RESUMEN
Parkinson's disease (PD) is a neurodegenerative disease featured by progressive loss of nigrostriatal dopaminergic neurons, the etiology of which is associated with the existence of neuroinflammatory response and oxidative stress. Vincamine is an indole alkaloid that was reported to exhibit potent anti-inflammatory and antioxidant properties in many central and/or peripheral diseases. Nevertheless, the specific role of vincamine in PD development remains unknown. In our study, dopaminergic neuron loss was determined through immunohistochemistry staining and western blot analysis of tyrosine hydroxylase (TH) expression in the substantia nigra (SN) of PD mice. Reactive oxygen species (ROS) production and malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were detected through DHE staining and commercially available kits to assess oxidative stress. Pro-inflammatory cytokine (TNF-α, IL-1ß, and IL-6) levels in the SN were measured via RT-qPCR and western blot analysis. Microglial and astrocyte activation was examined through immunofluorescence staining of Iba-1 (microglia marker) and GFAP (astrocyte marker) in the SN. The regulation of vincamine on the NF-κB and Nrf2/HO-1 pathway was estimated through western blot analysis. Our results showed that vincamine treatment decreased TNF-α, IL-1ß, and IL-6 mRNA and protein levels, reduced GFAP and Iba-1 expression, decreased ROS production and MDA level, and increased SOD activity and GSH level in the SN of PD mice. Mechanically, vincamine repressed the phosphorylation levels of p65, IKKß, and IκBα but enhanced the protein levels of Nrf2 and HO-1 in PD mice. Collectively, vincamine plays a neuroprotective role in PD mouse models by alleviating neuroinflammation and oxidative damage via suppressing the NF-κB pathway and activating the Nrf2/HO-1 pathway.
Asunto(s)
Enfermedad de Parkinson , Vincamina , Animales , Ratones , Lesiones Encefálicas , Interleucina-6/metabolismo , Enfermedades Neurodegenerativas , Enfermedades Neuroinflamatorias , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Estrés Oxidativo , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Especies Reactivas de Oxígeno , Transducción de Señal , Superóxido Dismutasa/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Vincamina/administración & dosificaciónRESUMEN
Innovative discovery strategies are essential to address the ongoing opioid epidemic in the United States. Misuse of prescription and illegal opioids (e.g., morphine, heroin) has led to major problems with addiction and overdose. We used vincamine, an indole alkaloid, as a synthetic starting point for dramatic structural alterations of its complex, fused ring system to synthesize 80 diverse compounds with intricate molecular architectures. A select series of vincamine-derived compounds were screened for both agonistic and antagonistic activities against a panel of 168 G protein-coupled receptor (GPCR) drug targets. Although vincamine was without an effect, the novel compound 4 (V2a) demonstrated antagonistic activities against hypocretin (orexin) receptor 2. When advanced to animal studies, 4 (V2a) significantly prevented acute morphine-conditioned place preference (CPP) and stress-induced reinstatement of extinguished morphine-CPP in mouse models of opioid reward and relapse. These results demonstrate that the ring distortion of vincamine offers a promising way to explore new chemical space of relevance to opioid addiction.
