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Identifying the metabolites of a drug has become an indispensable task in the development of new drugs. Dipfluzine (Dip) is a promising candidate for the treatment of cerebral vascular diseases and has 5 metabolites (M1∼M5) in rat urine and liver microsomes, but their biological activity is still unknown. Because selective cerebral vasodilation is a main role of Dip, we investigated the vasodilation of Dip and its 5 metabolites in isolated Sprague-Dawley (SD) male rat basilar arteries preconstricted with high-K + or 5-HT. The results showed that only M1 possessed concentration-dependent inhibitory activity on the vasoconstriction of arteries with or without the endothelium, and M1 has a more potent vasodilatory effect than Dip on both contraction models. Like Dip, the vasodilatory mechanisms of M1 may be not only related to receptor-operated and voltage-dependent calcium ion channels of smooth muscle cells but also to the release of NO and EDHF from endothelial cells and the opening of Ca 2+ -activated K + channels and ATP-sensitive potassium ion channels. Unlike Dip, the vasodilation mechanism of M1 is also related to the opening of voltage-sensitive K + channel. Together with more selectivity to non-VDCC than Dip, this may partially explain why M1 has stronger vasodilatory effects than Dip. The mechanisms of vasodilation of Dip and M1 may result from the combined action of these or other factors, especially blocking non-endothelium dependent non-VDCC and endothelium dependent IK Ca channels. These results point to the possibility that M1 provides synergism for the clinical use of Dip, which may inform the synthesis of new drugs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: Despite the available prophylactic and acute drugs for migraine management, this disabling disorder remains undertreated especially among pediatrics. In this review, the authors aim at assessing the preventive role cinnarizine plays in treating migraine based on previously published studies., Areas Covered: Randomized clinical trials, randomized controlled trials, non-randomized open-label trials, and retrospective studies concerning cinnarizine in migraine prevention in children and adults were reviewed. Especial attention was given to the response rate, migraine characteristics, and tolerability., Expert Opinion: The majority of reviewed trials demonstrated that cinnarizine is comparable to the conventional drugs used in migraine prophylaxis. However, most of the reviewed studies were limited by a non-controlled open-label design. Due to poor planning and possibility of high placebo responses, particularly in children and adolescents, the interpretation of open-label studies' results should be done cautiously. The evidence shows that cinnarizine's effectiveness was more promising in pediatric migraineurs and adults with migraine-associated vertigo such as vestibular migraine. Therefore, while the efficacy of cinnarizine cannot be dismissed, before reaching a definite conclusion on its effectiveness, it is necessary to do further high-quality RCTs among both children and adults.

Natural edible oils (NEOs) are common excipients for lipid-based formulations. Many of them are complex mixtures comprising hundreds of different triglycerides (TGs). One major challenge in developing lipid-based formulations is the variety in NEO compositions affecting the solubility of active pharmaceutical ingredients. In this work, solubilities of indomethacin (IND), ibuprofen (IBU), and fenofibrate (FFB) in soybean oil and in coconut oil were measured via differential scanning calorimetry, high-performance liquid chromatography, and Raman spectroscopy. Furthermore, this work proposes an approach that mimics NEOs using one key TG and models the API solubilities in these NEOs based on perturbed-chain statistical associating fluid theory (PC-SAFT). Key TGs were determined using the 1,2,3-random hypothesis, and PC-SAFT parameters were estimated via a group-contribution method. Using the proposed approach, the solubility of IBU and FFB was modeled in soybean oil and coconut oil. Furthermore, the solubilities of five more APIs (IND, cinnarizine, naproxen, griseofulvin, and felodipine) were modeled in soybean oil. All modeling results were found in very good agreement with the experimental data. The influence of different NEO kinds on API solubility was examined by comparing FFB and IBU solubilities in soybean oil and refined coconut oil. PC-SAFT was thus found to allow assessing the batch-to-batch consistency of NEO batches in silico .

As an important global disease, cutaneous leishmaniasis is associated with complications such as secondary infections and atrophic scars. The first line treatment with antimonials is expensive and reported to have serious side effects and enhance resistance development. The main objective of this study was to evaluate the effect of Cinnarizine on standard strains of Leishmania major because of paucity of information on this subject., Methods: In this experimental study, four concentrations of the drug (5, 10, 15 and 20 μg/ml) were added to Leishmania major cultures at 24, 48 and 72 hours intervals. MTT assays were performed to determine parasite viability and drug toxicity. Leishmania major promastigotes were augmented to the in vitro cultured macrophages (J774 cells) and then incubated for 72 hours. Half maximal inhibitory concentration (IC50) was ascertained by counting parasites. The inhibitory effect of the drug was compared with that of Glucantime. Flow-cytometry was performed to investigate apoptosis. Each test was repeated thrice., Results: The IC50 values of Cinnarizine after 72 hours were calculated to be 34.76 μg/ml and 23.73 μg/ml for promastigotes and amastigotes, respectively. The results of MTT assays showed 48 % promastigote viability after 72 hour-exposure to Cinnarizine at 20 μg/ml concentration. Programmed cell death in promastigote- and amastigote-infected macrophages was quantified to be 13.66 % and 98.7 %, respectively. Flow- cytometry analysis indicated that Cinnarizine induced early and late apoptosis in parasites. All treatments produced results which differed significantly from control group (P<0.05)., Conclusion: Cinnarizine showed low toxicity with anti-leishmanial and apoptosis effects on both promastigote and intracellular amastigote forms. Therefore, we may suggest further assessment on animal models of this drug as candidates for cutaneous leishmaniasis therapy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose: The objective of this study was to compare the in vitro Fick's first law, in vitro lipolysis, and in vivo rat assays for oral absorption of Biopharmaceutical Classification Systems Class II (BCS II) drugs in self-nanoemulsifying drug delivery system (SNEDDS), and studied drugs and oils properties effects on the absorption., Methods: The transport abilities of griseofulvin (GRI), phenytoin (PHE), indomethacin (IND), and ketoprofen (KET) in saturated water solutions and SNEDDS were investigated using the in vitro Madin-Darby canine kidney cell model. GRI and cinnarizine (CIN) in medium-chain triglycerides (MCT)-SNEDDS and long-chain triglycerides (LCT)-SNEDDS were administered in the in vivo SD rat and in vitro lipolysis models to compare the oral absorption and the distribution behaviors in GIT and build an in vitro-in vivo correlation (IVIVC)., Results: In the cell model, the solubility of GRI, PHE, IND, and KET increased 6-8 fold by SNEDDS, but their permeability were only 18%, 4%, 8%, and 33% of those of their saturated water solutions, respectively. However, in vivo absorption of GRI-SNEDDS was twice that of the GRI suspension and those of CIN-SNEDDS were 15-21 fold those of the CIN suspension. In the lipolysis model, the GRI% in aqueous and pellet phases of MCT were similar to that in LCT. In contrast, the CIN% in the aqueous and pellet phases were decreased but that of the lipid phase increased. In addition, an IVIVC was found between the CIN% in the lipid phase and in vivo relative oral bioavailability ( F r )., Conclusion: The in vitro cell model was still a suitable tool to study drug properties effects on biofilm transport and SNEDDS absorption mechanisms. The in vitro lipolysis model provided superior oral absorption simulation of SNEDDS and helped to build correlation with in vivo rats. The oral drug absorption was affected by drug and oil properties in SNEDDS., Competing Interests: The authors report no conflicts of interest in this work.

