Neonatal hypoxia impairs serotonin release and cognitive functions in adult mice.

Children who experienced moderate perinatal asphyxia (MPA) are at risk of developing long lasting subtle cognitive and behavioral deficits, including learning disabilities and emotional problems. The prefrontal cortex (PFC) regulates cognitive flexibility and emotional behavior. Neurons that release serotonin (5-HT) project to the PFC, and compounds modulating 5-HT activity influence emotion and cognition. Whether 5-HT dysregulations contribute to MPA-induced cognitive problems is unknown. We established a MPA mouse model, which displays recognition and spatial memory impairments and dysfunctional cognitive flexibility. We found that 5-HT expression levels, quantified by immunohistochemistry, and 5-HT release, quantified by in vivo microdialysis in awake mice, are reduced in PFC of adult MPA mice. MPA mice also show impaired body temperature regulation following injection of the 5-HT1A receptor agonist 8-OH-DPAT, suggesting the presence of deficits in 5-HT auto-receptor function on raphe neurons. Finally, chronic treatment of adult MPA mice with fluoxetine, an inhibitor of 5-HT reuptake transporter, or the 5-HT1A receptor agonist tandospirone rescues cognitive flexibility and memory impairments. All together, these data demonstrate that the development of 5-HT system function is vulnerable to moderate perinatal asphyxia. 5-HT hypofunction might in turn contribute to long-term cognitive impairment in adulthood, indicating a potential target for pharmacological therapies.

Fluoxetine Successfully Treats Intracranial Enterovirus E18 Infection in a Patient with CD79a Deficiency Arising from Segmental Uniparental Disomy of Chromosome 19.

The pre BCR complex plays a crucial role in B cell production, and its successful expression marks the B cell differentiation from the pro-B to pre-B. The CD79a and CD79b mutations, encoding Igα and Igß respectively, have been identified as the cause of autosomal recessive agammaglobulinemia (ARA). Here, we present a case of a patient with a homozygous CD79a mutation, exhibiting recurrent respiratory infections, diarrhea, growth and development delay, unique facial abnormalities and microcephaly, as well as neurological symptoms including tethered spinal cord, sacral canal cyst, and chronic enteroviral E18 meningitis. Complete blockade of the early B cell development in the bone marrow of the patient results in the absence of peripheral circulating mature B cells. Whole exome sequencing revealed a Loss of Heterozygosity (LOH) of approximately 19.20Mb containing CD79a on chromosome 19 in the patient. This is the first case of a homozygous CD79a mutation caused by segmental uniparental diploid (UPD). Another key outcome of this study is the effective management of long-term chronic enteroviral meningitis using a combination of intravenous immunoglobulin (IVIG) and fluoxetine. This approach offers compelling evidence of fluoxetine's utility in treating enteroviral meningitis, particularly in immunocompromised patients.

Pharmaceutical pollution alters the cost of bacterial infection and its relationship to pathogen load.

The relationship between pathogen proliferation and the cost of infection experienced by a host drives the ecology and evolution of host-pathogen dynamics. While environmental factors can shape this relationship, there is currently limited knowledge on the consequences of emerging contaminants, such as pharmaceutical pollutants, on the relationship between a pathogen's growth within the host and the damage it causes, termed its virulence. Here, we investigated how exposure to fluoxetine (Prozac), a commonly detected psychoactive pollutant, could alter this key relationship using the water flea Daphnia magna and its bacterial pathogen Pasteuria ramosa as a model system. Across a variety of fluoxetine concentrations, we found that fluoxetine shaped the damage a pathogen caused, such as the reduction in fecundity or intrinsic growth experienced by infected individuals, but with minimal change in average pathogen spore loads. Instead, fluoxetine modified the relationship between the degree of pathogen proliferation and its virulence, with both the strength of this trade-off and the component of host fitness most affected varying by fluoxetine concentration and host genotype. Our study underscores the potential for pharmaceutical pollution to modify the virulence of an invading pathogen, as well as the fundamental trade-off between host and pathogen fitness, even at the trace amounts increasingly found in natural waterways.

Fluoxetine exerts anti-inflammatory effects on human epidermal keratinocytes and suppresses their endothelin release.

