Fluphenazine versus low-potency first-generation antipsychotic drugs for schizophrenia

Melanocytotoxic chemicals and their toxic mechanisms

Melanocyte cell death can lead to various melanocyte-related skin diseases including vitiligo and leukoderma. Melanocytotoxic chemicals are one of the most well-known causes of nongenetic melanocyte-related diseases, which induce melanocyte cell death through apoptosis. Various chemicals used in cosmetics, medicine, industry and food additives are known to induce melanocyte cell death, which poses a significant risk to the health of consumers and industrial workers. This review summarizes recently reported melanocytotoxic chemicals and their mechanisms of toxicity in an effort to provide insight into the development of safer chemicals.

Naphthalene vs. Benzene as a Transmitting Moiety: Towards the More Sensitive Trifluoromethylated Molecular Probes for the Substituent Effects

The application of DFT computational method (B3LYP/6-311++G(d,p)) to mono- and poly(CF₃)substituted naphthalene derivatives helps to study changes in the electronic properties of these compounds under the influence of 11 substituents (-Br, -CF₃, -CH₃, -CHO, -Cl, -CN, -F, -NH₂, -NMe₂, -NO₂, and -OH) to confront substituent effects in naphthalene with an analogous situation in benzene. This paper shows the dependencies of theoretically calculated SESE (Substituent Effect Stabilization Energy) values on empirically determined, well-defined Hammett-type constants (σ_p, σ_m, R, and F). Described poly(CF₃)substituted derivatives of naphthalene are, so far, the most sensitive molecular probes for the substituent effects in the aromatic system. The presence of the trifluoromethyl groups of such an expressive nature significantly increases the sensitivity of the SESE to changes caused by another substitution. Further, the more -CF₃ groups are attached to the naphthalene ring, the more sensitive the probe is. Certain groups of probes show additivity of sensitivity: the obtained sensitivity relates to the sum of the sensitivities of the mono(CF₃)substituted probes.

Mechanical tibial loading remotely suppresses brain tumors by dopamine-mediated downregulation of CCN4

Mechanical loading to the bone is known to be beneficial for bone homeostasis and for suppressing tumor-induced osteolysis in the loaded bone. However, whether loading to a weight-bearing hind limb can inhibit distant tumor growth in the brain is unknown. We examined the possibility of bone-to-brain mechanotransduction using a mouse model of a brain tumor by focusing on the response to Lrp5-mediated Wnt signaling and dopamine in tumor cells. The results revealed that loading the tibia with elevated levels of tyrosine hydroxylase, a rate-limiting enzyme in dopamine synthesis, markedly reduced the progression of the brain tumors. The simultaneous application of fluphenazine (FP), an antipsychotic dopamine modulator, enhanced tumor suppression. Dopamine and FP exerted antitumor effects through the dopamine receptors DRD1 and DRD2, respectively. Notably, dopamine downregulated Lrp5 via DRD1 in tumor cells. A cytokine array analysis revealed that the reduction in CCN4 was critical for loading-driven, dopamine-mediated tumor suppression. The silencing of Lrp5 reduced CCN4, and the administration of CCN4 elevated oncogenic genes such as MMP9, Runx2, and Snail. In summary, this study demonstrates that mechanical loading regulates dopaminergic signaling and remotely suppresses brain tumors by inhibiting the Lrp5-CCN4 axis via DRD1, indicating the possibility of developing an adjuvant bone-mediated loading therapy.