Purpose: The use of three-dimensional printing (3DP) in the development of pharmaceutical dosage forms is growing rapidly. However, the research is almost exclusively focussed on polymer-based systems with very little reported on 3D printing of lipid-based formulations. Thus, the aim of the work was to explore the feasibility of 3DP technology to prepare solid lipid-based formulations. Here, 3DP was applied for the preparation of solid self-microemulsifying drug delivery systems (S-SMEDDS) with defined surface area to volume (SA/V) ratios., Methods: The S-SMEDDS formulations, comprised of Gelucire® 44/14, Gelucire® 48/16 and Kolliphor® P 188 were loaded with fenofibrate or cinnarizine as model drugs. The formulations were printed into four geometrical shapes - cylindrical, prism, cube and torus, and compared to a control cube manually prepared from bulk formulation., Results: The printing process was not significantly affected by the presence of the model drugs. The as-printed S-SMEDDS formulations were characterised using differential scanning calorimetry and wide-angle X-ray scattering. The kinetics of dispersion depended on the SA/V ratio values. The digestion process was affected by the initial geometry of the dosage form by virtue of the kinetics of dispersion of the dosage forms into the digestion medium., Conclusions: This proof of concept study has demonstrated the potential of 3DP for the development of customised S-SMEDDS formulations without the need for an additional carrier or additive and with optimisation could elaborate a new class of dosage forms based on 3D printed lipids. Graphical abstract Lipid based formulations were 3D printed in various shapes to control the surface are to volume ratio and consequently the kinetics of dispersion.

The main hurdle in the oral delivery of cinnarizine is its supersaturation, precipitation and re-dissolution process, influencing the oral bioavailability. To overcome this problem, an attempt was made to develop immediate and prolong buoyant tablet of cinnarizine. For this purpose, polyacrylamide-g-corn fibre gum (p-CFG) was synthesized as mucoadhesive cum swellable polymer and it was compared with already used HPMC K4M polymer. The central composite design with two numeric and one categorical factor was choosen to optimize conc. of p-CFG (X 1 ), concentration of NaHCO 3 (X 2 ) and type of effervescent agents (X 3 ). The bioadhesive strength of p-CFG tablet was 2.4 times higher than HPMC K4M containing tablet. The formulation composition comprises of p-CFG (64.3%), sodium bi‑carbonate (12.9%) and citric acid (2%) (F CNZ ) fulfilled the maximum requirement of an optimized formulation. The in-vivo animal pharmacokinetic performance revealed larger plasma half-life and reduced elimination rate as compared to CNZ suspension. Interestingly, the absorption of CNZ from optimized formulation was 3 times enhanced than from CNZ suspension. Overall, the enhancement in the oral bioavailability of CNZ was evident that is due to its prolonged gastric residence time. Furthermore, the swelling associated floating followed by mucoadhesive nature of tablet was observed by X-ray imaging studies., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Inhibition of mTOR activity (mechanistic target of rapamycin) is an anti-cancer therapeutic strategy. mTOR participates in two functional complexes, mTORC1 and mTORC2. Since mTORC1 is specifically activated in multiple tumors, novel molecules that inhibit mTORC1 could be therapeutically important. To identify potentially novel modulators of mTOR pathways, we screened 1600 small molecule human drugs for mTOR protein binding, using novel biolayer interferometry technology. We identified several small molecules that bound to mTOR protein in a dose-dependent manner, on multiple chemical scaffolds. As mTOR participates in two major complexes, mTORC1 and mTORC2, the functional specificities of the binders were measured by S6Kinase and Akt phosphorylation assays. Three novel 'mTOR general' binders were identified, carvedilol, testosterone propionate, and hydroxyprogesterone, which inhibited both mTORC1 and mTORC2. By contrast, the piperazine drug cinnarizine dose-dependently inhibited mTORC1 but not mTORC2, suggesting it as a novel mTORC1-specific inhibitor. Some of cinnarizine's chemical analogs also inhibited mTORC1 specifically, whereas others did not. Thus we report the existence of a novel target for some related piperazines including cinnarizine and hydroxyzine, i.e. specific inhibition of mTORC1 activity. Since mTOR inhibition is a general anti-cancer strategy, and mTORC1 is specifically activated in some tumors, we suggest the piperazine scaffold, including cinnarizine and hydroxyzine, could be proposed for rational therapy in tumors in which mTORC1 is specifically activated. Related piperazines have shown toxicity to cancer cells in vitro as single agents and in combination chemotherapy. Thus piperazine-based mTOR inhibitors could become a novel chemotherapeutic strategy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Chemical libraries constitute a reservoir of pharmacophoric molecules to identify potent anti-cancer agents. Virtual screening of heterocyclic compound library in conjugation with the agonist-competition assay, toxicity-carcinogenicity analysis, and string-based structural searches enabled us to identify several drugs as potential anti-cancer agents targeting protein kinase C (PKC) as a target. Molecular modeling study indicates that Cinnarizine fits well within the PKC C2 domain and exhibits extensive interaction with the protein residues. Molecular dynamics simulation of PKC-Cinnarizine complex at different temperatures (300, 325, 350, 375, and 400[Formula: see text]K) confirms that Cinnarizine fits nicely into the C2 domain and forms a stable complex. The drug Cinnarizine was found to bind PKC with a dissociation constant Kd of [Formula: see text]M. The breast cancer cells stimulated with Cinnarizine causes translocation of PKC-[Formula: see text] to the plasma membrane as revealed by immunoblotting and immunofluorescence studies. Cinnarizine also dose dependently reduced the viability of MDAMB-231 and MCF-7 breast cancer cells with an IC[Formula: see text] of [Formula: see text] and [Formula: see text]g/mL, respectively. It is due to the disturbance of cell cycle of breast cancer cells with reduction of S-phase and accumulation of cells in G1-phase. It disturbs mitochondrial membrane potentials to release cytochrome C into the cytosol and activates caspase-3 to induce apoptosis in cancer cells. The cell death was due to induction of apoptosis involving mitochondrial pathway. Hence, the current study has assigned an additional role to Cinnarizine as an activator of PKC and potentials of the approach to identify new molecules for anti-cancer therapy. Thus, in silico screening along with biochemical experimentation is a robust approach to assign additional roles to the drugs present in the databank for anti-cancer therapy.

