Alterations in brain antioxidant enzymes and redox proteomic identification of oxidized brain proteins induced by the anti-cancer drug adriamycin: implications for oxidative stress-mediated chemobrain

Evaluation of the Therapeutic Effect of Curcumin-Conjugated Zinc Oxide Nanoparticles on Reserpine-Induced Depression in Wistar Rats

Depression, a devastating brain illness, necessitates the exploration of novel antidepressant treatments. We evaluated the antidepressant effects of free curcumin, zinc oxide nanoparticles (ZnO NPs), and curcumin-conjugated zinc oxide nanoparticles (Zn(cur)O NPs). The nanoformulations were extensively characterized using advanced techniques. An acute toxicity study ensured the safety of Zn(cur)O NPs. Rats were assigned to one of five groups: control, reserpine-induced depression model, treatment with ZnO NPs, free curcumin, or Zn(cur)O NPs. Behavioral assessments (forced swimming test [FST] and open-field test [OFT]) and neurochemical analyses were conducted. Zn(cur)O NPs exhibited superior efficacy in ameliorating reserpine-induced behavioral and neurochemical effects compared to free curcumin and ZnO NPs. The reserpine-induced model displayed reduced motor activity, swimming time, and increased immobility time in the FST and OFT. Treatment with Zn(cur)O NPs 45 mg/kg significantly improved motor activity and reduced immobility time. Furthermore, Zn(cur)O NPs decreased malondialdehyde (MDA) levels while increasing reduced glutathione (GSH) and catalase (CAT) levels. Additionally, concentrations of serotonin (5-HT) and norepinephrine (NE) increased. In conclusion, curcumin-conjugated zinc oxide nanoparticles demonstrate potent antidepressant effects, alleviating depressive-like behavior in rats. These findings support Zn(cur)O NPs as a promising therapeutic strategy for depression management, warranting further investigation and clinical validation.

The molecular mechanisms of peptidyl-prolyl cis/trans isomerase Pin1 and its relevance to kidney disease

Pin1 is a member of the peptidyl-prolyl cis/trans isomerase subfamily and is widely expressed in various cell types and tissues. Alterations in Pin1 expression levels play pivotal roles in both physiological processes and multiple pathological conditions, especially in the onset and progression of kidney diseases. Herein, we present an overview of the role of Pin1 in the regulation of fibrosis, oxidative stress, and autophagy. It plays a significant role in various kidney diseases including Renal I/R injury, chronic kidney disease with secondary hyperparathyroidism, diabetic nephropathy, renal fibrosis, and renal cell carcinoma. The representative therapeutic agent Juglone has emerged as a potential treatment for inhibiting Pin1 activity and mitigating kidney disease. Understanding the role of Pin1 in kidney diseases is expected to provide new insights into innovative therapeutic interventions and strategies. Consequently, this review delves into the molecular mechanisms of Pin1 and its relevance in kidney disease, paving the way for novel therapeutic approaches.

Integrating transcriptomics and metabolomics to elucidate the mechanism by which taurine protects against DOX-induced depression

Doxorubicin (DOX) is an effective anticancer drug with potent antitumour activity. However, the application of DOX is limited by its adverse reactions, such as depression. Taurine can alleviate depression induced by multiple factors. However, it is still unclear whether and how taurine improves DOX-induced depression. To address this question, the aim of this study was to explore the potential mechanism by which taurine protects against DOX-induced depression. Mice were randomly divided into three groups (n = 8): (1) the control group, (2) the DOX group, and (3) the DOX + taurine group. The open field test (OFT), elevated plus maze test, and forced swim test (FST) were first performed to assess the effects of DOX and taurine on the behaviour of mice. Next, a combined transcriptomic and metabolomic analysis was performed to analyse the possible antidepressive effect of taurine. Taurine pretreatment increased the total distance travelled and speed of mice in the OFT, increased the number of entries into the open arm and the time spent in the open arm, and reduced the immobility time in the FST. In addition, 179 differential genes and 51 differentially abundant metabolites were detected in the DOX + taurine group compared to the DOX group. Furthermore, differential genes and differentially abundant metabolites were found to be jointly involved in 21 pathways, which may be closely related to the antidepressant effect of taurine. Taurine alleviated DOX-induced depressive behaviour. The various pathways identified in this study, such as the serotonergic synapse and the inflammatory mediator regulation of TRP channels, may be key regulatory pathways related to depression and antidepressant effects.

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.

Damage to endothelial barriers and its contribution to long COVID

The world continues to contend with COVID-19, fueled by the emergence of viral variants. At the same time, a subset of convalescent individuals continues to experience persistent and prolonged sequelae, known as long COVID. Clinical, autopsy, animal and in vitro studies all reveal endothelial injury in acute COVID-19 and convalescent patients. Endothelial dysfunction is now recognized as a central factor in COVID-19 progression and long COVID development. Different organs contain different types of endothelia, each with specific features, forming different endothelial barriers and executing different physiological functions. Endothelial injury results in contraction of cell margins (increased permeability), shedding of glycocalyx, extension of phosphatidylserine-rich filopods, and barrier damage. During acute SARS-CoV-2 infection, damaged endothelial cells promote diffuse microthrombi and destroy the endothelial (including blood-air, blood-brain, glomerular filtration and intestinal-blood) barriers, leading to multiple organ dysfunction. During the convalescence period, a subset of patients is unable to fully recover due to persistent endothelial dysfunction, contributing to long COVID. There is still an important knowledge gap between endothelial barrier damage in different organs and COVID-19 sequelae. In this article, we mainly focus on these endothelial barriers and their contribution to long COVID.

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.

Association of Longitudinal Changes in Cerebral Microstructure with Cognitive Functioning in Breast Cancer Survivors after Adjuvant Chemotherapy

Background: Adjuvant chemotherapy for breast cancer might impact cognitive function and brain structure. Methods: In this study, we investigated the cerebral microstructural changes in breast cancer survivors after adjuvant chemotherapy and the correlation with cognitive function with both cross-sectional and longitudinal study designs. All participants underwent structural MRI. In total, we recruited 67 prechemotherapy patients (BB), 67 postchemotherapy patients (BA), and 77 healthy controls (BH). For the follow-up study, 28 participants in the BH and 28 in the BB groups returned for imaging and assessment (BHF, BBF). Voxel-based morphometry analysis was performed to evaluate differences in brain volume; vertex-based shape analysis was used to assess the shape alterations of subcortical regions. Moreover, multiple regression was applied to assess the association between the changes in neuropsychological assessment and brain volume. Results: The results showed brain volume reduction in the temporal and parietal gyrus in BB and BA patients. Among each group, we also found significant shape alterations in the caudate and thalamus. Volume reductions in the temporal regions and shape changes in the caudate and hippocampus were also observed in patients from time point 1 to time point 2 (postchemotherapy). An association between brain volume and cognitive performance was also found in the limbic system. Conclusions: Based on our findings, we can provide a better understanding of the cerebral structural changes in breast cancer survivors, establish a subsequent prediction model, and serve as a reference for subsequent treatment.

