Protective effect of leukotriene receptor antagonist, montelukast, against cyclophosphamide-induced placental toxicity via modulation of NLRP3/IL-1β signaling pathway in rats

BACKGROUNDS & AIM

Placental insufficiency is a serious complication that affects pregnancy and fetal growth. Cyclophosphamide (CYC) is considered one of the chemotherapeutic agents. Unfortunately, CYC not only affects tumor cells but also affects healthy cells causing multiple injuries including the placenta. The present study aimed to evaluate the effect of cysteinyl leukotriene receptor antagonist; montelukast (MK), on CYC-induced placental injury in rats.

MATERIALS AND METHODS

Forty-eight female Wister rats were randomly divided into 8 experimental groups. Group 1: control pregnant group; Group 2: MK 5 mg-treated pregnant rats; Group 3: MK 10 mg-treated pregnant rats; Group 4: MK 20 mg-treated pregnant rats; Group 5: pregnant rats received CYC (20 mg/kg, i.p); Group 6: pregnant rats received MK 5 mg and CYC; Group 7: pregnant rats received MK 10 mg and CYC; Group 8: pregnant rats received MK 20 mg and CYC. Placental malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), placental growth factor (PlGF), and Nod-like receptor p3 (NLRP3) inflammasome were measured. Histological changes, interleukin-1β (IL-1β), and cleaved caspase-3 immuno-expressions were also evaluated.

RESULTS

CYC showed a significant decrease in placental GSH, TAC, and PlGF with a significant increase in placental MDA, NLRP3, and immuno-expression of IL-1β and caspase-3. MK showed significant improvement in all oxidative stress (MDA, GSH and TAC), inflammatory (NLRP3 and IL-1β), and apoptotic (caspase-3) parameters.

CONCLUSION

According to the findings, MK was proved to have a possible protective role in CYC-induced placental injury via modulation of NLRP3/IL-1β signaling pathway with anti-oxidant, anti-inflammatory, and anti-apoptotic effects.

The effect of acute crocin on behavioral changes and BDNF expression level in socially isolated rats

Social isolation is a reliable method used for the induction of depression and psychiatric disorders in rodents. It has been suggested that social isolation can lead to hyperlocomotion, as a schizophrenic-like symptom in rodents. On the other hand, crocin (the major constituent of Crocus sativus) induces a wide-range of neuroprotective and mood enhancer effects. In the present study, we aimed to investigate the effect of acute crocin on social isolation-induced behavioral changes and BDNF expression in the hippocampus. Novelty-suppressed feeding test, open field test, marble burying test, hot plate, forced swim test, and the shuttle box were used to assess anxiety-like behavior, locomotor activity, obsessive-compulsive-like (OCD-like) behavior, pain threshold, depressive-like behavior, and passive avoidance memory, respectively. Real-time PCR was used to assess BDNF hippocampal expression level. The results showed that social isolation decreased anxiety- and depressive-like behavior, pain threshold, and BDNF expression, and induced OCD-like behavior and hyperlocomotion. Crocin dose-dependently restored the effect of social isolation on pain threshold, locomotor activity, depressive-like behavior, OCD-like behavior, and BDNF expression. Passive avoidance memory performance was also unaffected. In conclusion, we showed a hyperlocomotion profile and OCD-like behaviors, and a robust decrease in pain threshold in socially isolated rats. It can be suggested that social isolation from adolescence induces a "hyperlocomotion state" that affects all the behavioral functions of rats. Also, the function of BDNF can be related to a hyperlocomotion state and OCD-like symptom. It seems that BDNF expression level can be related to the therapeutic effect of crocin.

