Chemotherapy-induced cognitive impairment: focus on the intersection of oxidative stress and TNFα

Protective effects of omega-3 against procarbazine-induced brain damage in the cerebellum and CA1 Hippocampus of male rats: a focus on oxidative stress mechanisms

The study examined the combined effects of procarbazine (PCZ) and omega-3 on cognitive functions, motor skills, and brain histology in male rats over ten days. While PCZ has antitumor properties, omega-3 is a dietary supplement with potential health benefits. Here, forty-eight adult male Wistar rats, averaging 230 to 250 g, were used in this study. Novel Object Recognition (NOR), Open Field Tests (OFT), and rotarod assessments were employed to evaluate cognitive and motor functions. Also, cell degeneration in pyramidal cells of the CA1 region and Purkinje cells in the cerebellum, along with measuring serum oxidant and antioxidant levels to gauge treatment impact on brain functions. Results showed significant weight loss in PCZ-treated rats, alongside fewer rearing instances and reduced distance traveled in OFT compared to the sham group (P < 0.05). However, cognitive performance in the NOR test remained unchanged. The PCZ group demonstrated lower rotarod performance than the sham group (P < 0.05), but the PCZ + omega-3 group showed improved balance. Antioxidant enzyme levels decreased in the PCZ group relative to the sham group (P < 0.05), with no significant change in malondialdehyde levels; omega-3 did not influence these levels in PCZ-treated rats. PCZ caused damage to pyramidal cells in the hippocampus and cerebellum, but omega-3 mitigated some of the cerebellar damage, suggesting it may partially reduce PCZ-induced toxicity. These findings suggest omega-3 could alleviate some negative effects of PCZ on brain functions, especially in the cerebellum.

Chemotherapy-related cognitive impairment and kidney dysfunction

Cancer and kidney diseases (KD) intersect in many ways resulting in worse outcomes. Both conditions are correlated with cognitive impairment, which can be exacerbated in cancer patients by known effects of many antineoplastic drugs on cognition, leading to a phenomenon known as chemotherapy-related cognitive impairment (CRCI). This manifests as poor attention span, disturbed short-term memory, and general mental sluggishness. This literature review explores CRCI and investigates the potential impact of KD on this phenomenon. Additionally, we highlight the shared pathogenetic mechanisms (including neurotoxicity, neuroinflammation, oxidative stress, vascular disease, electrolyte, and acid-base imbalances), clinical presentation and imaging findings between cognitive impairment in KD and CRCI. The disruption of the blood-brain barrier might be a key mechanism for increased brain permeability to anticancer drugs in nephropathic patients with cancer. Based on existing knowledge, we found a potential for heightened neurotoxicity of antineoplastic drugs and a synergistic potentiation of cognitive impairment in cancer patients with KD. However, further translational research is urgently required to validate this hypothesis.

Neuromodulatory effect of troxerutin against doxorubicin and cyclophosphamide-induced cognitive impairment in rats: Potential crosstalk between gut-brain and NLRP3 inflammasome axes

"Chemobrain" refers to the cognitive impairment induced by chemotherapy. The doxorubicin and cyclophosphamide cocktail has been used for various cancers, especially breast cancer. However, both have been linked to chemobrain as well as gastrointestinal toxicity. Despite being distinct organs, the gut and the brain have a bidirectional connection between them known as the gut-brain axis. This research aimed to study the neuroprotective effect of troxerutin, a rutin derivative, in chemobrain induced by doxorubicin and cyclophosphamide via a potential impact on the gut-inflammasome-brain axis. Troxerutin was administered at 75, 150, and 300 mg/kg doses. Furthermore, behavioral, histological, and acetylcholinesterase assessments were performed. Accordingly, the highest dose of troxerutin was selected to investigate the potential underlying mechanisms. Troxerutin treatment reversed the chemotherapy-fecal metabolite alterations. Additionally, troxerutin demonstrated positive effects against deterioration of intestinal integrity, permeability, and microbial endotoxins translocation, as evidenced by its effect on tight junction proteins; ZO-1, and claudin-1 expression, and lipopolysaccharide serum levels. Consequently, troxerutin hindered lipopolysaccharide-induced oxidative damage, systemic inflammation, and neuroinflammation. Moreover, troxerutin demonstrated antioxidant effects via its impact on lipid peroxidation, catalase levels, and the Nrf2/HO-1 pathway. Furthermore, chemotherapy-induced inflammation was opposed by troxerutin via downregulation of NLRP3, caspase-1, and the downstream cytokines; IL-18 and IL-1β. Importantly, troxerutin did not abrogate the anticancer activity of doxorubicin and cyclophosphamide in human MCF7 cells. Collectively, our study suggested the potentiality of troxerutin as a therapeutic choice against chemobrain by inhibiting the gut-inflammasome-brain axis and hindering acetylcholinesterase, oxidative stress, and neuroinflammation.