Objective: It has long been suggested that antivertiginous medications exert their symptomatic effect through inhibition of the vestibulo-ocular reflex (VOR). We tested this hypothesis by directly measuring the VOR after administration of three agents from different substance classes: an antihistamine, a benzodiazepine and a calcium channel antagonist., Methods: The gain and the variability of the high velocity VOR was assessed using video head impulses (vHIT) under the following conditions: baseline, after dimenhydrinate, after diazepam and after cinnarizine., Results: We found that all three medications did not change any VOR gain or variability parameter: At 60ms, the gain was 0.95 at baseline, 0.99 under dimenhydrinate, 0.99 under diazepam and 0.96 under cinnarizine. The gain variability across repetitive head impulses remained also uninfluenced., Conclusions: The human high frequency VOR remains robust to pharmacological perturbations at common clinical doses and the assumption that symptomatic vertigo relief is achieved merely through impairment of the VOR requires re-examination., Significance: Alternative mechanisms of pharmacological action might be operant, such as the modulation of vestibulo-cortical pathways, a differential effect on the low frequency VOR and an altered sensitivity to drugs in acute unilateral vestibulopathy., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background/aim: Multiple myeloma, a well-known but still incurable disease, is a hematological malignancy of B-lymphocytes. While standard chemotherapy regimens have been used for years, novel agents, such as lenalidomide and bortezomib, have become an essential part of today's therapies. Nevertheless, new therapeutical strategies are required in the future. Aberrant activation of wingless-related integration site (WNT)/β-catenin signaling promotes the development of several types of cancer. Recently, it has been demonstrated that the WNT pathway is also activated in lymphoma and myeloma. Thus, the WNT signaling molecules are attractive candidates for the development of targeted therapies. To this extent, we recently confirmed that the diuretic agent ethacrynic acid (EA) and the antifungal agent ciclopirox olamine (CIC) inhibit WNT signaling. Cinnarizine has similar chemical features to those of CIC., Materials and Methods: Thus, in this study the antitumor effect of cinnarizine on myeloma and lymphoma cells was investigated by DiOC6 and propidium iodide (PI)-staining in flow cytometry., Results: Cinnarizine triggered a significant apoptotic activity in all tested myeloma and lymphoma cell lines in a concentration-dependent manner. Interestingly, healthy cells were mainly unaffected., Conclusion: These results reveal a significant selective induction of apoptosis by cinnarizine that might result from an inhibition of WNT signaling and suggest an in vivo efficacy against lymphoma and myeloma., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Cinnarizine is a piperazine derivative with antihistaminic, antiserotonergic, antidopaminergic, and calcium channel-blocking activities. A comprehensive profile was performed on cinnarizine including its description and the different methods of analysis. The 1H NMR and 13C one- and two-dimensional NMR methods were used. In addition, infrared and mass spectral analyses were performed which all confirmed the structure of cinnarizine., (© 2015 Elsevier Inc. All rights reserved.)

Background/aims: Calcium influx, inflammatory infiltration, cytokine production, immunoglobulin E activation and oxidative stress play coordinated roles in bronchial asthma pathogenesis. We aim to assess the protective effect of cinnarizine against experimentally induced bronchial asthma., Methods: Bronchial asthma was induced by ovalbumin sensitization and challenge. Rats were allocated into a normal control, an asthma control, a dexamethasone (standard) treatment, and 2 cinnarizine treatment groups. The respiratory functions tidal volume (TV) and peak expiratory flow rate (PEFR), the inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-5 (IL-5) in lung tissue, the allergic immunoglobulin IgE in serum, the absolute eosinophil count (AEC) in bronchoalveolar lavage fluid (BALF), as well as the oxidative and nitrosative markers glutathione reduced (GSH) and superoxide dismutase (SOD) in lung tissue and nitric oxide end products (NOx) in BALF were assessed, followed by a histopathological study., Results: Cinnarizine administration significantly restored TV, PEFR, TNF-α, IL-5, IgE, AEC, GSH, SOD and NOx values back to normal levels, and significantly decreased perivascular and peribronchiolar inflammatory scores., Conclusion: Cinnarizine may protect against experimental bronchial asthma. Suppressant effect of cinnarizine on pro-inflammatory cytokines release, IgE antibody production, eosinophil infiltration as well as oxidative and nitrosative stress may explain its anti-asthmatic potential., (© 2015 S. Karger AG, Basel.)

Background: In spite of the high occurrence of migraine headaches in school-age children, there are currently no approved and widely accepted pharmacologic agents for migraine prophylaxis in children. Our previous open-label study in children revealed the efficacy of cinnarizine, a calcium channel blocker, in migraine prophylaxis. A placebo-controlled trial was conducted to demonstrate the efficacy and safety of cinnarizine in the prophylaxis of migraine in children., Trial Design: A double-blind, placebo-controlled, parallel-group study conducted in a tertiary medical center in Tehran, Iran., Methods: Children (5-17 years) who experienced migraines with and without aura, as defined on the basis of 2004 International Headache Society criteria, were recruited into the study. Children were excluded if they had complicated migraine, epilepsy, or a history of use of migraine prophylactic agents. Each participant was randomly assigned to receive cinnarizine (a single 1.5 mg/kg/day dose in children weighing less than 30 kg and a single 50 mg dose in children weighing more than 30 kg, administered at bedtime) or placebo. The frequency, severity, and duration of headaches over the trial period were assessed and adverse effects were monitored., Results: A total of 68 children (34 in each group) with migraine were enrolled and 62 participants completed the study. After 3 months of taking cinnarizine or placebo, children in both groups experienced significantly reduced frequency, severity, and duration of headaches compared with baseline measurements (P < 0.001). However, compared with 31.3% of children in the placebo group, 60% of children in the cinnarizine group reported more than 50% reduction in monthly headache frequency (P = 0.023), suggesting that cinnarizine was significantly more effective than placebo in reducing the frequency of headaches. No serious adverse effects of the medications were observed in the treated children, including no abnormal weight gain or extrapyramidal signs., Conclusion: Our results indicate that the use of cinnarizine at doses administered in this study is effective and safe for prophylaxis of migraine headaches in children., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The growth of new lymphatic vessels (lymphangiogenesis) in tumors is an integral step in the metastatic spread of tumor cells, first to the sentinel lymph nodes that surround the tumor and then elsewhere in the body. Currently, no selective agents designed to prevent lymphatic vessel growth have been approved for clinical use, and there is an important potential clinical niche for antilymphangiogenic agents. Using a zebrafish phenotype-based chemical screen, we have identified drug compounds, previously approved for human use, that have antilymphatic activity. These include kaempferol, a natural product found in plants; leflunomide, an inhibitor of pyrimidine biosynthesis; and cinnarizine and flunarizine, members of the type IV class of calcium channel antagonists. Antilymphatic activity was confirmed in a murine in vivo lymphangiogenesis Matrigel plug assay, in which kaempferol, leflunomide, and flunarizine prevented lymphatic growth. We show that kaempferol is a novel inhibitor of VEGFR2/3 kinase activity and is able to reduce the density of tumor-associated lymphatic vessels as well as the incidence of lymph node metastases in a metastatic breast cancer xenograft model. However, in this model, kaempferol administration was also associated with tumor deposits in the pancreas and diaphragm, and flunarizine was found to be tumorigenic. Although this screen revealed that zebrafish is a viable platform for the identification and development of mammalian antilymphatic compounds, it also highlights the need for focused secondary screens to ensure appropriate efficacy of hits in a tumor context., (©2014 American Association for Cancer Research.)

This study aimed to investigate the clinical and cognitive side effects of baclofen (10 mg), meclizine (25 mg), dimenhydrinate (40 mg) plus cinnarizine (25 mg) and promethazine (25 mg) plus d-amphetamine (10 mg). The study had a double-blind, placebo controlled, repeated measures design and was conducted on healthy male volunteers. The psychomotor vigilance test, the Sternberg working memory task, the implicit memory test and the automated Operation Span (Ospan) task were performed. The Stanford, the Karolinska and the Epworth Sleepiness scale determined the degree of sleepiness. The Profile of Mood States (POMS) evaluated mood states and adverse effects were reported on a 22-item questionnaire. Letter recalls and time for solving mathematical problems, recorded during the Ospan task, were impaired by baclofen and dimenhydrinate-cinnarizine respectively, suggesting an influence of these drugs on the working memory. Significant side effects for baclofen were: sleepiness, tiredness, blurred vision, concentration problems and dizziness whereas for dimenhydrinate-cinnarizine only sleepiness and blurred vision were reported. Meclizine decreased the accuracy on the Sternberg working memory task and thus seemed to affect short-term memory. A reported side effect was increased sleepiness. Promethazine plus d-amphetamine did not affect any of the tested cognitive functions. However, many side effects such as sleepiness, dry mouth, dizziness, vertigo, confusion, insomnia and tremors were reported. The results show that meclizine and dimenhydrinate combined with cinnarizine were the two drugs with the most acceptable combination of side effects., (© The Author(s) 2013.)