Chemobrain in blood cancers: How chemotherapeutics interfere with the brain's structure and functionality, immune system, and metabolic functions

Cancer treatment brings about a phenomenon not fully clarified yet, termed chemobrain. Its strong negative impact on patients' well-being makes it a trending topic in current research, interconnecting many disciplines from clinical oncology to neuroscience. Clinical and animal studies have often reported elevated concentrations of proinflammatory cytokines in various types of blood cancers. This inflammatory burst could be the background for chemotherapy-induced cognitive deficit in patients with blood cancers. Cancer environment is a dynamic interacting system. The review puts into close relationship the inflammatory dysbalance and oxidative/nitrosative stress with disruption of the blood-brain barrier (BBB). The BBB breakdown leads to neuroinflammation, followed by neurotoxicity and neurodegeneration. High levels of intracellular reactive oxygen species (ROS) induce the progression of cancer resulting in increased mutagenesis, conversion of protooncogenes to oncogenes, and inactivation of tumor suppression genes to trigger cancer cell growth. These cell alterations may change brain functionality, as well as morphology. Multidrug chemotherapy is not without consequences to healthy tissue and could even be toxic. Specific treatment impacts brain function and morphology, functions of the immune system, and metabolism in a unique mixture. In general, a chemo-drug's effects on cognition in cancer are not direct and/or in-direct, usually a combination of effects is more probable. Last but not least, chemotherapy strongly impacts the immune system and could contribute to BBB disruption. This review points out inflammation as a possible mechanism of brain damage during blood cancers and discusses chemotherapy-induced cognitive impairment.

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.

Potential roles of 4HNE-adducted protein in serum extracellular vesicles as an early indicator of oxidative response against doxorubicin-induced cardiomyopathy in rats

Late-onset cardiomyopathy is becoming more common among cancer survivors, particularly those who received doxorubicin (DOXO) treatment. However, few clinically available cardiac biomarkers can predict an unfavorable cardiac outcome before cell death. Extracellular vesicles (EVs) are emerging as biomarkers for cardiovascular diseases and others. This study aimed to measure dynamic 4-hydroxynonenal (4HNE)-adducted protein levels in rats treated chronically with DOXO and examine their link with oxidative stress, antioxidant gene expression in cardiac tissues, and cardiac function. Twenty-two male Wistar rats were randomly assigned to receive intraperitoneal injection of normal saline (n = 8) or DOXO (3 mg/kg, 6 doses, n = 14). Before and after therapy, serum EVs and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were determined. Tunable resistive pulse sensing was used to measure EV size and concentration. ELISA was used to assess 4HNE-adducted protein in EVs and cardiac tissues. Differential-display reverse transcription-PCR was used to quantitate cardiac Cat and Gpx1 gene expression. Potential correlations between 4HNE-adducted protein levels in EVs, cardiac oxidative stress, antioxidant gene expression, and cardiac function were determined. DOXO-treated rats showed more serum EV 4HNE-adducted protein than NSS-treated rats at day 9 and later endpoints, whereas NT-proBNP levels were not different between groups. Moreover, on day 9, surviving rats' EVs had higher levels of 4HNE-adducted protein, and these correlated positively with concentrations of heart tissue 4HNE adduction and copy numbers of Cat and Gpx1, while at endpoint correlated negatively with cardiac functions. Therefore, 4HNE-adducted protein in serum EVs could be an early, minimally invasive biomarker of the oxidative response and cardiac function in DOXO-induced cardiomyopathy.

Targeting ryanodine receptor type 2 to mitigate chemotherapy-induced neurocognitive impairments in mice

Chemotherapy-induced cognitive dysfunction (chemobrain) is an important adverse sequela of chemotherapy. Chemobrain has been identified by the National Cancer Institute as a poorly understood problem for which current management or treatment strategies are limited or ineffective. Here, we show that chemotherapy treatment with doxorubicin (DOX) in a breast cancer mouse model induced protein kinase A (PKA) phosphorylation of the neuronal ryanodine receptor/calcium (Ca2+) channel type 2 (RyR2), RyR2 oxidation, RyR2 nitrosylation, RyR2 calstabin2 depletion, and subsequent RyR2 Ca2+ leakiness. Chemotherapy was furthermore associated with abnormalities in brain glucose metabolism and neurocognitive dysfunction in breast cancer mice. RyR2 leakiness and cognitive dysfunction could be ameliorated by treatment with a small molecule Rycal drug (S107). Chemobrain was also found in noncancer mice treated with DOX or methotrexate and 5-fluorouracil and could be prevented by treatment with S107. Genetic ablation of the RyR2 PKA phosphorylation site (RyR2-S2808A) also prevented the development of chemobrain. Chemotherapy increased brain concentrations of the tumor necrosis factor-α and transforming growth factor-β signaling, suggesting that increased inflammatory signaling might contribute to oxidation-driven biochemical remodeling of RyR2. Proteomics and Gene Ontology analysis indicated that the signaling downstream of chemotherapy-induced leaky RyR2 was linked to the dysregulation of synaptic structure-associated proteins that are involved in neurotransmission. Together, our study points to neuronal Ca2+ dyshomeostasis via leaky RyR2 channels as a potential mechanism contributing to chemobrain, warranting further translational studies.

ABCB1 and ABCG2 Regulation at the Blood-Brain Barrier: Potential New Targets to Improve Brain Drug Delivery

The drug efflux transporters ABCB1 and ABCG2 at the blood-brain barrier limit the delivery of drugs into the brain. Strategies to overcome ABCB1/ABCG2 have been largely unsuccessful, which poses a tremendous clinical problem to successfully treat central nervous system (CNS) diseases. Understanding basic transporter biology, including intracellular regulation mechanisms that control these transporters, is critical to solving this clinical problem.In this comprehensive review, we summarize current knowledge on signaling pathways that regulate ABCB1/ABCG2 at the blood-brain barrier. In Section I, we give a historical overview on blood-brain barrier research and introduce the role that ABCB1 and ABCG2 play in this context. In Section II, we summarize the most important strategies that have been tested to overcome the ABCB1/ABCG2 efflux system at the blood-brain barrier. In Section III, the main component of this review, we provide detailed information on the signaling pathways that have been identified to control ABCB1/ABCG2 at the blood-brain barrier and their potential clinical relevance. This is followed by Section IV, where we explain the clinical implications of ABCB1/ABCG2 regulation in the context of CNS disease. Lastly, in Section V, we conclude by highlighting examples of how transporter regulation could be targeted for therapeutic purposes in the clinic. SIGNIFICANCE STATEMENT: The ABCB1/ABCG2 drug efflux system at the blood-brain barrier poses a significant problem to successful drug delivery to the brain. The article reviews signaling pathways that regulate blood-brain barrier ABCB1/ABCG2 and could potentially be targeted for therapeutic purposes.

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.

High-mobility group box 1 (HMGB1) crosses the BBB bidirectionally

High-mobility group box 1 (HMGB1) is a ubiquitous protein that regulates transcription in the nucleus, and is an endogenous damage-associated molecular pattern molecule that activates the innate immune system. HMGB1 activates the TLR4 and RAGE recepto, inducing downstream signals reminiscent of cytokines that have been found to cross the blood-brain barrier (BBB). Blood HMGB1 increases in stroke, sepsis, senescence, alcohol binge drinking and other conditions. Here, we examined the ability of HMGB1 radioactively labeled with iodine (I-HMGB1) to cross the BBB. We found that I-HMGB1 readily entered into mouse brain from the circulation with a unidirectional influx rate of 0.654 μl/g-min. All brain regions tested took up I-HMGB1; uptake was greatest by the olfactory bulb and least in the striatum. Transport was not reliably inhibited by unlabeled HMGB1 nor by inhibitors of TLR4, TLR2, RAGE, or CXCR4. Uptake was enhanced by co-injection of wheatgerm agglutinin, suggestive of involvement of absorptive transcytosis as a mechanism of transport. Induction of inflammation/neuroinflammation with lipopolysaccharide is known to increase blood HMGB1; we report here that brain transport is also increased by LPS-induced inflammation. Finally, we found that I-HMGB1 was also transported in the brain-to-blood direction, with both unlabeled HMGB1 or lipopolysaccharide increasing the transport rate. These results show that HMGB1 can bidirectionally cross the BBB and that those transport rates are enhanced by inflammation. Such transport provides a mechanism by which HMGB1 levels would impact neuroimmune signaling in both the brain and periphery.