Asunto(s)
Ingeniería Química/métodos , Comportamiento de Búsqueda de Drogas/efectos de los fármacos , Morfina/administración & dosificación , Vincamina/administración & dosificación , Vincamina/síntesis química , Animales , Comportamiento de Búsqueda de Drogas/fisiología , Inyecciones Intraperitoneales , Inyecciones Intraventriculares , Masculino , Ratones , Ratones Endogámicos C57BL , Trastornos Relacionados con Opioides/tratamiento farmacológico , Trastornos Relacionados con Opioides/metabolismo , Antagonistas de los Receptores de Orexina/administración & dosificación , Antagonistas de los Receptores de Orexina/síntesis química , Antagonistas de los Receptores de Orexina/metabolismo , Receptores de Orexina/metabolismo , Estructura Secundaria de Proteína , Vincamina/metabolismoRESUMEN
Methotrexate (MTX) is a cytotoxic chemotherapeutic agent widely used in the treatment of cancer and autoimmune diseases like rheumatoid arthritis. However, its use has been limited by its nephrotoxicity. MTX-induced renal injury results in uremia which may influence both the peripheral and central nervous systems causing cognitive and memory problems. The nephroprotective and neuroprotective activities of vincamine (10, 20 and 40 mg/kg), a natural alkaloid with known anti-oxidant, anti-apoptotic and neuroprotective properties, were investigated against MTX-induced toxicity. MTX treatment increased the markers of kidney injury and relative kidney weight, lipid peroxidation, nuclear factor-κB (NF-κB), inflammatory markers, tumor necrosis factor-α, interleukin-1ß, myeloperoxidase and cyclooxygenase-2 and caspase-3 expressions, decreased catalase and superoxide dismutase activities, interleukin-10 and ATP levels and antioxidant proteins, nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1). Moreover, it disturbed rats' behavior in the locomotor activity test, Y-maze and passive avoidance task. Treatment with vincamine (40 mg/kg) effectively ameliorated MTX-induced renal injury via increasing the expression of Nrf2 and HO-1 suppressing oxidative stress, decreasing the expression of inflammatory markers, NF-κB and caspase-3 pathways and enhancing ATP levels. Additionally, it restored locomotor activity in the locomotor test and memory functions in passive avoidance and Y-maze tests.
Asunto(s)
Riñón/efectos de los fármacos , Metotrexato/toxicidad , Síndromes de Neurotoxicidad/prevención & control , Vincamina/farmacología , Animales , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/toxicidad , Antioxidantes/administración & dosificación , Antioxidantes/farmacología , Relación Dosis-Respuesta a Droga , Hemo Oxigenasa (Desciclizante)/metabolismo , Riñón/patología , Locomoción/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Metotrexato/administración & dosificación , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/farmacología , Síndromes de Neurotoxicidad/etiología , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Vincamina/administración & dosificaciónRESUMEN
The aim of the research was to investigate three "critical steps" that deserve particular attention during the mechanochemical activation of vincamine. The first step consisted in the selection of the best polymeric carrier/most affine stabiliser between linear PVP and NaCMC by using the GRID and the GRID based AutoDock software packages which permit to calculate their surface features and interactions. Moreover, the calculation of the partial and total solubility parameters supported the results obtained by GRID and AutoDock software. Then, after the selection of linear PVP-K30 as the suitable carrier, the influence of process and formulation variables on the amorphisation degree and solubility enhancement was studied, to select the most suitable process conditions and formulation parameters. Subsequently, the best performing samples were widely characterised using XRPD, TEM and SSNMR (including the proton relaxation ((1)H T1 NMR) time) techniques. These studies highlighted that all the coground samples were nanocrystalline solid dispersions indicating a dramatic difference between the amorphisation capacities of linear PVP-K30 and cross-linked PVP, used in previous analogous experiences. In particular, (13)C, (15)N and (1)H T1 NMR data point to a description of the system as a dispersion of nanocrystals in the polymer. In these dispersions vincamine is in a disordered crystalline state due to extensive interactions and contacts with PVP-K30 but the main hydrogen bonding motif characterising its packing remains. Again, differently from cross-linked PVP, dissolution studies revealed that linear PVP-K30 was able to promote a complete in vitro solubilisation of vincamine in some coground samples. What is more important, by using a linear polymer, drug-to-polymer and milling time variables appeared less influent on the solid state and in vitro properties of the composites. Finally, stability studies conducted for a period of 1year highlighted the high physical stability of the selected samples.