Background/aim: Modulating agents are used to circumvent drug resistance in the clinical setting. However achievable serum concentrations are often lower than those which are optimal in vitro. Combination of modulating agents with non-overlapping toxicities may overcome this obstacle. We have investigated combinations of three modulating agents (quinine, verapamil, and cinnarizine) to circumvent inherent or acquired resistance to the cytotoxic drugs doxorubicin, vincristine and paclitaxel., Materials and Methods: Dose-response curves to cytotoxic drugs in the presence/absence of modulating agents were determined using colony formation and cell proliferation assays. Doxorubicin accumulation into cell monolayers was measured by fluorescence spectrophotometry., Results: Greater (1.9-fold) sensitisation to particular cytotoxic drugs was observed for certain combinations of modulating agents compared to individual effects. The most effective combination was quinine-plus-verapamil with the cytotoxic drug doxorubicin. This increase in sensitivity was associated with increased doxorubicin accumulation. Such enhanced activity was, however, not observed for all combinations of modulating agents or for all studied cytotoxic drugs., Conclusion: The findings of the present study suggest certain combinations of modulating agents to have a clinical role in circumventing drug resistance. Particular combinations of modulating agents must be carefully chosen to suit particular cytotoxic drug treatments.

In narcotized rats, verapamil and cinnarizine modified some heart rate variability (HRV) indices and heart rate (HR) indicating up-regulation of parasympathetic tone in contrast to nifedipine that elevated activity of sympathetic subdivision of ANS producing no influence on HR. In wakeful stressed rats, the time-domain and geometric analysis established that verapamil decreased HR and up-regulated sympathetic tone; nifedipine elevated sympathetic tone and produced no effect on HR, while cinnarizine enhanced parasympathetic tone without any effect on HR. Spectrum analysis of HRV revealed probable activation of some other neurohumoral mechanisms by the employed calcium blockers.

Objective: To investigate the effects of meclizine (50 mg), baclofen (10 mg), cinnarizine (20 mg) + dimenhydrinate (40 mg), and promethazine (25 mg) + dextro-amphetamine (5 mg) on the parameters of the vestibular evoked myogenic potential (VEMP) test., Study Design: Double-blind placebo-controlled prospective randomized trial., Setting: University hospital., Subjects: Twenty-four (first block: baclofen versus placebo) and 20 healthy male subjects (second block: meclizine, cinnarizine + dimenhydrinate and promethazine + dextro-amphetamine versus placebo)., Interventions: VEMP test., Main Outcome Measures: Threshold, p13 and n23 latencies, p13-n23 latency difference, p13-n23 peak-to-peak amplitude, mean rectified voltage of the sternocleidomastoid muscle contraction and the corrected amplitude., Results: There were no clinically significant pharmacologic effects on the VEMP outcome parameters. However, there was a statistically significant left-right asymmetry after intake of the combination promethazine + d-amphetamine for the parameters p13 and latency difference., Conclusion: The absence of clinically significant effects can be explained by the predominant presence of the target receptors for the applied drugs in the medial vestibular nucleus, which receives the lowest grade of saccular projections. It also can be hypothesized that the VEMP methodology and techniques in general do not allow determining pharmacologic effects in a healthy group of subjects because of a too small discriminative power. The left-right asymmetry can be explained by a depressive action of the drugs on the central compensation mechanisms. Because there were no significant differences between the VEMP parameters obtained after intake of the placebos of both blocks, we concluded that there were no training effects., (© 2011, Otology & Neurotology, Inc.)

More than 200 generic drugs were screened to identify the inhibitory activity on melanogenesis in mouse B16 melanoma cells. Cinnarizine and trazodone were identified as melanogenesis inhibitors. The inhibitory effects of the two drugs on cell survival, melanogenesis, and tyrosinase activity were investigated. The results showed that both cinnarizine and trazodone inhibited melanogenesis in B16 cells by a dose-dependent manner at the non-cytotoxic concentrations. Based on the results of the present study, seeking new melanogenesis inhibitors from generic drugs is an alternative approach to developing new depigmenting agents in cosmeceuticals. Moreover, cinnarizine and trazodone were proven to be good candidates as skin-whitening agents for treatment of skin hyperpigmentation.

Lysosomes accumulate many drugs several fold higher compared to their extracellular concentration. This mechanism is believed to be responsible for many pharmacological effects. So far, uptake and release kinetics are largely unknown and interactions between concomitantly administered drugs often provoke mutual interference. In this study, we addressed these questions in a cell culture model. The molecular mechanism for lysosomal uptake kinetics was analyzed by live cell fluorescence microscopy in SY5Y cells using four drugs (amantadine, amitriptyline, cinnarizine, flavoxate) with different physicochemical properties. Drugs with higher lipophilicity accumulated more extensively within lysosomes, whereas a higher pK(a) value was associated with a more rapid uptake. The drug-induced displacement of LysoTracker was neither caused by elevation of intra-lysosomal pH, nor by increased lysosomal volume. We extended our previously developed numerical single cell model by introducing a dynamic feedback mechanism. The empirical data were in good agreement with the results obtained from the numerical model. The experimental data and results from the numerical model lead to the conclusion that intra-lysosomal accumulation of lipophilic xenobiotics enhances lysosomal membrane permeability. Manipulation of lysosomal membrane permeability might be useful to overcome, for example, multi-drug resistance by altering subcellular drug distribution., ((c) 2010 Wiley-Liss, Inc.)

Vestibular vertigo may be induced by increases in the endolymphatic pressure that activate pressure-dependent K(+) currents (I(K,p)) in vestibular hair cells. I(K,p) have been demonstrated to modulate transmitter release and are inhibited by low concentrations of cinnarizine. Beneficial effects against vestibular vertigo of cinnarizine have been attributed to its inhibition of calcium currents. Our aim was to determine the extent by which the inhibition of I(K,p) by cinnarizine may alter the voltage response to stimulating currents and to analyze whether such alterations may be sufficient to modulate the activation of Ca(2+) currents and transmitter release. Vestibular type II hair cells from guinea pigs were studied using the whole-cell patch-clamp technique. In current clamp, voltage responses to trains of stimulating currents were recorded. In voltage clamp, transmitter release was assessed from changes in the cell capacitance, as calculated from the phase shift during application of sine waves. Cinnarizine (0.05-3 microM) concentration dependently reversed the depressing effects of increases in the hydrostatic pressure (from 0.2 to 0.5 cm H(2)O) on the voltage responses to stimulating currents. Voltage protocols that simulated these responses were applied in voltage clamp and revealed a significantly enhanced transmitter release in conditions mimicking an inhibition of I(K,p). Cinnarizine (< or =0.5 microM) did not inhibit calcium currents. We conclude that cinnarizine, in pharmacologically relevant concentrations, enhances transmitter release in the presence of elevated hydrostatic pressure by an indirect mechanism, involving inhibition of I(K,p), enhancing depolarization, and increasing the voltage-dependent activation of Ca(2+) currents, without directly affecting Ca(2+) current.

The aim of the present work was to perform a morphological assessment of the cerebroprotective action of lanthanum acetate in chronic cerebral ischemia in rats. Chronic ischemia was produced in Wistar rats (weighing 160-180 g) by ligation of both common carotid arteries. Ischemic lesions were corrected by intragastric lanthanum acetate (3 mg/kg per day) throughout the experimental period. Ischemic damage to the cortex was assessed morphometrically on histological sections stained by the Nissl method. Lanthanum acetate was found to suppress the development of ischemic neuron damage in the cerebral cortex, with reductions in the numbers of hyperchromic neurons, cells with focal chromatolysis, and ghost cells, as well as an increase in the number of normochromic cells as compared with controls.

