Doxorubicin-Induced Cognitive Impairment: The Mechanistic Insights

Real-time monitoring of a 3D blood-brain barrier model maturation and integrity with a sensorized microfluidic device

A significant challenge in the treatment of central nervous system (CNS) disorders is represented by the presence of the blood-brain barrier (BBB), a highly selective membrane that regulates molecular transport and restricts the passage of pathogens and therapeutic compounds. Traditional in vivo models are constrained by high costs, lengthy experimental timelines, ethical concerns, and interspecies variations. In vitro models, particularly microfluidic BBB-on-a-chip devices, have been developed to address these limitations. These advanced models aim to more accurately replicate human BBB conditions by incorporating human cells and physiological flow dynamics. In this framework, here we developed an innovative microfluidic system that integrates thin-film electrodes for non-invasive, real-time monitoring of BBB integrity using electrochemical impedance spectroscopy (EIS). EIS measurements showed frequency-dependent impedance changes, indicating BBB integrity and distinguishing well-formed from non-mature barriers. The data from EIS monitoring was confirmed by permeability assays performed with a fluorescence tracer. The model incorporates human endothelial cells in a vessel-like arrangement to mimic the vascular component and three-dimensional cell distribution of human astrocytes and microglia to simulate the parenchymal compartment. By modeling the BBB-on-a-chip with an equivalent circuit, a more accurate trans-endothelial electrical resistance (TEER) value was extracted. The device demonstrated successful BBB formation and maturation, confirmed through live/dead assays, immunofluorescence and permeability assays. Computational fluid dynamics (CFD) simulations confirmed that the device mimics in vivo shear stress conditions. Drug crossing assessment was performed with two chemotherapy drugs: doxorubicin, with a known poor BBB penetration, and temozolomide, conversely a specific drug for CNS disorders and able to cross the BBB, to validate the model predictive capability for drug crossing behavior. The proposed sensorized microfluidic device represents a significant advancement in BBB modeling, offering a versatile platform for CNS drug development, disease modeling, and personalized medicine.

Repurposing Aprepitant: Can it protect against doxorubicin-induced Chemobrain beyond its antiemetic role?

The substance P (SP) and neurokinin-1 receptor (NK-1R) axis is crucial in numerous pathological processes, including inflammation, stress responses, pain perception, and vomiting. Consequently, aprepitant, an NK-1R blocker, is used as an antiemetic in chemotherapy, including the use of doxorubicin (DOX), but whether aprepitant can also assuage DOX-mediated chemobrain remains to be unveiled. Here, we scrutinized the potential neuroprotective effect and underlying mechanisms of aprepitant using DOX-induced chemobrain model, where rats were allocated into 4 groups (control, aprepitant, DOX, and DOX+ aprepitant). Cognitive deficits were assessed through behavioral tests and hippocampal structural alterations were determined by H&E and toluidine blue staining. Biochemical measurements were performed using ELISA, real-time quantitative PCR, western blotting, and immunohistochemical methods. Aprepitant improved cognitive responses, and hippocampal morphology, enhancing the presence of intact neurons. At the molecular tier, aprepitant significantly reduced hippocampal contents of SP and the inflammatory markers NF-κB and IL-1β. Additionally, it signified its antioxidant and antiapoptotic capacities by downregulating cleaved caspase-3 protein expression and curbing the content of malondialdehyde but boosted those of glutathione and Bcl-2. Aprepitant also downregulated the expression of miR-146a and turned off the endoplasmic reticulum (ER) stress cascade PERK/eIF-2α/ATF-4/CHOP. To recapitulate, aprepitant demonstrates a neuroprotective effect against DOX-mediated chemobrain by alleviating inflammatory, oxidative, and apoptotic responses, partly by reducing SP, ER stress, and miR-146a. These findings not only underscore the potential of aprepitant as a neuroprotective agent but also offer new understanding of the mechanisms behind chemobrain, leading to better therapeutic strategies for cancer patients.

Silver Nanoparticles Loaded with Oleuropein Reduce Doxorubicin-Induced Testicular Damage by Regulating Endoplasmic Reticulum Stress, and Apoptosis

Doxorubicin (DOX) is the most used chemotherapeutic agent for treating solid tumors. DOX treatment may lead to testicular damage using oxidative stress, resulting in infertility. These adverse effects may be prevented by the activation of antioxidant systems. Oleuropein (OLE) is a powerful flavonoid with several ameliorative effects, including antioxidative, antiproliferative, and anti-inflammatory. It would be more efficient and applicable in treating chronic human diseases if its poor bioavailability improves with a nano-delivery system. The current study aims to assess the histopathological changes and antioxidative effects of OLE loaded with silver nanoparticles oleuropein (OLE-AgNP) on the testicular injury triggered by DOX in rats. Forty-eight male albino rats were randomly divided into six groups as follows: the control, DOX (2.5 mg/kg), OLE (50 mg/kg), AgNP (100 mg/kg), OLE + AgNP (50 mg/kg), OLE (50 mg/kg) + DOX (2.5 mg/kg), AgNP (100 mg/kg) + DOX (2.5 mg/kg), and OLE-AgNP (50 mg/kg) + DOX (2.5 mg/kg) for 11 days. Oxidative stress, inflammation, apoptosis, endoplasmic reticulum stress markers, sperm analysis, and histopathological analyses were performed on testicular tissues taken from rats decapitated after the applications and compared between the experimental groups. The tissue MDA level was lower in the OLE and OLE+AgNP-treated groups than in the DOX-treated group. In addition, SOD and GSH levels significantly increased in both the OLE and OLE+AgNP-treated groups compared to the DOX group. Both OLE and OLE+AgNP, particularly OLE+AgNP, ameliorated DOX-induced testicular tissue injury, as evidenced by reduced injury and improved seminiferous tubules and spermatocyte area. In addition, OLE and OLE+AgNP, especially OLE+AgNP, inhibited DOX-induced testicular tissue inflammation, apoptosis, and endoplasmic reticulum stress. The findings suggest that nanotechnology and the production of OLE+AgNP can ameliorate DOX-induced testicular damage.

Effects of Cannabidiol (CBD) on Doxorubicin-Induced Anxiety and Depression-like Behaviors and mRNA Expression of Inflammatory Markers in Rats

Background: Post-treatment side effects of chemotherapy can include cognitive deficits commonly known as Chemo-brain. The treatment of patients with Doxorubicin (DOX), one of the most widely used chemotherapeutic drugs in the treatment of cancer, can induce depression, anxiety, and impaired cognitive function. Cannabidiol (CBD) is a non-psychoactive component of Cannabis sativa that has been identified as a possible therapeutic agent against many neurodegenerative disorders, including traumatic brain injury, spinal cord injury, Tau-protein-induced neurodegeneration, and neuropathic pain. Therefore, this study aimed to assess whether oral CBD administration could reduce DOX-induced anxiety and depression-like behaviors and alter the expression of mRNA associated with neuroinflammation. Methods: Female Long Evans Hooded rats received intraperitoneal injections of DOX (6 mg/kg) or the vehicle (0.9% saline) once a week for four weeks, followed by oral administration of CBD (10 mg/kg) three times a week for the same period. Results: CBD was significantly protective against DOX-induced anxiety and depression-like behaviors, as measured by several behavioral tests. Furthermore, CBD improved DOX-induced alterations in the gene expression of biomarkers of neuroinflammation in the hippocampus and prefrontal cortex. Conclusions: This provides insights into future studies on possible mechanisms by which DOX-induced cognitive dysfunction could be alleviated by CBD.

Dietary EPA and DHA enrichment of a high fat diet during doxorubicin-based chemotherapy attenuated neuroinflammatory gene expression in the brain of C57bl/6 ovariectomized mice

Chemotherapy agents in breast cancer are associated with chemotherapy-related cognitive impairments (CRCI). Mechanisms are not fully clear, but alterations of glucose and lipid metabolism, neuroinflammation and neurodegeneration may contribute to CRCI. The aim of this study was to investigate the combined effects of a high fat (HF) diet combined with doxorubicin-based chemotherapy on glucose and lipid metabolism, neuroinflammation, and neurodegeneration in mice. Additionally, we examined the therapeutic potential of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to attenuate these effects. Female C57Bl/6 mice (n = 42) were fed HF, HFn-3 (2 % kcals as EPA + DHA) or Low Fat (LF) diets for seven weeks, with and without chemotherapy. In this study, two chemotherapy injections led to weight and body fat loss associated with a decrease in insulin resistance measured by HOMA-IR. HOMA-IR was significantly greater in HF versus LF groups; but HOMA-IR in HFn-3 group did not significantly differ from either HF or LF groups. Chemotherapy resulted in higher brain concentrations of the inflammatory chemokine KC/GRO. Compared to LF diet plus chemotherapy, HF diet plus chemotherapy upregulated multiple genes involved in neuroinflammation and neurodegeneration pathways. HFn-3 diet plus chemotherapy attenuated gene expression by downregulating multiple genes involved in neuroinflammation and blood brain barrier regulation, including Mapkapk2, Aqp4, and s100b, and upregulating Kcnb1 and Atxn3, genes involved in reduction of oxidative stress and anxiety, respectively. Overall, a HF diet combined with chemotherapy is associated with neuroinflammatory and neurodegenerative gene expression changes in this mouse model; dietary enrichment of EPA and DHA attenuated these effects. Further studies are needed to understand how diet impacts behavioral outcomes of CRCI.