Insights into the Pathogenesis and Treatment of Chemotherapy-Induced Neuropathy: A Focus on Oxidative Stress and Neuroinflammation

Cancer is a high-morbidity disease prevalent worldwide. Chemotherapy is the primarily used regimen for cancer treatment; however, it also brings severe side effects. Chemotherapy-induced Peripheral Neuropathy (CIPN) and Chemotherapy-induced Cognitive Impairment (CICI) are two main complications occurring in chemotherapy. They are both associated with nervous system injury and are therefore collectively referred to as Chemotherapy-induced Neuropathy (CIN). CIPN induces neuralgia and numbness in limbs, while CICI causes amnesia and cognitive dysfunction. Currently, there are no effective therapeutics to prevent or cure CIN, so research into new drugs to alleviate CIN becomes urgent. Oxidative stress and neuroinflammation are the common pathogenic mechanisms of CIPN and CICI. Excessive Reactive Oxygen Species (ROS) and pro-inflammatory cytokines cause peripheral nervous system damage and hence CIPN. Peripheral ROS and cytokines also change the permeability of the blood-brain barrier, thereby increasing oxidative stress and neuroinflammation in the central nervous system, ultimately leading to CICI. Several antidepressants have been used to treat CIN and exhibited good clinical effects. Their potential pharmacological mechanism has been reported to ameliorate oxidative stress and neuroinflammation, guiding a new feasible way for effective therapeutic development against CIN. This mini-review has summarized the latest advances in the research on CIN with respect to clinical status, pathogenesis, and treatment. It has also discussed the potential of repurposing antidepressants for CIN treatment and prospected the strategy of developing therapeutics by targeting oxidative stress and neuroinflammation against CIN.

Neurotoxicity of the antineoplastic drugs: "Doxorubicin" as an example

There is an increased prevalence of cancer, and chemotherapy is widely and routinely utilized to manage the majority of cancers; however, administration of chemotherapeutic drugs has faced limitations concerning the "off-target" cytotoxicity. Chemobrain and impairment of neurocognitive functions have been observed in a significant fraction of cancer patients or survivors and reduce their life quality; this could be ascribed to the ability of chemotherapeutic drugs to alter the structure and function of the brain. Doxorubicin (DOX), an FDA-approved chemotherapeutic drug with therapeutic effectiveness, is commonly used to treat several carcinomas clinically. DOX-triggered neurotoxicity is the most serious adverse reaction after DOX-induced cardiotoxicity which greatly limits its clinical application. DOX-induced neurotoxicity is a net of multiple mechanisms that have been verified in pre-clinical and clinical studies, such as oxidative stress, neuroinflammation, mitochondrial disruption, apoptosis, autophagy, disruption of neurotransmitters, and impairment of neurogenesis. There is a massive need for developing novel therapeutics for both cancer and DOX-associated neurotoxicity; therefore investigating the implicated mechanisms of DOX-induced chemobrain will reveal multi-targets for novel curative strategies. Recently, various neuroprotective mechanisms were employed to mitigate DOX-mediated neurotoxicity. For this purpose, therapeutic interventions using pharmacological compounds were developed to protect healthy "off-target" tissues from DOX-induced toxicity. In addition, nanoplatforms were used to enable target delivery of DOX; to prevent its deposition in non-cancerous tissues. The aim of the current review is to provide some reference value for the future management of DOX-induced neurotoxicity and to summarize the underlying mechanisms of DOX-mediated neurotoxicity and the potential therapeutic interventions.