A Small Molecule Targeting Human MEK1/2 Enhances ERK and p38 Phosphorylation under Oxidative Stress or with Phenothiazines

Small molecules are routinely used to inhibit protein kinases, but modulators capable of enhancing kinase activity are rare. We have previously shown that the small molecule INR119, designed as an inhibitor of MEK1/2, will enhance the activity of its fission yeast homologue, Wis1, under oxidative stress. To investigate the generality of these findings, we now study the effect of INR119 in human cells under similar conditions. Cells of the established breast cancer line MCF-7 were exposed to H2O2 or phenothiazines, alone or combined with INR119. In line with the previous results in fission yeast, the phosphorylation of the MAPKs ERK and p38 increased substantially more with the combination treatment than by H2O2 or phenothiazines, whereas INR119 alone did not affect phosphorylation. We also measured the mRNA levels of TP53 and BAX, known to be affected by ERK and p38 activity. Similarly, the combination of INR119 and phenothiazines increased both mRNAs to higher levels than for phenothiazines alone. In conclusion, the mechanism of action of INR119 on its target protein kinase may be conserved between yeast and humans.

Drug repurposing for the treatment of COVID-19: Pharmacological aspects and synthetic approaches

In December 2019, a new variant of SARS-CoV emerged, the so-called acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus causes the new coronavirus disease (COVID-19) and has been plaguing the world owing to its unprecedented spread efficiency, which has resulted in a huge death toll. In this sense, the repositioning of approved drugs is the fastest way to an effective response to a pandemic outbreak of this scale. Considering these facts, in this review we provide a comprehensive and critical discussion on the chemical aspects surrounding the drugs currently being studied as candidates for COVID-19 therapy. We intend to provide the general chemical community with an overview on the synthetic/biosynthetic pathways related to such molecules, as well as their mechanisms of action against the evaluated viruses and some insights on the pharmacological interactions involved in each case. Overall, the review aims to present the chemical aspects of the main bioactive molecules being considered to be repositioned for effective treatment of COVID-19 in all phases, from the mildest to the most severe.

Dopamine receptors in emesis: Molecular mechanisms and potential therapeutic function

Dopamine is a member of the catecholamine family and is associated with multiple physiological functions. Together with its five receptor subtypes, dopamine is closely linked to neurological disorders such as schizophrenia, Parkinson's disease, depression, attention deficit-hyperactivity, and restless leg syndrome. Unfortunately, several dopamine receptor-based agonists used to treat some of these diseases cause nausea and vomiting as impending side-effects. The high degree of cross interactions of dopamine receptor ligands with many other targets including G-protein coupled receptors, transporters, enzymes, and ion-channels, add to the complexity of discovering new targets for the treatment of nausea and vomiting. Using activation status of signaling cascades as mechanism-based biomarkers to foresee drug sensitivity combined with the development of dopamine receptor-based biased agonists may hold great promise and seems as the next step in drug development for the treatment of such multifactorial diseases. In this review, we update the present knowledge on dopamine and dopamine receptors and their potential roles in nausea and vomiting. The pre- and clinical evidence provided in this review supports the implication of both dopamine and dopamine receptor agonists in the incidence of emesis. Besides the conventional dopaminergic antiemetic drugs, potential novel antiemetic targeting emetic protein signaling cascades may offer superior selectivity profile and potency.

In vitro melanogenesis inhibition by fluphenazine and prochlorperazine in normal human melanocytes lightly pigmented

Purpose

Fluphenazine and prochlorperazine as phenothiazine-class antipsychotic drugs are widely used to treat schizophrenia, however their use is associated with significant side effects such as extrapyramidal symptoms, as well as ocular and skin disorders. Our goal was to determine the effect of fluphenazine and prochlorperazine on cell viability and melanogenesis in lightly pigmented normal human melanocytes.

Methods

The viability of melanocytes was evaluated by the WST-1 colorimetric assay, while melanin content and tyrosinase activity were tested spectrophotometrically.

Results

It has been shown that both phenothiazines induce the concentration-dependent loss in cell viability. The EC₅₀ values were calculated to be 6.13 and 0.63 μM for fluphenazine and prochlorperazine, respectively. Fluphenazine in the concentration of 5.0 μM and prochlorperazine in concentrations of 0.5 and 0.75 μM decreased melanin content and tyrosinase activity. The observed inhibition of melanogenesis may be explained by the decrease of enzyme activity.