Empagliflozin Dampens Doxorubicin-Induced Chemobrain in Rats: The Possible Involvement of Oxidative Stress and PI3K/Akt/mTOR/NF-κB/TNF-α Signaling Pathways

Chemobrain is a cognitive impairment observed in up to 75% of cancer patients treated with doxorubicin (DOX). Cognitive deficits associated with DOX are complex, and multiple interplay pathways contribute to memory impairment and the loss of concentration. Empagliflozin (EMPA), a sodium-glucose co-transporter-2 (SGLT-2) inhibitor with neuroprotective potential, has recently been elucidated because of its regulatory effects on oxidative stress and neuroinflammation. Thus, this study aimed to explore the protective mechanisms of EMPA in DOX-induced chemobrain. Rats were allocated to four groups: normal (NC), EMPA, DOX, and EMPA + DOX. Chemobrain was induced in the third and fourth groups by DOX (2 mg/kg, IP) on the 0th, 7th, 14th, and 21st days of the study, while EMPA was administered (10 mg/kg, PO) for 28 consecutive days in both the EMPA and EMPA + DOX groups. Behavioral and biochemical assessments were then performed. Rats treated with DOX exhibited significant memory, learning, and muscle coordination dysfunctions. Moreover, DOX boosted oxidative stress in the brain, as evidenced by elevated malondialdehyde (MDA) content together with decreased levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and reduced glutathione (GSH). Neuroinflammation was also observed as an upsurge of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) (p65). Additionally, DOX diminished the expression of brain-derived neurotrophic factor (BDNF) and increased phosphoinositol-3-kinase (PI3K), phosphorylated-Akt (pAkt), and mammalian target of rapamycin (mTOR) content. EMPA exhibited potent neuroprotective potential in DOX-induced cognitive impairment, attributed to its antioxidant and neuroplasticity-enhancing properties and suppression of the PI3K/Akt/mTOR/NF-κB/TNF-α signaling pathway.

CCR5 antagonist maraviroc alleviates doxorubicin-induced neuroinflammation and neurobehavioral deficiency by regulating NF-κB/NLRP3 signaling in a breast cancer mouse model

The chemotherapeutic agent Doxorubicin (DOX) is known to cause chemotherapy-induced cognitive impairment (CICI). Maraviroc, a potent C-C chemokine receptor 5 (CCR5) antagonist, shows neuroprotective properties, while its role in CICI remains unclear. This study determined the therapeutic potential of maraviroc on CICI. Adult C57BL/6J mice with implanted breast cancer cells received four weekly intraperitoneal injections of saline (Control group), 5 mg/kg DOX (DOX group), 10 mg/kg maraviroc (MVC group), or 5 mg/kg DOX with 10 mg/kg maraviroc (DOX + MVC group). The Morris Water Maze (MWM) was used for neurobehavioural test. Western blot analysis and immunofluorescence were used to evaluate the expressions of inflammatory markers, apoptosis-related proteins, and synaptic-related proteins. The volume and weight of tumor were also evaluated after treatments. DOX treatment significantly increased chemokines (CCL3, CCL4) and inflammatory cytokines (IL-1β, TNF-α) in tumor-bearing mice hippocampus. While maraviroc administration reduced hippocampal proinflammatory factors compared to the DOX group. Furthermore, it also lowered apoptosis markers, restored synaptic proteins levels, and inhibited the NF-κB/NLRP3 pathway. Accordingly, maraviroc treatment significantly improved DOX-induced neurobehavioural impairments as evidenced by an increased number of platform crossings and percentage of target quadrant time in the MWM test. Additionally, when combined with DOX, maraviroc had additional inhibitory effects on tumor growth. These findings suggest that maraviroc can mitigate DOX-induced CICI by suppressing elevated proinflammatory chemokines and cytokines through the NF-κB/NLRP3 pathway, potentially offering an anti-tumor benefit. This research presents a promising therapeutic approach for DOX-induced CICI, enhancing the safety and efficacy of cancer treatments.

Amantadine mitigates the cytotoxic and genotoxic effects of doxorubicin in SH-SY5Y cells and reduces its mutagenicity

Amantadine (AMA) is a useful drug in neuronal disorders, but few studies have been performed to access its toxicological profile. Conversely, doxorubicin (Dox) is a well-known antineoplastic drug that has shown neurotoxic effects leading to cognitive impairment. The aims of this study are to evaluate the cytotoxic, genotoxic, and mutagenic effects of AMA, as well as its possible protective actions against deleterious effects of Dox. The Salmonella/microsome assay was performed to assess mutagenicity while cytotoxicity and genotoxicity were evaluated in SH-SY5Y cells using MTT and comet assays. Possible modulating effects of AMA on the cytotoxicity, genotoxicity, and mutagenicity induced by Dox were evaluated through cotreatment procedures. Amantadine did not induce mutations in the Salmonella/microsome assay and decreased Dox-induced mutagenicity in the TA98 strain. AMA reduced cell viability and induced DNA damage in SH-SY5Y cells. In cotreatment with Dox, AMA attenuated the cytotoxicity of Dox and showed an antigenotoxic effect. In conclusion, AMA does not induce gene mutations, although it has shown a genotoxic effect. Furthermore, AMA decreases frameshift mutations induced by Dox as well as the cytotoxic and genotoxic effects of Dox in SH-SY5Y cells, suggesting that AMA can interfere with Dox mutagenic activity and attenuate its neurotoxic effects.

Hyaluronic Acid-Based Nanoparticles Loaded with Rutin as Vasculo-Protective Tools against Anthracycline-Induced Endothelial Damages

Anthracycline-based therapies exert endothelial damages through peroxidation and the production of proinflammatory cytokines, resulting in a high risk of cardiovascular complications in cancer patients. Hyaluronic acid-based hybrid nanoparticles (LicpHA) are effective pharmacological tools that can target endothelial cells and deliver drugs or nutraceuticals. This study aimed to prepared and characterized a novel LicpHA loaded with Rutin (LicpHA Rutin), a flavonoid with high antioxidant and anti-inflammatory properties, to protect endothelial cells against epirubicin-mediated endothelial damages. LicpHA Rutin was prepared using phosphatidylcholine, cholesterol, poloxamers, and hyaluronic acid by a modified nanoprecipitation technique. The chemical-physical characterization of the nanoparticles was carried out (size, zeta potential, morphology, stability, thermal analysis, and encapsulation efficiency). Cytotoxicity studies were performed in human endothelial cells exposed to epirubicin alone or in combination with Free-Rutin or LicpHA Rutin. Anti-inflammatory studies were performed through the intracellular quantification of NLRP-3, MyD-88, IL-1β, IL-6, IL17-α, TNF-α, IL-10, and IL-4 using selective ELISA methods. Morphological studies via TEM and image analysis highlighted a heterogeneous population of LicpHA particles with non-spherical shapes (circularity equal to 0.78 ± 0.14), and the particle size was slightly affected by Rutin entrapment (the mean diameter varied from 179 ± 4 nm to 209 ± 4 nm). Thermal analysis and zeta potential analyses confirmed the influence of Rutin on the chemical-physical properties of LicpHA Rutin, mainly indicated by the decrease in the surface negative charge (from -35 ± 1 mV to -30 ± 0.5 mV). Cellular studies demonstrated that LicpHA Rutin significantly reduced cell death and inflammation when compared to epirubicin alone. The levels of intracellular NLRP3, Myd-88, and proinflammatory cytokines were significantly lower in epirubicin + LicpHA Rutin-exposed cells when compared to epirubicin groups (p < 0.001). Hyaluronic acid-based nanoparticles loaded with Rutin exerts significant vasculo-protective properties during exposure to anthracyclines. The overall picture of this study pushes towards preclinical and clinical studies in models of anthracycline-induced vascular damages.

Potential of Natural Phenolic Compounds against Doxorubicin-Induced Chemobrain: Biological and Molecular Mechanisms Involved

Chemotherapy-induced cognitive impairment or "chemobrain" is a prevalent long-term complication of chemotherapy and one of the more devastating. Most of the studies performed so far to identify the cognitive dysfunctions induced by antineoplastic chemotherapies have been focused on treatment with anthracyclines, frequently administered to breast cancer patients, a population that, after treatment, shows a high possibility of long survival and, consequently, of chemobrain development. In the last few years, different possible strategies have been explored to prevent or reduce chemobrain induced by the anthracycline doxorubicin (DOX), known to promote oxidative stress and inflammation, which have been strongly implicated in the development of this brain dysfunction. Here, we have critically analyzed the results of the preclinical studies from the last few years that have evaluated the potential of phenolic compounds (PheCs), a large class of natural products able to exert powerful antioxidant and anti-inflammatory activities, in inhibiting DOX-induced chemobrain. Several PheCs belonging to different classes have been shown to be able to revert DOX-induced brain morphological damages and deficits associated with learning, memory, and exploratory behavior. We have analyzed the biological and molecular mechanisms implicated and suggested possible future perspectives in this research area.

Evaluating the Readability of Online Blood Cancer Education Materials Across Different Readability Measures

Introduction The National Institutes of Health and the American Medical Association recommend patient education materials (EMs) be at or below the sixth-grade reading level. The American Cancer Society, Leukemia & Lymphoma Society, and National Comprehensive Cancer Network have accurate blood cancer EMs. Methods One hundred one (101) blood cancer EMs from the above organizations were assessed using the following: Flesch Reading Ease Formula (FREF), Flesch-Kincaid Grade Level (FKGL), Gunning Fog Index (GFI), Simple Measure of Gobbledygook Index (SMOG), and the Coleman-Liau Index (CLI). Results Only 3.96% of patient EMs scored at or below the seventh-grade reading level in all modalities. Healthcare professional education materials (HPEMs) averaged around the college to graduate level. For leukemia and lymphoma patient EMs, there were significant differences for FKGL vs. SMOG, FKGL vs. GFI, FKGL vs. CLI, SMOG vs. CLI, and GFI vs. CLI. For HPEMs, there were significant differences for FKGL vs. GFI and GFI vs. CLI. Conclusion The majority of patient EMs were above the seventh-grade reading level. A lack of easily readable patient EMs could lead to a poor understanding of disease and, thus, adverse health outcomes. Overall, patient EMs should not replace physician counseling. Physicians must close the gaps in patients' understanding throughout their cancer treatment.