Neuroprotective effect of empagliflozin against doxorubicin-induced chemobrain in rats: Interplay between SIRT-1/MuRF-1/PARP-1/NLRP3 signaling pathways and enhanced expression of miRNA-34a and LncRNA HOTAIR

Chemobrain, a challenging side effect of doxorubicin (DOX)-based chemotherapy, impairs cognitive abilities in cancer survivors. DOX triggers chemobrain via oxidative stress, leading to inflammation and apoptosis. Empagliflozin (EMPA), a sodium glucose co-transporter-2 inhibitor, demonstrated neuroprotective effects by reducing reactive oxygen species (ROS) and inflammation, but its protective mechanisms against DOX-induced chemobrain is not fully known. Thus, this study aimed to investigate EMPA's neuroprotective effects on DOX-induced chemobrain in rats and to uncover the underlying protective mechanisms. Fifty male Wistar rats were divided into control, EMPA, DOX (2 mg/kg, IP, once/week for 4 weeks), and two treated groups (DOX+ EMPA 5 and 10 mg/kg/day, PO, for 4 weeks). Behavioral tests showed improved memory, motor performance, and reduced anxiety in EMPA-treated groups compared to DOX, with superior results at the higher dose. Histopathological analysis revealed increased intact neurons in the cortex and hippocampus in EMPA-treated groups, with 346.4 % increase in CA3 (p < 0.0001), 19.1 % in dentate gyrus (p = 0.0006), and 362.6 % in cortex (p < 0.0001) in the high-dose EMPA group. Biochemical investigations of the high-dose EMPA group revealed significant decreases in inflammatory and apoptotic markers (JNK/PARP-1/NLRP3/MuRF-1/FOXO-1), increased SIRT-1 protein expression by 389.9 % (p < 0.0001), and reduced miRNA-34a and LncRNA HOTAIR gene expression (50.4 % and 53.4 % respectively, p < 0.0001) relative to DOX group. Conclusively, EMPA demonstrated superior behavioral and histopathological outcomes particularly at higher dose, positioning it as a promising neuroprotective candidate against DOX-induced chemobrain, possibly through modulating SIRT-1, NF-κb, NLRP3, and oxidative stress pathways.

The Mediating Role of Oxidative Stress on the Association Between Oxidative Balance Score and Cancer-Related Cognitive Impairment in Lung Cancer Patients: A Cross-Sectional Study

OBJECTIVES

To explore the association between the oxidative balance score (OBS) and cancer-related cognitive impairment (CRCI) in patients with lung cancer, as well as the oxidative stress biomarkers involved.

METHODS

In this cross-sectional study, 315 lung cancer patients were recruited, from whom 142 blood samples were collected to determine oxidative stress biomarkers. Dietary intake was assessed using 3-day, 24 h dietary recalls. The OBS was calculated by summing up pro- and antioxidant factors from a diet and lifestyles assessment. CRCI was evaluated using the Montreal Cognitive Assessment (MoCA) test.

RESULTS

A total of 103 patients (32.7%) developed CRCI, with significantly lower OBS and dietary OBS and lower superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities than non-CRCI patients (p < 0.05). For every 1-point increase in OBS, the risk of CRCI was reduced by 10.6% (OR = 0.894; 95% CI 0.819, 0.977; p = 0.013). Both vitamin E (OR = 0.922; 95% CI 0.868, 0.980; p = 0.009) and dietary fiber (OR = 0.909; 95% CI 0.832, 0.992; p = 0.032) were significantly inversely related to CRCI. The association between the total OBS and CRCI was mediated by SOD (ACME = -0.0061; 95% CI -0.0170, -0.0004; p = 0.015) and GPx (ACME = -0.0069; 95% CI -0.0203, -0.0002; p = 0.032), respectively.

CONCLUSIONS

Lung cancer patients with a greater balance of antioxidant to pro-oxidant diet, especially rich in dietary fiber and vitamin E, may decrease their CRCI in part by affecting SOD and GPx activities.

Chemotherapy-induced cognitive impairment and glia: A new take on chemobrain?