Asunto(s)
Carboximetilcelulosa de Sodio/química , Portadores de Fármacos/química , Modelos Químicos , Nanopartículas/química , Povidona/química , Vincamina , Simulación por Computador , Reactivos de Enlaces Cruzados , Cristalización , Composición de Medicamentos , Estabilidad de Medicamentos , Modelos Biológicos , Modelos Moleculares , Estructura Molecular , Tamaño de la Partícula , Solubilidad , Propiedades de Superficie , Vincamina/administración & dosificación , Vincamina/químicaRESUMEN
In the present research a salt of vincamine, a poorly bioavailable indole alkaloid derived from the leaves of Vinca minor L., was synthesized in the solid state by means of a mechanochemical process employing citric acid as a reagent. The mechanochemical process was adopted as a solvent-free alternative to classical citrate synthetic route that involves the use of solvents. Since the mechanochemical salification is little studied to date and presents the disadvantage of offering a low yield, in this work, the influence of three process and formulation variables on the percentage of vincamine citrate was studied. In particular, the time of mechanical treatment (in planetary mill Fritsch P5) and the amount of citric acid were varied in order to evaluate their effect on the yield of the process, and the introduction of a solid solvent, a common pharmaceutical excipient (sodium carboxymethylcellulose, NaCMC), was considered. Due to the complexity of the resulting samples' matrix, an appropriate experimental design was employed to project the experimental trials and the influence of the three variables on the experimental response was estimated with the help of a statistical analysis. The experimental response, that is, the yield of the process corresponding to the percentage of vincamine in the protonated form, was unconventionally calculated by means of X-ray photoelectron spectroscopy analysis (XPS). Out of 16 samples, the one with the highest yield was the coground sample containing vincamine and citric acid in a 1:2 molar ratio, treated for 60 min in the presence of NaCMC. Under the above conditions the salification reaction was completed highlighting the importance of a proper selection of process and formulation variables of the mechanochemical salification, and emphasizing the crucial role of the solid solvent in facilitating the salification. The second step of the research encompassed the characterization of the citrate salt obtained by solid excipient assisted mechanochemical salification (SEAMS) in comparison with the vincamine citrate obtained by classical synthetic route. The samples were characterized by, besides XPS, high resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRPD), in vitro solubilization kinetics and in vivo oral pilot study in rats. Finally, in order to monitor over time possible disproportionation phenomena, stability studies have been performed by repeating XPS analysis after 8 months. As expected, the the SEAMS-vincamine salt consisted of particles both crystalline and amorphous. The solubilization kinetics was superior to the corresponding salt probably thanks to the favorable presence of the hydrophilic excipient although the two salts were bioequivalent in rats after oral administration. Furthermore, no evidence of disporportionation phenomena in the SEAMS-vincamine salt was found after storage. In conclusion, in the case of forming salts of poorly soluble drugs, the SEAMS process may be an interesting alternative to both classical synthetic routes, eliminating the need for solvent removal, and simple neat mechanochemical salification, overcoming the problem of limited process yield.
Asunto(s)
Ácido Cítrico/química , Vincamina/química , Animales , Disponibilidad Biológica , Química Farmacéutica/métodos , Estabilidad de Medicamentos , Excipientes/química , Cinética , Tamaño de la Partícula , Espectroscopía de Fotoelectrones/métodos , Proyectos Piloto , Ratas , Ratas Sprague-Dawley , Sales (Química)/química , Solubilidad , Solventes/química , Vincamina/administración & dosificación , Vincamina/sangre , Vincamina/farmacocinética , Difracción de Rayos X/métodosRESUMEN
Vincamine is a poorly soluble potent neuroprotector and cerebral vasodilator, used for the treatment for CNS disorders. In some cases, the bioavailability of pure compounds is strongly influenced by the co-administration of other constituents, and in some cases, the so called 'phytocomplex' may act as enhancer of absorption of selected phytochemicals. In this paper, the oral bioavailability of vincamine when administered as a standardised Vinca minor L. leaf dry extract rather than pure indole alkaloid is demonstrated to be higher. The chosen alkaloid-enriched and standardised dry extract was widely characterised by means of HPLC-MS, PXRD, DSC, XPS, (13)C and (15)N solid-state NMR (SSNMR) using pure vincamine as a matter of comparison. Then, the in vitro dissolution performances of the two products and their in vivo bioavailability in rats were evaluated. The sevenfold improvement in oral bioavailability of the dry extract with respect to the pure vincamine was ascribed to interactions between the indole alkaloid and the corollary of ingredients of the dry extract, giving rise to the protonation of the alkaloid vincamine, thus enhancing its dissolution in physiological fluids. Present data demonstrate that alkaloid vincamine administered as a whole plant extract has a higher bioavailability compared to the pure chemical compound.
