Search

Meclizine (Antivert, Bonine) is a first-generation H1 antihistamine used in the treatment of motion sickness and vertigo. Despite its wide medical use for over 70 years, its crystal structure and the details of protein-drug interactions remained unknown. Single-crystal X-ray diffraction (SC-XRD) is previously unsuccessful for meclizine. Today, microcrystal electron diffraction (MicroED) enables the analysis of nano- or micro-sized crystals that are merely a billionth the size needed for SC-XRD directly from seemingly amorphous powder. In this study, MicroED to determine the 3D crystal structure of meclizine dihydrochloride is used. Two racemic enantiomers (R/S) are found in the unit cell, which is packed as repetitive double layers in the crystal lattice. The packing is made of multiple strong N-H-Cl- hydrogen bonding interactions and weak interactions like C-H-Cl- and pi-stacking. Molecular docking reveals the binding mechanism of meclizine to the histamine H1 receptor. A comparison of the docking complexes between histamine H1 receptor and meclizine or levocetirizine (a second-generation antihistamine) shows the conserved binding sites. This research illustrates the combined use of MicroED and molecular docking in unraveling elusive drug structures and protein-drug interactions for precision drug design and optimization.

In genetically heterogeneous (UM-HET3) mice produced by the CByB6F1 × C3D2F1 cross, the Nrf2 activator astaxanthin (Asta) extended the median male lifespan by 12% (p = 0.003, log-rank test), while meclizine (Mec), an mTORC1 inhibitor, extended the male lifespan by 8% (p = 0.03). Asta was fed at 1840 ± 520 (9) ppm and Mec at 544 ± 48 (9) ppm, stated as mean ± SE (n) of independent diet preparations. Both were started at 12 months of age. The 90th percentile lifespan for both treatments was extended in absolute value by 6% in males, but neither was significant by the Wang-Allison test. Five other new agents were also tested as follows: fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate. None of these increased lifespan significantly at the dose and method of administration tested in either sex. Amounts of dimethyl fumarate in the diet averaged 35% of the target dose, which may explain the absence of lifespan effects. Body weight was not significantly affected in males by any of the test agents. Late life weights were lower in females fed Asta and Mec, but lifespan was not significantly affected in these females. The male-specific lifespan benefits from Asta and Mec may provide insights into sex-specific aspects of aging.

Neuroinflammation is identified as significant inflammatory reactions occurring in the central nervous system. Lipopolysaccharide (LPS) stimulates innate immune reactions and is used as an in vivo animal model for the investigation of inflammation. Meclizine (MCLZ) is a histamine antagonist with potential neuroprotective qualities. Forty adult male Swiss albino mice were divided into four groups (n = 10). Group 1 served as a control negative group. Groups 2–4 were injected with LPS (5 mg/kg; i.p). Group 2 served as LPS-control. Groups 3 & 4 were given MCLZ (12.5 & 25 mg/kg; p.o) respectively for 14 days. LPS administration resulted in significant neuroinflammation in mice as was revealed by significant inflammatory histopathological changes and positive immunohistochemical staining of glial fibrillary acidic proteins (GFAP) accompanied by significant elevations of brain tissue contents of interleukin-1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-beta (NF-κβ), protein kinase B (AKT), extracellular signal-regulated kinase (ERK) and C-Jun N-Terminal Kinases (JNK). MCLZ treatment significantly down-regulated all the aforementioned parameters in mice brains. Moreover, MCLZ treatment ameliorated the inflammatory histopathological changes and GFAP immunostaining in brain tissues. The current study identifies for the first time the protective anti-neuroinflammatory effects of MCLZ against LPS-induced neuroinflammation in mice. MCLZ protected against neuroinflammation via the amelioration of inflammatory histopathological changes as well as neuronal GFAP immunostaining and down-regulated the AKT/NF-κβ/ERK/JNK signaling pathway. MCLZ is anticipated as a potential protective candidate for the addition to the treatment protocol of neuroinflammation. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is an aggressive tumor of the brain, with an average post-diagnosis survival of 15 months. GBM stem cells (GBMSC) resist the standard-of-care therapy, temozolomide, and are considered a major contributor to tumor resistance. Mammalian target of rapamycin Complex 1 (mTORC1) regulates cell proliferation and has been shown by others to have reduced activity in GBMSC. We recently identified a novel chemical series of human-safe piperazine-based brain-penetrant mTORC1-specific inhibitors. We assayed the piperazine-mTOR binding strength by two biophysical measurements, biolayer interferometry and field-effect biosensing, and these confirmed each other and demonstrated a structure-activity relationship. As mTORC1 is altered in human GBMSC, and as mTORC1 inhibitors have been tested in previous GBM clinical trials, we tested the killing potency of the tightest-binding piperazines and observed that these were potent GBMSC killers. GBMSCs are resistant to the standard-of-care temozolomide therapy, but temozolomide supplemented with tight-binding piperazine meclizine and flunarizine greatly enhanced GBMSC death over temozolomide alone. Lastly, we investigated IDH1-mutated GBMSC mutations that are known to affect mitochondrial and mTORC1 metabolism, and the tight-binding meclizine provoked 'synthetic lethality' in IDH1-mutant GBMSCs. In other words, IDH1-mutated GBMSC showed greater sensitivity to the coadministration of temozolomide and meclizine. These data tend to support a novel clinical strategy for GBM, i.e., the co-administration of meclizine or flunarizine as adjuvant therapy in the treatment of GBM and IDH1-mutant GBM.