Anti-inflammatory, antioxidant and anti-mitophagy effects of trans sodium crocetinate on experimental autoimmune encephalomyelitis in BALB/C57 mice

Multiple sclerosis (MS) is an autoimmune disorder characterized by the degeneration of myelin and inflammation in the central nervous system. Trans sodium crocetinate (TSC), a novel synthetic carotenoid compound, possesses antioxidant, anti-inflammatory and neuroprotective effects. This study aimed to evaluate the protective effects of TSC against the development of experimental autoimmune encephalomyelitis (EAE), a well-established model for MS. Female BALB/C57 mice were divided into different groups, including control, EAE, vehicle, TSC-treated (25, 50, and 100 mg/kg, administered via gavage) + EAE, methyl prednisone acetate + EAE, and TSC-treated (100 mg/kg, administered via gavage for 28 days) groups. EAE was induced using MOG35-55, complete Freund's adjuvant, and pertussis toxin. In the mice spinal cord tissues, the oxidative markers (GSH and MDA) were measured using spectrophotometry and histological evaluation was performed. Mitophagic pathway proteins (PINK1and PARKIN) and inflammatory factors (IL-1β and TNF-α) were evaluated by western blot. Following 21 days post-induction, EAE mice exhibited weight loss, and the paralysis scores increased on day 13 but recovered after TSC (100 mg/kg) administration on day 16. Furthermore, TSC (50 and 100 mg/kg) reversed the altered levels of MDA and GSH in the spinal cord tissue of EAE mice. TSC (100 mg/kg) also decreased microgliosis, demyelination, and the levels of inflammatory markers IL-1β and TNF-α. Notably, TSC (100 mg/kg) modulated the mitophagy pathway by reducing PINK1 and Parkin protein levels. These findings demonstrate that TSC protects spinal cord tissue against EAE-induced MS through anti-inflammatory, antioxidant, and anti-mitophagy mechanisms.

Modulating effects of crocin on lipids and lipoproteins: Mechanisms and potential benefits

Dyslipidemia poses a significant risk to cardiovascular health in both diabetic and non-diabetic individuals. Therefore, it is crucial to normalize lipid homeostasis in order to prevent or minimize complications associated with dyslipidemia. However, pharmacological interventions for controlling lipid metabolism often come with adverse effects. As an alternative, utilizing herbal-based agents, which typically have fewer side effects, holds promise. Crocin, a naturally occurring nutraceutical, has been shown to impact various intracellular pathways, reduce oxidative stress, and alleviate inflammatory processes. Recent evidence suggests that crocin may also confer lipid-related benefits and potentially contribute to the normalization of lipid homeostasis. However, the specific advantages and the cellular pathways involved are not yet well understood. In this review, we present the latest findings regarding the lipid benefits of crocin, which could be instrumental in preventing or reducing disorders associated with dyslipidemia. Additionally, we explore the potential cellular mechanisms and pathways that mediate these lipid benefits.

Saffron carotenoids reversed the UCMS-induced depression and anxiety in rats: Behavioral and biochemical parameters, and hippocampal BDNF/ERK/CREB and NR2B signaling markers

BACKGROUND

Depression is a debilitating condition that affects the mind and the individual's body. The improving effects of saffron on depression and anxiety have long been discussed, with limited information about the molecular mechanism of action.

HYPOTHESIS/PURPOSE

Investigating the effect of saffron carotenoids, Crocin and Crocetin, on depression and anxiety in rats by emphasizing some signaling pathways involved.

STUDY DESIGN

Depression and anxiety were induced in rats via unpredictable chronic mild stress (UCMS). Then different rat groups were treated with Crocin, Crocetin, Fluoxetine, and vehicle. Behavioral tests were done before and after treatment.

METHODS

The serum Serotonin and Corticosterone and the expression of some hippocampal signaling proteins were studied. Furthermore, bioinformatics tools were used to predict the interactions of Crocin/ Crocetin with the Serotonin transporter and NMDA receptor subunit NR2B. Then, the patch-clamp was used to study the interaction of Crocetin with the NMDA receptor.