Effect of vitamin E on doxorubicin and paclitaxel-induced memory impairments in male rats

PURPOSE

In addition to peripheral neuronal dysfunction, conventional chemotherapy can be associated with other neurological treatment-limiting adverse effects, including cognitive dysfunction, memory impairment, and anxiety, which are referred to as "chemobrain". This study aimed to investigate the effects of doxorubicin (DOX) and paclitaxel (PAC) on learning and memory in rats using radial arm water maze (RAWM) and investigated a potential beneficial effect of vitamin E (Vit. E).

METHODS

Adult male rats were injected with four doses of 2 mg/kg/week DOX, or 2 mg/kg PAC every other day intraperitoneally. Vit. E was co-administered with these drugs in other groups to study its antioxidative effects. Using the RAWM, each rat was assessed for learning and memory performance through two sets of six trials separated by a 5-min rest period evaluating both short- and long-term effects on memory.

RESULTS

There was no deficit in learning or long-term memory in both drug groups compared to control. However, rats in both drug groups made significantly more errors in all short-term memory trials. This effect was mitigated when Vit. E was co-administered with either drug. Moreover, PAC (but not DOX) induced hippocampal lipid peroxidation by increasing the levels of standard biomarker thiobarbituric acid reactive substances (TBARS). Interestingly, Vit. E prevented PAC-induced hippocampal oxidative stress. Furthermore, both DOX and PAC were correlated with reduction in Brain-Derived Neurotrophic Factor (BDNF) expression levels in the hippocampus, which was overcome by the co-administration of Vit. E.

CONCLUSION

There is a potential role of Vit. E in alleviating short-term memory impairment in rats exposed to chemotherapy, possibly by reducing hippocampal oxidative stress and neurodegeneration.

Lercanidipine ameliorated doxorubicin-induced neuroinflammation and maintained the expressions of choline acetyltransferase via enhancing the levels of PI3K/AKT/HIF1-α expressions

BACKGROUND

Doxorubicin (DOX) may cause various neurological side effects in the brain. Lercanidipine (LRD) has antioxidant, anti-inflammatory, and anti-apoptotic properties. The aim of this study was to investigate the potential benefits of.

METHODS AND RESULTS

Lercanidipine in reducing doxorubicin-induced neuroinflammation and maintaining the expressions of choline acetyltransferase. Thirty-two adult Wistar albino female rats were divided into four groups as Control, DOX (20 mg/kg intraperitoneally), DOX + LRD 0.5 (0.5 mg/kg orally), and DOX + LRD2(2 mg/kg orally). Twenty-four hours after the last drug administration (9th day), brain tissues were taken for histopathological, immunohistochemical (choline acetyltransferase [CHAT], interleukin-10 [IL-10], and caspase-3 [Cas-3] staining), biochemical (total antioxidant status [TAS], total oxidant status [TOS], and oxidative stress index [OSI]), and genetic analyzes (PI3K/AKT/HIF1-α and IL-6 gene expressions). Histopathological analyses revealed hyperemia, slight hemorrhage, degeneration, neuronal loss, gliosis in the cerebellum, and neuronal loss in the brain cortex and hippocampus in the DOX group. According to other analyzes, decreased CHAT, PI3K, AKT, HIF1-α and increased IL-6, IL-10, Cas-3 expression were observed in the DOX group.

CONCLUSIONS

Both LRD doses reversed all these findings, but LRD2 was observed to be more effective. In conclusion, we determined that LRD has potential therapeutic effect by reducing DOX-induced neuroinflammation, oxidative stress and apoptosis in brain tissues.

Pioglitazone ameliorates DOX-induced cognitive impairment by mitigating inflammation, oxidative stress, and apoptosis of hippocampal neurons in rats

Doxorubicin (DOX) is broadly used as a medication for cancer treatment. However, DOX has been connected with chemotherapy-related complications, for instance, cognitive impairment (chemobrain). Chemobrain developed in up to 70% of cancer patients; therapeutic is unavailable. This study investigated the preventive effect of pioglitazone (PIO) on neurotoxicity caused by (DOX) in the hippocampus. Forty rats were separated into four groups; control (normal saline 10 ml/kg), DOX (5 mg/kg, intraperitoneally every 3rd day, equivalent to 20 mg/kg cumulative dose), PIO (2 mg/kg in drinking water), and DOX+PIO (DOX, 5 mg/kg, intraperitoneally every 3rd day concurrently PIO, 2 mg/kg in drinking water) and duration of drug treatment lasted for 14 days. The animals were subjected to contextual fear memory tests to characterize the cognitive impairment following DOX treatment. ELISA assessed hippocampal protein expression related to inflammation, oxidative damage, and apoptosis. DOX-treatment produced significant reduction in freezing duration in contextual fear memory tests, which was reversed by PIO co-administration. DOX increased neuroinflammation, oxidative stress, apoptosis, and mitochondrial activity by increasing NF-κB and COX-2 levels, reducing SOD levels, and increasing Bax, caspase-3, and lipid peroxidation. However, DOX did not affect GSH or catalase levels. PIO co-administration reduces NF-κB, COX-2, MDA, Bax, and caspase-3 levels and improves mitochondrial activity and SOD expression. To sum up, DOX therapy accelerates cognitive decline in rats by increasing neuroinflammation, oxidative stress, mitochondrial dysfunction, lipid peroxidation, and apoptosis. PIO is a promising treatment for DOX-induced cognitive impairment.

Senolytic treatment alleviates doxorubicin-induced chemobrain

Doxorubicin (Dox), a widely used treatment for cancer, can result in chemotherapy-induced cognitive impairments (chemobrain). Chemobrain is associated with inflammation and oxidative stress similar to aging. As such, Dox treatment has also been used as a model of aging. However, it is unclear if Dox induces brain changes similar to that observed during aging since Dox does not readily enter the brain. Rather, the mechanism for chemobrain likely involves the induction of peripheral cellular senescence and the release of senescence-associated secretory phenotype (SASP) factors and these SASP factors can enter the brain to disrupt cognition. We examined the effect of Dox on peripheral and brain markers of aging and cognition. In addition, we employed the senolytic, ABT-263, which also has limited access to the brain. The results indicate that plasma SASP factors enter the brain, activating microglia, increasing oxidative stress, and altering gene transcription. In turn, the synaptic function required for memory was reduced in response to altered redox signaling. ABT-263 prevented or limited most of the Dox-induced effects. The results emphasize a link between cognitive decline and the release of SASP factors from peripheral senescent cells and indicate some differences as well as similarities between advanced age and Dox treatment.

Natural products for the treatment of chemotherapy-related cognitive impairment and prospects of nose-to-brain drug delivery

Chemotherapy-related cognitive deficits (CRCI) as one of the common adverse drug reactions during chemotherapy that manifest as memory, attention, and executive function impairments. However, there are still no effective pharmacological therapies for the treatment of CRCI. Natural compounds have always inspired drug development and numerous natural products have shown potential therapeutic effects on CRCI. Nevertheless, improving the brain targeting of natural compounds in the treatment of CRCI is still a problem to be overcome at present and in the future. Accumulated evidence shows that nose-to-brain drug delivery may be an excellent carrier for natural compounds. Therefore, we reviewed natural products with potential anti-CRCI, focusing on the signaling pathway of these drugs' anti-CRCI effects, as well as the possibility and prospect of treating CRCI with natural compounds based on nose-to-brain drug delivery in the future. In conclusion, this review provides new insights to further explore natural products in the treatment of CRCI.

The Distant Molecular Effects on the Brain by Cancer Treatment

Cancer survivors experience cancer-related cognitive impairment (CRCI) secondary to treatment. Chemotherapy and radiation therapy independently contribute to cognitive dysfunction; however, the underlying mechanisms leading to dysfunction remain unclear. We characterized brain gene expression changes in a mouse model of CRCI to identify the mechanistic underpinnings. Eleven-to-twelve-week-old SKH1 mice were treated with doxorubicin (DOX), hindlimb radiation (RT), concurrent hindlimb radiation and doxorubicin (DOX-RT), or no treatment (control). Sixteen days following treatment, gene expression was measured from murine brains using the NanoString nCounter® glial profiling panel. Gene expression was normalized and compared between groups. No two groups shared the same expression pattern, and only Gnb1 and Srpr were upregulated in multiple treatment groups. Brains from DOX-treated mice had upregulated Atf2, Atp5b, Gnb1, Rad23b, and Srpr and downregulated Sirt5 expression compared to control brains. Brains from RT-treated mice demonstrated increased Abcg2 and Fgf2 and decreased C1qa and C1qb expression compared to control brains. Brains from DOX-RT-treated mice had upregulated Adar, E2f3, Erlec1, Gnb1, Srpr, Vim, and Pdgfra expression and downregulated Rock2 and Inpp5f expression compared to control brains. The gene expression changes demonstrated here highlight roles for neuronal transmission and oxidative stress in the pathogenesis of doxorubicin-related CRCI and inflammation in RT-related CRCI.