The use of competing agents is considered a powerful tool for the development of a drug-delivery system with drug/cyclodextrin inclusion complexes. However, there are very few studies examining this issue. To explain this phenomenon, it was thought that a competing agent with a sufficiently high stability constant had not yet been reported. In this study, cinnarizine (CN), which has a high stability constant with beta-cyclodextrin (beta-CD) and unique solubility characteristics, was selected, and its ability as a competing agent was examined in a membrane permeability study. The permeability study showed that the permeation rates of the drugs flurbiprofen, progesterone, and spironolactone decreased with their stability constants with the addition of beta-CD. In one of the drugs, progesterone (Pro), the decrease was restored by the addition of CN. The amount of CN added was a 1:1 molar ratio to the amount of Pro. However, no similar action was induced with the addition of DL-phenylalanine (Phe) in the permeation study at the 1:5 (Pro:Phe) molar ratio. These finding indicate that CN acts as a competing agent, and its action is much stronger than that of Phe.

Pensacola Simulator Sickness Questionnaire (SSQ) is a valuable method to analyse symptoms evoked by exposure to a flight simulator environment that can also be adopted to evaluate the effectiveness of preventive tools, aiming at reducing simulator sickness (SS). In this study we analysed SSQ data in subjects undergoing a standard ground based spatial disorientation training inside a flight simulator, in order to evaluate the SS prevention obtained with two different pharmacological tools. Twelve males volunteers participated to an experimental design based on a double-blind, balanced administration of either 30 mg cinnarizine (CIN), or Cocculus Indicus 6CH (COC), or placebo (PLC) before one trial of about one hour spent inside a spatial disorientation trainer. All subjects underwent the three different conditions (CIN, COC, PLC) during 3 non-consecutive days separated by at least 2 weeks. During each experimental day, all subjects filled in SSQ. In addition, both postural instability (with the use of a static stabilometric platform), and sleepiness symptoms were evaluated. All the tests were performed before and after the simulated flight, at different times, in one-and-half-hour intervals. Results indicated a strong increase of sickness after flight simulation that linearly decreased, showing pre-simulator scores after 1.30 hours. In contrast to both PLC and COC, CIN showed significant side effects immediately following flight simulation, with no benefit at the simultaneous SSQ scores. Globally, no highly significant differences between COC and PLC were observed, although a minor degree of postural instability could be detected after COC administration. As far as the present exposure to a simulator environment is concerned, none of the pharmacological tools administered in this study resulted effective in reducing SS symptoms as detected by the SSQ. Moreover, CIN significantly increased sleepiness and postural instability in most subjects.

Aim: To evaluate the effects of dipfluzine on the expressions of E-selectin, P-selectin, and ICAM-1 and the infiltration of polymorphonuclear leukocytes in brain ischemia-reperfusion rats., Methods: The model of focal cerebral ischemia was established with the Zea-Longa occluding suture. Dipfluzine (0.25, 0.5 and 1 mg x kg(-1)), flunarizine 0.5 mg x kg(-1) and solvent were injected separately into lingual vein at 30 min after ischemia. The occluding suture was slowly taken away to cause reperfusion at 1 h after ischemia. Rats were decapitated under anesthesia at 24 h after ischemia-reperfusion and brains were immediately removed to do the following procedures. Effects of dipfluzine on morphology of the brain tissue were observed through hematoxylin-eosin (HE) staining. By immunohistochemistry and flow cytometry technique and biochemical method, effects of dipfluzine on P-selectin, E-selectin, ICAM-1 and myeloperoxidase (MPO) were observed., Results: Dipfluzine could relieve pathological damages in the brain tissue after ischemia-reperfusion, and reduce the expressions of E-selectin, P-selectin and ICAM-1 and activities of MPO in dose-dependent manner., Conclusion: Dipfluzine depresses the expressions of P-selectin, E-selectin, and ICAM-1, which are correlated with their effects on the activities of MPO, suggesting that dipfluzine has anti-inflammation effect in certain extent and could protect brain tissue from ischemia-reperfusion injury.

The complex treatment in 25 patients with non-exudative forms of senile macular degeneration (ARMD) included the use of the nootropic agent fezam. Better visual acuity after a course of therapy was noted in 76% of the eyes of patients with ARMD. Color Doppler mapping prior to treatment indicated that all the patients had a significant reduction in the maximum systolic and end-diastolic blood flow velocities (Vs and Vd, respectively), and the increased peripheral resistance index (RI) in the ophthalmic artery, central artery of the retina, and short posterior ciliary arteries as compared to the normal values. Higher ophthalmic arterial blood flow velocities after a course of therapy are indicative of better blood supply to the tunics of the eye, which is a favorable sign for the prognosis of the disease. The use of fezam is effective in the complex therapy of non-exudative forms of senile macular degeneration.

Cinnarizine, a drug known as a calcium channel blocker, is currently used for the treatment of migraine and vertigo. Induction of extrapyramidal signs by cinnarizine has been reported in the elderly, which is related to its moderate antagonistic properties at dopamine D2 receptors, resembling the mechanism of action of most antipsychotic drugs. Despite this effect, cinnarizine has never been tested as a putative antipsychotic drug. Here we evaluate the potential effect of cinnarizine in two pharmacological models of psychosis, namely amphetamine- and MK-801-induced hyperlocomotion, as well as its ability to induce catalepsy. Cinnarizine significantly counteracted MK-801 (0.25 mg/kg) and amphetamine (5mg/kg) locomotor effects at doses as low as 20mg/kg, having no incremental effect at 60 or 180 mg/kg. Regarding side-effects, cinnarizine induced no catalepsy in mice at the effective dose of 20 mg/kg, inducing only mild catalepsy at the doses of 60 and 180 mg/kg. Based on these results and on the antagonist effect of cinnarizine on dopamine D2 receptors, we suggest that it has a potential antipsychotic effect with an atypical profile that should be evaluated clinically.

In vestibular hair cells, K+ currents induced by rises in hydrostatic pressure have recently been demonstrated. These currents are inhibited by charybdotoxin, a blocker of Ca2+-dependent K+ channels. On the other hand, cinnarizine is a blocker of voltage-gated Ca2+ currents in hair cells and is used as a drug in conditions with vestibular vertigo. Our aim was to test in patch-clamp experiments (conventional whole-cell mode) whether cinnarizine, by reducing Ca2+ influx, inhibited Ca2+ and pressure-sensitive K+ currents in vestibular type-II hair cells of guinea pigs. A quantitatively similar inhibition of K+ currents was evoked by extracellular Ca2+ removal, cinnarizine (0.5 microM), and the L-type Ca2+ channel blocker nifedipine (3 microM). Cinnarizine abrogated increases of K+ currents induced by increases in the hydrostatic pressure (from 0.2 to 0.5 cm H2O). At a higher concentration (1 microM), cinnarizine elicited K+ current inhibitions larger than those elicited by Ca2+ removal. Moreover, it reduced K+ currents in the absence of Ca2+, in contrast to nifedipine. However, charybdotoxin abolished these effects of cinnarizine. We thus conclude that cinnarizine inhibits, by two mechanisms, pressure-induced currents that are sensitive to charybdotoxin and Ca2+. It reduces Ca2+ influx and exerts a Ca2+-independent inhibition, with a lower IC50 than that required for Ca2+ channel blockade. These two actions may importantly contribute to its therapeutic effects.