Conclusions

The demonstrated changes in melanization process in lightly pigmented cells exposed to fluphenazine and prochlorperazine in vitro suggest a significant role of melanin and melanocytes in the mechanisms of undesirable side effects of these drugs in vivo.

Graphical abstract

Osteocyte-Driven Downregulation of Snail Restrains Effects of Drd2 Inhibitors on Mammary Tumor Cells

While bone is a frequent target of breast cancer-associated metastasis, little is known about the effects of tumor-bone interactions on the efficacy of tumor-suppressing agents. Here we examined the effect of two FDA-approved dopamine modulators, fluphenazine and trifluoperazine, on mammary tumor cells, osteoclasts, osteoblasts, and osteocytes. These agents suppressed proliferation and migration of mammary tumor cells chiefly by antagonizing dopamine receptor D2 and reduced bone resorption by downregulating nuclear factor of activated T cells, cytoplasmic 1 (Nfatc1). Three-dimensional spheroid formation assays revealed that tumor cells have high affinity to osteocytes and type I collagen, and interactions with osteocytes as well as administration of fluphenazine and trifluoperazine downregulated Snail and suppressed migratory behaviors. Unlike the inhibitory action of fluphenazine and trifluoperazine on tumor growth, tumor-osteocyte interactions stimulated tumor proliferation by upregulating NFκB and Akt. In the bone microenvironment, osteocytes downregulated Snail and acted as an attractant as well as a stimulant to mammary tumor cells. These results demonstrate that tumor-osteocyte interactions strengthen dopamine receptor-mediated suppression of tumor migration but weaken its inhibition of tumor proliferation in the osteocyte-rich bone microenvironment.Significance: These findings provide novel insight into the cellular cross-talk in the bone microevironment and the effects of dopamine modulators on mammary tumor cells and osteocytes. Cancer Res; 78(14); 3865-76. ©2018 AACR.

Importance of Toxicokinetics to Assess the Utility of Zebrafish Larvae as Model for Psychoactive Drug Screening Using Meta-Chlorophenylpiperazine (mCPP) as Example

The number of new psychoactive substances (NPS) increases rapidly, harming society and fuelling the need for alternative testing strategies. These should allow the ever-increasing number of drugs to be tested more effectively for their toxicity and psychoactive effects. One proposed strategy is to complement rodent models with zebrafish (Danio rerio) larvae. Yet, our understanding of the toxicokinetics in this model, owing to the waterborne drug exposure and the distinct physiology of the fish, is incomplete. We here explore the toxicokinetics and behavioral effects of an NPS, meta-chlorophenylpiperazine (mCPP), in zebrafish larvae. Uptake kinetics of mCPP, supported by toxicokinetic modeling, strongly suggested the existence of active transport processes. Internal distribution showed a dominant accumulation in the eye, implying that in zebrafish, like in mammals, melanin could serve as a binding site for basic drugs. We confirmed this by demonstrating significantly lower drug accumulation in two types of hypo-pigmented fish. Comparison of the elimination kinetics between mCPP and previously characterized cocaine demonstrated that drug affinities to melanin in zebrafish vary depending on the structure of the test compound. As expected from mCPP-elicited responses in rodents and humans, zebrafish larvae displayed hypoactive behavior. However, significant differences were seen between zebrafish and rodents with regard to the concentration-dependency of the behavioral response and the comparability of tissue levels, corroborating the need to consider the organism-internal distribution of the chemical to allow appropriate dose modeling while evaluating effects and concordance between zebrafish and mammals. Our results highlight commonalities and differences of mammalian versus the fish model in need of further exploration.