Modulatory effect of liraglutide on doxorubicin-induced testicular toxicity and behavioral abnormalities in rats: role of testicular-brain axis

Doxorubicin (DOX) is a powerful chemotherapeutic agent used in many types of malignancies. However, its use results in testicular damage. DOX-induced testicular damage results in low level of serum testosterone which may affect cognitive function. The current study investigated the protective effect of liraglutide (50, 100 μg/kg/day) in testicular toxicity and the consequent cognitive impairment induced by DOX. DOX treatment reduced sperm count (62%) and sperm motility (53%) and increased sperm abnormalities (786%), as compared to control group. DOX also reduced serum testosterone level (85%) and the gene expression of testicular 3β-HSD (68%) and 17β-HSD (82%). Moreover, it increased testicular oxidative stress (MDA and GSH) by 103% and 59%, respectively, apoptotic (caspase-3 and P53) by 996% and 480%, respectively. In addition, DOX resulted in increasing autophagic markers including PAKT, mTOR, and LC3 by 48%, 56%, and 640%, respectively. Additionally, rats' behavior in Y-maze (60%) and passive avoidance task (85%) was disrupted. The histopathological results of testis and brain supported the biochemical findings. Treatment with liraglutide (100 μg/kg/day) significantly abrogated DOX-induced testicular damage by restoring testicular architecture, increasing sperm count (136%) and sperm motility (106%), and decreasing sperm abnormalities (84%) as compared to DOX group. Furthermore, liraglutide increased serum testosterone (500%) and steroidogenesis enzymes 3β-HSD (105%) and 17β-HSD (181%) along with suppressing oxidative stress (MDA and GSH) by 23% and 85%, respectively; apoptotic (caspase-3 and P53) by 59% and55%, respectively; and autophagic markers including PAKT, mTOR, and LC3 by 48%, 97%, and 60%, respectively. Moreover, it enhanced the memory functions in passive avoidance and Y-maze tests (132%). In conclusion, liraglutide is a putative agent for protection against DOX-induced testicular toxicity and cognitive impairment through its antioxidant, antiapoptotic, and antiautophagic effects.

Engineered biomaterial delivery strategies are used to reduce cardiotoxicity in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. Chemotherapy drugs play an integral role in OS treatment. Preoperative neoadjuvant chemotherapy and postoperative conventional adjuvant chemotherapy improve survival in patients with OS. However, the toxic side effects of chemotherapy drugs are unavoidable. Cardiotoxicity is one of the common side effects of chemotherapy drugs that cannot be ignored. Chemotherapy drugs affect the destruction of mitochondrial autophagy and mitochondria-associated proteins to cause a decrease in cardiac ejection fraction and cardiomyocyte necrosis, which in turn causes heart failure and irreversible cardiomyopathy. Biomaterials play an important role in nanomedicine. Biomaterials act as carriers to deliver chemotherapy drugs precisely around tumor cells and continuously release carriers around the tumor. It not only promotes anti-tumor effects but also reduces the cardiotoxicity of chemotherapy drugs. In this paper, we first introduce the mechanism by which chemotherapy drugs commonly used in OS cause cardiotoxicity. Subsequently, we introduce biomaterials for reducing cardiotoxicity in OS chemotherapy. Finally, we prospect biomaterial delivery strategies to reduce cardiotoxicity in OS.

Suppression of sonic hedgehog pathway-based proliferation in glioblastoma cells by small-size silver nanoparticles in vitro

Glioblastomas (GBs) are one of the most aggressive and invasive intracranial cancers. Recently, it has been postulated that, among other factors, the hedgehog (HH) pathway may be a key factor in this phenomenon. Moreover, it has been reported that small-size silver nanoparticles (AgNPs) are characterized by a high cytotoxic effect towards GBs. However, their effect on the sonic hedgehog (SHH) pathway has never been demonstrated in any cancer cells. Therefore, the aim of the present study was to evaluate the impact of the anti-proliferative properties of 5-nm AgNPs on the SHH pathway in the GB cell line (U-87MG) in vitro. The results showed a time- and dose-dependent decrease in the metabolic activity in the U-87MG cells treated with AgNPs, with IC50 reaching 30.41 and 21.16 µg/mL after 24 h and 48 h, respectively, followed by an increase in the intracellular reactive oxygen species (ROS) level. The co-treatment of the cells with AgNPs and Robotnikinin (SHH inhibitor) abolished and/or strengthened the effect of AgNPs, especially on the SHH mRNA levels and on the PCNA, PTCH1, Gli1, and SUFU protein levels. Interestingly, no changes in the level of ERK1/2, Akt, and SRC kinase protein expression were detected, suggesting a direct impact of AgNPs and/or ROS on the inhibition of the canonical SHH pathway. However, more studies are needed due to the increase in the mTOR protein expression after the treatment of the cells with AgNPs, as in the Robotnikinin treatment. In conclusion, small-size AgNPs are able to inhibit the proliferation of GB cells in vitro by suppressing the canonical SHH pathway.

Chemotherapy-Mediated Neuronal Aberration

Chemotherapy is a life-sustaining therapeutic option for cancer patients. Despite the advancement of several modern therapies, such as immunotherapy, gene therapy, etc., chemotherapy remains the first-line therapy for most cancer patients. Along with its anti-cancerous effect, chemotherapy exhibits several detrimental consequences that restrict its efficacy and long-term utilization. Moreover, it effectively hampers the quality of life of cancer patients. Cancer patients receiving chemotherapeutic drugs suffer from neurological dysfunction, referred to as chemobrain, that includes cognitive and memory dysfunction and deficits in learning, reasoning, and concentration ability. Chemotherapy exhibits neurotoxicity by damaging the DNA in neurons by interfering with the DNA repair system and antioxidant machinery. In addition, chemotherapy also provokes inflammation by inducing the release of various pro-inflammatory cytokines, including NF-kB, IL-1β, IL-6, and TNF-α. The chemotherapy-mediated inflammation contributes to chemobrain in cancer patients. These inflammatory cytokines modulate several growth signaling pathways and reactive oxygen species homeostasis leading to systemic inflammation in the body. This review is an effort to summarize the available information which discusses the role of chemotherapy-induced inflammation in chemobrain and how it impacts different aspects of therapeutic outcome and the overall quality of life of the patient. Further, this article also discusses the potential of herbal-based remedies to overcome chemotherapy-mediated neuronal toxicity as well as to improve the quality of life of cancer patients.

Age-related decline in hippocampal tyrosine phosphatase PTPRO is a mechanistic factor in chemotherapy-related cognitive impairment

Chemotherapy-related cognitive impairment (CRCI) or "chemo brain" is a devastating neurotoxic sequela of cancer-related treatments, especially for the elderly individuals. Here we show that PTPRO, a tyrosine phosphatase, is highly enriched in the hippocampus, and its level is tightly associated with neurocognitive function but declined significantly during aging. To understand the protective role of PTPRO in CRCI, a mouse model was generated by treating Ptpro-/- female mice with doxorubicin (DOX) because Ptpro-/- female mice are more vulnerable to DOX, showing cognitive impairments and neurodegeneration. By analyzing PTPRO substrates that are neurocognition-associated tyrosine kinases, we found that SRC and EPHA4 are highly phosphorylated/activated in the hippocampi of Ptpro-/- female mice, with increased sensitivity to DOX-induced CRCI. On the other hand, restoration of PTPRO in the hippocampal CA3 region significantly ameliorate CRCI in Ptpro-/- female mice. In addition, we found that the plant alkaloid berberine (BBR) is capable of ameliorating CRCI in aged female mice by upregulating hippocampal PTPRO. Mechanistically, BBR upregulates PTPRO by downregulating miR-25-3p, which directly targeted PTPRO. These findings collectively demonstrate the protective role of hippocampal PTPRO against CRCI.

Doxorubicin Dose-Dependent Impact on Physiological Balance-A Holistic Approach in a Rat Model

Doxorubicin (DOX) is commonly used in several chemotherapies to treat various cancers, but it is known to cause cardiotoxicity and cardiac symptoms. Autonomic dysfunction is thought to contribute to the cardiotoxic effects of DOX, but the specific dose required to disrupt homeostatic processes is still unclear and is influenced by numerous factors. This study aimed to investigate how the DOX dosage affects autonomic function and physiological parameters, to elucidate the neurocardiac mechanisms underlying the observed cardiovascular side effects. Wistar rats were treated with DOX for four weeks and divided into three dosing groups: DOX8 (2 mg/kg/week), DOX16 (4 mg/kg/week), and DOX20 (5 mg/kg/week). A control group received NaCl 0.9% saline (1 mL/kg/week). In an acute experiment, we recorded blood pressure (BP), electrocardiogram, heart rate (HR), and respiratory rate (RF). Baroreflex gain and chemoreflex sensitivity were calculated, and cardiac tissue was analyzed with picrosirius histochemistry to measure collagen content. Our results showed that the LF/HF ratio, indicative of autonomic activity, was altered along with hypotension and bradycardia at a cumulative DOX dose threshold of 16 mg/kg. We observed a positive correlation between DOX dose and BP, HR, urinary norepinephrine, LF/HF ratio, and fibrotic heart area. Lower LF/HF ratios were associated with high DOX doses, reflecting drug-induced impairment of autonomic control of HR. This study provides valuable insights into the dose-dependent effects of DOX on physiological parameters and the development of cardiovascular dysfunction. These findings are critical, which is important for optimizing the management and therapeutic strategies for patients undergoing DOX-based chemotherapy.

