinal cord, and DRG. Our findings revealed that GBP treatment enhanced the paw withdrawal latency and paw withdrawal threshold and restored Vin-induced sciatic nerve damage in rats. GBP also attenuated the Vin-induced increase of proinflammatory cytokine levels, including IL-6, IL-8, TNF-α, IL-1β, and NF-κB. On the molecular level, treatment with GBP downregulated the mRNA levels of IL-6, IL-8, TNF-α, and IL-1β in the sciatic nerve, spinal cord, and DRG. Meanwhile, GBP increased SIRT1 activity and mRNA expression levels. Our data indicated that GBP exerted a potential protective effect against chemotherapy-induced neuropathic pain which might be mediated via the inhibition of neuroinflammation.

Drug-Induced Peripheral Neuropathy: Diagnosis and Management

Peripheral neuropathy comes in all shapes and forms and is a disorder which is found in the peripheral nervous system. It can have an acute or chronic onset depending on the multitude of pathophysiologic mechanisms involving different parts of nerve fibers. A systematic approach is highly beneficial when it comes to cost-effective diagnosis. More than 30 causes of peripheral neuropathy exist ranging from systemic and auto-immune diseases, vitamin deficiencies, viral infections, diabetes, etc. One of the major causes of peripheral neuropathy is drug induced disease, which can be split into peripheral neuropathy caused by chemotherapy or by other medications. This review deals with the latest causes of drug induced peripheral neuropathy, the population involved, the findings on physical examination and various workups needed and how to manage each case.

Peripheral Nervous System Involvement in Non-Primary Pediatric Cancer: From Neurotoxicity to Possible Etiologies

Peripheral neuropathy is a well described complication in children with cancer. Oncologists are generally well aware of the toxicity of the main agents, but fear the side effects of new drugs. As chemotherapeutic agents have been correlated with the activation of the immune system such as in Chemotherapy Induced Peripheral Neuropathy (CIPN), an abnormal response can lead to Autoimmune Peripheral Neuropathy (APN). Although less frequent but more severe, Radiation Induced Peripheral Neuropathy may be related to irreversible peripheral nervous system (PNS). Pediatric cancer patients also have a higher risk of entering a Pediatric Intensive Care Unit for complications related to therapy and disease. Injury to peripheral nerves is cumulative, and frequently, the additional stress of a malignancy and its therapy can unmask a subclinical neuropathy. Emerging risk factors for CIPN include treatment factors such as dose, duration and concurrent medication along with patient factors, namely age and inherited susceptibilities. The recent identification of individual genetic variations has advanced the understanding of physiopathological mechanisms and may direct future treatment approaches. More research is needed on pharmacological agents for the prevention or treatment of the condition as well as rehabilitation interventions, in order to allow for the simultaneous delivery of optimal cancer therapy and the mitigation of toxicity associated with pain and functional impairment. The aim of this paper is to review literature data regarding PNS complications in non-primary pediatric cancer.

A focused review on CB2 receptor-selective pharmacological properties and therapeutic potential of β-caryophyllene, a dietary cannabinoid

The endocannabinoid system (ECS), a conserved physiological system emerged as a novel pharmacological target for its significant role and potential therapeutic benefits ranging from neurological diseases to cancer. Among both, CB1 and CB2R types, CB2R have received attention for its pharmacological effects as antioxidant, anti-inflammatory, immunomodulatory and antiapoptotic that can be achieved without causing psychotropic adverse effects through CB1R. The ligands activate CB2R are of endogenous, synthetic and plant origin. In recent years, β-caryophyllene (BCP), a natural bicyclic sesquiterpene in cannabis as well as non-cannabis plants, has received attention due to its selective agonist property on CB2R. BCP has been well studied in a variety of pathological conditions mediating CB2R selective agonist property. The focus of the present manuscript is to represent the CB2R selective agonist mediated pharmacological mechanisms and therapeutic potential of BCP. The present narrative review summarizes insights into the CB2R-selective pharmacological properties and therapeutic potential of BCP such as cardioprotective, hepatoprotective, neuroprotective, nephroprotective, gastroprotective, chemopreventive, antioxidant, anti-inflammatory, and immunomodulator. The available evidences suggest that BCP, can be an important candidate of plant origin endowed with CB2R selective properties that may provide a pharmacological rationale for its pharmacotherapeutic application and pharmaceutical development like a drug. Additionally, given the wide availability in edible plants and dietary use, with safety, and no toxicity, BCP can be promoted as a nutraceutical and functional food for general health and well-being. Further, studies are needed to explore pharmacological and pharmaceutical opportunities for therapeutic and preventive applications of use of BCP in human diseases.