The significant rise in cancer survivorship stands out as one of the most notable achievements of modern science. However, this comes with a significant burden, as cancer treatment is not without adverse effects. Lately, there has been a growing focus on cognitive dysfunction associated with cancer treatment, often referred to as 'chemobrain'. It significantly impacts the quality of life for cancer survivors. The underlying mechanisms studied so far usually focus on neurons, while other cells of the central nervous system are often overlooked. This review seeks to place the hypothesis that glial cells may play a role in the development of chemotherapy-induced cognitive dysfunction. It summarizes the primary mechanisms proposed to date while underscoring the existing gaps in this research field. Inflammation and release of pro-inflammatory mediators by M1 microglia and A1 astrocytes are the most prevalent findings after chemotherapy. However, activation of A1 astrocytes by some chemotherapeutic agents may contribute to neuronal degeneration, alterations in synaptic branches, as well as glutamate excitotoxicity, which can contribute to cognitive impairment. Furthermore, the reduction in the number of oligodendrocytes after chemotherapy may also impact the myelin sheath, contributing to 'chemobrain'. Furthermore, some chemotherapeutic drugs activate M1 microglia, which is associated with decreased neuroplasticity and, possibly, cognitive impairment. In conclusion, data regarding the effects of chemotherapy on glial cells are scarce, and it is essential to understand how these cells are affected after cancer treatment to enable reliable therapeutic or preventive actions on cancer-treated patients.

Extraction of redox extracellular vesicles using exclusion-based sample preparation

Studying specific subpopulations of cancer-derived extracellular vesicles (EVs) could help reveal their role in cancer progression. In cancer, an increase in reactive oxygen species (ROS) happens which results in lipid peroxidation with a major product of 4-hydroxynonenal (HNE). Adduction by HNE causes alteration to the structure of proteins, leading to loss of function. Blebbing of EVs carrying these HNE-adducted proteins as a cargo or carrying HNE-adducted on EV membrane are methods for clearing these molecules by the cells. We have referred to these EVs as Redox EVs. Here, we utilize a surface tension-mediated extraction process, termed exclusion-based sample preparation (ESP), for the rapid and efficient isolation of intact Redox EVs, from a mixed population of EVs derived from human glioblastoma cell line LN18. After optimizing different parameters, two populations of EVs were analyzed, those isolated from the sample (Redox EVs) and those remaining in the original sample (Remaining EVs). Electron microscopic imaging was used to confirm the presence of HNE adducts on the outer leaflet of Redox EVs. Moreover, the population of HNE-adducted Redox EVs shows significantly different characteristics to those of Remaining EVs including smaller size EVs and a more negative zeta potential EVs. We further treated glioblastoma cells (LN18), radiation-resistant glioblastoma cells (RR-LN18), and normal human astrocytes (NHA) with both Remaining and Redox EV populations. Our results indicate that Redox EVs promote the growth of glioblastoma cells, likely through the production of H2O2, and cause injury to normal astrocytes. In contrast, Remaining EVs have minimal impact on the viability of both glioblastoma cells and NHA cells. Thus, isolating a subpopulation of EVs employing ESP-based immunoaffinity could pave the way for a deeper mechanistic understanding of how subtypes of EVs, such as those containing HNE-adducted proteins, induce biological changes in the cells that take up these EVs.

Blood-brain barrier disruption: a culprit of cognitive decline?

Cognitive decline covers a broad spectrum of disorders, not only resulting from brain diseases but also from systemic diseases, which seriously influence the quality of life and life expectancy of patients. As a highly selective anatomical and functional interface between the brain and systemic circulation, the blood-brain barrier (BBB) plays a pivotal role in maintaining brain homeostasis and normal function. The pathogenesis underlying cognitive decline may vary, nevertheless, accumulating evidences support the role of BBB disruption as the most prevalent contributing factor. This may mainly be attributed to inflammation, metabolic dysfunction, cell senescence, oxidative/nitrosative stress and excitotoxicity. However, direct evidence showing that BBB disruption causes cognitive decline is scarce, and interestingly, manipulation of the BBB opening alone may exert beneficial or detrimental neurological effects. A broad overview of the present literature shows a close relationship between BBB disruption and cognitive decline, the risk factors of BBB disruption, as well as the cellular and molecular mechanisms underlying BBB disruption. Additionally, we discussed the possible causes leading to cognitive decline by BBB disruption and potential therapeutic strategies to prevent BBB disruption or enhance BBB repair. This review aims to foster more investigations on early diagnosis, effective therapeutics, and rapid restoration against BBB disruption, which would yield better cognitive outcomes in patients with dysregulated BBB function, although their causative relationship has not yet been completely established.