Fluoxetine is a safe antidepressant with remarkable anti-inflammatory actions; therefore, we aimed to investigate its effects on immortalized (HaCaT) as well as primary human epidermal keratinocytes in a polyinosinic-polycytidylic acid (p(I:C))-induced inflammatory model. We found that a non-cytotoxic concentration (MTT-assay, CyQUANT-assay) of fluoxetine significantly suppressed p(I:C)-induced expression and release of several pro-inflammatory cytokines (Q-PCR, cytokine array, ELISA), and it decreased the release of the itch mediator endothelins (ELISA). These effects were not mediated by the inhibition of the NF-κB or p38 MAPK pathways (western blot), or by the suppression of the p(I:C)-induced elevation of mitochondrial ROS production (MitoSOX Red labeling). Instead, unbiased activity profiling revealed that they were most likely mediated via the inhibition of the phosphoinositide 3-kinase (PI3K) pathway. Importantly, the PI3K-inhibitor GDC0941 fully mimicked the effects of fluoxetine (Q-PCR, ELISA). Although fluoxetine was able to occupy the binding site of GDC0941 (in silico molecular docking), and exerted direct inhibitory effect on PI3K (cell-free PI3K activity assay), it exhibited much lower potency and efficacy as compared to GDC0941. Finally, RNA-Seq analysis revealed that fluoxetine deeply influenced the transcriptional alterations induced by p(I:C)-treatment, and exerted an overall anti-inflammatory activity. Collectively, our findings demonstrate that fluoxetine exerts potent anti-inflammatory effects, and suppresses the release of the endogenous itch mediator endothelins in human keratinocytes, most likely via interfering with the PI3K pathway. Thus, clinical studies are encouraged to explore whether the currently reported beneficial effects translate in vivo following its topical administration in inflammatory and pruritic dermatoses.

Inhibitory modulation of action potentials in crayfish motor axons by fluoxetine.

The goal of this report is to explore how K2P channels modulate axonal excitability by using the crayfish ventral superficial flexor preparation. This preparation allows for simultaneous recording of motor nerve extracellular action potentials (eAP) and intracellular excitatory junctional potential (EJP) from a muscle fiber. Previous pharmacological studies have demonstrated the presence of K2P-like channels in crayfish. Fluoxetine (50 µM) was used to block K2P channels in this study. The blocker caused a gradual decline, and eventually complete block, of motor axon action potentials. At an intermediate stage of the block, when the peak-to-peak amplitude of eAP decreased to ∼60%-80% of the control value, the amplitude of the initial positive component of eAP declined at a faster rate than that of the negative peak representing sodium influx. Furthermore, the second positive peak following this sodium influx, which corresponds to the after-hyperpolarizing phase of intracellularly recorded action potentials (iAP), became larger during the intermediate stage of eAP block. Finally, EJP recorded simultaneously with eAP showed no change in amplitude, but did show a significant increase in synaptic delay. These changes in eAP shape and EJP delay are interpreted as the consequence of depolarized resting membrane potential after K2P channel block. In addition to providing insights to possible functions of K2P channels in unmyelinated axons, results presented here also serve as an example of how changes in eAP shape contain information that can be used to infer alterations in intracellular events. This type of eAP-iAP cross-inference is valuable for gaining mechanistic insights here and may also be applicable to other model systems.

Fluoxetine accelerates epileptogenesis and magnifies disease severity in a rat model of acquired epilepsy.

OBJECTIVE: Many people with epilepsy experience comorbid anxiety and depression, and antidepressants remain a primary treatment for this. Emerging evidence suggests that these agents may modulate epileptogenesis to influence disease severity. Here, we assessed how treatment with the selective serotonin reuptake inhibitor (SSRI) antidepressant fluoxetine impacts epileptogenic, behavioral, and pathological sequelae following status epilepticus. METHODS: Male Wistar rats received kainic acid to induce status epilepticus (SE) or vehicle (sham). Animals then received either fluoxetine (10 mg/kg/day) or vehicle for 8 weeks via subcutaneous osmotic pump. Video-electroencephalography was recorded continuously until behavioral testing at day 56, including assessments of anxiety- and depression-like behavior and spatial cognition. Postmortem immunocytochemistry studies examined mossy fiber sprouting. RESULTS: Fluoxetine treatment significantly accelerated epileptogenesis following SE, reducing the average period to the first spontaneous seizure (from 32 days [vehicle] to 6 days [fluoxetine], p < .01). Also, fluoxetine exposure magnified the severity of the resultant epilepsy, increasing seizure frequency compared to vehicle (p < .01). Exposure to fluoxetine was associated with improved anxiety- and depression-like behaviors but significantly worsened cognition. Mossy fiber sprouting was more pronounced in fluoxetine-treated rats compared to vehicle (p < .0001). SIGNIFICANCE: Our studies demonstrate that, using a model exhibiting spontaneous seizures, epileptogenesis is accelerated and magnified by fluoxetine, an effect that may be related to more severe pathological neuroplasticity. The differential influence of fluoxetine on behavior indicates that different circuitry and mechanisms are responsible for these comorbidities. These findings suggest that caution should be exercised when prescribing SSRI antidepressants to people at risk of developing epilepsy.