Translationally controlled tumor protein (TCTP), a highly conserved protein present in most eukaryotes, is involved in numerous biological processes. Only the dimeric form of TCTP (dTCTP) formed during inflammatory conditions exhibits cytokine-like activity. Therefore, dTCTP is considered as a therapeutic target for allergic diseases. Because monomeric TCTP (mTCTP) and dTCTP share a high topological similarity, we hypothesized that small molecules interacting with mTCTP would also bind to dTCTP and interfere with dTCTP-based cellular processes. In this study, nine compounds listed in the literature as interacting with mTCTP were investigated for their ability to suppress the activity of extracellular dTCTP in bronchial epithelial cells. It was found that one of the nine, meclizine, a piperazine-derivative antihistamine, significantly reduced IL-8 release and suppressed the NF-κB pathway. The direct interaction of meclizine with dTCTP was confirmed by surface plasmon resonance (SPR). Also, we found that meclizine can attenuate ovalbumin (OVA)-induced airway inflammation in mice. Therefore, meclizine might be a potential anti-allergic drug as an inhibitor for dTCTP.

Adenomyosis is one of the structural causes of abnormal uterine bleeding, which often presents as heavy menstrual bleeding. Mostly because of the poor understanding of its pathophysiology, medical management of adenomyosis-induced heavy menstrual bleeding is still a challenge. We have previously reported that glycolysis is crucial to endometrial repair following menstruation and that suppressed glycolysis can cause heavy menstrual bleeding. This study aimed to test the hypothesis that meclizine, a drug with an excellent safety profile, alleviates heavy menstrual bleeding in mice with induced adenomyosis using a simulated menstruation model. Adenomyosis was induced in 36 female C57BL/6 mice using endometrial–myometrial interface disruption. Three months after induction, the mice were randomly divided into the following 3 groups: low-dose meclizine, high-dose meclizine, and controls. Treatment with meclizine or vehicle started shortly before the simulated menstruation procedure and ended before progesterone withdrawal. The amount of blood loss was quantified and uterine tissue was harvested for histologic evaluation of the grade of endometrial repair. We performed immunohistochemistry analysis of 4 proteins critically involved in glycolysis: Glut1 (glucose transporter 1), Hk2 (hexokinase 2), Pfkfb3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3), and Pkm2 (pyruvate kinase M2). The extent of tissue fibrosis in both ectopic and eutopic endometria was evaluated using Masson trichrome staining. In mice with induced adenomyosis, meclizine accelerated endometrial repair in a dose-dependent manner and reduced the amount of menstrual bleeding. Meclizine administration raised endometrial immunoexpression of Hk2 and Pfkfb3 but not of Glut1 or Pkm2. The extent of endometrial fibrosis was reduced following the meclizine administration. Remarkably, these favorable changes were accompanied by the suppression of lesional progression, as evidenced by the dose-dependent reduction in the extent of fibrosis (a surrogate for lesional progression). These encouraging results, taken together, suggest that glycolysis may be a promising therapeutic target and that meclizine may hold therapeutic potential as a nonhormonal treatment for adenomyosis-induced heavy menstrual bleeding without exacerbating the disease. [ABSTRACT FROM AUTHOR]