Inhibition of NLRP3 alleviated chemotherapy-induced cognitive impairment in rats

Chemotherapy results in long-term effects on cognitive dysfunction called chemotherapy-induced cognitive impairment (CICI) in cancer survivors. However, little is known about the potential molecular mechanisms of CICI. This study aimed to determine the role and potential underlying mechanisms of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in cognitive impairments induced by chemotherapeutic agents commonly used in breast cancer. The cognitive effects of chemotherapy were investigated in a rat model using the cocktail of doxorubicin and cyclophosphamide. The NLRP3 pathway was found to be differentially expressed after chemotherapy by iTRAQ-based proteomic analysis of normal and chemotherapeutic hippocampi. Treatment with the NLRP3 inhibitor MCC950 following chemotherapy significantly reduced cognitive impairment and decreased the expression of NLRP3, caspase-1 and ASC. Chemotherapy led to increased expression of the glial response markers Iba-1 and GFAP and the axonal injury markers NF-L and NF-M, an elevated number of apoptotic cells and enhanced microstructural damage to axons and mitochondria, while MCC950 treatment alleviated the glial response, cell death and axonal injury. The protective effect of MCC950 was related to the NLRP3 pathway and levels of inflammatory cytokines (TNF-α, IL-1β, IL-18, IL-6, IL-4, and IL-10) and oxidative stress-responsive markers (SOD, MDA, CAT and GSH). The results indicate that CICI is associated with NLRP3 pathway-induced oxidative damage and the inflammatory response and provide a potential therapeutic target to treat cognitive impairment after chemotherapy (doxorubicin and cyclophosphamide).

Protein Glutathionylation and Glutaredoxin: Role in Neurodegenerative Diseases

Oxidative stress has been implicated in the pathogenesis and progression of many neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. One of the major enzyme systems involved in the defense against reactive oxygen species are the tripeptide glutathione and oxidoreductase glutaredoxin. Glutathione and glutaredoxin system are very important in the brain because of the oxidative modification of protein thiols to protein glutathione mixed disulfides with the concomitant formation of oxidized glutathione during oxidative stress. Formation of Pr-SSG acts as a sink in the brain and is reduced back to protein thiols during recovery, thus restoring protein functions. This is unlike in the liver, which has a high turnover of glutathione, and formation of Pr-SSG is very minimal as liver is able to quickly quench the prooxidant species. Given the important role glutathione and glutaredoxin play in the brain, both in normal and pathologic states, it is necessary to study ways to augment the system to help maintain the protein thiol status. This review details the importance of glutathione and glutaredoxin systems in several neurodegenerative disorders and emphasizes the potential augmentation of this system as a target to effectively protect the brain during aging.

The Blood-Brain Barrier in Neuroimmune Interactions and Pathological Processes

The blood-brain barrier (BBB) is a kind of filter, highly selective in relation to various types of substances. The BBB supports the immune status of the brain and is an important regulator of neuroimmune interactions. Some of the molecular and cellular features of the BBB, as well as the five main pathways of neuroimmune communication mediated by the BBB, are analyzed in this article. The functions of the BBB in neuroimmune interactions in various diseases are discussed: multiple sclerosis and Alzheimer's and Parkinson's diseases. The latest data on BBB dysfunction in COVID-19 coronavirus infection caused by the SARS-CoV-2 virus are considered.

Effects of meditation compared to music listening on biomarkers in breast cancer survivors with cognitive complaints: secondary outcomes of a pilot randomized control trial

CONTEXT

We previously reported positive behavioral effects of both daily mantra meditation and classical music listening interventions in breast cancer survivors with cancer related cognitive complaints.

OBJECTIVE

The objective of this pilot study was to compare the effects of the meditation intervention to a music listening intervention on biomarkers of inflammation and cellular aging (secondary outcomes) in breast cancer survivors.

DESIGN

Randomized control trial, baseline data collection (time 1), post intervention data collection (time 2) SETTING: Community-based, Central Texas PARTICIPANTS: 25 breast cancer survivors (BCS) who were 3 months to 6 years post chemotherapy completion and reported cognitive changes.

INTERVENTION(S)

Kirtan Kriya meditation (KK) or classical music listening (ML), 8 weeks, 12 min a day MAIN OUTCOME: Telomerase activity [TA], c-reactive protein [CRP], soluble IL-2 receptor alpha [sIL-2Rα], soluble IL-4 receptor [sIL-4R], soluble IL-6 receptor [sIL-6R], soluble tumor necrosis factor receptor II [sTNF-RII], VEGF receptor 2 [sVEGF-R2], and VEGF receptor 3 [sVEGF-R3] RESULTS: Repeated measures analysis of variance models were analyzed from time 1 to time 2 by group for each biomarker. A pattern of greater telomerase activity across time in both groups (F (1,15) = 3.98, p = .06, ω2 = 0.04); significant decreases in sIL-4R across time for both groups (F (1,22) = 6.28, p = .02, ω2 = .003); group*time effect was nominally different but not statistically different for sIL-4R (F(1,22) = 3.82, p = .06, ω2 = .001); and a pattern for a group*time effect with ML group showing higher levels of sVEGF-R3 at time 2 (F (1,20) = 2.59, p = .12, ω2 = .009). No significant effects were found for CRP, sIL-2Rα, sIL-6R, sTNF-RII, or sVEGF-R2.

Novel lipid-coated mesoporous silica nanoparticles loaded with thymoquinone formulation to increase its bioavailability in the brain and organs of Wistar rats

AIMS

The Blood-Brain Barrier (BBB) is a filter for most medications and blocks their passage into the brain. More effective drug delivery strategies are urgently needed to transport medications into the brain. This study investigated the biodistribution of thymoquinone (TQ) and the effect on enzymatic and non-enzymatic oxidative stress indicators in different brain regions, either in free form or incorporated into nanocarriers as mesoporous silica nanoparticles (MSNs). Lipid bilayer-coated MSNs.

MATERIALS AND METHODS

MSNs and LB-MSNs were synthesized and characterized using a transmission electron microscope and dynamic light scattering to determine the particle size and zeta potential. TQ encapsulation efficiency and TQ's release profile from LB-MSNs were also examined. The impact of loading LB-MSNs with TQ-on-TQ delivery to different brain areas was examined using chromatographic measurement. Furthermore, nitric oxide, malondialdehyde (MDA), reduced glutathione, and catalase were evaluated as oxidant and antioxidant stress biomarkers.

KEY FINDINGS

The LB-MSNs formulation successfully transported TQ to several areas of the brain, liver, and kidney, revealing a considerable increase in TQ delivery in the thalamus (81.74%) compared with that in the free TQ group and a considerable reduction in the cortex (-44%). The LB-MSNs formulation had no significant effect on TQ delivery in the cerebellum, striatum, liver, and kidney.

SIGNIFICANCE

TQ was redistributed in different brain areas after being encapsulated in LB-MSNs, indicating that LB-MSNs have the potential to be developed as a drug delivery system for selective clinical application of specific brain regions.

CONCLUSIONS

LB-MSNs are capable nanoplatforms that can be used to target medications precisely to specific brain regions.