Aim: To explore the relations between anti-apoptotic role of dipfluzine (DIP) and the death signaling transduction pathway initiated by CD95 molecules, and the transcription factor involved in the transcription regulation of CD95 molecules in the hippocampal CA1 region after transient forebrain ischemia., Methods: The rat forebrain transient ischemia model was established through 15 min ischemia followed by 3 days reperfusion by using the four-vessel method. The rats were divided randomly into five groups: sham control group, ischemia/reperfusion (I/R) group, DIP treated groups (20, 40 and 80 mg x kg(-1) body weight, ig, separately). Western blotting and RT-PCR were performed to detect the expression changes of Fas, FasL, caspase 10 p20, caspase 8, I-kappaB-alpha, and p-I-kappaB-alpha molecules in protein and mRNA levels, separately, and immunohistochemistry for molecular localization of Fas and FasL in rat hippocampus., Results: The expression of Fas, FasL, and caspase 10 p20 in protein and mRNA levels increased after I/R, which was inhibited significantly after treatment with 20 and 40 mg x kg(-1) of DIP (P < 0.01). In 80 mg x kg(-1) of DIP group, the expression of Fas and FasL protein was not significantly different from that of I/R group (P > 0.05). The expression of caspase 8 and I-kappaB-alpha showed no significant differences in all groups (P > 0.05), and no gene expression was observed for p-I-kappaB-alpha protein in the study. DIP significantly affected molecular distribution of Fas and FasL protein in CA1 subregion of hippocampus., Conclusion: DIP inhibits the death signaling transduction pathway initiated by CD95 molecules in rat hippocampal CA1 subregion, and NF-kappaB transcription factor may not be involved in the transcription regulation of CD95 molecules after transient forebrain ischemia.

The efficacy of combined medication which comprised compounds with nootropic (piracetam) and vasoactive (cinnarisin) effects, was studied in patients with cerebral blood flow insufficiency. The main inclusion criterion was a diagnosis of chronic brain ischemia (CI). The study consisted of two stages: (1) a randomized comparative trial in neurological clinic (60 patients) and (2) estimation of the drug efficacy in routine practice (60 patients). The clinical examination was accompanied by neuropsychological tasks, kinetic tests and ultrasound investigation of brain vessels. At the first stage, a positive neurological and neuropsychological dynamics was found after 8 weeks of phezam treatment. Also a statistically significant positive dynamics was observed for a number of blood flow velocity parameters in the middle brain artery. In routine medical practice, a positive effect of phezam was seen after 2 months of the treatment for all but CI main symptoms and confirmed by the data of kinetic investigation. The patients reported good tolerability and convenience of the drug intake (one capsule instead of two tablets of nootropic and vasoactive drugs).

Cinnarizine is pharmaceutically used in conditions with vestibular vertigo such as Meniere's disease. It is thought to act on extra-vestibular targets. We hypothesized that cinnarizine, as a blocker of L-type Ca2+ channels, may directly target vestibular hair cells where Ca2+ currents are important for the mechano-electrical transduction and transmitter release. Our aim was to clarify whether cinnarizine affected voltage-dependent Ca2+ currents in vestibular type II hair cells. Such cells were isolated from inner ears of guinea pigs by enzymatic and mechanical dissection from the gelatinous otolithic membrane and studied with the patch-clamp technique in conventional whole-cell mode. Ca2+ currents were elicited by depolarizing pulses in a solution containing 1.8 mM Ca2+ and 40 mM Ba2+. These currents resembled L-type currents (I(Ca,L)) with respect to their voltage-dependence and their inhibition by nifedipine and Cd2+ but did not show time-dependent inactivation. The currents were inhibited by cinnarizine in a concentration-dependent and reversible manner. The IC50 was 1.5 microM. A block exceeding 80% was achieved with 10 microM. The onset of current block was faster with higher concentrations but the reversibility after wash-out was less, suggesting accumulation in the membrane. We conclude that these direct actions of cinnarizine on hair cells should be considered as molecular mechanisms contributing to therapeutic effects of cinnarizine in vertigo.

In the present comparative, double-blind, 3-way crossover study, possible effects of an antivertiginous combination preparation on event-related potentials (ERPs) and performance were investigated. Twenty-one healthy volunteers received 4 doses (within 24 h) of a fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg (Arlevert, ARL), dimenhydrinate 50 mg, or a placebo, in randomized order at 1-week intervals. Auditory event-related potentials (ERPs), reaction time (RT) and psychometric tests were assessed before as well as 60 and 150 minutes after the intake of the 1st (Day 1) and the 4th (Day 2) dose of study medication. The evaluation was primarily based on the difference in the outcomes measured 150 min after the 4th dose (t5) and those before the start of medication intake (t0). None of the medications affected the latency and amplitude of the sensory ERP component N100, neither under passive listening nor under discrimination task conditions. The latency of P300 in response to the rare target tones (oddball paradigm and binary series), showed significant (p < 0.05) delays after 4 doses of dimenhydrinate (18-24 ms), and no significant differences between ARL (3-17 ms) and either dimenhydrinate or placebo (4-13 ms). Responses to nontarget tones remained almost unaffected after medication intake. The secondary analysis of the P300 amplitude showed the greatest decreases under DH in both active series, with no significant differences between ARL and either DH or placebo. The 3 medications did not significantly prolong RT nor did they impair the performance of psychometric tests, or cause significant shifts of current mood. The combination preparation ARL showed the lowest rate of adverse events (n = 1), followed by dimenhydrinate (n = 3) and placebo (n = 6). Two subjects withdrew because of adverse events, both after the intake of placebo. In conclusion, the results gave no evidence for an impairment of central information processing and psychomotor performance after multiple dosing with the fixed combination ARL in healthy volunteers, which might, when present, represent an adverse reaction limiting its use in antivertiginous therapy. No significant differences were found between ARL and placebo.

The effect of cinnarizine on the functional state of brain mitochondria, the activity of blood antioxidant system, and the behavior of rats was studied under model hypoxic hypoxia conditions. A four-day treatments with cinnarizine (50 mg/kg, twice per day via a gastric tube) prevents the hypoxic brain edema development, restores NAD+ dependent oxidation of a succinate substrate, normalizes emotional-exploratory activity, and causes hyperlocomotion of the experimental animals, while not influencing a high level of activity of the blood antioxidant system.

Aim: To investigate the effects of dipfluzine (Dip) on delayed afterdepolarizations (DADs) and triggered activity (TA) induced by ouabain and high Ca2+ in guinea pig papillary muscles., Methods: Stable and reproducible DADs and TA in guinea pig papillary muscles were induced by ouabain (1 micromol/L) and high Ca2+ (5.4 mmol/L). DADs and TA were recorded using intracellular glass microelectrode technique., Results: (1) DADs and TA were markedly inhibited by pretreatment with Dip (10, 30 micromol/L). The amplitude and duration of DADs were reduced by Dip (30 micromol/L) from 10.5 mV +/- 2.2 mV and 230 ms +/- 19 ms to 3.6 mV +/- 0.3 mV and 152 ms +/- 14 ms, respectively, and the induced time of DADs was prolonged from (21+/-5) to (66+/-11) min. TA was not observed. (2) Dip (10, 30 micromol/L) had significant therapeutic effects on DADs and TA. The amplitude and duration of DADs were reduced by Dip (30 micromol/L) from 10.4 mV +/- 1.2 mV and 218 ms +/- 22 ms to 3.3 mV +/- 0.6 mV and 159 ms+/-26 ms. The occurrence of TA was also abolished., Conclusion: Dip has inhibitory effects on DADs and TA induced by ouabain and high Ca2+ in guinea pig papillary muscles, which might be related to alleviation of intracellular calcium overload through inhibiting calcium channel and/or calcium release from sarcoplasmic reticulum. The effects of Dip on DADs and TA might produce anti-arrhythmic effects.