Meclizine is antihistamine and is used in combination with pyridoxine to treat motion sickness. The in-silico study of meclizine prediction studied showed that meclizine has anti-eczema activity with possible activity 95. This research aimed to explore the anti-eczema activity of meclizine. Therefore, five formulations of meclizine ointment have been prepared using different bases (white base, simple ointment base, hydrophilic petrolatum base, hydrophilic, and emulsifying ointment bases). The efficiency of meclizine ointment has been evaluated by testing the physical compatibility and stability, homogeneity and irritant effect, absorbance and spreadability, chemical identification, calibration curve, drug content (assay), and dissolution test. This is followed by evaluating the ointment's effectiveness on volunteers and molecular docking. Five creams trials have been prepared, and two formulas (F3, and F5) have been selected for further evaluation. The formulas three and five (F3, F5) have passed the physical and chemical tests and showed compatibility, homogenous, absorbed, non-irritant, and stable with calibration curve (R = 0.9999). Then, the F3 formula was selected by testing them on seven volunteers after evaluating the irritant test. Four of the volunteers showed excellent recovery, and three of the volunteers suffered from uncomforting feelings and the formation of new pills. Therefore, F5 has been tested by eight volunteers that contain high oleaginous activity; five showed an excellent recovery, while three of the volunteers showed no difference. According to that, F5 is more efficient for eczema patients than F3, and Meclizine showed promising activity as an anti-eczema that requires further evaluation in the future. [ABSTRACT FROM AUTHOR]

Chemotherapy-induced peripheral neuropathy (CIPN) affects; 68% of patients undergoing chemotherapy, causing debilitating neuropathic pain and reducing quality of life. Cisplatin is a commonly used platinum-based chemotherapeutic drug known to cause CIPN, possibly by causing oxidative stress damage to primary sensory neurons. Metabotropic glutamate receptors (mGluRs) are widely hypothesized to be involved in pain processing and pain mitigation. Meclizine is an H1 histamine receptor antagonist known to have neuroprotective effects, including an anti-oxidative effect. Here, we used a mouse model of cisplatin-induced CIPN using male and female mice to test agonists of mGluR8 and Group II mGluR as well as meclizine as interventions to reduce cisplatin-induced pain. We performed behavioral pain tests, and we imaged Ca2+ activity of the large population of dorsal root ganglia (DRG) neurons in vivo. For the latter, we used a genetically-encoded Ca2+ indicator, Pirt-GCaMP3, which enabled us to monitor different drug interventions at the level of the intact DRG neuronal ensemble. We found that CIPN increased spontaneous Ca2+ activity in DRG neurons, increased number of Ca2+ transients, and increased hyper-responses to mechanical, thermal, and chemical stimuli. We found that mechanical and thermal pain caused by CIPN was significantly attenuated by the mGluR8 agonist, (S)23,4-DCPG, the Group II mGluR agonist, LY379268, and the H1 histamine receptor antagonist, meclizine. DRG neuronal Ca2+ activity elevated by CIPN was attenuated by LY379268 and meclizine, but not by (S)23,4-DCPG. Furthermore, meclizine and LY379268 attenuated cisplatin-induced weight loss. These results suggest that Group II mGluR agonist, mGluR8 agonist, and meclizine are promising candidates as new treatment options for CIPN, and studies of their mechanisms are warranted. [ABSTRACT FROM AUTHOR]