RESULTS

Various behavioral tests confirmed the induction of depression and the improvement of depression by these natural carotenoids. In addition, Crocin/ Crocetin significantly increased the decreased serum Serotonin and reduced the increased serum Corticosterone in the depressed groups. They also increased or caused a trend of increase in the CREB, ERK, BAD, BDNF, p11, and 5-HT1B expression in the hippocampus of the depressed groups. In addition, there were an increase or a trend in p-CREB/CREB, p-ERK1/2 /ERK1/2, and p-BAD/BAD ratios in the Crocin/ Crocetin treated depressed groups. However, the NR2B and FOXO3a expression showed a trend of decrease in depressed groups after treatment. The bioinformatics data indicated that Crocin/ Crocetin could bind to the Serotonin transporter (SLC6A4) and NR2B subunit of the NMDA receptor. Both carotenoids bind to the same site as Fluoxetine in the SLC6A4. However, they bound to different sites on the NR2B. So, Crocetin binds to NR2B at the same site as Ifenprodil. But Crocin bound to another site. The whole cell patch-clamp recording on the normal rat hippocampus revealed a significant decrease in the NMDA peak amplitude after Crocetin treatment, indicating its inhibitory effect on this receptor.

CONCLUSION

The antidepressant activities of Crocin/ Crocetin are possibly due to their effects on Serotonin and Corticosterone serum concentrations, NR2B expression, and the downstream signaling pathways. Furthermore, these natural carotenoids, like Fluoxetine, induced an increasing tendency in p11 and 5HT1B in depressed rats.

The impact of psychostimulants on central and peripheral neuro-immune regulation: a scoping review of cytokine profiles and their implications for addiction

It is now well-accepted that psychostimulants act on glial cells causing neuroinflammation and adding to the neurotoxic effects of such substances. Neuroinflammation can be described as an inflammatory response, within the CNS, mediated through several cytokines, reactive oxygen species, chemokines and other inflammatory markers. These inflammatory players, in particular cytokines, play important roles. Several studies have demonstrated that psychostimulants impact on cytokine production and release, both centrally and at the peripheral level. Nevertheless, the available data is often contradictory. Because understanding how cytokines are modulated by psychoactive substances seems crucial to perspective successful therapeutic interventions, here, we conducted a scoping review of the available literature. We have focused on how different psychostimulants impact on the cytokine profile. Publications were grouped according to the substance addressed (methamphetamine, cocaine, methylphenidate, MDMA or other amphetamines), the type of exposure and period of evaluation (acute, short- or long-term exposure, withdrawal, and reinstatement). Studies were further divided in those addressing central cytokines, circulating (peripheral) levels, or both. Our analysis showed that the classical pro-inflammatory cytokines TNF-α, IL-6, and IL-1β were those more investigated. The majority of studies have reported increased levels of these cytokines in the central nervous system after acute or repeated drug. However, studies investigating cytokine levels during withdrawal or reinstatement have shown higher variability in their findings. Although we have identified fewer studies addressing circulating cytokines in humans, the available data suggest that the results may be more robust in animal models than in patients with problematic drug use. As a major conclusion, an extensive use of arrays for relevant cytokines should be considered to better determine which cytokines, upon the classical ones, may be involved in the progression from episodic use to the development of addiction. A concerted effort is still necessary to address the link between peripheral and central immune players, including from a longitudinal perspective. Until there, the identification of new biomarkers and therapeutic targets to envision personalized immune-based therapeutics will continue to be unlikely.

Therapeutic implications of crocin in Parkinson's disease: A review of preclinical research