Immunomodulatory effect of protocatechuic acid on cyclophosphamide induced brain injury in rat: Modulation of inflammosomes NLRP3 and SIRT1

Modulation of the inflammasome NLRP3 and SIRT1 are new combat strategy for brain injury protection. The inflammasome activates proinflammatory cytokines releasing interleukin-1β and interleukin-18 which in turn affect the toxins release from immune cells. In addition, SIRT1 controls many biological functions, such as immune response and oxidative stress. Protocatechuic has versatile biological activities and possesses antioxidant, anti-inflammatory and neuroprotective effects. So this work aims to study immunomodulatory effect of protocatechuic acid on cyclophosphamide chemotherapy drug-induced brain injury via modulation of inflammosomes NLRP3 and SIRT1. Rats were randomly assigned to four experimental groups. Normal control group was injected with a single i.p injection of saline. Cyclophosphamide group was injected with a single i.p injection of cyclophosphamide (200 mg/kg). Protocatechuic acid groups were orally administered (50 &100 mg/kg) once daily for 10 consecutive days after cyclophosphamide injection. Protocatechuic acid administration exhibited improvements of the cognition function and memory, a reduction in brain contents of MDA, NLRP3, IL-1 β, NF-κB, IKBKB and Galectin 3 and an elevation of GSH and SIRT1 compared to cyclophosphamide group. In addition, protocatechuic acid administration ameliorated the elevation of caspase 3 and iNOS gene expression and alleviated the neuron degeneration caused by cyclophosphamide. In conclusion, the therapeutic action of protocatechuic acid and its cellular and molecular mechanisms are new insights against various human ailments, especially, neuroprotective disease as brain injury induced by cyclophosphamide chemotherapy drug in rats through modulation of inflammosomes NLRP3 and SIRT1.

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.

Evaluation of the therapeutic effect of mesoporous silica nanoparticles loaded with Gallic acid on reserpine-induced depression in Wistar rats

Background

The current study evaluates the free gallic acid (GA) and GA-loaded mesoporous silica nanoparticles (MSNs) antidepressant efficacy in a rat model of depression caused by reserpine.

Methods

By using a scanning electron microscope (SEM), dynamic light scattering (DLS), and zeta potential, MSNs and GA-loaded MSNs were characterized. The efficiency of encapsulation and the release of GA-loaded MSNs were also investigated. The effect of GA, either in its free form or loaded on (MSNs) on oxidative stress biomarkers and monoamine neurotransmitters levels (serotonin (5-HT), norepinephrine (NEP), and dopamine (DA)), were evaluated in these areas (cortex, hippocampus, striatum, and hypothalamus) of control, a depression model of rat, a depression model of rat treated with either free GA, MSNs or GA loaded MSNs. The forced swimming test (FST) also the open field test (OFT) were carried out to evaluate the behavioral changes in all groups.

Results

Reserpine caused a decrease in the time spent in motor and swimming activity besides increasing the time of immobility, as demonstrated by OFT and FST. Significantly reductions in 5-HT, NEP, and DA were obtained in the cortex, hippocampus, hypothalamus, and striatum of reserpine-treated rats. Free GA was more effective in increasing the serotonin level in the cortex, hippocampus, and hypothalamus, while GA-loaded MSNs were more effective in increasing it in the striatum. GA-loaded MSNs also increased the level of NEP in the four studied brain areas. Free GA increased dopamine levels in the cortex and striatum, whereas GA-loaded MSNs increased DA levels in the hippocampus and hypothalamus compared with the depressed untreated group.

Conclusions

MSNs can be used as a drug delivery system to target GA selectively to specific brain areas.

Mechanisms of Chemotherapy-Induced Neurotoxicity

Since the first clinical trials conducted after World War II, chemotherapeutic drugs have been extensively used in the clinic as the main cancer treatment either alone or as an adjuvant therapy before and after surgery. Although the use of chemotherapeutic drugs improved the survival of cancer patients, these drugs are notorious for causing many severe side effects that significantly reduce the efficacy of anti-cancer treatment and patients’ quality of life. Many widely used chemotherapy drugs including platinum-based agents, taxanes, vinca alkaloids, proteasome inhibitors, and thalidomide analogs may cause direct and indirect neurotoxicity. In this review we discuss the main effects of chemotherapy on the peripheral and central nervous systems, including neuropathic pain, chemobrain, enteric neuropathy, as well as nausea and emesis. Understanding mechanisms involved in chemotherapy-induced neurotoxicity is crucial for the development of drugs that can protect the nervous system, reduce symptoms experienced by millions of patients, and improve the outcome of the treatment and patients’ quality of life.

A review on the neuroprotective effect of berberine against chemotherapy-induced cognitive impairment

Chemobrain is one of the major side effects of chemotherapy, despite increased research, the mechanisms underlying chemotherapy-induced cognitive changes remain unknown. Though, several possibly important candidate mechanisms have been identified and will be studied further in the future. Chemobrain is characterized by memory loss, cognitive impairment, difficulty in language, concentration, acceleration, and learning. The major characteristic of chemobrain is oxidative stress, mitochondrial dysfunction, immune dysregulation, hormonal alteration, white matter abnormalities, and DNA damage. Berberine (BBR) is an isoquinoline alkaloid extracted from various berberine species. BBR is a small chemical that easily passes the blood-brain barrier (BBB), making it useful for treating neurodegenerative diseases. Many studies on the pharmacology of BBR have been reported in the past. Furthermore, several clinical and experimental research indicates that BBR has a variety of pharmacological effects. So, in this review, we explore the pathogenesis of chemobrain and the neuroprotective potential of BBR against chemobrain. We also introduced the therapeutic role of BBR in various neurodegenerative and neurological diseases such as Alzheimer's, Parkinson's disease, mental depression, schizophrenia, anxiety, and also some stroke.

Potential Protective Effect of Coenzyme Q10 on Doxorubicin-Induced Neurotoxicity and Behavioral Disturbances in Rats

The aim of this study was to investigate the potential neuroprotective efficacy of coenzyme Q10 (CoQ10) against doxorubicin (DOX) -induced behavioral disturbances in rats. Female rats were randomly assigned into 4 groups as control, CoQ10, DOX, and DOX plus CoQ10. The CoQ10 groups received CoQ10 (200 mg kg^-1) for 21 days, and the DOX groups received DOX (4 mg kg^-1) on days 7 and 14 of the study. The open field (OF) and elevated plus maze (EPM) tests were performed to assess locomotor activity and anxiety levels. Additionally, malondialdehyde (MDA), and protein carbonyl (PC) levels and acetylcholinesterase (AChE), and glutathione peroxidase (GPx) activities and total antioxidant capacity (TAC) were quantified in brain tissue. DOX administration caused alterations in locomotor activity, and anxiety-like behaviors. Moreover, DOX produced significant elevation in AChE activity . PC level and GPx activity tended to alter with DOX administration. Co-treatment with CoQ10 significantly attenuated DOX-induced behavioral alterations via improving AChE activity in the brain tissue of rats. CoQ10 treatment may be potential for the alleviation of DOX-induced behavioral disturbances. This improvement might be due to the inhibition of AChE activity.

Crosstalk between anticancer drugs and mitochondrial functions

Chemotherapy is an important component of cancer treatment, which has side effects like vomiting, peripheral neuropathy, and numerous organ toxicity but the most significant outcomes of chemotherapy are cognitive impairment, which is mainly referred to as chemobrain or CICI (chemotherapy-induced cognitive impairment). It is characterized by difficulty with language, concentrating, processing speed, learning, and memory, as it affects the hippocampus areas of the brain. Mitochondrial dysfunction and oxidative stress are one of the major mechanisms causing chemobrain. The generation of reactive oxygen species (byproducts of oxidative phosphorylation) mainly occurs in mitochondria that play a prominent role in the induction of oxidative stress. The homeostasis of ROS in the mitochondria is maintained by mitochondrial antioxidant mechanism via enzymes like catalase, glutathione, and superoxide dismutase. Lungs and breast cancer are the two most common types of cancer, which are the most leading cancers in the world with about 4.18 million cases. In this review we exposed the current knowledge regarding chemotherapy-induced oxidative stress and mitochondrial dysfunction to cause cognitive impairment.We especially focused on the antineoplastic agent (ADRIAMYCIN, CYCLOPHOSPHAMIDE), platinum group agent CISPLATIN, antimetabolite agents (METHOTREXATE), and nitrogen mustard agent (CARMUSTINE) which increase oxidative stress and inflammatory markers in the PNS (peripheral nervous system) as well as the central nervous system. We also highlight the behavioural and functional changes in the brain.