Background: The mitochondrial unfolded protein response (UPR mt ) is an evolutionarily conserved mitochondrial response that is critical for maintaining mitochondrial and energetic homeostasis under cellular stress after tissue injury and disease. Here, we ask whether UPR mt may be a potential therapeutic target for ischemic stroke., Methods: We performed the middle cerebral artery occlusion and oxygen-glucose deprivation models to mimic ischemic stroke in vivo and in vitro, respectively. Oligomycin and meclizine were used to trigger the UPR mt . We used 2,3,5-triphenyltetrazolium chloride staining, behavioral tests, and Nissl staining to evaluate cerebral injury in vivo. The Cell Counting Kit-8 assay and the Calcein AM Assay Kit were conducted to test cerebral injury in vitro., Results: Inducing UPR mt with oligomycin protected neuronal cultures against oxygen-glucose deprivation. UPR mt could also be triggered with meclizine, and this Food and Drug Administration-approved drug also protected neurons against oxygen-glucose deprivation. Blocking UPR mt with siRNA against activating transcription factor 5 eliminated the neuroprotective effects of meclizine. In a mouse model of focal cerebral ischemia, pretreatment with meclizine was able to induce UPR mt in vivo, which reduced infarction and improved neurological outcomes., Conclusions: These findings suggest that the UPR mt is important in maintaining the survival of neurons facing ischemic/hypoxic stress. The UPR mt mechanism may provide a new therapeutic avenue for ischemic stroke., Competing Interests: Disclosures None.

Background: Women suffering from severe nausea and vomiting during pregnancy, hyperemesis gravidarum, have poor quality of life and increased risk of potentially fatal maternal and fetal complications. There is increasing and reassuring knowledge about safety of antiemetics in pregnancy. In 2013, the European Medical Agency (EMA) issued a warning on metoclopramide limiting treatment to maximum five days. Metoclopramide was the most used antiemetic in pregnancy at the time the warning was implemented in the Norwegian hyperemesis guidelines (2014). We aimed at describing changes in the treatment of hyperemesis over time, including changes associated with the EMA warning.Methods: Retrospective chart review of all women hospitalized for hyperemesis gravidarum with metabolic disturbances between 01/Jan/2002 and 31/Dec/2019 at a university hospital serving nearly 10% of the pregnant population in Norway. Time-series analysis described changes over time and interrupted time series analysis quantified changes in treatment and clinical outcomes related to the EMA warning.Results: In total, 1,064 women (1.2% of the birthing population) were included. The use of meclizine, prochlorperazine, and ondansetron increased during 2002-2019. This led to a yearly increase in the percentage of women using any antiemetic of 1.5% (95%CI 0.6; 2.4) pre-hospital, 0.6% (95%CI 0.2; 1.1) during hospitalization, and 2.6% (95%CI 1.3; 3.8) at discharge. Overall, only 50% of the women received antiemetics pre-hospital. Following the EMA warning, prehospital use of metoclopramide dropped by 30% (95%CI 25; 36), while use of any antiemetic pre-hospital dropped by 20% (95%CI 5.7; 34). In timely association, we observed a decrease in gestational age (-3.8 days, 98.75%CI 0.6; 7.1) at first admission, as well as indication of increased rate of termination of pregnancy with an absolute increase of 4.8% (98.75%CI 0.9; 8.7) in 2014.Conclusion: During 2002-2019, the overall use of antiemetics in treatment of hyperemesis increased. The EMA-warning on metoclopramide in 2013 temporarily limited pre-hospital antiemetic provision associated with hospitalization at lower gestational length and indication of an increase in termination of pregnancy. [ABSTRACT FROM AUTHOR]

Coronaviruses are a large family of RNA viruses without segment, positive-sense RNA genomes and single-stranded, which cause illnesses. The disease ranging from mild in most people to diseases that is more dangerous. It may progress to pneumonia, acute respiratory distress syndrome and finally failure in vital function. Many people did not show symptoms of the disease. Clinical laboratory finding are low white cell counts with high rate of C-reactive protein. Chloroquine has positive antiviral effects on virus infection of primitive cells. In addition, these inhibitory effects were seen when the drug was used before and after exposure to the virus, this is important for both the preventive and curative architecture as well as therapeutic advantage of chloroquine. Meclizine and pyridoxine hydrochloride are considered strong anti-inflammatory, which help in controlling cytokine storm. Treatment by mixture of chloroquine, corticosterone, meclizine and pyridoxine may be protecting against blood clotting, which limits the spread of the disease. Accordingly, chloroquine, corticosterone, meclizine and pyridoxine can be used as prevention and treatment against pathogenic viral infections.