Clinical study of chemotherapy-related cognitive impairment in patients with non-Hodgkin lymphoma

BACKGROUND

Chemotherapy for malignant tumors can cause brain changes and cognitive impairment, leading to chemotherapy-induced cognitive impairment (CICI). Current research on CICI has focused on breast cancer and Hodgkin's lymphoma. Whether patients with non-Hodgkin's lymphoma (NHL) undergoing chemotherapy have cognitive impairment has not been fully investigated.

AIM

To investigate whether NHL patients undergoing chemotherapy had cognitive impairments.

METHODS

The study included 100 NHL patients who were required to complete a comprehensive psychological scale including the Brief Psychiatric Examination Scale (MMSE) at two time points: before chemotherapy and within 2 wk of two chemotherapy courses. A language proficiency test (VFT), Symbol Number Pattern Test (SDMT), Clock Drawing Test (CDT), Abbreviated Daily Cognition Scale (ECog-12), Prospective and Retrospective Memory Questionnaire, and Karnofsky Performance Status were used to assess cognitive changes before and after chemotherapy.

RESULTS

The VFT scores for before treatment (BT) and after treatment (AT) groups were 45.20 ± 15.62, and 42.30 ± 17.53, respectively (t -2.16, P < 0.05). The CDT scores were 8 (3.5-9.25) for BT and 7 (2.5-9) for AT groups (Z -2.1, P < 0.05). Retrospective memory scores were 13.5 (9-17) for BT and 15 (13-18) for AT (Z -3.7, P < 0.01). The prospective memory scores were 12.63 ± 3.61 for BT and 14.43 ± 4.32 for AT groups (t -4.97, P < 0.01). The ECog-12 scores were 1.71 (1.25-2.08) for BT and 1.79 (1.42-2.08) for AT groups (Z -2.84, P < 0.01). The SDMT and MMSE values did not show a significant difference between BT and AT groups.

CONCLUSION

Compared to the AT group, the BT group showed impaired language, memory, and subjective cognition, but objective cognition and execution were not significantly affected.

Constituents, pharmacological activities, pharmacokinetic studies, clinical applications, and safety profile on the classical prescription Kaixinsan

Kaixinsan (KXS) is a noteworthy classical prescription, which consists of four Chinese medicinal herbs, namely Polygalae Radix, Ginseng Radix et Rhizoma, Poria, and Acori Tatarinowii Rhizoma. KXS was initially documented in the Chinese ancient book Beiji Qianjin Yaofang written by Sun Simiao of the Tang Dynasty in 652 A.D. As a traditional Chinese medicine (TCM) prescription, it functions to nourish the heart and replenish Qi, calm the heart tranquilize the mind, and excrete dampness. Originally used to treat amnesia, it is now also effective in memory decline and applied to depression. Although there remains an abundance of literature investigating KXS from multiple aspects, few reviews summarize the features and research, which impedes better exploration and exploitation of KXS. This article intends to comprehensively analyze and summarize up-to-date information concerning the chemical constituents, pharmacology, pharmacokinetics, clinical applications, and safety of KXS based on the scientific literature, as well as to examine possible scientific gaps in current research and tackle issues in the next step. The chemical constituents of KXS primarily consist of saponins, xanthones, oligosaccharide esters, triterpenoids, volatile oils, and flavonoids. Of these, saponins are the predominant active ingredients, and increasing evidence has indicated that they exert therapeutic properties against mental disease. Pharmacokinetic research has illustrated that the crucial exposed substances in rat plasma after KXS administration are ginsenoside Re (GRe), ginsenoside Rb1 (GRb1), and polygalaxanthone III (POL). This article provides additional descriptions of the safety. In this review, current issues are highlighted to guide further comprehensive research of KXS and other classical prescriptions.