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

Chemotherapy-induced cognitive impairment (CICI) has been observed in a large fraction of cancer survivors. Although many of the chemotherapeutic drugs do not cross the blood-brain barrier, following treatment, the structure and function of the brain are altered and cognitive dysfunction occurs in a significant number of cancer survivors. The means by which CICI occurs is becoming better understood, but there still remain unsolved questions of the mechanisms involved. The hypotheses to explain CICI are numerous. More than 50% of FDA-approved cancer chemotherapy agents are associated with reactive oxygen species (ROS) that lead to oxidative stress and activate a myriad of pathways as well as inhibit pathways necessary for proper brain function. Oxidative stress triggers the activation of different proteins, one in particular is tumor necrosis factor alpha (TNFα). Following treatment with various chemotherapy agents, this pro-inflammatory cytokine binds to its receptors at the blood-brain barrier and translocates to the parenchyma via receptor-mediated endocytosis. Once in brain, TNFα initiates pathways that may eventually lead to neuronal death and ultimately cognitive impairment. TNFα activation of the c-jun N-terminal kinases (JNK) and Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathways may contribute to both memory decline and loss of higher executive functions reported in patients after chemotherapy treatment. Chemotherapy also affects the brain's antioxidant capacity, allowing for accumulation of ROS. This review expands on these topics to provide insights into the possible mechanisms by which the intersection of oxidative stress and TNFΑ are involved in chemotherapy-induced cognitive impairment.

Thymoquinone has a neuroprotective effect against inflammation, oxidative stress, and endoplasmic reticulum stress in the brain cortex, medulla, and hippocampus due to doxorubicin

Although doxorubicin (DOX) is used in many cancer treatments, it causes neurotoxicity. In this study, the effect of thymoquinone (THQ), a powerful antioxidant, on DOX-induced neurotoxicity was evaluated. In total, 40 rats were used and 5 groups were formed. Group I: control group (n = 8); Group II: olive oil group (n = 8); Group III: the THQ group (n = 8); THQ 10 mg/kg per day was given intraperitoneally (i.p.) throughout the experiment; group IV: DOX group (n = 8); On Day 7 of the experiment, a single dose of 15 mg/kg intraperitoneally DOX injected; group V: DOX + THQ group (n = 8); Throughout the experiment, 10 mg/kg THQ per day and intraperitoneally 15 mg/kg DOX on Day 7 were injected. Immunohistochemically, tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), hypoxia-inducible factor 1α (HIF1-α), glucose regulatory protein 78 (GRP78), and the gene inducible by growth arrest and DNA damage 153 (GADD153) proteins were evaluated in the brain cortex, medulla, and hippocampus regions. Total oxidant status (TOS) levels and total antioxidant status (TAS) in the brain tissue were measured. TNF-α, IL-17, HIF1-α, GRP78, and GADD153 immunoreactivities significantly increased in the DOX group in the study. THQ significantly reduced these values. THQ increased the TAS level significantly and decreased the TOS level significantly compared to the DOX group. THQ may play a role as a neuroprotective agent in DOX-induced neurotoxicity in the cortex, medulla, and hippocampus regions of the brain.

Elevated Oxidative Stress and DNA Damage in Cortical Neurons of Chemotherapy Patients

The unintended neurologic sequelae of chemotherapy contribute to significant patient morbidity. Chemotherapy-related cognitive impairment (CRCI) is observed in up to 80% of cancer patients treated with chemotherapy and involves multiple cognitive domains including executive functioning. The pathophysiology underlying CRCI and the neurotoxicity of chemotherapy is incompletely understood, but oxidative stress and DNA damage are highly plausible mechanisms based on preclinical data. Unfortunately, validating pathways relevant to CRCI in humans is limited by an absence of relevant neuropathologic studies of patient brain tissue. In the present study, we stained sections of frontal lobe autopsy tissue from cancer patients treated with chemotherapy (n = 15), cancer patients not treated with chemotherapy (n = 10), and patients without history of cancer (n = 10) for markers of oxidative stress (nitrotyrosine, 4-hydroxynonenal) and DNA damage (pH2AX, pATM). Cancer patients treated with chemotherapy had increased staining for markers of oxidative stress and DNA damage in frontal lobe cortical neurons compared to controls. We detected no statistically significant difference in oxidative stress and DNA damage by the duration between last administration of chemotherapy and death. The study highlights the potential relevance of oxidative stress and DNA damage in the pathophysiology of CRCI and the neurotoxicity of chemotherapy.

Oxidative Stress and Cognitive Alterations Induced by Cancer Chemotherapy Drugs: A Scoping Review

Cognitive impairment is one of the most deleterious effects of chemotherapy treatment in cancer patients, and this problem sometimes remains even after chemotherapy ends. Common classes of chemotherapy-based regimens such as anthracyclines, taxanes, and platinum derivatives can induce both oxidative stress in the blood and in the brain, and these effects can be reproduced in neuronal and glia cell cultures. In rodent models, both the acute and repeated administration of doxorubicin or adriamycin (anthracyclines) or cisplatin impairs cognitive functions, as shown by their diminished performance in different learning and memory behavioural tasks. Administration of compounds with strong antioxidant effects such as N-acetylcysteine, gamma-glutamyl cysteine ethyl ester, polydatin, caffeic acid phenethyl ester, and 2-mercaptoethane sulfonate sodium (MESNA) counteract both oxidative stress and cognitive alterations induced by chemotherapeutic drugs. These antioxidant molecules provide the scientific basis to design clinical trials in patients with the aim of reducing the oxidative stress and cognitive alterations, among other probable central nervous system changes, elicited by chemotherapy in cancer patients. In particular, N-acetylcysteine and MESNA are currently used in clinical settings and are therefore attracting scientific attention.

Role of inflammatory, oxidative, and ER stress signaling in the neuroprotective effect of atorvastatin against doxorubicin-induced cognitive impairment in rats

Doxorubicin (DOX) is a potent chemotherapeutic agent widely used for the treatment of several malignancies. Despite its effectiveness, DOX has been implicated in induced neurotoxicity manifested as cognitive dysfunction with varying degrees, commonly referred to as chemobrain. DOX-induced chemobrain is presumed to be due to cytokine-induced inflammatory, oxidative, and apoptotic responses damaging the brain. Atorvastatin (ATV), 3-hydroxy 3-methylglutaryl co-enzyme A (HMG Co-A) reductase inhibitor, is a cholesterol-lowering statin possessing beneficial pleiotropic effects, including anti-inflammatory, antioxidant, and anti-apoptotic properties. Therefore, this study aims to investigate the potential neuroprotective effects of ATV against DOX-induced cognitive impairment studying the possible involvement of heme oxygenase-1 (HO-1) and endoplasmic reticulum (ER) stress biomarkers. Rats were treated with DOX (2 mg/kg/week), i.p. for 4 weeks. Oral treatment with ATV (10 mg/kg) ameliorated DOX-induced behavioral alterations, protected brain histological features, and attenuated DOX-induced inflammatory, oxidative, and apoptotic biomarkers. In addition, ATV upregulated the protective HO-1 expression levels and downregulated the DOX-induced apoptotic ER stress biomarkers. In conclusion, ATV (10 mg/kg) exhibited neuroprotective properties against DOX-induced cognitive impairment which could possibly be attributed to their anti-inflammatory, antioxidant, and anti-apoptotic effects in the brain.