Enhancing the action of serotonin by three different mechanisms prevents spontaneous seizure-induced mortality in Dravet mice.

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) is an underestimated complication of epilepsy. Previous studies have demonstrated that enhancement of serotonergic neurotransmission suppresses seizure-induced sudden death in evoked seizure models. However, it is unclear whether elevated serotonin (5-HT) function will prevent spontaneous seizure-induced mortality (SSIM), which is characteristic of human SUDEP. We examined the effects of 5-HT-enhancing agents that act by three different pharmacological mechanisms on SSIM in Dravet mice, which exhibit a high incidence of SUDEP, modeling human Dravet syndrome. METHODS: Dravet mice of both sexes were evaluated for spontaneous seizure characterization and changes in SSIM incidence induced by agents that enhance 5-HT-mediated neurotransmission. Fluoxetine (a selective 5-HT reuptake inhibitor), fenfluramine (a 5-HT releaser and agonist), SR 57227 (a specific 5-HT3 receptor agonist), or saline (vehicle) was intraperitoneally administered over an 8-day period in Dravet mice, and the effect of these treatments on SSIM was examined. RESULTS: Spontaneous seizures in Dravet mice generally progressed from wild running to tonic seizures with or without SSIM. Fluoxetine at 30 mg/kg, but not at 20 or 5 mg/kg, significantly reduced SSIM compared with the vehicle control. Fenfluramine at 1-10 mg/kg, but not .2 mg/kg, fully protected Dravet mice from SSIM, with all mice surviving. Compared with the vehicle control, SR 57227 at 20 mg/kg, but not at 10 or 5 mg/kg, significantly lowered SSIM. The effect of these drugs on SSIM was independent of sex. SIGNIFICANCE: Our data demonstrate that elevating serotonergic function by fluoxetine, fenfluramine, or SR 57227 significantly reduces or eliminates SSIM in Dravet mice in a sex-independent manner. These findings suggest that deficits in serotonergic neurotransmission likely play an important role in the pathogenesis of SSIM, and fluoxetine and fenfluramine, which are US Food and Drug Administration-approved medications, may potentially prevent SUDEP in at-risk patients.

Potentiation of Brain Bioavailability Using Thermoreversible Cubosomal Formulation.

The aim of the present study was to develop and evaluate intranasal formulations of the thermoreversible fluoxetine cubosomal in situ gel. This gel was intended for permeation and bioavailability enhancement to target the brain effectively by bypassing the blood-brain barrier (BBB). Fluoxetine-loaded cubosomes were prepared by the homogenization method followed by the cold method approach to develop in situ gel. Fluoxetine-loaded cubosomes displayed a higher encapsulation efficiency (82.60 ± 1.25%) than fluoxetine. This might be due to the solubilizing activity of the polymer to cause partitioning of the lipophilic drug into the aqueous phase during the change from the cubic gel phase to cubosomes. In vitro analysis of fluoxetine-loaded cubosomal in situ gel showed a sustained release profile (93.22 ± 2.47%) due to limited diffusion of fluoxetine. The formation of strong affinity bonds of the drug with GMO (drug transporter) decreased the drug release in comparison to that with fluoxetine-loaded cubosomes (90.68 ± 1.74%). The ex vivo drug release profile revealed the drug release of 96.31 ± 2.88% by the end of 24 h. This is attributed to the higher capability of the intranasal cubosomal in situ gel to prolong the retention and enable better permeation through the nasal mucosa. In male Wistar rats, in vivo biodistribution studies for cubosomal in situ gel administered via the intranasal route at a dose of 3.5 mg/kg demonstrated an increase in pharmacokinetic parameters like the AUC (406 ± 75.35 µg/mL), Cmax (368.07 ± 0.23 µg/mL), Tmax (4 h), and t1/2 (14.06 h). The mucoadhesive nature of the in situ gel led to an increase in the residence time of the gel in the nasal mucosa. The biodistribution study of intranasal in situ cubosomal gel improved the bioavailability 2.21-fold in comparison to that with the cubosomal dispersion but 2.83-fold in comparison to that with the drug solution. Therefore, fluoxetine-loaded cubosomal in situ gel proved as a promising carrier for effective transportation of fluoxetine via the intranasal route with significant brain bioavailability.