Objective: To examine the effect of dipfluzine (Dip), a novel calcium channel blocker first developed in China, on acute ischemic brain edema., Methods: One hundred and thirty gerbils, 65 males and 65 females, weighing 68 +/- 10 g, were used. Eighty gerbils randomly divided into four groups of 20 animals: sham operation group, Dip 25 mg/kg group, and Dip 50 mg/kg group. All of the 120 gerbils were injected with solution or Dip at different concentrations intraperitoneally. The skin of neck was incised one hour after injection. Except in the sham operation group, bilateral carotid artery ligation (BCAL) was performed in the other 70 gerbils to cause brain edema. Another 10 gerbils were used as normal controls without undergoing injection and operation. One hour after the operation, all of the animals were killed and the whole brain tissue was taken to detect the water and Na(+) and K(+) contents. The brain tissues of other 50 gerbils were used to produce homogenate to determine the Na(+), K(+)-ATPase activity., Results: The water and Na(+) contents in hippocampus of model control group were 77.4% and 279 +/- 22 micro mol/g dry tissue respectively, significantly higher than those in sham operation group (74.8% and 220 +/- 22 micro mol/g dry tissue). The K(+) content in the hippocampus of the model control group was 381 +/- 28 micro mol/g dry tissue respectively, significantly lower than that in the sham operation group (430 +/- 30 micro mol/g dry tissue). The Na(+), K(+)-ATPase activity in the plasmalemma of brain cells in model control group was 179 +/- 62 micro mol pi/mg protein/min, significantly lower than that in sham operation group (1006 +/- 130 micro mol pi/mg protein/min, P < 0.01). The water contents of hippocampus in Dip 25 mg/kg group and Dip 50 mg/kg group were 75.4 +/- 0.5% and 74.8 +/- 0.9% respectively, significantly lower than that in model control group (all P < 0.01). The Na(+) contents in hippocampus of Dip 25 mg/kg group and Dip 50 mg/kg group were 235 +/- 39 micro mol/g dry tissue and 223 +/- 36 micro mol/g dry tissue respectively, significantly lower than that in model control group (279 +/- 22 micro mol/g dry tissue, all P < 0.01). The K(+) content in hippocampus of Dip 25 mg/kg group and Dip 50 mg/kg group were 427 +/- 32 micro mol/g dry tissue and 434 +/- 29 micro mol/g dry tissue respectively, significantly higher than that in model control group (P < 0.05 and P < 0.01). The Na(+), K(+)-ATPase activity in the plasmalemma of brain cells in Dip 25 mg/kg group and Dip 50 mg/kg group was 649 +/- 45 and 1 198 +/- 218 micro mol pi/mg protein/min respectively, significantly higher than that in model control group (r = 0.9981, P < 0.01). The correlation between brain water content and Na(+), K(+)-ATPase activity was significant (r = -0.999 7, P < 0.01)., Conclusion: Dip attenuates dose-dependently the increased H(2)O and Na(+) contents, prevents the decrease in potassium level, and accelerates the restoration of lowered Na(+), K(+)-ATPase activity resulted from cerebral ischemia, thus preventing ischemic brain edema.

The aim of the present study was to characterize voltage-gated Ca2+ currents in smooth muscle cells freshly isolated from rat tail main artery in the presence of 5 mmol L(-1) external Ca2+. Calcium currents were identified on the basis of their voltage dependencies and sensitivity to nifedipine, Ni2+ and cinnarizine. In the majority of the cells studied, T- and L-type currents were observed, while the remaining cells showed predominantly L-type currents. In the latter group of cells, holding potential change from -50 to either -70 or -90 mV increased the corresponding inward current amplitude while its voltage activation threshold remained unchanged. The steady state inactivation of L-type Ca2+ channels showed half-maximal inactivation at -38 mV. A Ca2+-dependent inactivation was also evident. Nifedipine (3 micromol L(-1)) blocked L-type but not T-type Ca2+ currents. Ni2+ (50 micromol L(-1)) as well as cinnarizine (1 micromol L(-1)) suppressed the nifedipine-resistant, T-type component of the currents. At higher concentrations, both Ni2+ (0.3-1 mmol L(-1)) and cinnarizine (10 micromol L(-1)) blocked the net inward current. Replacement of Ca2+ with 10 mmol L(-)1 Ba2+ significantly increased the amplitude of L-type Ca2+ currents. These results demonstrate that smooth muscle cells freshly isolated from rat tail main artery may be divided into two populations, one expressing both L- and T-type and the other only L-type Ca2+ channels. Furthermore, this report shows that in arterial smooth muscle cells cinnarizine potently inhibited T-type currents at low concentrations (1 micromol L(-1)) but also blocked L-type Ca2+ currents at higher concentrations (10 micromol L(-1)).

Aim: To study the effect of dipfluzine (Dip) on L-type calcium current in guinea pig ventricular myocytes., Methods: Single myocytes were dissociated by enzymatic dissociation method. The current was recorded with the whole-cell configuration of the patch-clamp technique., Results: Dip (0.3 - 30 micromol/L) reduced the voltage-dependently activated peak value of I(Ca-L) in a concentration-dependent manner. The characteristics of I-V relationship were not greatly altered by Dip, and the maximal activation voltage of I(Ca-L) in the presence of Dip was not different from that of control. Steady-state activation of I(Ca-L) was not affected markedly, and the half activation potential V(0.5)) and the slope factor (kappa) in the presence of Dip 3 micromol/L were not markedly different from those of the control. V(0.5) value was (-12.8 +/- 1.7) mV in the control and (-13.2 +/- 2.4) mV in the presence of Dip 3 micromol/L. The kappa value was (7.1 +/- 0.4) mV in the control and (7.5 +/- 0.5) mV in the presence of Dip 3 micromol/L (n = 7 cells from 3 hearts, P > 0.05). Dip 3 micromol/L markedly shifted the steady-state inactivation curve of I(Ca-L) to the left, and accelerated the voltage-dependent steady-state inactivation of calcium current. V(0.5) value was (-19.7 +/- 2.4) mV in the control and (-31 +/- 6) mV in the presence of Dip 3 micromol/L. The kappa value was (3.6 +/- 0.3) mV in the control and (1.8 +/- 0.2) mV in the presence of Dip 3 micromol/L (n = 4 cells from 2 hearts, P < 0.05). Dip 3 micromol/L markedly delayed half-recovery time of Ca2+ channel from inactivation from (40 +/- 11) to (288 +/- 63) ms (n = 4, P < 0.01)., Conclusion: Dip mainly acts on the inactivated state of L-type calcium channel, accelerates the inactivation of calcium channel, and slows the recovery of calcium channel from inactivated state in guinea pig ventricular myocytes, through which the I(Ca-L) is inhibited.