More than a small adult brain: Lessons from chemotherapy-induced cognitive impairment for modelling paediatric brain disorders

Childhood is recognised as a period of immense physical and emotional development, and this, in part, is driven by underlying neurophysiological transformations. These neurodevelopmental processes are unique to the paediatric brain and are facilitated by augmented rates of neuroplasticity and expanded neural stem cell populations within neurogenic niches. However, given the immaturity of the developing central nervous system, innate protective mechanisms such as neuroimmune and antioxidant responses are functionally naïve which results in periods of heightened sensitivity to neurotoxic insult. This is highly relevant in the context of paediatric cancer, and in particular, the neurocognitive symptoms associated with treatment, such as surgery, radio- and chemotherapy. The vulnerability of the developing brain may increase susceptibility to damage and persistent symptomology, aligning with reports of more severe neurocognitive dysfunction in children compared to adults. It is therefore surprising, given this intensified neurocognitive burden, that most of the pre-clinical, mechanistic research focuses exclusively on adult populations and extrapolates findings to paediatric cohorts. Given this dearth of age-specific research, throughout this review we will draw comparisons with neurodevelopmental disorders which share comparable pathways to cancer treatment related side-effects. Furthermore, we will examine the unique nuances of the paediatric brain along with the somatic systems which influence neurological function. In doing so, we will highlight the importance of developing in vitro and in vivo paediatric disease models to produce age-specific discovery and clinically translatable research.

The chemotherapeutic agent doxorubicin induces brain senescence, with modulation by APOE genotype

Many cancer patients experience serious cognitive problems related to their treatment, which can greatly affect their quality of life. The molecular mechanisms of this cancer chemotherapy-induced cognitive impairment (CICI) are unknown, thus slowing the development of preventative approaches. We hypothesized that cancer chemotherapies could induce cellular senescence in the brain, creating a pro-inflammatory environment and damaging normal brain communication. We tested this hypothesis using the common chemotherapeutic agent doxorubicin in two independent mouse models. In the first model, we used mice that express tdTomato under the pdkn2a (p16) promoter; p16 is a regulator of cellular senescence, and its upregulation is denoted by the presence of fluorescently tagged cells. Two weeks after exposure to three doses of 5 mg/kg doxorubicin, the number of tdTomato positive cells were increased nearly three-fold in both the cerebral cortex and the hippocampus. tdTomato staining co-localized with neurons, microglia, oligodendrocyte precursor cells, and endothelial cells, but not astrocytes. In the second model, we used APOE knock-in mice, since the APOE4 allele is a risk factor for CICI in humans and mouse models. We isolated RNA from the cerebral cortex of APOE3 and APOE4 mice from one to 21 days after a single dose of 10 mg/kg doxorubicin. Using NanoString analysis of over 700 genes related to neuroinflammation and RT-qPCR analysis of cerebral cortex transcripts, we found two-fold induction of four senescence-related genes at three weeks in the APOE4 mice compared to the APOE3 control mice: p21(cdkn1a), p16, Gadd45a, and Egr1. We conclude that doxorubicin promotes cellular senescence pathways in the brain, supporting the hypothesis that drugs to eliminate senescent cells could be useful in preventing CICI.

Association between cognitive function and IL-18 levels in schizophrenia: Dependent on IL18 - 607 A/C polymorphism

Accumulating evidence suggests that immune system dysregulation is associated with debilitating neurodevelopment in schizophrenia (SZ). Cognitive impairment is a persistent feature that occurs during the onset of SZ and persists throughout the course of the disease. Early studies have found that elevated interleukin (IL)- 18 interacts with IL18 polymorphism and is correlated with psychotic symptoms in SZ. This study aimed to investigate whether elevated IL-18 levels interacted with the -607 A/C polymorphism to determine cognitive decline in patients with chronic SZ. We recruited 693 inpatients and 422 healthy controls to measure IL-18 levels and genotype the - 607 A/C polymorphism. Further, cognitive function was measured by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). We found that IL-18 serum levels were higher in patients than those in healthy controls, and were not associated with IL18 - 607 A/C in combined subjects or either patients or healthy controls, respectively. Moreover, - 607 A/C was correlated with the visuospatial/constructional index only in the patients. In addition, our research found that IL-18 levels were positively correlated to immediate memory only in patients with the C/C genotype, but not in patients with C/A or A/A genotype. This study suggests that the relationship of IL-18 with cognitive function depends on the IL18 - 607 A/C polymorphism of SZ patients.

