Vinpocetine scientific update |
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PMID: 17070874 [PubMed - as supplied by publisher]
Sitges M, Chiu LM, Guarneros A, Nekrassov V.
Departamento de Biologia Celular y Fisiologia, Instituto de Investigaciones Biomedicas, UNAM, Apartado Postal 70228, Ciudad Universitaria 04510, Mexico D.F., Mexico.
Effects of vinpocetine on Na(+) channel-mediated release of [(3)H]glutamate in hippocampal nerve endings.
The efficacy of vinpocetine on sodium channel-mediated release of [(3)H]glutamate in hippocampal nerve endings. Antiepileptic drugs needed to control seizures are often accompanied by adverse secondary effects. In this case the effectiveness of vinpocetine to reduce sodium channels permeability may be useful.
Several of the most effective antiepileptic drugs are believed to stop the paroxysmal neuronal activity acting as Na(+) channel blockers. However, no single study comparing in parallel the potency and efficacy of the most commonly used antiepileptic drugs on brain Na(+) channel-mediated responses is available. In the present study the effects of increasing concentrations of carbamazepine, phenytoin, lamotrigine, oxcarbazepine and topiramate, which are among the most frequently used antiepileptic drugs, and of the new putative antiepileptic drug, vinpocetine, on the release of glutamate (Glu) elicited by the Na(+) channel opener, veratridine were investigated in hippocampal isolated nerve endings preloaded with the labeled excitatory amino acid neurotransmitter. The present results show that carbamazepine, phenytoin, lamotrigine and oxcarbazepine, in the range from 150 to 1500muM, progressively inhibit [(3)H]Glu release induced by veratridine. Also vinpocetine progressively inhibits the veratridine-induced response, but in a much lower range of concentrations (from 1.5 to 15muM), whereas topiramate only exerts a modest inhibition (20%) of Glu release to veratridine at the highest dose tested (1500muM). These results indicate that the mechanism of action of several of the most widely used antiepileptic drugs involves reduction in cerebral presynaptic voltage sensitive Na(+) channels permeability. Considering that the high doses of antiepileptic drugs required to control seizures are frequently accompanied by adverse secondary effects, the higher potency of vinpocetine to reduce Na(+) channels permeability might be advantageous.
Orv Hetil. 2003 May 18;144(20):973-8.
Szapary L, Horvath B, Alexy T, Marton Z, Kesmarky G, Szots M, Nagy F, Czopf J, Toth K.
Pecsi Tudomanyegyetem, Altalanos Orvostudomanyi Kar, Neurologiai Klinika.
Effect of vinpocetin on the hemorheologic parameters in patients with chronic cerebrovascular disease.
How vinpocetin affect the hemorheologic parameters in cerebrovascular patients? Vinpocetine is widely used in the treatment of cerebrovascular diseases. High dose of parenteral vinpocetine treatment considerably reduce the hematocrit.
INTRODUCTION: Data collected from large number of multicenter, randomized trials in acute and chronic stroke patients provide evidence, that incidence and high mortality of cerebrovascular disorders can be decreased mainly by prevention and that the effectiveness of acute stroke treatment is limited. The terminology of "chronic cerebrovascular diseases" involves many pathologic entities and often atypical clinical symptoms refer to the focal or global hypoperfusion of the brain. However, hemorheological disturbances seem to be important factors of the complex pathomechanism. Vinpocetine has successfully been used in the treatment of cerebrovascular diseases, the part of the mechanism of action are the favourable rheological effects demonstrated after oral administration in more previous studies. AIMS AND METHODS: In this study the hemorheological changes after administration of small (30 mg/day) and high dose (increased to 70 mg/day) intravenous vinpocetine for 7 days in 30 patients in chronic phase of ischemic cerebrovascular disease were investigated. RESULTS: High dose parenteral vinpocetine treatment significantly (p < 0.05-0.005) decreased the hematocrit, the whole blood and plasma viscosity and red blood cell aggregation compared to the values before the treatment. Only red blood cell aggregation was improved significantly (p < 0.05) by small dose treatment. CONCLUSION: This study and other hemorheological studies in cerebrovascular patients demonstrated persistent rheological abnormalities despite the preventive therapy. The beneficial rheological effect of high dose parenteral vinpocetine indicates the use of this drug in the treatment of chronic cerebrovascular diseases.
Ideggyogy Sz. 2003 May 20;56(5-6):166-72.
Hadjiev D.
University Hospital of Neurology and Psychiatry, St. Naum Compl. Javorov, B-1504 Bulgaria, Sofia, bl. 21. A.