Toxicokinetics of the Antidepressant Fluoxetine and Its Active Metabolite Norfluoxetine in Caenorhabditis elegans and Their Comparative Potency.

The nematode Caenorhabditis elegans is a valuable model for ecotoxicological research, yet limited attention has been given to understanding how it absorbs, distributes, metabolizes, and excretes chemicals. This is crucial for C. elegans because the organism is known to have strong uptake barriers that are known to be susceptible to potential confounding effects of the presence of Escherichia coli as a food source. One frequently studied compound in C. elegans is the antidepressant fluoxetine, which has an active metabolite norfluoxetine. In this study, we evaluated the toxicokinetics and relative potency of norfluoxetine and fluoxetine in chemotaxis and activity tests. Toxicokinetics experiments were conducted with varying times, concentrations of fluoxetine, and in the absence or presence of E. coli, simulated with a one-compartment model. Our findings demonstrate that C. elegans can take up fluoxetine and convert it into norfluoxetine. Norfluoxetine proved slightly more potent and had a longer elimination half-life. The bioconcentration factor, uptake, and elimination rate constants depended on exposure levels, duration, and the presence of E. coli in the exposure medium. These findings expand our understanding of toxicokinetic modeling in C. elegans for different exposure scenarios, underlining the importance of considering norfluoxetine formation in exposure and bioactivity assessments of fluoxetine.

Pharmaceutical Pollution Alters the Structure of Freshwater Communities and Hinders Their Recovery from a Fish Predator.

Freshwater ecosystems are under threat from rising pharmaceutical pollution. While such pollutants are known to elicit biological effects on organisms, we have limited knowledge on how these effects might cascade through food-webs, disrupt ecological processes, and shape freshwater communities. In this study, we used a mesocosm experiment to explore how the community impacts of a top-order predator, the eastern mosquitofish (Gambusia holbrooki), are mediated by exposure to environmentally relevant low (measured concentration: ∼10 ng/L) and high concentrations (∼110 ng/L) of the pervasive pharmaceutical pollutant fluoxetine. We found no evidence that exposure to fluoxetine altered the consumptive effects of mosquitofish on zooplankton. However, once mosquitofish were removed from the mesocosms, zooplankton abundance recovered to a greater extent in control mesocosms compared to both low and high fluoxetine-exposed mesocosms. By the end of the experiment, this resulted in fundamental differences in community structure between the control and fluoxetine-treated mesocosms. Specifically, the control mesocosms were characterized by higher zooplankton abundances and lower algal biomass, whereas mesocosms exposed to either low or high concentrations of fluoxetine had lower zooplankton abundances and higher algal biomass. Our results suggest that fluoxetine, even at very low concentrations, can alter aquatic communities and hinder their recovery from disturbances.

Comparing the effect of fluoxetine, escitalopram, and sertraline, on the level of BDNF and depression in preclinical and clinical studies: a systematic review.

Brain-derived neurotrophic factor (BDNF) dysfunction is one of the most important mechanisms underlying depression. It seems that selective serotonin reuptake inhibitors (SSRIs) improve depression via affecting BDNF level. In this systematic review, for the first time, we aimed to review the effect of three SSRIs including fluoxetine, escitalopram, and sertraline, on both depression and BDNF level in preclinical and clinical studies. PubMed electronic database was searched, and 193 articles were included in this study. After reviewing all manuscripts, only one important difference was found: subjects. We found that SSRIs induce different effects in animals vs. humans. Preclinical studies showed many controversial effects, while human studies showed only two effects: improvement of depression, with or without the improvement of BDNF. However, most studies used chronic SSRIs treatment, while acute SSRIs were not effectively used and evaluated. In conclusion, it seems that SSRIs are reliable antidepressants, and the improvement effect of SSRIs on depression is not dependent to BDNF level (at least in human studies).