Cyclosporin A-mediated translocation of HuR improves MTX-induced cognitive impairment in a mouse model via NCOA4-mediated ferritinophagy

Chemotherapy-induced cognitive impairment (CICI) is a subject that requires critical solutions in neuroscience and oncology. However, its potential mechanism of action remains ambiguous. The aim of this study was to investigate the vital role of HuR in the neuroprotection of cyclosporin A (CsA) during methotrexate (MTX)-induced cognitive impairment. A series of Hu-antigen R (HuR) gain and loss experiments were used to examine cyclosporin A (CsA)-mediated translocation of HuR's ability to improve MTX-induced cognitive impairment through NCOA4-mediated ferritinophagy in vitro and in vivo. Obtained results show that the administration of CsA alleviated MTX-induced cognitive impairment in mice. The presence of MTX promoted the shuttling of HuR from the cytoplasm to the nucleus, whereas treatment with CsA increased cytoplasmic HuR expression levels and the levels of ferritinophagy-related proteins, such as NCOA4 and LC3II, compared to the MTX group. However, applying KH-3, an inhibitor of HuR, reversed CsA's impact on the expression of ferritinophagy-related proteins in the hippocampus and in vitro. Also, treatment with CsA attenuated microglial activation by altering Iba-1 expression and decreased TNF-α and IL-1β levels in mice hippocampi. Moreover, KH-3 neutralized CsA's effects on the expression of both Iba-1 and HuR in vivo and in vitro. In summary, CsA was confirmed to have a neuroprotective role in CICI. Its possible underlying mechanisms may be involved in the translocation of HuR. Mediating the translocation of HuR during CICI could mitigate neruoinflammation and neuronal apoptosis via NCOA4-mediated ferritinophagy and, thus, alleviate cognitive impairment in mice with CICI.

L-carnitine Modulates Cognitive Impairment Induced by Doxorubicin and Cyclophosphamide in Rats; Insights to Oxidative Stress, Inflammation, Synaptic Plasticity, Liver/brain, and Kidney/brain Axes

Chemotherapy-induced cognitive impairment in cancer patients is known as "chemobrain". Doxorubicin and Cyclophosphamide are two chemotherapeutic agents used in combination to treat solid tumors. L-carnitine was reported for its anti-oxidant and anti-inflammatory activities. The goal of the present study was to elucidate the neuroprotective effect of L-carnitine against chemobrain induced by Doxorubicin and Cyclophosphamide in rats. Rats were divided into five groups: Control group; Doxorubicin (4mg/kg, IV) and Cyclophosphamide (40mg/kg, IV)-treated group; two L-carnitine-treated groups (150 and 300mg/kg, ip) with Doxorubicin and Cyclophosphamide; and L-carnitine alone-treated group (300mg/kg). Doxorubicin and Cyclophosphamide induced histopathological changes in rats' hippocampi and prefrontal cortices, as well as reduced memory as evidenced by behavioural testing. L-carnitine treatment showed opposite effects. In addition, chemotherapy treatment enhanced oxidative stress via reducing catalase and glutathione levels, and inducing lipid peroxidation. By contrast, L-carnitine treatment showed powerful antioxidant effects reversing chemotherapy-induced oxidative damage. Moreover, chemotherapy combination induced inflammation via their effect on nuclear factor kappa B (p65), interleukin-1β, and tumor necrosis factor-α. However, L-carnitine treatment corrected such inflammatory responses. Furthermore, Doxorubicin and Cyclophosphamide reduced synaptic plasticity via hindering expression of brain-derived neurotrophic factor, phosphorylated cyclase response element binding protein, synaptophysin, and postsynaptic density protein 95 whereas protein expression of such synaptic plasticity biomarkers was enhanced by L-carnitine treatment. Finally, acetylcholinesterase activity was found to be enhanced by chemotherapy treatment affecting rats' memory while L-carnitine treatment reduced acetylcholinesterase activity. L-carnitine also showed hepatoprotective and renal protective effects suggesting liver/brain and kidney/brain axes as possible mechanisms for its neuroprotective effects.

Chemobrain: An accelerated aging process linking adenosine A2A receptor signaling in cancer survivors