Protective effect of nanocurcumin against neurotoxicity induced by doxorubicin in rat's brain

Cognitive impairment is one of the serious side effects that cancer-treated patients suffer from after treatment by doxorubicin (DOX). Investigating the mechanisms underlying this impairment is crucial for its treatment or prevention. The current study investigates the cortical and hippocampal neurochemical changes induced by an acute dose of DOX (20 mg/kg, i.p.) and evaluates the neuroprotective effect of nanocurcumin (NC) (50 mg/kg, p.o.) against these changes. Animals were randomly divided into four groups, control, rats treated with either NC or DOX, and the fourth group treated with NC prior to DOX. Cortical dopamine level has significantly increased (71.88 %) after DOX injection. This was associated with a significant rise in the levels of lipid peroxidation (183.99 %, 201.4 %) and nitric oxide (36.54 %, 55 %) and a significant reduction in reduced glutathione (13 %, 21.44 %) in the cortex and hippocampus, respectively. In addition, DOX inhibited the cortical and hippocampal activities of acetylcholinesterase (94.82 %, 62.75 %) and monoamine oxidase (64.40 %, 68.84 %), respectively. Protection with NC mitigates the changes induced in the oxidative stress parameters by DOX. However, the effect on the activities of AchE and MAO was insignificant. This was reflected in the level of dopamine that showed non-significant changes in comparison to control and DOX-treated rats. The present findings indicate that oxidative stress, inhibition in AchE, MAO, and the subsequent elevation in dopamine could have a crucial role in mediating the chemo-brain adverse effects induced by DOX. In addition, protection with NC mitigated some of these adverse effects thus rendering DOX more tolerable.

A standardized extract of Ziziphus jujuba Mill protects against adriamycin-induced liver, heart, and brain toxicity: An oxidative stress and biochemical approach

Due to the antioxidant effects of the Ziziphus jujuba Mill (Z. jujuba), we investigated the liver, heart, and brain-protective effects of this herb against toxicity induced by adriamycin (ADR). In this study, Wistar rats were divided into 1) control, 2) ADR and 3, 4, and 5) treated groups orally administrated three doses of Z. jujuba hydroalcoholic extract for 1 month. The liver, heart, and brain were removed for evaluation of the oxidative markers. Blood samples were evaluated to determine the levels of Lactate dehydrogenase, total and direct bilirubin, alkaline phosphatase, Aspartate transaminase, and Alanine aminotransferase. Administration of Z. jujuba significantly decreased the biochemical enzymes compared to the ADR. Oxidative condition in treated rats with different doses of Z. jujuba was improved compared to the ADR group. Z. jujuba could decrease the oxidative injury through invigoration of the tissues antioxidant system. The mentioned hepatic and cardiac parameters levels improved during extract administration. PRACTICAL APPLICATIONS: In the first stage, our findings and other supplementary works have shown that administration of jujube extract has prevented the effects of histotoxicity caused by adriamycin, so it seems that in the next stage, the effects of this herbal plant on patients with tissue toxicity caused by adriamycin should be evaluated and if the results are positive in pharmacological studies, it should be used as a complementary drug in the treatment of these patients.

Neuroprotective Potential of Ellagic Acid: A Critical Review

Ellagic acid (EA) is a dietary polyphenol present in various fruits, vegetables, herbs, and nuts. It exists either independently or as part of complex structures, such as ellagitannins, which release EA and several other metabolites including urolithins following absorption. During the past few decades, EA has drawn considerable attention because of its vast range of biological activities as well as its numerous molecular targets. Several studies have reported that the oxidative stress-lowering potential of EA accounts for its broad-spectrum pharmacological attributes. At the biochemical level, several mechanisms have also been associated with its therapeutic action, including its efficacy in normalizing lipid metabolism and lipidemic profile, regulating proinflammatory mediators, such as IL-6, IL-1β, and TNF-α, upregulating nuclear factor erythroid 2-related factor 2 and inhibiting NF-κB action. EA exerts appreciable neuroprotective activity by its free radical-scavenging action, iron chelation, initiation of several cell signaling pathways, and alleviation of mitochondrial dysfunction. Numerous in vivo studies have also explored the neuroprotective attribute of EA against various neurotoxins in animal models. Despite the increasing number of publications with experimental evidence, a critical analysis of available literature to understand the full neuroprotective potential of EA has not been performed. The present review provides up-to-date, comprehensive, and critical information regarding the natural sources of EA, its bioavailability, metabolism, neuroprotective activities, and underlying mechanisms of action in order to encourage further studies to define the clinical usefulness of EA for the management of neurological disorders.

Implications of Breast Cancer Chemotherapy-Induced Inflammation on the Gut, Liver, and Central Nervous System

Breast Cancer is still one of the most common cancers today; however, with advancements in diagnostic and treatment methods, the mortality and survivorship of patients continues to decrease and increase, respectively. Commonly used treatments today consist of drug combinations, such as doxorubicin and cyclophosphamide; docetaxel, doxorubicin, and cyclophosphamide; or doxorubicin, cyclophosphamide, and paclitaxel. Although these combinations are effective at destroying cancer cells, there is still much to be understood about the effects that chemotherapy can have on normal organ systems such as the nervous system, gastrointestinal tract, and the liver. Patients can experience symptoms of cognitive impairments or “chemobrain”, such as difficulty in concentrating, memory recollection, and processing speed. They may also experience gastrointestinal (GI) distress symptoms such as diarrhea and vomiting, as well as hepatotoxicity and long term liver damage. Chemotherapy treatment has also been shown to induce peripheral neuropathy resulting in numbing, pain, and tingling sensations in the extremities of patients. Interestingly, researchers have discovered that this array of symptoms that cancer patients experience are interconnected and mediated by the inflammatory response.

N-Acetylcysteine Attenuates the Anxiety-Like Behavior and Spatial Cognition Impairment Induced by Doxorubicin and Cyclophosphamide Combination Treatment in Rats

BACKGROUND

Cancer patients can suffer from psychological and cognitive disorders after chemotherapy, which influence quality of life.

OBJECTIVE

Oxidative stress may contribute to the psychological and cognitive disorders induced in rats by chemotherapy. In the present study, we examined the effects of N-acetylcysteine, an anti-oxidant, on anxiety-like behavior and cognitive impairment in rats treated with a combination of doxorubicin and cyclophosphamide.

METHODS

Rats were intraperitoneally injected with doxorubicin and cyclophosphamide once a week for 2 weeks. The light-dark test and the novel location recognition test were used to assess anxiety-like behavior and spatial cognition, respectively. The rats' hippocampal levels of glutathione (GSH) and glutathione disulfide (GSSG) were measured using a GSSG/GSH quantification kit.

RESULTS

Combined treatment with doxorubicin and cyclophosphamide produced anxiety-like behavior and cognitive impairment in rats. N-acetylcysteine reversed the anxiety-like behavior and inhibition of novel location recognition induced by the combination treatment. Furthermore, the combination of doxorubicin and cyclophosphamide significantly reduced the rats' hippocampal GSH/GSSG ratios. N-acetylcysteine reversed the reduction in the GSH/GSSG ratio seen in the doxorubicin and cyclophosphamide-treated rats.

CONCLUSION

These results suggest that N-acetylcysteine inhibits doxorubicin and cyclophosphamide-induced anxiety-like behavior and cognitive impairment by reducing oxidative stress in the hippocampus.