Structure-Activity Relationship Analysis of Fluoxetine for Suppression of Inflammatory Cytokine Production.

There is accumulating evidence that selective serotonin reuptake inhibitors (SSRIs), clinically used as antidepressants, have a beneficial effect on inflammatory diseases such as coronavirus disease 2019 (COVID-19). We previously compared the inhibitory effects of five U.S. Food and Drug Administration (FDA)-approved SSRIs on the production of an inflammatory cytokine, interleukin-6 (IL-6), and concluded that fluoxetine (FLX) showed the most potent anti-inflammatory activity. Here, we investigated the structure-activity relationship of FLX for anti-inflammatory activity towards J774.1 murine macrophages. FLX suppressed IL-6 production induced by the TLR3 agonist polyinosinic-polycytidylic acid (poly(I : C)) with an IC50 of 4.76 µM. A derivative of FLX containing chlorine instead of the methylamino group lacked activity, suggesting that the methylamino group is important for the anti-inflammatory activity. FLX derivatives bearing an N-propyl or N-(pyridin-3-yl)methyl group in place of the N-methyl group exhibited almost the same activity as FLX. Other derivatives showed weaker activity, and the N-phenyl and N-(4-trifluoromethyl)benzyl derivatives were inactive. The chlorine-containing derivative also lacked inhibitory activity against TLR9- or TLR4-mediated IL-6 production. These derivatives showed similar structure-activity relationships for TLR3- and TLR9-mediated inflammatory responses. However, the activities of all amino group-containing derivatives against the TLR4-mediated inflammatory response were equal to or higher than the activity of FLX. These results indicate that the substituent at the nitrogen atom in FLX strongly influences the anti-inflammatory effect.

Effect of depression and the antidepressant fluoxetine on osseointegration-A pre-clinical in vivo experimental study.

OBJECTIVE: The aim of this study was to explore the effect of depression and selective serotonin reuptake inhibitors on implant osseointegration and bone healing. METHODS: Forty-eight 6- to 8-week-old SPF Sprague-Dawley male rats were randomly divided into four groups: the Control group, the Fluoxetine group, the Depression group and the De&Flu group. The rats in the Depression group and the De&Flu group were subjected to a depression modelling process, and the rats in the Control group and the Fluoxetine group were raised normally. Then, a titanium implant was placed in the right tibia of each rat. In the Fluoxetine group and De&Flu group, fluoxetine was injected subcutaneously daily, while subcutaneously injecting physiological saline in the Control group and Depression group. Collecting serum from the rats used for ELISA. The surgical area was cut for microcomputed tomography and histology observation. RESULTS: After 12 weeks, bone mineral density was lower in the De&Flu group than in the Control group, Depression group and Fluoxetine group. Bone mineral density was also lower in the Depression group and the Fluoxetine group than in the Control group. The percentage of bone-implant contact (BIC%) in De&Flu rats was lower than in the Control, Depression and Fluoxetine groups. The BIC% in the Depression group and the Fluoxetine group was lower than in the Control group. CONCLUSIONS: Depression and fluoxetine negatively affect bone density and implant osseointegration independently, and this damaging effect is exacerbated when both factors are present. The mechanism may be related to the dysregulation of the hypothalamic-pituitary-adrenal axis and inflammation in the body.

Generalized seizures after acute fluoxetine overdose in four adolescents.

Fluoxetine is a selective serotonin reuptake inhibitor that is less frequently associated with severe toxicity in acute overdose compared with other psychotropic medications. Although rare, generalized seizure has been reported after isolated fluoxetine overdose. Most cases in the literature have occurred between one- and 16 h following acute ingestion of ≥1000 mg. Here, we present a series of four cases of adolescents who presented to our pediatric emergency department with reported or witnessed seizures after acute fluoxetine overdose between 3/2021 and 1/2022. These cases included intentional ingestions of fluoxetine at doses between 600 and 1200 mg (10-19.5 mg/kg), each of whom had a single, witnessed episode of generalized seizure activity which occurred between three- and nine-hours post-ingestion. All patients had signs of mild serotonin excess and two met conventional criteria for diagnosis of serotonin toxicity. All patients were evaluated by a medical toxicologist and were hospitalized for observation. No patient developed subsequent seizure or further complications related to overdose and no patient received neuroimaging, electroencephalography, or evaluation by a neurologist. Though previously described, seizure is an uncommon and potentially underappreciated complication after fluoxetine overdose and occurred in some of our patients at doses lower than those which have typically been reported in the literature.