Parkinson's disease is among the most common forms of neurodegenerative illness, with present treatment being primarily symptomatic and frequently coming with substantial adverse effects. Neuronal degeneration may arise due to a variety of pathological events, like inflammatory responses, neurotransmitter dysregulation, oxidative damage, mitochondrial malfunction, apoptosis, and genetic factors. The health issue and financial burden brought on by Parkinson's disease can worsen as the population ages. In the search for new and secure therapeutic agents for Parkinson's disease, several natural compounds have been shown to exert considerable neuroprotective benefits. Crocin, a naturally occurring carotenoid molecule, was found to have neuroprotective potential in the therapy of this disorder. Taking into account, the outcomes of various studies and the restorative actions of crocin, the present study emphasized the protective ability of crocin in this disease. Given the strong evidence supporting the neuroprotective ability of crocin, it is inferred that crocin inhibits inflammatory, apoptotic, and antioxidant processes through multiple mechanisms. Therefore, this compound is considered a safe and effective therapeutic choice for neurodegenerative illnesses like Parkinson's disease. However, more research on its efficacy as a treatment of Parkinson's disease is needed, specifically examining its mechanisms and the results obtained in clinical trials.

Resveratrol Ameliorates Trigeminal Neuralgia-Induced Cognitive Deficits by Regulating Neural Ultrastructural Remodelling and the CREB/BDNF Pathway in Rats

Chronic pain often leads to cognitive impairment. Resveratrol (Res), a natural polyphenol existing in Polygonum cuspidatum, has been widely investigated for its antinociceptive, anti-inflammatory, and neuroprotective properties. Our aim was to explore the ameliorating effects of resveratrol on pain-related behaviors and learning and memory deficits induced by cobra venom-induced trigeminal neuralgia (TN). The TN model of rats was established by injecting cobra venom solution beneath the epineurium of the infraorbital nerve. Resveratrol was intragastrically administered at a dose of 40 mg/kg twice daily beginning on postoperative day 15. CREB inhibitor 666-15 was intraperitoneally administered at a dose of 10 mg/kg from POD 35-42 after morning resveratrol treatment. Mechanical allodynia was measured via von Frey filaments. Rat free movement was videotaped and analyzed. Spatial learning and memory were evaluated via the Morris water maze test. Ultrastructures of the hippocampal DG region and infraorbital nerve were observed by transmission electron microscopy. We found that resveratrol alleviated TN-induced allodynia, ameliorated learning and memory deficits, restored the ultrastructure of hippocampal neurons and synapses, repaired the damaged myelin sheath of the infraorbital nerve, and activated the CREB/BDNF pathway in the hippocampus of TN rats. CREB inhibitor administration suppressed the resveratrol-rescued abnormal hippocampal ultrastructural changes and aggravated spatial learning and memory impairment by inhibiting CREB/BDNF pathway activation in the hippocampus. Our findings indicated that resveratrol alleviated pain and improved cognitive deficits, probably by regulating neural ultrastructure remodelling and the CREB/BDNF pathway.

Molecular Characterisation of the Mechanism of Action of Stimulant Drugs Lisdexamfetamine and Methylphenidate on ADHD Neurobiology: A Review

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood-onset neurodevelopmental disorder characterised by persistent inattention, hyperactivity and impulsivity. Moreover, ADHD is commonly associated with other comorbid diseases (depression, anxiety, bipolar disorder, etc.). The ADHD symptomatology interferes with subject function and development. The treatment of ADHD requires a multidisciplinary approach based on a combination of non-pharmacological and pharmacological treatments with the aim of ameliorating the symptomatology; among first-line pharmacological treatments are stimulants [such as methylphenidate (MPH) and lisdexamfetamine dimesylate (LDX)]. In this review we explored recent ADHD- and stimulants-related literature, with the aim of compiling available descriptions of molecular pathways altered in ADHD, and molecular mechanisms of current first-line stimulants MPH and LDX. While conducting the narrative review, we applied structured search strategies covering PubMed/MEDLINE database and performed handsearching of reference lists on the results of those searches. The aetiology and pathophysiology of ADHD are incompletely understood; both genetic and environmental factors have been associated with the disorder and its grade of burden, and also the relationship between the molecular mechanisms of pharmacological treatments and their clinical implications. The lack of comprehensive understanding of the underlying molecular pathology makes both the diagnosis and treatment difficult. Few published studies evaluating molecular data on the mechanism of action (MoA) of MPH and LDX on ADHD are available and most of them are based on animal models. Further studies are necessary to improve the knowledge of ADHD pathophysiology and how the MoAs of MPH and LDX differentially modulate ADHD pathophysiology and control ADHD symptomatology.