Chemotherapy has a significant positive impact in cancer treatment outcomes, reducing recurrence and mortality. However, many cancer surviving children and adults suffer from aberrant chemotherapy neurotoxic effects on learning, memory, attention, executive functioning, and processing speed. This chemotherapy-induced cognitive impairment (CICI) is referred to as "chemobrain" or "chemofog". While the underlying mechanisms mediating CICI are still unclear, there is strong evidence that chemotherapy accelerates the biological aging process, manifesting as effects which include telomere shortening, epigenetic dysregulation, oxidative stress, mitochondrial defects, impaired neurogenesis, and neuroinflammation, all of which are known to contribute to increased anxiety and neurocognitive decline. Despite the increased prevalence of CICI, there exists a lack of mechanistic understanding by which chemotherapy detrimentally affects cognition in cancer survivors. Moreover, there are no approved therapeutic interventions for this condition. To address this gap in knowledge, this review attempts to identify how adenosine signaling, particularly through the adenosine A2A receptor, can be an essential tool to attenuate accelerated aging phenotypes. Importantly, the adenosine A2A receptor uniquely stands at the crossroads of cancer treatment and improved cognition, given that it is widely known to control tumor induced immunosuppression in the tumor microenvironment, while also posited to be an essential regulator of cognition in neurodegenerative disease. Consequently, we propose that the adenosine A2A receptor may provide a multifaceted therapeutic strategy to enhance anticancer activity, while combating chemotherapy induced cognitive deficits, both which are essential to provide novel therapeutic interventions against accelerated aging in cancer survivors.

Drug-induced oxidative stress in cancer treatments: Angel or devil?

Oxidative stress (OS), defined as redox imbalance in favor of oxidant burden, is one of the most significant biological events in cancer progression. Cancer cells generally represent a higher oxidant level, which suggests a dual therapeutic strategy by regulating redox status (i.e., pro-oxidant therapy and/or antioxidant therapy). Indeed, pro-oxidant therapy exhibits a great anti-cancer capability, attributing to a higher oxidant accumulation within cancer cells, whereas antioxidant therapy to restore redox homeostasis has been claimed to fail in several clinical practices. Targeting the redox vulnerability of cancer cells by pro-oxidants capable of generating excessive reactive oxygen species (ROS) has surfaced as an important anti-cancer strategy. However, multiple adverse effects caused by the indiscriminate attacks of uncontrolled drug-induced OS on normal tissues and the drug-tolerant capacity of some certain cancer cells greatly limit their further applications. Herein, we review several representative oxidative anti-cancer drugs and summarize their side effects on normal tissues and organs, emphasizing that seeking a balance between pro-oxidant therapy and oxidative damage is of great value in exploiting next-generation OS-based anti-cancer chemotherapeutics.

Cold atmospheric plasma-induced oxidative stress and ensuing immunological response - a Neo-Vista in immunotherapy

Plasma, the fourth state of matter could be artificially generated at room temperature under atmospheric pressure - termed as cold atmospheric plasma (CAP). The reactive oxygen and nitrogen radicals emanated during plasma discharge accord manifold applications in medicine and have proven clinical applications in cancer treatment, dentistry, and dermatology. Developments in the field termed "Plasma medicine" has inclined research toward its prospects in immunotherapy. Controlled generation of reactive oxygen and nitrogen radicals during plasma formation produces oxidative stress on tissue of concern, selectively and activates a number of cytological and molecular reactions, triggering immunological response. Plasma treatment induces immunogenic cell death (ICD) in tumor cells and elicits enhanced adaptive and systemic immune response with memory cells, conferring better defense to cancer. HIV inactivation, reduced viral replication, reversal of latency in HIV-infected cells, and augmented infected cell opsonization has been observed with CAP treatment. Plasma-treated medium has shown to deactivate Herpes simplex virus (HSV-1) in human corneal explants and epithelial cells, and lessen the severity of herpes simplex keratitis. Perception of cellular changes that triggers innate and adaptive immune response during CAP treatment is quintessential for understanding and expansion of research in this arena. This review mentions the inimitable properties of plasma that makes it a safe and sensitive immunotherapeutic tool. The methods of plasma generation relied for the purpose are elucidated. The cellular mechanism of immunological stimulation in cancer, HIV, and keratitis during CAP treatment is detailed. The future prospects and challenges are briefly addressed.HighlightsReactive oxygen and nitrogen radicals produced by cold atmospheric plasma (CAP) triggers oxidative stress in exposed cells.Cells in oxidative stress incite immunological response that could be suitably manipulated for immunotherapy.The role of reactive radicals and methods of plasma generation for immunotherapy is elucidated.The cellular and molecular cascade of reactions leading to immunological cell death in cancer cells is detailed.The mechanism of HIV inactivation and reduced infection; further, deactivation of HSV in Herpes keratitis in intact human corneal explants is also described.