Asunto(s)
Extractos Vegetales/administración & dosificación , Hojas de la Planta , Vinca , Vincamina/administración & dosificación , Administración Oral , Animales , Disponibilidad Biológica , Sinergismo Farmacológico , Extractos Vegetales/química , Extractos Vegetales/farmacocinética , Ratas , Ratas Sprague-Dawley , Regulación hacia Arriba/efectos de los fármacos , Vincamina/química , Vincamina/farmacocinéticaRESUMEN
The aims of this research were to prepare highly bioavailable binary cogrounds (vincamine-AcDiSol(®) or PVP-Cl) by means of a mechanochemical process and to study the mediation of each polymer in the induction of physical transformations of the drug. From a set of fifteen cogrounds for each crosslinked polymer, two samples were selected in each group on the basis of the AUC of in vitro dissolution profiles with the help of a statistical comparison. The chosen samples were analysed by means of TEM, XRPD, Raman-spectroscopy/imaging, SSNMR, also including the study of (1)H spin-lattice relaxation times. The research encompassed in vivo oral absorption studies in rats, pharmacokinetic analysis and physical stability studies during 1 year. An intimate drug-polymer mixing was found in the coground samples with domain average dimensions smaller than 100 Å; this reflected in a remarkable enhancement of the in vitro and in vivo bioavailability. Different disordered states were detected in the coground samples as a function of cogrinding time and the type and amount of polymer used. Though both crosslinked polymers produced a remarkable enhancement of the oral bioavailability, coground systems based on AcDiSol(®) are preferable in terms of pharmacokinetic performance and physical stability.
Asunto(s)
Carboximetilcelulosa de Sodio/química , Portadores de Fármacos/química , Polímeros/química , Povidona/química , Vincamina/química , Animales , Disponibilidad Biológica , Carboximetilcelulosa de Sodio/administración & dosificación , Carboximetilcelulosa de Sodio/farmacocinética , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/farmacocinética , Estabilidad de Medicamentos , Polímeros/administración & dosificación , Polímeros/farmacocinética , Povidona/administración & dosificación , Povidona/farmacocinética , Ratas , Ratas Sprague-Dawley , Solubilidad , Vasodilatadores/administración & dosificación , Vasodilatadores/química , Vasodilatadores/farmacocinética , Vincamina/administración & dosificación , Vincamina/farmacocinéticaRESUMEN
Trace elements are essential for normal brain functions. Tiny amounts of these elements help in the formation of neurotransmitters and involved in the antioxidant defense and intracellular redox regulation and modulation of neural cells. Vincamine is a plant alkaloid used clinically as a peripheral vasodilator that increases cerebral blood flow and oxygen and glucose utilization by neural tissue to combat the effect of aging. Neurodegenerative diseases associated with aging characterized by a disturbance in trace element levels in the brain. The objective of this study was to determine the level of zinc (Zn), copper (Cu), iron (Fe), Selenium (Se), and chromium (Cr) in the brain of rats treated with vincamine. Vincamine was injected i.m. to rats at a dose of 15 mg/Kg bodyweight daily for 14 days. Twenty-four hours after the last injection, rats were killed, and brains were ashed and digested by concentrated acids and analyzed for trace elements concentrations by flame emission atomic absorption spectrophotometer. The results showed that Zn was the highest trace element in the brain of control rats (3.134 +/- 0.072 ppm) and Cr was the lowest (0.386 +/- 0.027 ppm). Vincamine administration significantly (p < 0.01) reduced the brain Fe concentration (1.393 +/- 0.165 ppm) compared to control (2.807 +/- 0.165 ppm). It was concluded that Zn was the highest trace element in the brain of rats. Vincamine administration resulted in approximately 50% reduction in brain Fe concentration which suggests its beneficial effect to prevent the oxidative stress of Fe in neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's diseases.