Quetiapine Moderates Doxorubicin-Induced Cognitive Deficits: Influence of Oxidative Stress, Neuroinflammation, and Cellular Apoptosis

Chemotherapy is considered a major choice in cancer treatment. Unfortunately, several cognitive deficiencies and psychiatric complications have been reported in patients with cancer during treatment and for the rest of their lives. Doxorubicin (DOX) plays an important role in chemotherapy regimens but affects both the central and peripheral nervous systems. Antipsychotic drugs alleviate the behavioral symptoms of aging-related dementia, and the atypical class, quetiapine (QUET), has been shown to have beneficial effects on various cognitive impairments. The present investigation aimed to determine the possible mechanism underlying the effect of thirty-day administrations of QUET (10 or 20 mg/kg, p.o.) on DOX-induced cognitive deficits (DICDs). DICDs were achieved through four doses of DOX (2 mg/kg, i.p.) at an interval of seven days during drug treatment. Elevated plus maze (EPM), novel object recognition (NOR), and Y-maze tasks were performed to confirm the DICDs and find the impact of QUET on them. The ELISA tests were executed with oxidative [malondialdehyde (MDA), catalase, and reduced glutathione (GSH)], inflammatory [cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB), and tumor necrosis factor-alpha (TNF-α)], and apoptosis [B-cell lymphoma 2 (Bcl2), Bcl2 associated X protein (Bax), and Caspase-3] markers were assessed in the brain homogenate to explore the related mechanisms. DICD lengthened the transfer latency time in EPM, shortened the exploration time of the novel object, reduced the discrimination ability of the objects in NOR, and lowered the number of arm entries and time spent in the novel arm. QUET alleviated DICD-related symptoms. In addition, QUET reduced neuronal oxidative stress by reducing MDA and elevating GSH levels in the rat brain. Moreover, it reduced neuronal inflammation by controlling the levels of COX-2, NF-κB, and TNF-α. By improving the Bcl-2 level and reducing both Bax and Caspase-3 levels, it protected against neuronal apoptosis. Collectively, our results supported that QUET may protect against DICD, which could be explained by the inhibition of neuronal inflammation and the attenuation of cellular apoptosis protecting against oxidative stress.

Protective Effect of Galantamine against Doxorubicin-Induced Neurotoxicity

BACKGROUND AND AIMS

Doxorubicin (DOX) causes cognitive impairment (chemobrain) in patients with cancer. While DOX damages the cholinergic system, few studies have focused on the protective effects of cholinergic function on chemobrain. The acetylcholinesterase inhibitor galantamine (GAL) demonstrates neuroprotective properties. We investigated the mechanisms associated with DOX-induced cognitive impairments and the potential protective role of GAL in preventing chemobrain.

MAIN METHODS

Female Wistar rats were divided into control, DOX, GAL, and DOX + GAL groups. The rats in the DOX group were administered DOX (5 mg/kg intraperitoneally twice weekly for two weeks), while those in the GAL group were orally administered GAL (2.5 mg/kg) via oral gavage once daily for 15 days. The combination group (DOX + GAL) received GAL (once daily) and DOX (two times per week) concurrently. The body weights and survival rates were monitored daily. The animals were subjected to behavioral tests to assess the memory function followed by the biochemical estimation of inflammatory markers, including tumor necrosis factor-α (TNF-α), interleukine-1β (IL-1β), and interleukine-6 (IL-6) in rat brain tissue and RT-qPCR.

KEY FINDINGS

DOX caused a reduction in the body weight and survival rate, which was alleviated by GAL concomitant treatment with DOX (DOX + GAL). These groups had reduced body weights and survival rates. DOX-treated animals exhibited an impairment of short-term spatial working memory, manifested as a behavioral alteration in the Y-maze test, the novel object recognition (NOR) test, and the elevated plus-maze (EPM) test. Concurrent treatment with GAL (DOX + GAL) showed improved memory function, as evidenced by an increase in the number of entries and time spent in the novel arm, the time spent exploring the novel object, and the transfer latency in the Y-maze, NOR test, and EPM test, respectively. These findings were also supported by biochemical observations showing the reversal of DOX-induced changes in IL-1β, IL-6, and TNF-α, as well as their relative expression of mRNA in brain tissue following concurrent GAL treatment.

CONCLUSION

GAL appeared to be a neuroprotective agent against neuroinflammation caused by DOX by reducing inflammatory markers in the brain.

Protective effect of metformin on methotrexate induced reduction of rat hippocampal neural stem cells and neurogenesis

Adult neurogenesis is a process in which the adult neural stem cells produce newborn neurons that are implicated in terms of learning and memory. Methotrexate (MTX) is a chemotherapeutic drug, which has a negative effect on memory and hippocampal neurogenesis in animal models. Metformin is an antidiabetic drug with strong antioxidant capacities. We found that metformin ameliorates MTX induced deteriorations of memory and hippocampal neurogenesis in adult rats. In this study, we focus to investigate neural stem cells, biomarkers of apoptosis, and the protein for synaptogenesis, which involves in the transcription factors of the hippocampus in rats that received metformin and MTX. Male Sprague-Dawley rats were composed of control, MTX, metformin, and MTX+metformin groups. MTX (75 mg/kg, i.v.) was given on days 7 and 14, whereas metformin (200 mg/kg, i.p.) was given for 14 days. Hippocampal neural stem cells in the subgranular zone (SGZ) were quantified using immunofluorescence staining of Sox2 and nestin. Protein expression including PSD95, Casepase-3, Bax, Bcl-2, CREB, and pCREB were determined using Western blotting. MTX-treated rats displayed decreases in Sox2 and nestin-positive cells in the SGZ. Increases in Caspase-3 and Bax levels and decreases in PSD95, Bcl-2, CREB, and pCREB protein expressions in the hippocampus were also detected. However, these negative impacts of MTX were ameliorated by co-treatment with metformin. These consequences postulate that metformin has a potential to increase neural stem cells, synaptic plasticity, decreased apoptotic activities, and transcription factors, resulting in upregulation of hippocampal neurogenesis in MTX-treated rats.

Protocol for a systematic review of the effects of gardening physical activity on neuroplasticity and cognitive function

Background

The beneficial effects of gardening as a form of physical activity have garnered growing interest in recent years. Existing research suggests that physical activity enhances brain function through modifying synaptic plasticity, growth factor synthesis, and neurogenesis. Gardening physical activity is a promising, cost-effective, non-invasive intervention that can easily be augmented in the rehabilitation of neurodegenerative conditions. However, there is still insufficient literature. This protocol describes a systematic review to be conducted of scientific literature on the benefits of gardening as a physical activity that can promote neuroplasticity and improve cognitive function. This information can be useful as an intervention for persons who experience cognitive impairment brought on by cancer and chemotherapy in developing countries such as South Africa where there is real need to access cognitive rehabilitation.

Methods and analysis

The systematic review strategy will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. An electronic literature database search of MEDLINE (PubMed), Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science will be carried out using medical search terms (MeSH), with English as the only permitted language, during the time period of January 2010 to December 2022. We will search for and review studies on how gardening as a physical activity impacts neuroplasticity and cognition. Two reviewers will read the titles, and abstracts and full text of the studies identified during the search to exclude records that do not meet the inclusion criteria. Data will then be extracted from the remaining studies. Any differences in opinion arising between the reviewers during the procedure will be resolved through discussion with a third reviewer. The Joanna Briggs Institute (JBI) Critical Appraisal Tool checklist will be utilized independently by two reviewers to evaluate the possibility of bias. The included articles will be subjected to narrative synthesis, with the results being presented in a thematic manner.

Ethics and dissemination

There are no need for ethical approval because no patient data will be gathered. The results will be disseminated through an open-access peer-reviewed indexed journal, presented scientific meetings.PROSPERO registration number: CRD42023394493.

Identification of region-specific amino acid signatures for doxorubicin-induced chemo brain

Doxorubicin (DOX) is a cornerstone of chemotherapy for solid tumors and leukemias. DOX-induced cognitive impairment, termed chemo brain, has been reported in cancer survivors, whereas its mechanism remains poorly understood. Here we initially evaluated the cognitive impairments of mice treated with clinically relevant, long-term, low-dosage of DOX. Using HILIC-MS/MS-based targeted metabolomics, we presented the changes of 21 amino acids across six anatomical brain regions of mice with DOX-induced chemo brain. By mapping the altered amino acids to the human metabolic network, we constructed an amino acid-based network module for each brain region. We identified phenylalanine, tyrosine, methionine, and γ-aminobutyric acid as putative signatures of three regions (hippocampus, prefrontal cortex, and neocortex) highly associated with cognition. Relying on the reported mouse brain metabolome atlas, we found that DOX might perturb the amino acid homeostasis in multiple brain regions, similar to the changes in the aging brain. Correlation analysis suggested the possible indirect neurotoxicity of DOX that altered the brain levels of phenylalanine, tyrosine, and methionine by causing metabolic disorders in the liver and kidney. In summary, we revealed the region-specific amino acid signatures as actionable targets for DOX-induced chemo brain, which might provide safer treatment and improve the quality of life among cancer survivors.

3-Heptylidene-4,6-Dimethoxy-3H-Isobenzofuran-1-One Is Genotoxic, Increases the Frequency of Cell Death, and Potentiates the Effects of Cyclophosphamide and Cisplatin

3-heptylidene-4,6-dimethoxy-3H-isobenzofuran-1-one (Phthalide 1) is the precursor of three resorcinol lipids that have been described as potential chemotherapeutic agents and capable of potentiating the effects of cyclophosphamide. In this study, we evaluated the genotoxic potential, cell-killing potential, and interactions with cyclophosphamide and cisplatin of phthalide 1. Twelve groups were created from 120 mice: Negative Control, cyclophosphamide (100 mg/kg), cisplatin (6 mg/kg), Phthalide 1 (5, 10 and 20 mg/kg), and associations of 1 with cyclophosphamide and 1 with cisplatin. The results demonstrate that 1 increases (p < 0.05) the frequency of chromosomal damage, liver and kidney cell death, and splenic phagocytosis. The association of 1 with cyclophosphamide and cisplatin demonstrated a chemopreventive effect and, therefore, a reduction (p < 0.05) in the frequency of chromosomal damage. However, cell death and splenic phagocytosis did not suffer significant variations. As a result of the above, 1 has potential chemotherapeutic application and may be a candidate for developing a new generation of chemotherapeutics. In addition, it has characteristics to be used as a chemotherapy adjuvant in association with cyclophosphamide and cisplatin since it increases the frequency of cell death induced by chemotherapy. We also reported that the chemopreventive effect of 1, in association with cyclophosphamide and cisplatin, can prevent adverse effects (induction of DNA damage in non-tumor cells) without interfering with the mode of action of chemotherapy drugs and, therefore, without reducing the induction of cell death.