Exercise training improves postural steadiness in cancer survivors undergoing chemotherapy

BACKGROUND

Cancer and cancer treatments negatively affect somatosensory, vestibular, and visual inputs that regulate postural stability and balance, increasing the risk of falling. Exercise training has been shown to mitigate other negative side effects of cancer treatments, such as reducing peripheral neuropathy.

RESEARCH QUESTION

How does 12 weeks of supervised exercise training influence postural stability in cancer survivors who receive chemotherapy?

METHODS

Postural stability of cancer survivors (n = 25; mass = 79.0 ± 22.6 kg; height = 1.66 ± 0.08 m; age = 61 ± 10 years) receiving chemotherapy was assessed prior to and following a 12-week individualized exercise training program by quantifying changes in center of pressure data. A series of 2-factor (pre/post x condition) analysis of variance with repeated measures were used to identify differences between conditions and pre- and post- training program on time and frequency domain measures.

RESULTS

Mediolateral root mean square excursion (p = 0.040; es = 0.20) and resultant mean frequency (p = 0.044; es = 0.29) of the center of pressure trajectory were found to be significantly different between pre- and post-training program. Further, participants dealt better with perturbations after completing the training program by reducing mediolateral root mean square excursion and 95 % confidence ellipse when visual stimulus was removed.

SIGNIFICANCE

Supervised exercise training in cancer patients undergoing chemotherapy improves postural stability in the mediolateral direction. Given that mediolateral movement of the center of pressure has previously been associated with fallers in other populations, exercise training during cancer treatments may be beneficial.

Effects of Chronic Oral Probiotic Treatment in Paclitaxel-Induced Neuropathic Pain

Chemotherapy-induced peripheral neuropathy (CIPN) represents one of the most prevalent and potentially disabling side effects due to the use of anticancer drugs, one of the primary neuropathies detected is peripheral neuropathy induced by administration of taxanes, including paclitaxel. It has been demonstrated that gut microbiota is crucial for the therapeutic effect of chemotherapeutic drugs for inhibiting tumor growth and contributed to the pathogenesis of the CIPN. The use of nutraceuticals has receiving growing attention from the research community due to their phytochemical, biological, and pharmacological properties. It has been demonstrated that probiotic formulations may both reduce inflammation and modulate the expression of pain receptors. Our studies tested the efficacy of a probiotic formulation, SLAB51, in preventing paclitaxel-induced neuropathy. Interestingly, our probiotic formulation was able to keep the gut integrity, preserving its functionality, in CIPN-mice, moreover, it prevented the mechanical and cold hypersensitivity induced in paclitaxel-mice. Additionally, ex-vivo analysis showed that in CIPN-mice the pro-biotic treatment increased the expression of opioid and cannabinoid receptors in spinal cord, it prevented in the reduction in nerve fiber damage in the paws and modulated the serum proinflammatory cytokines concentration. On basis of these data, the use of this specific probiotic formulation may represent a valid adjuvant agent to paclitaxel, useful and not toxic for long-lasting therapies.

Flavonoids Alleviate Peripheral Neuropathy Induced by Anticancer Drugs

Simple Summary

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating condition that severely reduces the quality of life of a considerable proportion of cancer patients. There is no cure for CIPN to date. Here, we explore the potential of flavonoids as pharmacological agents in combating CIPN. Flavonoids alleviate CIPN by reducing oxidative stress, inflammation, and neuronal damage, among other mechanisms. Future research should evaluate the efficacy and side effects of flavonoids in human models of CIPN.

Abstract

Purpose: This study aimed to assess the potential of flavonoids in combating CIPN. Methods: PubMed and Google Scholar were used, and studies that investigated flavonoids in models of CIPN and models of neuropathic pain similar to CIPN were included. Only studies investigating peripheral mechanisms of CIPN were used. Results: Flavonoids inhibit several essential mechanisms of CIPN, such as proinflammatory cytokine release, astrocyte and microglial activation, oxidative stress, neuronal damage and apoptosis, mitochondrial damage, ectopic discharge, and ion channel activation. They decreased the severity of certain CIPN symptoms, such as thermal hyperalgesia and mechanical, tactile, and cold allodynia. Conclusions: Flavonoids hold immense promise in treating CIPN; thus, future research should investigate their effects in humans. Specifically, precise pharmacological mechanisms and side effects need to be elucidated in human models before clinical benefits can be achieved.