Evidence of methylphenidate effect on mitochondria, redox homeostasis, and inflammatory aspects: Insights from animal studies

Methylphenidate (MPH) is a central nervous system (CNS) stimulant known for its effectiveness in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), a neuropsychiatric condition that has a high incidence in childhood and affects behavior and cognition. However, the increase in its use among individuals who do not present all the diagnostic criteria for ADHD has become a serious public health problem since the neurological and psychiatric consequences of this unrestricted use are not widely known. In addition, since childhood is a critical period for the maturation of the CNS, the high prescription of MPH for preschool children also raises several concerns. This review brings new perspectives on how MPH (in different doses, routes of administration and ages) affects the CNS, focusing on animal studies that evaluated changes in mitochondrial (bioenergetics), redox balance and apoptosis, as well as inflammatory parameters. MPH alters brain energy homeostasis, increasing glucose consumption and impairing the activity of enzymes in the Krebs cycle and electron transport chain, as well as ATP levels and Na⁺,K⁺-ATPase activity. MPH induces oxidative stress, increasing the levels of reactive oxygen and nitrogen species and altering enzymatic and non-enzymatic antioxidant defenses, which, consequently, is related to damage to proteins, lipids, and DNA. Among the harmful effects of MPH, studies also demonstrate its ability to induce inflammation as well as alter the apoptosis pathway. It is important to highlight that age, treatment time, administration route, and dose are factors that can influence MPH effects. However, young animals seem to be more susceptible to damage caused by MPH. It is possible that changes in mitochondrial function and markers of status oxidative, apoptosis and inflammation may be exerting important mechanisms associated with MPH toxicity and, therefore, the unrestricted use of this drug can cause brain damage.

Roflumilast Ameliorates Isoflurane-Induced Inflammation in Astrocytes via the CREB/BDNF Signaling Pathway

Background and purpose: Astrocyte-mediated neuroinflammation plays an important role in anesthetic isoflurane-induced cognitive impairment. Roflumilast, a selective inhibitor of phosphodiesterase-4 (PDE-4) used for the treatment of chronic obstructive pulmonary disease (COPD), has displayed a wide range of anti-inflammatory capacity in different types of cells and tissues. In the current study, we aimed to investigate whether roflumilast possesses a protective effect against isoflurane-induced insults in mouse primary astrocytes. Methods: Primary astrocytes were isolated from the cerebral cortices of immature rats. The production of NO was determined using DAF-FM DA staining assay. QRT-PCR and western blot were used to evaluate the expression levels of iNOS, COX-2, and BDNF in the astrocytes treated with different therapies. The gene expressions and concentrations of IL-6 and MCP-1 released by the astrocytes were detected using qRT-PCR and ELISA, respectively. The expression levels of phosphorylated CREB and PGE₂ were determined using western blot and ELISA, respectively. H89 was introduced to evaluate the function of CREB. Recombinant human BDNF and ANA-12 were used to verify the role of BDNF. Results: The upregulated iNOS, excessive production of NO, IL-6, and MCP-1, and activated COX-2/PGE₂ signaling pathways in the astrocytes induced by isoflurane were significantly reversed by the introduction of roflumilast, in a dose-dependent manner. Subsequently, we found that BDNF could be upregulated by roflumilast, which was verified to be related to the activation of CREB and blocked by H89 (a CREB inhibitor). In addition, the COX-2/PGE₂ signaling pathway activated by isoflurane can be inactivated by recombinant human BDNF. Finally, the regulatory effect of roflumilast against the isoflurane-activated COX-2/PGE₂ signaling pathway was significantly blocked by ANA-12, which is a BDNF inhibitor. Conclusion: Roflumilast might ameliorate isoflurane-induced inflammation in astrocytes via the CREB/BDNF signaling pathway.