Asymptomatic ischemic cerebrovascular disorders and neuroprotection with vinpocetine.
The efficacy if vinpocetine in the treatment of ischemic cerebrovascular disorders. Vinpocetine affect the multiple mechanisms of the AICVD. This may become a benefit for the treatment in the early stage of cerebrovascular disease.
The asymptomatic ischemic cerebrovascular disorders (AICVD) is an early manifestation of cerebrovascular disease. It is also known as latent insufficiency of the cerebrovascular circulation or as asymptomatic cerebrovascular disorders. Recently, the term subclinical disease, detected noninvasively, has been introduced by American Heart Association. The diagnosis is based on the following criteria: evidence of vascular risk factors; episodic nonspecific complaints without any focal cerebral symptoms; mild cognitive deficit, detected by neuropsychological tests; carotid ultrasonography often shows intimal-medial thickening, atherosclerotic plaques and carotid stenosis; CT and MRI occasionally reveal silent cerebral infarctions, white matter hyperintensities or cerebral atrophy; regional hypoperfusion above the ischemic threshold is also seen by rCBF measurements. Treatment of the AICVD, modifying the vascular risk factors and using neuroprotective agents, should be the cornerstone of primary prevention of ischemic stroke and cognitive decline, caused by cerebrovascular disorders. Vinpocetine has been found to interfere with various stages of the ischemic cascade: ATP depletion, activation of voltage-sensitive Na(+)- and Ca(++)-channels, glutamate and free radicals release. The inhibition of the voltage-sensitive Na(+)-channels appears to be especially relevant to the neuroprotective effect of vinpocetine. Pronounced antioxidant activity of the drug could also contribute to the neuroprotection. PET studies in primates and man showed that 11C labelled vinpocetine passes the blood-brain barrier rapidly. Heterogeneous brain distribution of the compound was observed mainly in the thalamus, basal ganglia, occipital, parietal and temporal cortex, regions which are closely related to the cognitive functions. PET studies in chronic ischemic stroke patients revealed favourable effects of vinpocetine on rCBF and glucose metabolism in the thalamus, basal ganglia and primary visual cortex. It seems, vinpocetine, affecting the multiple mechanisms of the AICVD, could be of benefit for the treatment in this early stage of cerebrovascular disease. Vinpocetine may also become a new therapeutic approach to prophylactic neuroprotection in patients at high risk of ischemic stroke.
Eur J Pharm Sci. 2005 Jan;24(1):1-13.
Ribeiro L, Carvalho RA, Ferreira DC, Veiga FJ.
Laboratory of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra, Portugal.
Multicomponent complex formation between vinpocetine, cyclodextrins, tartaric acid and water-soluble polymers monitored by NMR and solubility studies.
A research report on the multicomponent complex formation between vinpocetine, cyclodextrins, tartaric acid and water-soluble polymers. This was monitored by NMR and solubility studies. It is found that sulfobutyl ether beta-cyclodextrin was more effective in vinpocetine solubilization.
This work deals with multicomponent complex formation of vinpocetine (VP) with beta-cyclodextrin (betaCD), sulfobutyl ether beta-cyclodextrin (SBEbetaCD) and tartaric acid (TA), in the presence or absence of water-soluble polymers, in aqueous solution. Complexation was monitored by phase-solubility and proton nuclear magnetic resonance ((1)H NMR) studies. TA demonstrated a synergistic effect on VP solubility, and in the complexation efficiency of betaCD and SBEbetaCD. Additionally, water-soluble polymers increased even more the complexation efficiency of the CDs that was reflected by a 2.1-2.5 increase on K(C) values for VP-CD-TA-polymer multicomponent complexes. SBEbetaCD was more effective in VP solubilization, as K(C) values of VP-SBEbetaCD-TA multicomponent complexes were notably higher than in corresponding betaCD complexes. The large chemical shift displacements from protons located in the interior of the hydrophobic CD cavities (i.e., H-3 and H-5) coupled with significant chemical shift displacements of VP aromatic protons suggested that this moiety was included in the cavity of both betaCD and SBEbetaCD. Two-dimensional rotating frame nuclear Overhauser effect spectroscopy (ROESY) experiments were carried out in order to obtain information about the multicomponent complex geometry in solution. Inspection of ROESY spectra allowed the establishment of spatial proximities between all aromatic protons of VP and the internal protons of the CDs, confirming that the aromatic moiety of VP is included in CD cavities being deeply inserted in SBEbetaCD multicomponent complexes, since additional interactions with the sulfobutyl side chains were evidenced.
Vinpocetine description...
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Drug category:Nootropic and smart drugs
 Vinpocetine scientific update
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