Cancer Chemotherapy Related Cognitive Impairment and the Impact of the Alzheimer's Disease Risk Factor APOE

Cancer related cognitive impairment (CRCI) is a serious impairment to maintaining quality of life in cancer survivors. Cancer chemotherapy contributes to this condition through several potential mechanisms, including damage to the blood brain barrier, increases in oxidative stress and inflammation in the brain, and impaired neurogenesis, each of which lead to neuronal dysfunction. A genetic predisposition to CRCI is the E4 allele of the Apolipoprotein E gene (APOE), which is also the strongest genetic risk factor for Alzheimer's disease. In normal brains, APOE performs essential lipid transport functions. The APOE4 isoform has been linked to altered lipid binding, increased oxidative stress and inflammation, reduced turnover of neural progenitor cells, and impairment of the blood brain barrier. As chemotherapy also affects these processes, the influence of APOE4 on CRCI takes on great significance. This review outlines the main areas where APOE genotype could play a role in CRCI. Potential therapeutics based on APOE biology could mitigate these detrimental cognitive effects for those receiving chemotherapy, emphasizing that the APOE genotype could help in developing personalized cancer treatment regimens.

Protective effects of diallyl trisulfide (DATS) against doxorubicin-induced inflammation and oxidative stress in the brain of rats

Doxorubicin (DOX) is a widely used antitumor drug that causes severe neurotoxicity in patients. Diallyl trisulfide (DATS) is an organosulfur compound with established potent antioxidant and anti-inflammatory properties. Herein, we investigated the neuroprotective efficacy of DATS in preventing DOX-induced neurotoxicity in a rat model. Specifically, DATS (40 mg/kg) was administered to rats 24 h after DOX treatment, once a week for 8 weeks. Our results showed that DATS treatment led to a decrease in plasma levels of tumor necrosis factor-alpha (TNF-α) induced by DOX. DATS restored cerebral cortex and hippocampus histopathological architecture and neuronal loss. Immunohistochemical staining indicated that DATS decreased the expression of glial fibrillar acidic protein (GFAP) in DOX treated rats. Components of stress-related inflammatory proteins (TNF-α, phospho nuclear factor kappa B (NF-κB), inducible nitricoxide synthase (iNOS) and cyclooxygenase-2 (COX-2)) were all significantly increased in the DOX group, in comparison with the control group, whereas they were decreased after DATS treatment. In addition, the mRNA of antioxidant enzymes (superoxide dismutase 2 (SOD2), catalase, glutathione peroxidase 1, 4 (GPx1 and GPx4)) and antioxidant proteins (heme oxygenase-1 (HO-1), superoxide dismutase 1, 2 (SOD1 and SOD2), Γ-glutamylcysteine synthase (Γ-GCSc)) were markedly increased in DOX group compared with the control group, which were significantly attenuated by DATS treatment. The upregulation of antioxidants enzymes in DOX group was probably a compensatory effect against elevated oxidative stress induced by DOX. DATS treatment could ameliorate this oxidative stress in brain. Our results suggested that DATS has potential clinical applications in the prevention of DOX-induced neurotoxicity by ameliorating inflammatory insults and oxidative stress.

Doxorubicin chemotherapy-induced "chemo-brain": Meta-analysis

Doxorubicin is a leading chemotherapeutic halting cellular replication and inducing p53-dependent apoptosis in cancerous tissue. Like many chemotherapies, doxorubicin damages healthy tissue throughout the body through cellular mechanisms independent of its chemotherapeutic action. Although cognitive impairment is commonly recorded in patients after chemotherapy, the occurrence of doxorubicin-induced "chemo-brain" is debated, as doxorubicin cannot cross the blood-brain barrier. However, the potential of indirect doxorubicin neurotoxicity remains, providing a foundation for doxorubicin-mediated chemo-brain. We present the first meta-analysis of defined cognitive performance of doxorubicin-treated patients. A search of PubMed and MedLine collected 494 studies, 14 of which met analysis criteria. Performance of 511 doxorubicin-treated women with breast cancer was compared to that of 306 healthy controls across measures of defined cognitive modalities. Treated patients experience significant impairment in global cognition compared to controls (g₌ -0.41, P < 0.001), with select impairment in executive function (g = -0.25, P < 0.0001), language (g = -0.30, P < 0.0001), memory (g = -0.12, P < 0.01) and processing speed (g = -0.28, P < 0.01). Within memory, short-term verbal memory is most significantly affected (g = -0.21, P < 0.01). Impairment in select cognitive modalities (executive function, language, memory, short-term verbal memory, processing speed) is prevalent in doxorubicin-treated patients, with some cognitive functions remaining intact (attention, motor function, visuospatial abilities). This information can guide the development of future interventions to improve quality-of-life (QOL) and doxorubicin-derived therapies that target cytotoxicity to cancerous tissue, avoiding healthy tissue damage, which is mediated by seemingly independent mechanisms.

Biodistribution and toxicity assessment of copper nanoparticles in the rat brain

AIMS

The increase in the usage of copper nanoparticles (Cu NPs) in the industrial and medical fields has raised concerns about their possible adverse effects. The present study aims to investigate the potential adverse effects of Cu NPs on the brain of adult male Wistar rats through the estimation of some oxidative stress parameters and acetylcholinesterase (AChE) activity.

BASIC PROCEDURES

Cu NPs were prepared and characterized using different techniques: Dynamic Light Scattering, X-Ray Diffraction, Transmission and Scanning Electron Microscopy, Fourier transform Infrared Spectroscopy, in addition to Energy Dispersive X-ray Spectroscopy. Rats were divided into two groups: Cu NPs-treated group (IV injected with 15 mg/kg ˷ 13 nm Cu NPs for 2 successive days) and a control group (injected with saline). Rats of the 2 groups were decapitated simultaneously after 48 h of the last injection. The Cu content in different brain areas was analyzed using inductively coupled plasma mass spectrometry. Moreover, the effect of Cu NPs on brain edema was evaluated. The behavior of rats in an open-field was also examined 24 h post the last injection.

MAIN FINDINGS

Significant increases of Cu content in the cortex, cerebellum, striatum, thalamus and hippocampus were found. Moreover, Cu NPs lead to the induction of oxidative stress condition in the thalamus, hypothamaus and medulla. In addition, Cu NPs induced significant increases in AChE activity in the medulla, hippocampus, striatum besides midbrain. Cu NPs-injected rats showed also decreased exploratory behaviour.

PRINCIPAL CONCLUSION

The results obtained in the present study point to the importance of toxicity assessments in evaluating the efficiency of Cu NPs for the safe implementation in different applications.

A Bibliometric Review of Publications on Oxidative Stress and Chemobrain: 1990-2019

Oxidative stress is considered one of the possible mechanisms behind chemobrain or the cognitive dysfunction persistent after chemotherapy treatment. Breast cancer patients have reported chemobrain symptoms since the 1990s. In this present bibliometric review, we employed the VOSviewer tool to describe the existing landscape on literature concerning oxidative stress, breast cancer chemotherapies, and chemobrain. As of 2019, 8799 papers were listed in the Web of Science database, with more than 900 papers published each year. As expected, terms relating to oxidative stress, mitochondria, breast cancer, and antioxidants have occurred very often in the literature throughout the years. In recent years, there has been an increase in the occurrence of terms related to nanomedicine. Only within the last decade do the keywords 'brain', 'blood-brain barrier', and 'central nervous system' appear, reflecting an increased interest in chemobrain. China has become the most prolific producer of oxidative stress and chemotherapy related papers in the last decade followed by the USA and India. In conclusion, the subject of oxidative stress as a mechanism behind chemotherapies' toxicities is an active area of research.