Asunto(s)
Encéfalo/efectos de los fármacos , Oligoelementos/metabolismo , Vincamina/farmacología , Animales , Encéfalo/metabolismo , Cromo/metabolismo , Cobre/metabolismo , Femenino , Hierro/metabolismo , Estructura Molecular , Ratas , Selenio/metabolismo , Espectrofotometría Atómica , Vasodilatadores/administración & dosificación , Vasodilatadores/química , Vasodilatadores/farmacología , Vincamina/administración & dosificación , Vincamina/química , Zinc/metabolismoRESUMEN
PURPOSE: To prospectively study the effect of oral brovincamine, a relatively selective cerebral vasodilator, on further deterioration of visual field in patients with normal-tension glaucoma (NTG) with low-normal intraocular pressure (IOP). METHODS: Fifty-two patients with NTG (average age 57.7 years) with an IOP that was consistently less than 15 mmHg were randomly assigned to receive oral brovincamine (20 mg three times daily) or to an untreated control group. The groups were prospectively followed for 2 years with visual field examinations every 4 months, using the 30-2 Humphrey perimeter program. Changes in mean deviation (MD), corrected pattern standard deviation (CPSD), and total deviation (TD) at 74 test points were analyzed using regression analysis with linear mixed model. Data from one eye without media opacity of each subject were analyzed. RESULTS: There were no differences between groups in age; sex distribution; refraction; blood pressure; baseline IOP; MD, CPSD, or TD at each point. Changes in MD (standard error [SE]) during the study period were -0.778 (0.178) and -0.071 (0.195) dB/year in the control and brovincamine groups, respectively; change in the control group was significantly more negative than in the brovincamine group. Change in CPSD (SE) was 0.032 (0.015) and 0.004 (0.016) dB/year in the control and brovincamine groups, respectively. Change in the control group was significantly positive, but the intergroup difference was not significant. Change in TD was significantly negative at six test points in the control group, whereas no points showed a significant trend in the brovincamine group; the intergroup difference was significant. The average IOP was 13.2 mmHg and 13.1 mmHg in the control and brovincamine groups, respectively, and there was no significant intergroup difference. CONCLUSION: Oral brovincamine may retard further visual field deterioration in patients with NTG who have low-normal IOP.
Asunto(s)
Glaucoma de Ángulo Abierto/fisiopatología , Presión Intraocular/efectos de los fármacos , Vasodilatadores/administración & dosificación , Vincamina/análogos & derivados , Campos Visuales/efectos de los fármacos , Administración Oral , Enfermedad Crónica , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Glaucoma de Ángulo Abierto/patología , Humanos , Masculino , Persona de Mediana Edad , Disco Óptico/efectos de los fármacos , Disco Óptico/patología , Estudios Prospectivos , Resultado del Tratamiento , Vincamina/administración & dosificaciónRESUMEN
PURPOSE: A prospective investigation of the effect of brovincamine fumarate, a Ca2+-channel blocker, on visual field changes in normal-tension glaucoma (NTG). METHODS: A total of 28, age- and field-matched, patients with NTG were allocated randomly to either brovincamine fumarate (20 mg 3 times daily) or placebo (3 times daily). The patients were followed at least every 4 months for a minimum of 2.5 years, and visual field examinations were carried out at least every 6 months. The mean follow-up periods (+/-standard deviation) were 39.1 +/- 8.7 months in the brovincamine-treated group and 37.9 +/- 10.1 months in the placebo group. Stepwise discriminant analyses were performed to separate the patients who showed improvement of their visual fields from those who failed to improve in the brovincamine-treated group, and to identify factors that may determine the visual field prognosis of all patients with NTG enrolled in the study. RESULTS: In the brovincamine-treated group, six patients showed visual field improvement, whereas none showed improvement in the placebo group using the Statpac 2 linear regression analysis. Discriminant analyses identified better cold recovery rate and higher initial systolic blood pressure to be significantly contributory to a favorable outcome in the brovincamine-treated group, and the use of brovincamine, better cold recovery rate, and higher initial systolic blood pressure were identified to be significantly contributory to a favorable prognosis in all subjects. CONCLUSION: Brovincamine seems to have a favorable effect on visual field in at least some patients with NTG.