Pseudorabies virus (PRV) is a pathogen that causes substantial economic losses to the swine industry. With the emergence and widespread of PRV variants since 2011 in China, current commercial vaccines cannot provide complete protection against PRV infection. Therefore, antiviral drugs may work as an alternative way to control and prevent PRV. In this study, the inhibitory effects and underlying molecular mechanisms of meclizine against PRV were studied. Meclizine displayed a significant inhibitory effect against PRV when it was added before, simultaneously with, or after virus infection. The inhibitory effect of meclizine occurred during viral entry and cell-to-cell spreading but not at viral attachment into PK-15 cells. Meclizine also inhibited viral particle release at the late stage of infection. The antiviral effect of meclizine was tested in mice, and the results showed that meclizine reduced the severity of clinical symptoms and the viral loads in tissues, and delayed the death, after PRV challenge. The above results indicated that meclizine had an inhibitory effect on PRV. Our findings will contribute to the development of potential therapeutic drugs against PRV infection. [ABSTRACT FROM AUTHOR]

Pseudorabies virus (PRV) is a pathogen that causes substantial economic losses to the swine industry. With the emergence and widespread of PRV variants since 2011 in China, current commercial vaccines cannot provide complete protection against PRV infection. Therefore, antiviral drugs may work as an alternative way to control and prevent PRV. In this study, the inhibitory effects and underlying molecular mechanisms of meclizine against PRV were studied. Meclizine displayed a significant inhibitory effect against PRV when it was added before, simultaneously with, or after virus infection. The inhibitory effect of meclizine occurred during viral entry and cell-to-cell spreading but not at viral attachment into PK-15 cells. Meclizine also inhibited viral particle release at the late stage of infection. The antiviral effect of meclizine was tested in mice, and the results showed that meclizine reduced the severity of clinical symptoms and the viral loads in tissues, and delayed the death, after PRV challenge. The above results indicated that meclizine had an inhibitory effect on PRV. Our findings will contribute to the development of potential therapeutic drugs against PRV infection.

An enantiomeric separation of meclizine enantiomers by liquid chromatography with tandem mass spectrometry LC-MS method was developed and validated for the analysis of Meclizine enantiomers. Enantiomeric resolution of the drug products were successfully achieved on a Phenomenex® lux cellulose 1 C18 (250 mm × 4.6 mm i.d, 5 µm particle size) column with mobile phase consisting of acetonitrile: 5 mM ammonium format pH (5.5) adjusted with formic acid (90:10) (v/v), and a flow rate of 0.4 mL/min. The developed method provided linear responses within the concentration range 1–5 ng/mL, and regression analysis showed a correlation coefficient value (r2) of 0.999. The optimized mobile phase separated (+) Meclizine at 1.58 min and (-) Meclizine at 2.20 min, respectively. The LC/MS method was validated as per ICH guidelines with respect to specificity, precision, linearity and robustness. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.0 ng/mL and 5.0 ng/mL respectively. The proposed method is suitable for analysis of meclizine enantiomers in pharmaceutical formulations and quality control analysis. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is a neurodegenerative debilitating disorder characterized by progressive disturbances in motor, autonomic and psychiatric functions. One of the genes involved in familial forms of the disease is DJ-1 , whose mutations cause early-onset PD. Besides, it has been shown that an over-oxidized and inactive form of the DJ-1 protein is found in brains of sporadic PD patients. Interestingly, the DJ-1 protein plays an important role in cellular defense against oxidative stress and also participates in mitochondrial homeostasis. Valuable insights into potential PD pathogenic mechanisms involving DJ-1 have been obtained from studies in cell and animal PD models based on DJ-1 deficiency such as Drosophila. Flies mutant for the DJ-1β gene, the Drosophila ortholog of human DJ-1 , exhibited disease-related phenotypes such as motor defects, increased reactive oxygen species production and high levels of protein carbonylation. In the present study, we demonstrate that DJ-1β mutants also show a significant increase in the activity of several regulatory glycolytic enzymes. Similar results were obtained in DJ-1 -deficient SH-SY5Y neuroblastoma cells, thus suggesting that loss of DJ-1 function leads to an increase in the glycolytic rate. In such a scenario, an enhancement of the glycolytic pathway could be a protective mechanism to decrease ROS production by restoring ATP levels, which are decreased due to mitochondrial dysfunction. Our results also show that meclizine and dimethyl fumarate, two FDA-approved compounds with different clinical applications, are able to attenuate PD-related phenotypes in both models. Moreover, we found that they may exert their beneficial effect by increasing glycolysis through the activation of key glycolytic enzymes. Taken together, these results are consistent with the idea that increasing glycolysis could be a potential disease-modifying strategy for PD, as recently suggested. Besides, they also support further evaluation and potential repurposing of meclizine and dimethyl fumarate as modulators of energy metabolism for neuroprotection in PD. Image 1 • DJ-1β mutant flies show increased activity of several glycolytic enzymes. • DJ-1 -deficient human cells show increased activity of several glycolytic enzymes. • MEC/DMF attenuate H 2 O 2 -induced cytotoxicity in DJ-1 -deficient human cells. • MEC/DMF reduce motor defects, H 2 O 2 levels and protein carbonylation in DJ-1β mutants. • MEC/DMF suppress phenotypes in fly and cell PD models by increasing glycolysis. [ABSTRACT FROM AUTHOR]