Revisiting the Therapeutic Potential of Bothrops jararaca Venom: Screening for Novel Activities Using Connectivity Mapping

Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown. Using functional genomics coupled to the connectivity map (C-map) approach, we undertook a wide range indirect search for biological activities within the venom of the South American pit viper Bothrops jararaca. For that effect, venom was incubated with human breast adenocarcinoma cell line (MCF7) followed by RNA extraction and gene expression analysis. A list of 90 differentially expressed genes was submitted to biosimilar drug discovery based on pattern recognition. Among the 100 highest-ranked positively correlated drugs, only the antihypertensive, antimicrobial (both antibiotic and antiparasitic), and antitumor classes had been previously reported for B. jararaca venom. The majority of drug classes identified were related to (1) antimicrobial activity; (2) treatment of neuropsychiatric illnesses (Parkinson’s disease, schizophrenia, depression, and epilepsy); (3) treatment of cardiovascular diseases, and (4) anti-inflammatory action. The C-map results also indicated that B. jararaca venom may have components that target G-protein-coupled receptors (muscarinic, serotonergic, histaminergic, dopaminergic, GABA, and adrenergic) and ion channels. Although validation experiments are still necessary, the C-map correlation to drugs with activities previously linked to snake venoms supports the efficacy of this strategy as a broad-spectrum approach for biological activity screening, and rekindles the snake venom-based search for new therapeutic agents.

Fluphenazine (oral) versus atypical antipsychotics for schizophrenia

BACKGROUND

Fluphenazine is a typical antipsychotic drug from the phenothiazine group of antipsychotics. It has been commonly used in the treatment of schizophrenia, however, with the advent of atypical antipsychotic medications, use has declined over the years.

OBJECTIVES

To measure the outcomes (both beneficial and harmful) of the clinical effectiveness, safety and cost-effectiveness of oral fluphenazine versus atypical antipsychotics for schizophrenia.

SEARCH METHODS

We searched the Cochrane Central Register of Studies (25 April 2013). For the economic search, we searched the Cochrane Schizophrenia Group Health Economic Database (CSzGHED) on 31 January 2014 SELECTION CRITERIA: All randomised controlled trials (RCTs) comparing fluphenazine (oral) with any other oral atypical antipsychotics.

DATA COLLECTION AND ANALYSIS

Review authors worked independently to inspect citations and assess the quality of the studies and to extract data. For homogeneous dichotomous data we calculated the risk ratio (RR) and 95% confidence interval (CI), and calculated the mean differences (MDs) for continuous data. We assessed risk of bias for included studies and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to rate the quality of the evidence.

MAIN RESULTS

Four studies randomising a total of 202 people with schizophrenia are included. Oral fluphenazine was compared with oral amisulpride, risperidone, quetiapine and olanzapine.Comparing oral fluphenazine with amisulpride, there was no difference between groups for mental state using the Brief Psychiatric Rating Scale (BPRS) (1 RCT, n = 57, MD 5.10 95% CI -2.35 to 12.55, very low-quality evidence), nor was there any difference in numbers leaving the study early for any reason (2 RCTs, n = 98, RR 1.19 95% CI 0.63 to 2.28, very low-quality evidence). More people required concomitant anticholinergic medication in the fluphenazine group compared to amisulpride (1 RCT, n = 36, RR 7.82 95% CI 1.07 to 57.26, very low-quality evidence). No data were reported for important outcomes including relapse, changes in life skills, quality of life or cost-effectiveness.Comparing oral fluphenazine with risperidone, data showed no difference between groups for 'clinically important response' (1 RCT, n = 26, RR 0.67 95% CI 0.13 to 3.35, very low-quality evidence) nor leaving the study early due to inefficacy (1 RCT, n = 25, RR 1.08 95% CI 0.08 to 15.46, very low-quality evidence). No data were reported data for relapse; change in life skills; quality of life; extrapyramidal adverse effects; or cost-effectiveness.Once again there was no difference when oral fluphenazine was compared with quetiapine for clinically important response (1 RCT, n = 25, RR 0.62 95% CI 0.12 to 3.07, very low-quality evidence), nor leaving the study early for any reason (1 RCT, n = 25, RR 0.46 95% CI 0.05 to 4.46, very low-quality evidence). No data were reported for relapse; clinically important change in life skills; quality of life; extrapyramidal adverse effects; or cost-effectiveness.Compared to olanzapine, fluphenazine showed no superiority for clinically important response (1 RCT, n = 60, RR 1.33 95% CI 0.86 to 2.07, very low-quality evidence), in incidence of akathisia (1 RCT, n = 60, RR 3.00 95% CI 0.90 to 10.01, very low-quality evidence) or in people leaving the study early (1 RCT, n = 60, RR 3.00 95% CI 0.33 to 27.23, very low-quality evidence). No data were reported for relapse; change in life skills; quality of life; or cost-effectiveness.