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Glaucoma de Ángulo Abierto/complicaciones , Vasodilatadores/uso terapéutico , Vincamina/análogos & derivados , Trastornos de la Visión/prevención & control , Campos Visuales/efectos de los fármacos , Administración Oral , Bloqueadores de los Canales de Calcio/administración & dosificación , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Vasodilatadores/administración & dosificación , Vincamina/administración & dosificación , Vincamina/uso terapéutico , Trastornos de la Visión/etiología , Trastornos de la Visión/fisiopatología , Agudeza VisualRESUMEN
The blood flow changes in the optic nerve head in adult albino rabbits following intravenous administration of brovincamine fumarate, an improver of cerebral circulation and metabolism, were investigated employing the hydrogen clearance method. In the brovincamine fumarate (0.1 mg/kg)-administered group, the blood flow in the optic nerve head increased soon after injection and reached the maximal value of 124.2 +/- 7.3% against the value before injection, at 20 minutes after injection, followed by a gradual decrease in the blood flow. Statistical analysis showed a significant increase (p < 0.05) in the blood flow at 10 to 40 minutes after injection, compared with the value before injection in the brovincamine fumarate (0.1 mg/kg)-administered group, but no significant increases in the blood flow were observed in either the brovincamine fumarate (0.5 mg/kg)-administered group or the control group given no brovincamine fumarate throughout the course. No significant changes in the mean values of the blood pressure in the femoral artery, pulse rate, respiratory rate or rectal temperature were observed in any group through the experiment. To learn the mechanism of the different efficacy of the two doses, further studies are needed in light of the cyclic adenosine monophosphate (cyclic AMP) changes induced by brovincamine fumarate administration or in light of the receptor responsiveness to the drug concentration.
Asunto(s)
Encéfalo/efectos de los fármacos , Circulación Cerebrovascular/efectos de los fármacos , Disco Óptico/irrigación sanguínea , Vasodilatadores/farmacología , Vincamina/análogos & derivados , Animales , Encéfalo/metabolismo , Femenino , Infusiones Intravenosas , Masculino , Conejos , Flujo Sanguíneo Regional/efectos de los fármacos , Vasodilatadores/administración & dosificación , Vincamina/administración & dosificación , Vincamina/farmacologíaRESUMEN
In experiments with rats and dogs exposed to whole-body nonlethal and lethal gamma-radiation (2; 2,9 or 7.5 Gy) the radioprotective efficacy Vinca alkaloids drugs was investigated. It has been shown that enterally administered Vincanor (10 mg/kg over a three-day period) increased the radioresistance of animals. The prolonged radioprotective effect of Vincanor are discussed with regard to the phenomenon of sequential partial DNA synthesis inhibition in radiosensitive tissues.
Asunto(s)
Traumatismos Experimentales por Radiación/prevención & control , Protectores contra Radiación/farmacología , Alcaloides de la Vinca/farmacología , Animales , Médula Ósea/efectos de los fármacos , Médula Ósea/metabolismo , Médula Ósea/efectos de la radiación , Aberraciones Cromosómicas , ADN/biosíntesis , Perros , Femenino , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de la radiación , Masculino , Dosis de Radiación , Traumatismos Experimentales por Radiación/metabolismo , Protectores contra Radiación/administración & dosificación , Ratas , Bazo/efectos de los fármacos , Bazo/metabolismo , Bazo/efectos de la radiación , Factores de Tiempo , Alcaloides de la Vinca/administración & dosificación , Vincamina/administración & dosificación , Vincamina/farmacología , Irradiación Corporal TotalRESUMEN
The sublingual absorption of vincamine used as tracer occurs in two successive absorption steps: true sublingual absorption and absorption in the gastrointestinal tract of the drug dissolved in the saliva and not absorbed through the buccal mucosa. This is confirmed by a pharmacokinetic study and simulation. These two successive absorptions can explain the increase in the amounts of drug absorbed.