Aquatic ecosystems worldwide are strongly influenced by the productive activities of a region. These activities can generate pollution by compounds with little-known or unknown characteristics and without regulation. Emerging contaminants are a group of compounds that have worldwide begun to be frequently detected in the environment, raising concern about their possible adverse effects on human and environmental health. Thus, it is important to generate a broader panorama of the dissemination of contaminants of emerging concern in the environment, implement actions to regulate their usage. This study aims to evaluate the occurrence and temporal distribution of oxandrolone and meclizine in surface water, sediments, tilapia muscle, and otter feces of the Ayuquila-Armería river, Mexico. Oxandrolone was detected in 55 % of the total analyzed samples, while meclizine was present in 12 %. In surface water, oxandrolone was present in 56 % of the samples, while meclizine in 8 %. In sediments, oxandrolone was detected in 45 % and meclizine was not detected. In tilapia muscle, oxandrolone was present in 47 % of samples and meclizine was not detected. In otters feces samples, oxandrolone and meclizine were present in 100 %. Regardless of the season (wet or dry), oxandrolone was detected in all four sample types, while meclizine was only detected in surface water and otter feces samples. Oxandrolone in the aquatic ecosystem of the Ayuquila-Armería basin showed that season variation generates a significant effect on their concentrations, especially in surface water and sediments. Meclizine did not show temporal variations either in seasons or between years. Particularly, oxandrolone concentrations presented an influence with respect to the sites that present continuous residual discharges to the river. In this sense, this study could be considered as a starting point for further routine monitoring of emerging contaminants to support regulation policies regarding their use and disposal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The classical least squares (CLS) model and three augmented CLS models are adopted and validated for the analysis of pyridoxine HCl (PYR), cyclizine HCl (CYC), and meclizine HCl (MEC) in a quinary mixture with two related impurities: the CYC main impurity, Benzhydrol (BEH), which has carcinogenic and hepatotoxic effects, and the MEC official impurity, 4-Chlorobenzophenone (BEP). The proposed augmented CLS models are orthogonal signal correction CLS (OSC-CLS), direct orthogonal signal correction CLS (DOSC-CLS), and net analyte processing CLS (NAP-CLS). These models were applied to quantify the three active constituents in their raw materials and their corresponding dosage forms using their UV spectra. To evaluate the CLS-based models sensibly, we design a comparative study involving two sets: the training set to construct models and the validation set to assess the prediction abilities of these models. A five-level, five-factor calibration design was established to produce 25 mixtures for the calibration set. In addition, 16 experiments were performed for a test set distributed equally between the in-space and out-space samples. The primary criterion for comparing the models' performance was the validation set's root mean square error of prediction (RMSEP) value. Finally, augmented CLS models showed acceptable results for assaying the three analytes. The results were compared statistically with the reported HPLC methods; however, the DOSC-CLS model proved the best for assaying the dosage forms.