The Relationship between Cancer and Dementia: An Updated Review

The risk of cancer and dementia increases with age, raising complex questions about whether it is appropriate to continue cancer treatment in older patients. There is emerging research suggesting the association between cancer and dementia. However, the mechanistic underpinnings are still under investigation. Progress has already been made toward understanding the cognitive effects associated with cancer therapy. Such associations raise awareness about the need to establish better prevention methods and early screening in clinical practice. Additionally, recent studies have suggested possible therapeutic strategies for better preserving cognitive function and reducing the risk for dementia before patients start cancer treatment. We review the current literature and summarize the incidence and mechanisms of cognitive impairment in patients with lung cancer, breast cancer, head and neck cancer, gastric cancer, prostate cancer, colorectal cancer, and brain tumor/brain metastasis following different kinds of therapies. Possible risk factors are suggested to identify the early onset of cognitive changes in cancer patients and provide more insight into the pathophysiological process of dementia.

Monotropein attenuates doxorubicin-induced oxidative stress, inflammation, and arrhythmia via the AKT signal pathway

As a glycoside iridoid, monotropein (MON) has a wide range of pharmacological properties, including anti-inflammatory, antioxidant, and anti-apoptotic effects. However, few studies have investigated MON's cardiovascular protective effects. Therefore, this study aimed to explore the role of MON in doxorubicin (DOX)-induced cardiotoxicity. To establish the myocardial toxicity model, mice were intraperitoneally injected with DOX. After admimistration of DOX, myocardial injury markers were increased, cardiac function was reduced, and pathological changes were observed in the myocardium, indicating successful construction of the myocardial injury model. Our study showed that MON treatment mitigated DOX-induced myocardial damage and improved cardiac dysfunction. In addition, DOX-treated mice displayed higher levels of inflammation and oxidative stress, while MON treatment also reversed these pathological changes. Moreover, DOX-treated mice were more susceptible to ventricular fibrillation, whereas MON reduced ventricular fibrillation incidence. Further studies have shown that MON could reverse DOX-induced inhibition of the AKT signaling pathway. Besides, the application of AKT inhibitor could partially abolish MON's cardioprotective effects. To conclude, this study demonstrated the ability of MON to reduce DOX-induced myocardial damage, cardiac dysfunction, inflammation, and oxidative stress, as well as ventricular fibrillation risk. These may attributable to the activation of the AKT pathway.

Melatonin and metformin counteract cognitive dysfunction equally in male rats with doxorubicin-induced chemobrain

Melatonin (Mel) and metformin (Met) show beneficial effects in various brain pathologies. However, the effects of Mel and Met on doxorubicin (DOX)-induced chemobrain remain in need of elucidation. We aimed to investigate whether Mel and Met provide neuroprotective effects on glial dysmorphologies, brain inflammation, oxidative stress, brain mitochondrial dysfunction, apoptosis, necroptosis, neurogenesis, hippocampal dysplasticity, and cognitive dysfunction in rats with DOX-induced chemobrain. Thirty-two male Wistar rats were divided into 2 groups and received normal saline (NSS, as control, n = 8) or DOX (3 mg/kg/day; n = 24) by intraperitoneal (i.p.) injection on days 0, 4, 8, 15, 22, and 29. The DOX-treated group was divided into 3 subgroups receiving either vehicle (NSS; n = 8), Mel (10 mg/kg/day; n = 8), or Met (250 mg/kg/day; n = 8) by gavage for 30 consecutive days. Following this, cognitive function was assessed in all rats. The number of glial cells and their fluorescence intensity had decreased, while the glial morphology in DOX-treated rats showed a lower process complexity. Brain mitochondrial dysfunction, an increase in brain inflammation, oxidative stress, apoptosis and necroptosis, a decrease in the number of hippocampal dendritic spines and neurogenesis, and cognitive decline were also observed in DOX-treated rats. Mel and Met equally improved those brain pathologies, resulting in cognitive improvement in DOX-treated rats. In conclusion, concomitant treatment with either Mel or Met counteract DOX-induced chemobrain by preservation of glial morphology, brain inflammation, brain oxidative stress, brain mitochondrial function, hippocampal plasticity, and brain apoptosis. This study highlighted the role of the glia as key mediators in DOX-induced chemobrain.

Piracetam as a Therapeutic Agent for Doxorubicin-Induced Cognitive Deficits by Enhancing Cholinergic Functions and Reducing Neuronal Inflammation, Apoptosis, and Oxidative Stress in Rats

Cancer chemotherapy is known to cause cognitive defects in patients. Our study investigated the effect of piracetam (PIRA; 200 or 400 mg/kg) against doxorubicin (DOX)-induced cognitive deficits in a rat model. The cognitive parameters were analyzed using elevated plus-maze, novel object recognition, and Y-maze tests. Acetylcholinesterase (AChE), neuroinflammatory mediators (cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α)), apoptotic proteins (B-cell lymphoma-2 (Bcl-2), Bcl2 associated X protein (Bax), cysteine aspartate specific protease-3 (caspase-3)), oxidative parameters (malondialdehyde (MDA), catalase (CAT), and glutathione (GSH)) were also determined in the brain. PIRA administration offered significant protection against DOX-induced cognitive deficits in all maze tests and restored cholinergic functions via a significant reduction in AChE levels. Additionally, PIRA suppressed DOX-induced neuroinflammatory mediators (COX-2, PGE2, NF-κB, and TNF-α), pro-apoptotic proteins (Bax and caspase-3), and oxidative stress (MDA). Besides, it facilitated antioxidant (CAT and GSH) levels. Hence, our study highlighted that the neuroprotective activity of PIRA against DOX-induced cognitive deficits can be linked to reductions of AChE levels, neuro-inflammatory mediators, pro-apoptotic proteins, and oxidative stress.

Changes in Degree Centrality and Functional Connectivity after the First Cycle of Neoadjuvant Chemotherapy in Newly Diagnosed Breast Cancer: A Longitudinal Study

Purpose

To evaluate the longitudinal changes of brain degree centrality (DC) and functional connectivity (FC) in breast cancer patients after the first cycle of neoadjuvant chemotherapy (NAC).

Methods

Thirty-five breast cancer patients were included in the NAC group. Resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological test were performed at baseline before NAC (time point 0, TP0) and after the first cycle of NAC (time point 1, TP1). The healthy controls (HC) included 30 healthy subjects and received the same rs-fMRI scan and neuropsychological test as the above-mentioned NAC group at one time point. DC and FC analyses were conducted to assess brain connectivity of all participants. Receiver operating characteristic (ROC) curve was used to assess the ability of DC and FC in distinguishing patients before and after chemotherapy.

Results

In the NAC group, the Self-Rating Anxiety Scale scores decreased significantly over time. At TP0 and TP1, the Digital Span Test forward score of the NAC group was significantly lower than that of the HC group. In the NAC group, DC in the right middle frontal gyrus and left precentral gyrus/middle frontal gyrus decreased significantly at TP1, and FC between the left precentral gyrus/middle frontal gyrus and bilateral precuneus was significantly reduced at TP1. Through ROC analysis, we found that the area under the curve (AUC) of DC, FC, and the combined model in distinguishing patients in TP0 or TP1 was 0.7886, 0.7665, and 0.8278, respectively.

Conclusions

Brain connectivity, involving executive and motor function related brain areas, changes in the short term after NAC treatment in breast cancer patients.

Levetiracetam Ameliorates Doxorubicin-Induced Chemobrain by Enhancing Cholinergic Transmission and Reducing Neuroinflammation Using an Experimental Rat Model and Molecular Docking Study

Cancer chemotherapy-induced cognitive impairment (chemobrain) is a major complication that affects the prognosis of therapy. Our study evaluates the nootropic-like activity of levetiracetam (LEVE) against doxorubicin (DOX)-induced memory defects using in vivo and molecular modelling. Rats were treated with LEVE (100 and 200 mg/kg, 30 days) and chemobrain was induced by four doses of DOX (2 mg/kg, i.p.). Spatial memory parameters were evaluated using an elevated plus maze (EPM) and Y-maze. Additionally, acetylcholinesterase (AChE) and the neuroinflammatory biomarkers cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nuclear factor-κB (NF-κB), and tumor necrosis factor-alpha (TNF-α) were analyzed using brain homogenate. PharmMapper was used for inverse docking and AutoDock Vina was used for molecular docking. LEVE treatment significantly diminished the DOX-induced memory impairment parameters in both the EPM and Y-maze. In addition, the drug treatment significantly reduced AChE, COX-2, PGE2, NF-κB, and TNF-α levels compared to DOX-treated animals. The inverse docking procedures resulted in the identification of AChE as the potential target. Further molecular modelling studies displayed interactions with residues Gly118, Gly119, and Ser200, critical for the hydrolysis of ACh. Analysis of the results suggested that administration of LEVE improved memory-related parameters in DOX-induced animals. The ‘nootropic-like’ activity could be related to diminished AChE and neuroinflammatory mediator levels.