In myenteric neurons two different receptor subtypes govern the intracellular Ca(2+) stores: the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) and the ryanodine receptor (RyR). Their degree of functional overlap was determined by examining Ca(2+) release in these cells through both superfusion techniques and intracellular microinjection. Microinjection of IP(3) (50 microM) and cADP-ribose (cADPr, 50 microM), specific ligands for the IP(3)R and RyR, respectively, demonstrated mobilization of intracellular Ca(2+) stores. Perfusion with cinnarizine (50 microM) or dantrolene (10 microM), antagonists of the IP(3)R and RyR, respectively, eliminated the Ca(2+) response to microinjected IP(3) and cADPr. Superfusion of the neurons with 100 microM ATP, an IP(3)-mediated Ca(2+)-mobilizing agonist, caused intracellular Ca(2+) increments, which were antagonized by cinnarizine, and the RyR antagonists dantrolene, procaine (5 mM), and ryanodine (1 microM). Caffeine (10 mM) was applied repetitively in Ca(2+)-free conditions to deplete RyR-sensitive stores; subsequent perfusion with ATP demonstrated a Ca(2+) response. Conversely, caffeine caused a Ca(2+) response after repetitive ATP exposures. The internal Ca(2+) stores of myenteric neurons are governed by two receptor subtypes, IP(3)R and RyR, which share partial functional overlap.

Flunarizine and cinnarizine (IC50 6.8x10(-6) and 2.8x10(-5) M, respectively) inhibited 3H-serotonin uptake by platelets. In higher doses, they blocked serotonin-induced platelet aggregation and stimulated 3H-serotonin release from these cells. Imipramine did not affect serotonin-releasing effects of preparations. In all patients cinnarizine was more potent in inhibiting serotonin uptake, and in half of the patients cinnarizine displayed higher activity as an inductor of serotonin release.

In experiments on Wistar and Long Evans rats, using behavioral methods for passive (step-down and step-through) and active (shuttle-box two-way avoidance with punishment reinforcement) the newly synthesized diphenyl-methyl-piperazine derivative with Ca2+ and 5-HT antagonistic action dotarizine (DOT) administered repeatedly at oral doses of 50 and 10 mg/kg in some cases improve memory process. Under the same experimental conditions the chemically related to dotarizine Ca2+ antagonist flunarizine significantly facilitated retention. In old (Long Evans and Wistar) rats DOT in large dose decreases values of learning criterion. Probably this is a manifestation of the inherent to drugs with nootropic action "therapeutic window". Earlier investigations of the same and other authors suggest the participation of serotonergic neurotransmission in the mechanism of the memory effects of the drug DOT.

Severe seasickness could pose a serious problem in diving, and anti-seasickness medication should therefore be prescribed for the seasickness-susceptible diver. Cinnarizine may be used as a medication if it does not increase the risk of central nervous system (CNS) oxygen toxicity when diving with closed-circuit oxygen or O2-enriched gas mixtures. Twenty-six male, white Sprague-Dawley rats were exposed to high O2 pressures (507 and 608 kPa) before and after cinnarizine ingestion (3.3 mg.kg-1), until the appearance of the first electrical discharge (FED) in the electroencephalogram (EEG) which precedes the clinical convulsions. Each rat was tested on five exposure protocols (control and cinnarizine at 507 kPa O2, control, cinnarizine, and 15 h starvation as a control for cinnarizine at 608 kPa O2) at intervals of at least 2 days or until the EEG connector became detached (a mean of 3.1 exposures per rat). Latency to the FED increased after cinnarizine ingestion in 16 of the 17 pairs of measurements at 507 kPa O2 (by more than 61%, P < 0.002) and in 17 of the 19 pairs of measurements at 608 kPa O2 (by 36%, P < 0.002). There was no significant effect of 15 h starvation. Cinnarizine can be further considered for use in seasickness-susceptible divers as it does not increase the risk of CNS O2 toxicity.

Experiments with male mice (28-32 g) of the CFLP strain showed that cinnarizine in doses of 2.5, 5.0 or 10.0 mg kg-1 significantly inhibited the extent of ear oedema induced by croton oil, capsaicin or dithranol, in a dose-dependent manner. In rats of the Wistar strain, oedema was induced in the hind paw by subplantar injection of carrageenin, and simultaneously by the application of croton oil to the inner surface of the ear. Preliminary cinnarizine treatment (5, 10 or 20 mg kg-1) inhibited the development of both types of oedema, to a statistically significant extent, in a dose-dependent manner.

Background: Oxygen radicals are believed to play a significant role in glomerular disease. In part this may be due to oxidation of lipids, but protein oxidation may play a contributory role as well. We have demonstrated that the mesangial extracellular matrix is susceptible to metal-catalyzed oxidation and that this increases scavenger receptor-mediated adhesion of macrophages, cells which appear to be important participants in glomerular injury via their secretory products. As other scavenger receptor ligands can increase macrophage nitric oxide generation, we examined whether oxidation of matrix could increase the activity of macrophage inducible nitric oxide synthase (iNOS)., Methods: Extracellular matrix was oxidized using a metal-catalyzed oxidation system. Matrix oxidation was measured using carbonyl analysis, and iNOS activity in macrophages seeded onto the matrix was measured by nitrite determination and Western and Northern analyses for iNOS., Results: Macrophages exposed to oxidized matrix demonstrated a significant enhancement of iNOS activity. This enhancement could be antagonized by cotreatment of matrix with the radical spin trap N-tert-butyl-a-phenylnitrone, resulting in a corresponding decrease in protein carbonyl content, a measure of protein oxidation. Seeding macrophages onto oxidized matrix and adding the scavenger receptor ligand polyinosinic acid further augmented iNOS activity, suggesting that additional scavenger receptors were available to bind ligand and that further augmentation of iNOS activity did not require an additional change in cell shape. Western blot analysis revealed an increase in iNOS protein expression as a consequence of interaction with the oxidized matrix, but there was no difference in iNOS mRNA expression by Northern analysis suggesting a post-transcriptional mechanism for enhanced iNOS activity., Conclusion: These data demonstrate that oxidation of extracellular matrix enhances macrophage nitric oxide generation, and suggest a previously undescribed role for extracellular matrix modification in the regulation of cellular function and possibly the mediation of glomerular injury.

Studies showed that 15-day restriction of motor activity inhibits the reuptake of GABA by sections of the rat brain cortex and hypothalamus. In prolonged intraperitoneal injection of 10 mg/kg cinnarizine in hyperkinesia, further inhibition of this process in hypothalamic sections is encountered on the 15th days. Flunarizin (1 mg/kg) administered in a like manner has no significant effect on GABA reuptake. A course of GABA injections in a dose of 5 mg/kg improves in rats with restricted motor activity the local blood flow in the frontal lobe of the brain.

To study the mechanism of cinnarizine in preventing motion sickness, TXB2, 6-Keto-PGF1 alpha in rats' blood plasma and Na(+)-K(+)-ATPase activity in the endothelial cells of their cerebellar capillary were measured and analysed by a radioactive immunity analyser and a computer image system. The results showed that TXB2 and 6-Keto-PGF1 alpha in rats' blood plasma in the cinnarizine preventing group (CPG) decreased remarkably, compared with those in the motion sickness group(MSG) (p < 0.05). The activity of Na(+)-K(+)-ATPase in the endothelial cells of rats' cerebellar capillary in CPG was higher than that in MSG (p < 0.01). The authors suggest that the lower concentration of TXB2 and 6-Keto-PGF1 alpha in rats' blood plasma in CPG is closely related to cinnarizine which prevents Ca2+ from entering into the platelets and into the endothelial cells of blood vessels. The higher activity of Na(+)-K(+)-ATPase in the cerebellum may be caused by cinnarizene which dilates the blood vessels in the brain, increases the blood flow therein, and hinders Ca2+ from getting into the cerebellum cells. These change are believed to be the important mechanism of how cinnarizine prevents motion sickness.