Post-chemotherapy cognitive impairment in hematological patients: current understanding of chemobrain in hematology

Introduction: Cognitive impairment caused by chemotherapies, a condition known as chemobrain, is a possible side effect that affects alertness, learning, memory, and concentration.Areas covered: Chemobrain has been principally investigated as a possible side-effect among cancer patients. However, numerous drugs used to treat hematological malignancies can determine the appearance of chemobrain. In this review, we have examined some commonly used drugs for the treatment of hematological malignancies which are known to have a deleterious action on cognitive functions.Numerous mechanisms have been suggested, comprising the direct neurotoxicity of chemotherapeutic drugs, oxidative stress, genetic predisposition, cytokine-provoked damage, histone modifications, immune alteration, and the action of chemotherapeutic on trophic factors and structural proteins of brain cells.Expert commentary: Cognitive dysfunction provoked by the treatment of hematological diseases is an actual challenge in clinical practice. Actually, there are no totally efficient and innocuous treatments for this syndrome. It is important that further investigations specify the existence of predictors and gravity factors to pre- and post-therapy cognitive change and identify the influence of tumor treatments on the cognitive alterations in long-term, cancer survivors. Moreover, future studies are needed to analyze the interactions between genetic risk, amyloid accumulation, intrinsic brain networks, and chemotherapy.

Polydatin ameliorates chemotherapy-induced cognitive impairment (chemobrain) by inhibiting oxidative stress, inflammatory response, and apoptosis in rats

Most breast cancer survivors receiving chemotherapy have severe cognitive impairment, often referred to as "chemobrain." Polydatin (PLD) is known to have many biological activities. Thus, this study aimed to determine whether symptoms of chemobrain can be prevented or relieved by PLD. The chemobrain models were established by intraperitoneal injection of doxorubicin (DOX, 2 mg/kg) in rats once a week for 4 weeks (DOX group and DOX+PLD group). In the PLD group and DOX+PLD group, PLD (50 mg/kg) was administered orally to rats every day. We found that PLD treatment significantly protected against DOX-induced learning and memory impairment, restored hippocampal histopathological architecture. Furthermore, PLD suppressed DOX-induced oxidative stress through up-regulating Nrf2, inhibited inflammatory response by activating the NF-κB pathway, and reduced hippocampal apoptosis. Therefore, the present study indicated that PLD offered neuroprotection against DOX-induced chemobrain. PLD may assist in preventing chemobrain after chemotherapy in patients with cancers.

Plausible biochemical mechanisms of chemotherapy-induced cognitive impairment ("chemobrain"), a condition that significantly impairs the quality of life of many cancer survivors

Increasing numbers of cancer patients survive and live longer than five years after therapy, but very often side effects of cancer treatment arise at same time. One of the side effects, chemotherapy-induced cognitive impairment (CICI), also called "chemobrain" or "chemofog" by patients, brings enormous challenges to cancer survivors following successful chemotherapeutic treatment. Decreased abilities of learning, memory, attention, executive function and processing speed in cancer survivors with CICI, are some of the challenges that greatly impair survivors' quality of life. The molecular mechanisms of CICI involve very complicated processes, which have been the subject of investigation over the past decades. Many mechanistic candidates have been studied including disruption of the blood-brain barrier (BBB), DNA damage, telomere shortening, oxidative stress and associated inflammatory response, gene polymorphism of neural repair, altered neurotransmission, and hormone changes. Oxidative stress is considered as a vital mechanism, since over 50% of FDA-approved anti-cancer drugs can generate reactive oxygen species (ROS) or reactive nitrogen species (RNS), which lead to neuronal death. In this review paper, we discuss these important candidate mechanisms, in particular oxidative stress and the cytokine, TNF-alpha and their potential roles in CICI.

β-elemene inhibits radiation and hypoxia-induced macrophages infiltration via Prx-1/NF-κB/HIF-1α signaling pathway

Background: In cancers, tumor-associated macrophages (TAMs) play an important role in the progression, evasion of immunity and sensitivity to therapy. Unfortunately, radiation and hypoxia could induce the M2 macrophages infiltration and polarization. Materials and methods: In this study, we investigated the relevance of macrophage recruitment with radiation and hypoxia by transwell. We also evaluated the effect of β-elemene on the infiltration of M2 macrophages and explored its underlying molecular mechanism by a series of in vitro and in vivo experiments. Results: Irradiated or hypoxia lung cancer cells recruit macrophages, and the recruitment is MCP-1 dependent. We also found that radiation and hypoxia-induced MCP-1 secretion follows upregulation of Prx-1, which leads to nuclear accumulation of NF-κB and HIF-1α expression. In addition, β-elemene could effectively suppress this recruitment phenomenon through Prx-1/NF-κB/HIF-1α signaling. Conclusion: Our study showed that radiation and hypoxia significantly promoted the macrophages recruitment. β-elemene could effectively suppress this recruitment phenomenon and MCP-1 expression via inhibiting Prx-1/NF-κB/HIF-1α pathways.

Evaluation of the effects of chemotherapy on brain glucose metabolism in children with Hodgkin's lymphoma

OBJECTIVE

Chemobrain is a recently proposed pathological entity. ¹⁸F-FDG PET/CT can show objective abnormalities to explain brain disorders caused by chemotherapy, although no study has investigated these phenomena in children to date. The main objective of the present study was to examine quantitatively the effects of chemotherapy on brain metabolism in a homogeneous population of children treated for Hodgkin's lymphoma using 18F-FDG PET/CT.

METHODS

In this retrospective study, we included 20 children, newly diagnosed with Hodgkin's lymphoma, who underwent ¹⁸F-FDG PET/CT at initial staging and at least one PET/CT in follow-up. The SPM12 software provided t-maps to show the difference in metabolism between these PET/CTs. The statistical maps were analyzed with xjView software to identify the brain regions associated with the clusters detected.

RESULTS

Altered glucose metabolism was found in the frontal, cingular, and temporoinsular regions after two cycles of chemotherapy. Results in children were compared to a group of 35 adults. For the same statistical threshold, the extent and depth of the metabolic alterations were less in the adult group than in children.

CONCLUSIONS

¹⁸F-FDG PET/CT is useful in providing objective data to explain brain disorders caused by chemotherapy. This could lead to better care and should be compared to neuropsychological test results.

Chemotherapy-Induced Cognitive Impairment Is Associated with Increased Inflammation and Oxidative Damage in the Hippocampus

Increasing evidence indicates that chemotherapy results in long-term effects on cognitive dysfunction in some cancer survivors. While many studies have established the domains of cognition and corresponding regions in the brain most affected, little is revealed about the potential molecular mechanisms that mediate these adverse changes after treatment. The effects of chemotherapy on the brain are likely attributed to various mechanisms, including oxidative stress and immune dysregulation, features that are also reminiscent of cognitive aging. We have investigated the cognitive effects of a cocktail composed of doxorubicin and cyclophosphamide (AC-chemo) in a surgical ovariectomized rodent model. In this study, we address whether the levels of pro-inflammatory cytokines and oxidative stress-responsive gene markers are altered in the CNS of rats treated with systemic AC-chemo. We further evaluated the levels of nucleic acids modified by oxidative stress in the hippocampus using both immunohistochemical and Northern blotting techniques with a monoclonal antibody against 8-hydroxyguanosine (8-OHG) and 8-OHdG base lesions. We demonstrate that ERK 1/2 and JNK/SAPK signaling activities are elevated in the hippocampus of AC-chemo rats. The levels of pro-inflammatory, oxidative stress-responsive, and RNA/DNA damage markers were also higher in drug-injected animals relative to saline controls. The results indicate that the effects of AC chemotherapy are associated with oxidative damage and a global stress response in the hippocampus. These alterations in the molecular signature of the brain may underlie the processes that contribute to cognitive impairment after treatment.