Glioblastoma (GBM) is an aggressive tumor of the brain, with an average post-diagnosis survival of 15 months. GBM stem cells (GBMSC) resist the standard-of-care therapy, temozolomide, and are considered a major contributor to tumor resistance. Mammalian target of rapamycin Complex 1 (mTORC1) regulates cell proliferation and has been shown by others to have reduced activity in GBMSC. We recently identified a novel chemical series of human-safe piperazine-based brain-penetrant mTORC1-specific inhibitors. We assayed the piperazine-mTOR binding strength by two biophysical measurements, biolayer interferometry and field-effect biosensing, and these confirmed each other and demonstrated a structure–activity relationship. As mTORC1 is altered in human GBMSC, and as mTORC1 inhibitors have been tested in previous GBM clinical trials, we tested the killing potency of the tightest-binding piperazines and observed that these were potent GBMSC killers. GBMSCs are resistant to the standard-of-care temozolomide therapy, but temozolomide supplemented with tight-binding piperazine meclizine and flunarizine greatly enhanced GBMSC death over temozolomide alone. Lastly, we investigated IDH1-mutated GBMSC mutations that are known to affect mitochondrial and mTORC1 metabolism, and the tight-binding meclizine provoked ‘synthetic lethality’ in IDH1-mutant GBMSCs. In other words, IDH1-mutated GBMSC showed greater sensitivity to the coadministration of temozolomide and meclizine. These data tend to support a novel clinical strategy for GBM, i.e., the co-administration of meclizine or flunarizine as adjuvant therapy in the treatment of GBM and IDH1-mutant GBM.

Pregnane X receptor (PXR) which belongs to the nuclear hormone receptor superfamily plays vital roles in several biological functions, especially in the inflammatory procedure. Besides that, PXR is revealed by recent studies to have essential effects on bone tissue. As an agonist of PXR, meclizine is a piperazine-derived histamine H1 antagonist, and has been frequently used for prevention and treatment of vomiting and nausea. Because osteoclastogenesis is characterized by the activation of inflammation-related signaling pathways, we speculated that meclizine may affect formation and function of osteoclast. In the present study, we explored the effect of meclizine on RANKL-induced osteoclastogenesis both in vivo and in vitro. In primary bone marrow-derived macrophages (BMMs), meclizine reduced osteoclast formation and bone resorption in a dose-dependent manner, while knockdown of PXR with siRNA partially abrogated the osteoclastogenesis inhibition of meclizine. On the one hand, at the molecular level, meclizine attenuated RANKL-induced activation of c-Fos, NFATc1, nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPKs), including ERK and p38, but not JNK. Meanwhile, meclizine reduced the expression of osteoclast-specific genes, including TRAP, MMP9, Cathepsin K and NFATc1. On the other hand, meclizine decreased OVX-induced bone loss by repressing osteoclast activity. In conclusion, our results indicated that meclizine inhibits osteoclastogenesis via regulation of several RANKL signaling pathways and PXR was involved in the processes. Therefore, meclizine may be considered as a novel therapeutic candidate for osteoclast-related diseases.

Achondroplasia (ACH) is a common skeletal dysplasia characterized by a disproportionately short stature. We found that meclizine, which is an over-the-counter drug for motion sickness, inhibited the fibroblast growth factor receptor 3 (FGFR3) gene using a drug repositioning strategy, and meclizine 1 and 2 mg/kg/day promoted bone growth in a mouse model of ACH. A previous phase 1a clinical trial for children with ACH demonstrated that a single dose of meclizine 25 and 50 mg was safe and that the simulated plasma concentration achieved steady state approximately 10 days after the first dose. The current study aimed to evaluate the safety and pharmacokinetics (PK) of meclizine in children with ACH after a 14-day-repeated dose of meclizine. Twelve patients with ACH aged 5-10 years were enrolled. Meclizine 12.5 (cohort 1) and 25 mg/day (cohort 2) were administered after meals for 14 days, and adverse events (AEs) and PK were evaluated. No patient experienced serious AEs in either group. The average (95% confidential interval [CI]) maximum drug concentration (Cmax), peak drug concentration (Tmax), area under the curve (AUC) from 0 to 24 h, and terminal elimination half-life (t1/2) after a 14-day-repeated administration of meclizine (12.5 mg) were 167 (83-250) ng/mL, 3.7 (3.1-4.2) h, 1170 (765-1570) ng·h/mL, and 7.4 (6.7-8.0) h, respectively. The AUC0-6h after the final administration was 1.5 times that after the initial dose. Cmax and AUC were higher in cohort 2 than in cohort 1 in a dose-dependent manner. Regarding the regimen of meclizine 12.5 and 25 mg in patients < 20 kg and ≥ 20 kg, respectively, the average (95% CI) AUC0-24h was 1270 (1100-1440) ng·h/mL. Compartment models demonstrated that the plasma concentration of meclizine achieved at a steady state after the 14th administration. Long-term administration of meclizine 12.5 or 25 mg/day is recommended for phase 2 clinical trials in children with ACH., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Matsushita et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Several classes of antihistamine drugs are widely distributed over the world's medication although their intensive side effects are in the high dosages. In the present manuscript, we report a simple, cost-effective and sensitive voltammetric determination of the meclizine antihistamine drug using unmodified/bare graphite screen-printed electrodes (GSPE) within physiological micellar medium of sodium dodecyl sulphate (SDS). The GSPE show an electrochemical oxidation peak of meclizine at +1.0 V vs. Ag/AgCl. It was found that, the voltammetric peak height of meclizine was markedly increased almost three-times in B. R. Buffer of pH 7.0 containing 0.067 g/L of SDS. This significant enhancement is due to their uniform assemblage of SDS molecules on the graphite surface which promotes the electrostatic interactions of the meclizine drug with GSPE. Under the optimum experimental conditions, the determination of meclizine were explored in a wide concentration range of 33 × 10 −8 –29.13 × 10 −6  mol/L with a nanomolar detection limit (LOD) of 80 × 10 −9  mol/L. Furthermore, the GSPE was utilized for determination of meclizine within pharmaceutical tablets and human fluids with satisfactory accuracy and precision. [ABSTRACT FROM AUTHOR]