The impact of chronic fluoxetine treatment in adolescence or adulthood on context fear memory and perineuronal nets.

Selective serotonin reuptake inhibitors, such as fluoxetine (Prozac), are commonly prescribed pharmacotherapies for anxiety. Fluoxetine may be a useful adjunct because it can reduce the expression of learned fear in adult rodents. This effect is associated with altered expression of perineuronal nets (PNNs) in the amygdala and hippocampus, two brain regions that regulate fear. However, it is unknown whether fluoxetine has similar effects in adolescents. Here, we investigated the effect of fluoxetine exposure during adolescence or adulthood on context fear memory and PNNs in the basolateral amygdala (BLA), the CA1 subregion of the hippocampus, and the medial prefrontal cortex in rats. Fluoxetine impaired context fear memory in adults but not in adolescents. Further, fluoxetine increased the number of parvalbumin (PV)-expressing neurons surrounded by a PNN in the BLA and CA1, but not in the medial prefrontal cortex, at both ages. Contrary to previous reports, fluoxetine did not shift the percentage of PNNs toward non-PV cells in either the BLA or CA1 in the adults, or adolescents. These findings demonstrate that fluoxetine differentially affects fear memory in adolescent and adult rats but does not appear to have age-specific effects on PNNs.

Involvement of the GABAA Receptor in the Antidepressant-Like Effects Produced by Low and High Doses of the Flavonoid Chrysin in the Rat: A Longitudinal Study.

BACKGROUND: The flavonoid chrysin produces rapid and long-lasting anxiolytic- and antidepressant-like effects in rats. However, it is not known whether low and high doses of chrysin produce differential anti-immobility effects through the Gamma-Aminobutyric Acid sub-type A (GABAA) receptor. The goal of this work was therefore to compare low and high doses of chrysin for their effects on depression-like behavior in a longitudinal study. Moreover, chrysin was compared with the serotonergic fluoxetine and Gamma-Aminobutyric Acid (GABA)ergic allopregnanolone, and its involvement with the GABAA receptor after chronic treatment was also investigated. METHODS: Male Wistar rats were assigned to five groups (n = 8 each): vehicle, 1 mg/kg chrysin, 5 mg/kg chrysin, 1 mg/kg fluoxetine, and 1 mg/kg allopregnanolone. In the first experiment, treatments were injected daily and the effects on locomotor activity and the forced swim test were evaluated at 0, 1, 14, and 28 days of treatment, and 48 h after the final treatment. In the second experiment, similar groups were treated for 28 days with injection of 1 mg/kg picrotoxin to investigate the role of the GABAA receptor. Depending on the experimental design, one- and two-way analysis of variance (ANOVA) tests were used for statistical analysis, with p < 0.05 set as the criteria for significance. RESULTS: In both experiments, the treatments did not alter locomotor activity. However, low and high doses of chrysin, allopregnanolone, and fluoxetine gradually produced antidepressant-like effects in the forced swim test, and maintained this effect for 48 h post-treatment, except with low dose chrysin. Picrotoxin blocked the antidepressant-like effects produced by low dose chrysin, but did not affect those produced by high dose chrysin, allopregnanolone, or fluoxetine. CONCLUSIONS: The differential antidepressant-like effects caused by low and high doses of chrysin are time-dependent. Low dose chrysin produces a rapid antidepressant-like effect, whereas high dose chrysin produces a delayed but sustained the effect, even 48 h after withdrawal. The effect with high dose chrysin was similar to that observed with allopregnanolone and fluoxetine. The mechanism for the antidepressant-like effect of low chrysin appears to be GABAergic, whereas the effect of high dose chrysin may involve other neurotransmission and neuromodulation systems related to the serotonergic system.

Synthesis of [3 H]Org24598 using in-house prepared [3 H]MeI.