Activation of SIRT-1 Pathway by Nanoceria Sheds Light on Its Ameliorative Effect on Doxorubicin-Induced Cognitive Impairment (Chemobrain): Restraining Its Neuroinflammation, Synaptic Dysplasticity and Apoptosis

Chemo fog is one of the most serious health concerns encountered by cancer survivors receiving doxorubicin (DOX)-based chemotherapy. Oxidative stress, neuroinflammation, apoptosis and impairment of synaptic plasticity are regarded as the key factors implicated in DOX-induced cognitive impairment. This research aimed to assess the possible neuroprotective effect of cerium oxide nanoparticles (CeNPs) against DOX-induced neurotoxicity. Forty-eight rats were divided into four groups (12 rats/group): control group, CeNPs group (received oral CeNPs solution (35 mg/kg) daily for 4 weeks), and DOX group (were administered DOX intraperitoneally (2 mg/kg, once/week for 4 weeks)) and DOX+ CeNPs group. The findings revealed that CeNPs mitigated behavioral alterations in DOX-induced cognitive deficit. Additionally, CeNPs alleviated the histopathological abnormalities in hippocampus and ameliorated DOX-induced neuroinflammation by downregulating the expression of NF-κB, TNF-α, IL-1β and IL6. In addition, CeNPs antagonized the apoptosis through reducing the protein expression of cytochrome c and caspase 3. In addition, it stimulated the antioxidant defense, as indicated by upregulating the expression of the Nrf2, HO-1 and PGC-1α genes. CeNPs improved synaptic plasticity via acting on the BDNF. These actions were related through the modification of SIRT-1 expression. Based on the aforementioned results, CeNPs antagonized the doxorubicin-induced neurodegeneration by its antioxidant, anti-inflammatory and antiapoptotic effects, alongside its SIRT-1 mediated mechanisms.

Galangin Mitigates DOX-induced Cognitive Impairment in Rats: Implication of NOX-1/Nrf-2/HMGB1/TLR4 and TNF-α/MAPKs/RIPK/MLKL/BDNF

The cognitive and behavioral decline observed in cancer survivors who underwent doxorubicin (DOX)-based treatment raises the need for therapeutic interventions to counteract these complications. Galangin (GAL) is a flavonoid-based phytochemical with pronounced protective effects in various neurological disorders. However, its impact on DOX-provoked neurotoxicity has not been clarified. Hence, the current investigation aimed to explore the ability of GAL to ameliorate DOX-provoked chemo-brain in rats. DOX (2mg/kg, once/week, i.p.) and GAL (50mg/kg, 5 times/week., via gavage) were administered for four successive weeks. The MWM and EPM tests were used to evaluate memory disruption and anxiety-like behavior, respectively. Meanwhile, targeted biochemical markers and molecular signals were examined by the aid of ELISA, Western blotting, and immune-histochemistry. In contrast to DOX-impaired rats, GAL effectively preserved hippocampal neurons, improved cognitive/behavioral functions, and enhanced the expression of the cell repair/growth index and BDNF. The antioxidant feature of GAL was confirmed by the amelioration of MDA, NO and NOX-1, along with restoring the Nrf-2/HO-1/GSH cue. In addition, GAL displayed marked anti-inflammatory properties as verified by the suppression of the HMGB1/TLR4 nexus and p-NF-κB p65 to inhibit TNF-α, IL-6, IL-1β, and iNOS. This inhibitory impact extended to entail astrocyte activation, as evidenced by the diminution of GFAP. These beneficial effects were associated with a notable reduction in p-p38^MAPK, p-JNK1/2, and p-ERK1/2, as well as the necroptosis cascade p-RIPK1/p-RIPK3/p-MLKL. Together, these pleiotropic protective impacts advocate the concurrent use of GAL as an adjuvant agent for managing DOX-driven neurodegeneration and cognitive/behavioral deficits. DATA AVAILABILITY: The authors confirm that all relevant data are included in the supplementary materials.

Altered Regional Brain Glucose Metabolism in Diffuse Large B-Cell Lymphoma Patients Treated With Cyclophosphamide, Epirubicin, Vincristine, and Prednisone: An Fluorodeoxyglucose Positron Emission Tomography Study of 205 Cases

Background

A growing number of neuroimaging studies reported that chemotherapy might impair brain functions, leading to persistent cognitive alterations in a subset of cancer patients. The present study aimed to investigate the regional brain glucose metabolism differences between diffuse large B cell lymphoma (DLBCL) patients treated with cyclophosphamide, epirubicin, vincristine, and prednisone and controls using positron emission tomography with ¹⁸F-labeled fluoro-2-deoxyglucose integrated with computed tomography (¹⁸F-FDG PET/CT) scanning.

Methods

We analyzed ¹⁸F-FDG PET data from 205 right-handed subjects (for avoiding the influence of handedness factors on brain function), including 105 post-chemotherapy DLBCL patients and 100 controls. The two groups had similar average age, gender ratio, and years of education. First, we compared the regional brain glucose metabolism using a voxel-based two-sample t-test. Second, we compared the interregional correlation. Finally, we investigated the correlations between the regional brain glucose metabolism and the number of chemotherapy cycles.

Results

Compared with the controls, the post-chemotherapy group showed higher metabolism in the right hippocampus and parahippocampal gyrus (region of interest (ROI) 1) and the left hippocampus (ROI 2), and lower metabolism in the left medial orbitofrontal gyrus (ROI 3), the left medial superior frontal gyrus (ROI 4), and the left superior frontal gyrus (ROI 5). The two groups had different interregional correlations between ROI 3 and ROI 5. In some brain regions—mainly located in the bilateral frontal gyrus—the number of chemotherapy cycles was positively correlated with the regional brain glucose metabolism. Meanwhile, in some bilateral hippocampus regions, these two parameters were negatively correlated.

Conclusion

The present study provides solid data on the regional brain glucose metabolism differences between post-chemotherapy DLBCL patients and controls. These results should improve our understanding of human brain functions alterations in post-chemotherapy DLBCL patients and suggest that ¹⁸F-FDG PET/CT scanning is a valuable neuroimaging technology for studying chemotherapy-induced brain function changes.

Alterations in degree centrality and cognitive function in breast cancer patients after chemotherapy

The goal of this study was to determine the presence or absence of persistent functional impairments in specific brain regions in breast cancer patients during the recovery period after chemotherapy. We calculated degree centrality (DC) and explored the correlation between brain changes and cognitive scores in 29 female patients with breast cancer who had completed chemotherapy within 1-6 years (C + group) and in 28 age-matched patients with breast cancer who did not receive chemotherapy (C- group). All patients underwent rs-fMRI and cognitive testing. Differences in brain functional activity were explored using DC parameters. Correlations between brain features and cognitive scores were analyzed via correlation analysis. Compared with the C- group, the C + group obtained significantly lower motor and cognitive subscores on the Fatigue Scale for Motor and Cognitive Functions and four subscale scores of the Functional Assessment of Cancer Therapy-Cognitive Function (P < 0.05). Furthermore, the C + group exhibited a significantly higher DC z-score (zDC) in the right superior temporal gyrus and left postcentral gyrus (P < 0.01, FWE-corrected), and a lower zDC in the left caudate nucleus (P < 0.01, FWE-corrected). We found a positive correlation between digit symbol test (DST) scores and zDC values in the right superior temporal gyrus (r = 0.709, P < 0.001), and a negative correlation between DST scores and zDC values in the right angular gyrus (r = -0.784, P < 0.001) and left superior parietal gyrus (r = -0.739, P < 0.001). Chemotherapy can cause abnormal brain activity and cognitive decline in patients with breast cancer, and these effects are likely to persist. DC can be used as an imaging marker for chemotherapy-related cognitive impairment after chemotherapy in breast cancer patients.

Chemobrain in Breast Cancer: Mechanisms, Clinical Manifestations, and Potential Interventions

Among the potential adverse effects of breast cancer treatment, chemotherapy-related cognitive impairment (CRCI) has gained increased attention in the past years. In this review, we provide an overview of the literature regarding CRCI in breast cancer, focusing on three main aspects. The first aspect relates to the molecular mechanisms linking individual drugs commonly used to treat breast cancer and CRCI, which include oxidative stress and inflammation, reduced neurogenesis, reduced levels of specific neurotransmitters, alterations in neuronal dendrites and spines, and impairment in myelin production. The second aspect is related to the clinical characteristics of CRCI in patients with breast cancer treated with different drug combinations. Data suggest the incidence rates of CRCI in breast cancer vary considerably, and may affect more than 50% of treated patients. Both chemotherapy regimens with or without anthracyclines have been associated with CRCI manifestations. While cross-sectional studies suggest the presence of symptoms up to 20 years after treatment, longitudinal studies confirm cognitive impairments lasting for at most 4 years after the end of chemotherapy. The third and final aspect is related to possible therapeutic interventions. Although there is still no standard of care to treat CRCI, several pharmacological and non-pharmacological approaches have shown interesting results. In summary, even if cognitive impairments derived from chemotherapy resolve with time, awareness of CRCI is crucial to provide patients with a better understanding of the syndrome and to offer them the best care directed at improving quality of life.

Infliximab and/or MESNA alleviate doxorubicin-induced Alzheimer's disease-like pathology in rats: A new insight into TNF-α/Wnt/β-catenin signaling pathway

AIMS

The current study aimed to elucidate the neurotoxic potential of DOX to induce AD-like pathology paying attention to the role of wingless-integrated/β-catenin (Wnt/β-catenin) signaling pathway. A major aim was to evaluate the efficacy of infliximab (IFX) either individually or in combination with 2-mercaptoethane sulfonate sodium (MESNA) on the DOX-induced neurotoxicity in rats.