This article presents the use of acupuncture and Chinese herbal medicine to treat a case of Meniere's Disease. The patient presented with a five-month history of Meniere's disease which was caused by prolonged exposure to elevated temperatures. The patient had been evaluated by a head, ear, eye, nose and throat (HEENT) doctor, and a neurologist, along with being hospitalised weekly for severe episodes of vertigo. The patient had been treated with conventional medication, which did not resolve their symptoms. Over a period of ten weeks involving 14 acupuncture treatments and Chinese herbal medication, the patient's vertigo completely resolved and concomitant symptoms such as tinnitus and sensorineural hearing loss also improved. The patient also completely discontinued their meclizine, which at the beginning of treatment they had been taking every six hours. [ABSTRACT FROM AUTHOR]

Chemotherapy-induced neurotoxicity of peripheral nervous system (PNS) hinders efficacy of cancer treatments. Mechanisms initiating PNS injury by anticancer drugs are incompletely understood delaying development of effective management strategies. To understand events triggered in PNS by cancer drugs, we exposed dorsal root ganglion (DRG) neurons to cisplatin, a drug from platinum-based class of chemotherapeutics frequently implicated in peripheral neuropathies. While cisplatin enters cancer cells and forms cisplatin/DNA crosslinks that block cell proliferation, circulating cisplatin can also reach the PNS and produce crosslinks that impede critical DNA transactions in postmitotic neurons. Cisplatin forms crosslinks with both, nuclear and mitochondrial DNA (mtDNA). Crosslinks are repairable primarily via the nucleotide excision repair (NER) pathway, which is present in nuclei but absent from mitochondrial compartment. Hence, high mitochondrial content and limited shielding by blood nerve barrier make DRG neurons particularly vulnerable to mitochondrial injury by cisplatin. We report that in DRG neurons, cisplatin elevates reactive oxygen species, depletes mtDNA, and impairs mitochondrial respiration, whereas concomitant meclizine supplementation preserves redox balance, attenuates mitochondrial compromise, and augments DNA repair. Meclizine is an antihistamine drug recently implicated in neuroprotection via modulation of energy metabolism. Our data demonstrate that in the mitochondria-rich DRG neurons, meclizine mitigates cisplatin-induced mitochondrial compromise via enhancement of pentose phosphate pathway and repletion of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione stores. The findings suggest that meclizine-mediated preservation of redox balance sustains mitochondrial respiration and supports execution of cellular processes, including timely removal of cisplatin crosslinks from nuclear DNA, thereby attenuating cisplatin toxicity in DRG neurons. Collectively, the findings reveal potential for pharmacologic modulation of dorsal root ganglion neurons metabolism for protection against toxicity of chemotherapeutic drugs. [ABSTRACT FROM AUTHOR]