Asunto(s)
Alcaloides de la Vinca/farmacocinética , Vincamina/farmacocinética , Administración Oral , Administración Sublingual , Adulto , Humanos , Absorción Intestinal , Masculino , Modelos Biológicos , Distribución Aleatoria , Vincamina/administración & dosificaciónRESUMEN
The dose-response relationship of vindeburnol has been investigated by assessing postural activity in a population of elderly patients, using posturography, an objective method for measuring balance. A controlled double blind trial was done in two periods: during the first week each patient received placebo, and during the second week either placebo or vindeburnol 30, 60 or 90 mg/d was given. Subjects underwent three posturographic recordings at weekly intervals (prior to treatment, after one week on placebo and after one week of treatment). There was no placebo effect. A significant decrease in the sagittal and lateral energies of body sway was found after vindeburnol, which indicates an improvement in balance. The improvement was proportional to the daily dose of vindeburnol.
Asunto(s)
Equilibrio Postural/efectos de los fármacos , Alcaloides de la Vinca/farmacología , Vincamina/farmacología , Anciano , Ensayos Clínicos como Asunto , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Postura , Distribución Aleatoria , Vincamina/administración & dosificación , Vincamina/análogos & derivadosRESUMEN
The results obtained by the authors in the pharmacokinetic study of vincamine teprosilate after oral and i.v. administration to young healthy volunteers and after oral administration to patients aged 68 to 84 years are presented. The description of the assay for each administration route is reported in the protocol. Plasma levels of vincamine teprosilate were assayed by reverse phase HPLC with spectrofluorimetric detection. The data obtained after i.v. administration made it possible to define the pharmacokinetic model and to estimate parameters. Concentration-time data were adapted to a biocompartmental open model with alpha value of 2.9080 and beta value 0.1047. In oral administration, the overlapping of the fast disposition phase and the absorption phase led to an apparent monocompartmental fit; in both young and aged volunteers, the absorption rate constants as well as the elimination rate constants were calculated. In both groups no significant differences in tmax values were found and no latency period was noticed . Cmax values were similar in both groups of patients; the lower distribution volume in aged volunteers compared to younger ones contributed to this finding. Differences in absorption rate constants in aged and young volunteers (0.53 h-1 and 0.73 h-1 respectively) are analysed. Vincamine teprosilate bioavailability after oral administration was found to be 20 +/- 5%. Possible vincamine teprosilate dose dependence kinetics are suggested.
Asunto(s)
Alcaloides de la Vinca/metabolismo , Vincamina/metabolismo , Administración Oral , Adulto , Anciano , Femenino , Humanos , Inyecciones Intravenosas , Cinética , Masculino , Vincamina/administración & dosificación , Vincamina/análogos & derivados , Vincamina/sangreRESUMEN
The EEG changes in elderly subjects with chronic cerebrovascular disorders (CCVD) are well known and have been described by many authors. Vincamine teprosilate (Teproside), a drug supposed to act on the electrical activity of the brain, has the properties of modifying and, to some extent, improving age-related changes. Ten subjects, whose age ranged from 60 to 70 years, underwent the trial. Each received 1 ampoule i.v. of the active drug and 1 ampoule of placebo (or vice versa) after a 48-hour wash-out period, according to a double-blind randomized schedule. EEG recordings were performed at time 0 and then 30 min, 1 h, 2 h, and 4 h after injection. A double effect of vincamine teprosilate could be observed at the quantified EEG: 1) an early effect, i.e., an improvement of the EEG pattern within the first hour following administration; and (2) a slow-occurring effect that prevented negative EEG modifications from taking place at the fourth hour following administration.
Asunto(s)
Electroencefalografía , Alcaloides de la Vinca/farmacología , Vincamina/farmacología , Anciano , Trastornos Cerebrovasculares/fisiopatología , Enfermedad Crónica , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Factores de Tiempo , Vincamina/administración & dosificación , Vincamina/efectos adversos , Vincamina/análogos & derivadosRESUMEN
Polyhexylcyanoacrylate nanoparticles have been prepared with vincamine as the model drug. These particles had an average size of 200 nm and adsorbed approximately 43% of vincamine. The adsorption of vincamine to nanoparticles modified the distribution of vincamine in tissues. After iv injection the distribution volumes were increased in comparison with an aqueous solution of drug. In comparison with an aqueous solution of drug, the absolute bioavailability of vincamine was also increased after an oral administration of nanoparticles.