The synthesis of tritium-labelled glycine transporter 1 inhibitor Org24598 is reported. Because of the instability of the Org24598 skeleton under hydrogenation conditions, a synthetic approach using an in-house prepared tritium-labelled alkylating agent ([3 H]MeI, SA = 26.2 Ci/mmol) was employed. Alternative methods of labelling are discussed.

Beyond Psychotropic: Potential Repurposing of Fluoxetine toward Cancer Therapy.

Drug repurposing, rebranding an existing drug for a new therapeutic indication, is deemed a beneficial approach for a quick and cost-effective drug discovery process by skipping preclinical, Phase 1 trials and pharmacokinetic studies. Several psychotropic drugs, including selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs), were studied for their potential application in different diseases, especially in cancer therapy. Fluoxetine (FLX) is one of the most prescribed psychotropic agents from the SSRIs class for the treatment of several neuropsychiatric disorders with a favorable safety profile. FLX exhibited different oncolytic effects via mechanisms distinct from its main serotonergic activity. Taking advantage of its ability to rapidly penetrate the blood-brain barrier, FLX could be particularly useful in brain tumors. This was proved by different in vitro and in vivo experiments using FLX as a monotherapy or combination with temozolomide (TMZ) or radiotherapy. In this review of the literature, we summarize the potential pleiotropic oncolytic roles of FLX against different cancers, highlighting the multifaceted activities of FLX and its ability to interrupt cancer proliferation via several molecular mechanisms and even surmount multidrug resistance (MDR). We elaborated on the successful synergistic combinations such as FXR/temozolomide and FXR/raloxifene for the treatment of glioblastoma and breast cancer, respectively. We showcased beneficial pharmaceutical trials to load FLX onto carriers to enhance its safety and efficacy on cancer cells. This is the first review article extensively summarizing all previous FLX repurposing studies for the management of cancer.

Emerging Therapeutic Potential of Fluoxetine on Cognitive Decline in Alzheimer's Disease: Systematic Review.

Fluoxetine, a commonly prescribed medication for depression, has been studied in Alzheimer's disease (AD) patients for its effectiveness on cognitive symptoms. The aim of this systematic review is to investigate the therapeutic potential of fluoxetine in cognitive decline in AD, focusing on its anti-degenerative mechanisms of action and clinical implications. According to PRISMA, we searched MEDLINE, up to 1 April 2024, for animal and human studies examining the efficacy of fluoxetine with regard to the recovery of cognitive function in AD. Methodological quality was evaluated using the ARRIVE tool for animal AD studies and the Cochrane tool for clinical trials. In total, 22 studies were analyzed (19 animal AD studies and 3 clinical studies). Fluoxetine promoted neurogenesis and enhanced synaptic plasticity in preclinical models of AD, through a decrease in Aß pathology and increase in BDNF, by activating diverse pathways (such as the DAF-16-mediated, TGF-beta1, ILK-AKT-GSK3beta, and CREB/p-CREB/BDNF). In addition, fluoxetine has anti-inflammatory properties/antioxidant effects via targeting antioxidant Nrf2/HO-1 and hindering TLR4/NLRP3 inflammasome. Only three clinical studies showed that fluoxetine ameliorated the cognitive performance of people with AD; however, several methodological issues limited the generalizability of these results. Overall, the high-quality preclinical evidence suggests that fluoxetine may have neuroprotective, antioxidant, and anti-inflammatory effects in AD animal models. While more high-quality clinical research is needed to fully understand the mechanisms underlying these effects, fluoxetine is a promising potential treatment for AD patients. If future clinical trials confirm its anti-degenerative and neuroprotective effects, fluoxetine could offer a new therapeutic approach for slowing down the progression of AD.

Theoretical insights of the pharmaceutical compound fluoxetine in water: Role in direct photolysis and indirect photolysis by free radicals.

The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness, which may pose a major threat to the aquatic environment. In this study, photodegradation (direct and indirect photolysis) of two different dissociation states of fluoxetine (FLU) was investigated in water, mainly including the determination of photolytic transition states and products, and the mechanisms of indirect photodegradation with ·OH, CO3*- and NO3*. The main direct photolysis pathways are defluorination and C-C bond cleavage. In addition, the indirect photodegradation of FLU in water is mainly through the reactions with ·OH and NO3*, and the photodegradation reaction with CO3*- is relatively difficult to occur in the water environment. Our results provide a theoretical basis for understanding the phototransformation process of FLU in the water environment and assessing its potential risk.