AUTHORS' CONCLUSIONS

Measures of clinical response and mental state do not highlight differences between fluphenazine and amisulpride, risperidone, quetiapine or olanzapine. Largely measures of adverse effects are also unconvincing for substantive differences between fluphenazine and the newer drugs. All included trials carry a substantial risk of bias regarding reporting of adverse effects and this bias would have favoured the newer drugs. The four small short included studies do not provide much clear information about the relative merits or disadvantages of oral fluphenazine compared with newer atypical antipsychotics.

Different presence of Chlamydia pneumoniae, herpes simplex virus type 1, human herpes virus 6, and Toxoplasma gondii in schizophrenia: meta-analysis and analytical study

In the present study we have performed both a meta-analysis and an analytical study exploring the presence of Chlamydia pneumoniae, herpes simplex virus type 1, human herpes virus 6, and Toxoplasma gondii antibodies in a sample of 143 schizophrenic patients and 143 control subjects. The meta-analysis was performed on papers published up to April 2014. The presence of serum immunoglobulin G and immunoglobulin A was performed by enzyme-linked immunosorbent assay test. The detection of microbial DNA in total peripheral blood was performed by nested polymerase chain reaction. The meta-analysis showed that: 1) C. pneumoniae DNA in blood and brain are more common in schizophrenic patients; 2) there is association with parasitism by T. gondii, despite the existence of publication bias; and 3) herpes viruses were not more common in schizophrenic patients. In our sample only anti-Toxoplasma immunoglobulin G was more prevalent and may be a risk factor related to schizophrenia, with potential value for prevention.

Treatment resistant schizophrenia: a comprehensive survey of randomised controlled trials

BACKGROUND

Schizophrenia is a common serious mental health condition which has significant morbidity and financial consequences. The mainstay of treatment has been antipsychotic medication but one third of people will have a 'treatment resistant' and most disabling and costly illness. The aim of this survey was to produce a broad overview of available randomised evidence for interventions for people whose schizophrenic illness has been designated 'treatment resistant'.

METHOD

We searched the Cochrane Schizophrenia Group's comprehensive Trials Register, selected all relevant randomised trials and, taking care not to double count, extracted the number of people randomised within each study. Finally we sought relevant reviews on the Cochrane Library and investigated how data on this subgroup of people had been presented.

RESULTS

We identified 542 relevant papers based on 268 trials (Average size 64.8 SD 61.6, range 7-526, median 56 IQR 47.3, mode 60). The most studied intervention is clozapine with 82 studies (total n = 6299) comparing it against other anti-psychotic medications. Cognitive behavioural therapy (CBT), electroconvulsive therapy (ECT), or transcranial magnetic stimulation (TMS) supplementing a standard care and risperidone supplementation of clozapine has also been extensively evaluated within trials. Many approaches, however, were clearly under researched. There were only four studies investigating combinations of non-clozapine antipsychotics. Only two psychological approaches (CBT and Family Rehabilitation Training) had more than two studies. Cochrane reviews rarely presented data specific to this important clinical sub-group.

CONCLUSIONS

This survey provides a broad taxonomy of how much evaluative research has been carried out investigating interventions for people with treatment resistant schizophrenia. Over 280 trials have been undertaken but, with a few exceptions, most treatment approaches--and some in common use--have only one or two relevant but small trials. Too infrequently the leading reviews fail to highlight the paucity of evidence in this area--as these reviews are maintained this shortcoming should be addressed.