METHODOLOGY

AD-like pathology was induced in adult male Wistar rats by intraperitoneal (i.p.) administration of DOX at a dose of 3.5 mg/kg twice a week for 3 weeks. DOX-injected rats were then treated with either INF at a single dose of 5 mg/kg i.p. (IFX group), MESNA at a dose of 160 mg/kg/day i.p. for 4 weeks (MESNA group) or their combination at the same specified doses (INF + MESNA group). At the end of the study period, behavioral assessment was performed and the brain tissue samples were harvested at sacrifice.

KEY FINDINGS

DOX-treated rats significantly exhibited AD-like brain injury, increased amyloid burden, enhanced neuroinflammation and apoptosis, and multifocal histological injury in the cerebral cortex with widespread vacuolations. IFX and MESNA significantly reversed all the aforementioned detrimental effects in the DOX-treated rats.

SIGNIFICANCE

The study has provided sufficient evidence of the potential of IFX and/or MESNA to ameliorate the DOX-induced neurotoxicity, with the best improvement observed with their combined administration. A new insight has been introduced into the critical role of Wnt/β-catenin activation.

Doxorubicin induced aggregation of α-synuclein: Insights into the mechanism of drug induced Parkinsonism

The aggregation of α-synuclein is a prominent feature of Parkinson's disease. It is induced by factors such as genetic mutations and presence of metal salts leading to Parkinson's like symptoms. Existing case studies show that patients undergoing cancer chemotherapeutics are also prone to developing Parkinson's like symptoms. However, the underlying cause behind onset of these symptoms is not understood. It is not clear whether the administration of chemotherapeutic drugs alter the structural stability of α-synuclein. In the present study, we address this question by looking into the effect of chemotherapeutic drug namely doxorubicin on the α-synuclein stability. Using complementary spectroscopic, molecular docking and imaging techniques, we observe that doxorubicin interacted with central aggregation prone region of α-synuclein and induces destabilization leading to aggregation. We also show that the combination of doxorubicin and L-DOPA drugs impedes the α-synuclein aggregation. This may explain the reason behind the effectiveness of using L-DOPA against Parkinson's like symptoms.

Protective effect of Juglanin against doxorubicin-induced cognitive impairment in rats: Effect on oxidative, inflammatory and apoptotic machineries

Doxorubicin (DOX) is an effective anticancer drug, however, side effects such as cognitive impairment and cardiotoxicity have limited its clinical use. Juglanin (JUG) is a flavonoid with excellent antioxidant, anti-inflammatory, neuroprotective and anticancer properties. This study investigated the protective effects of JUG against DOX-induced cognitive decline, oxidative stress and inflammatory response in rats. The rats were orally administrated with JUG or JUG in combination with DOX. After treatment, the animals were subjected to series of behavioral test including Morris water maze, Y-maze and forced swimming tests. After the study, the rats were sacrificed and the level of acetylcholinesterase (AchE), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), malondialdehyde (MDA), interleukin 6 (IL-6), interleukin 1β (IL-1β), tumor necrosis factor alpha (TNF-α), caspase 3 and Nuclear factor kappa B (NF-кB) were assayed in the brain. Histopathological analysis was also performed on the brain of the rats. JUG significantly protected against DOX-induced cognitive impairment and depressive behaviors. In addition, JUG attenuated altered brain histopathological architecture, reduced oxido-inflammatory responses, acetylcholinesterase and caspase 3 activity in the brain of the treated rats. Collectively, the results suggested that JUG offered neuroprotection against DOX induced Chemobrain via ameliorating oxidative stress and inflammation.

Cardiorenal Protective Effect of Costunolide against Doxorubicin-Induced Toxicity in Rats by Modulating Oxidative Stress, Inflammation and Apoptosis

Doxorubicin (DXB) is one of the most commonly used anticancer agents for treating solid and hematological malignancies; however, DXB-induced cardiorenal toxicity presents a limiting factor to its clinical usefulness in cancer patients. Costunolide (COST) is a naturally occurring sesquiterpene lactone with excellent anti-inflammatory, antioxidant and antiapoptotic properties. This study evaluated the effect of COST on DXB-induced cardiorenal toxicity in rats. Rats were orally treated with COST for 4 weeks and received weekly 5 mg/kg doses of DXB for three weeks. Cardiorenal biochemical biomarkers, lipid profile, oxidative stress, inflammatory cytokines, histological and immunohistochemical analyses were evaluated. DXB-treated rats displayed significantly increased levels of lipid profiles, markers of cardiorenal dysfunction (aspartate aminotransferase, creatine kinase, lactate dehydrogenase, troponin T, blood urea nitrogen, uric acid and creatinine). In addition, DXB markedly upregulated cardiorenal malondialdehyde, tumor necrosis factor-α, interleukin-1β, interleukin-6 levels and decreased glutathione, superoxide dismutase and catalase activities. COST treatment significantly attenuated the aforementioned alterations induced by DXB. Furthermore, histopathological and immunohistochemical analyses revealed that COST ameliorated the histopathological features and reduced p53 and myeloperoxidase expression in the treated rats. These results suggest that COST exhibits cardiorenal protective effects against DXB-induced injury presumably via suppression of oxidative stress, inflammation and apoptosis.

Cyclophosphamide and epirubicin induce high apoptosis in microglia cells while epirubicin provokes DNA damage and microglial activation at sub-lethal concentrations

Chemotherapy Related Cognitive Impairment (CRCI), also called chemobrain, diminishes cancer patient's life quality. Breast cancer (BC) patients have been described to be importantly affected, however, the mechanism leading to CRCI has not been fully elucidated. Recent research proposes microglia as the main architect of CRCI, thus dysregulations in these cells could trigger CRCI. The aim of this research was to evaluate the effects of two drugs commonly used against breast cancer, cyclophosphamide (CTX) and epirubicin (EPI), on the microglia cell line SIM-A9, using the BC cell line, 4T1, as a control. Our results show that CTX and EPI decrease microglia-cell viability and increase cell death on a concentration-dependent manner, being 5 and 2 times more cytotoxic to microglia cell line than to breast cancer 4T1cells, respectively. Both chemotherapies induce cell cycle arrest and a significant increase in p53, p16 and γ-H2AX in breast cancer and microglia cells. Furthermore, mitochondrial membrane potential (ΔΨm) diminishes as cell death increases, and both chemotherapies induce reactive oxygen species (ROS) production on SIM-A9 and 4T1. Moreover, caspase activation increases with treatments and its pharmacological blockade inhibits CTX and EPI induced-cell death. Finally, low concentrations of CTX and EPI induce γ-H2AX, and EPI induces cytokine release, NO production and Iba-1 overexpression. These findings indicate that microglia cells are more sensitive to CTX and EPI than BC cells and undergo DNA damage and cell cycle arrest at very low concentrations, moreover EPI induces microglia activation and a pro-inflammatory profile.

Long-Term Cognitive Dysfunction in Cancer Survivors

Cancer-related cognitive impairment (CRCI) is a frequent side effect experienced by an increasing number of cancer survivors with a significant impact on their quality of life. Different definitions and means of evaluation have been used in available literature; hence the exact incidence of CRCI remains unknown. CRCI can be described as cognitive symptoms reported by cancer patients in self-reported questionnaires or as cognitive changes evaluated by formal neuropsychological tests. Nevertheless, association between cognitive symptoms and objectively assessed cognitive changes is relatively weak or absent. Studies have focused especially on breast cancer patients, but CRCI has been reported in multiple types of cancer, including colorectal, lung, ovarian, prostate, testicular cancer and hematological malignancies. While CRCI has been associated with various treatment modalities, including radiotherapy, chemotherapy, hormone therapy and novel systemic therapies, it has been also detected prior to cancer treatment. Therefore, the effects of cancer itself with or without the psychological distress may be involved in the pathogenesis of CRCI as a result of altered coping mechanisms after cancer diagnosis. The development of CRCI is probably multifactorial and the exact mechanisms are currently not completely understood. Possible risk factors include administered treatment, genetic predisposition, age and psychological factors such as anxiety, depression or fatigue. Multiple mechanisms are suggested to be responsible for CRCI, including direct neurotoxic injury of systemic treatment and radiation while other indirect contributing mechanisms are hypothesized. Chronic neuroinflammation mediated by active innate immune system, DNA-damage or endothelial dysfunction is hypothesized to be a central mechanism of CRCI pathogenesis. There is increasing evidence of potential plasma (e.g., damage associated molecular patterns, inflammatory components, circulating microRNAs, exosomes, short-chain fatty acids, and others), cerebrospinal fluid and radiological biomarkers of cognitive dysfunction in cancer patients. Discovery of biomarkers of cognitive impairment is crucial for early identification of cancer patients at increased risk for the development of CRCI or development of treatment strategies to lower the burden of CRCI on long-term quality of life. This review summarizes current literature on CRCI with a focus on long-term effects of different cancer treatments, possible risk factors, mechanisms and promising biomarkers.

Methotrexate Neurotoxicity Is Related to Epigenetic Modification of the Myelination Process

With the improvement of the survival rate of acute lymphoblastic leukemia (ALL) in children, some children ALL survivors reveal inferior intellectual and cognition outcome. Methotrexate (MTX), while serving as an essential component in ALL treatment, has been reported to be related to various neurologic sequelae. Using combined intrathecal (IT) and intraperitoneal (IP) MTX model, we had demonstrated impaired spatial memory function in developing rats, which can be rescued by melatonin treatment. To elucidate the impact of MTX treatment on the epigenetic modifications of the myelination process, we examined the change of neurotrophin and myelination-related transcriptomes in the present study and found combined IT and IP MTX treatment resulted in altered epigenetic modification on the myelination process, mainly in the hippocampus. Further, melatonin can restore the MTX effect through alterations of the epigenetic pathways.