Acute and Chronic Effects of Vinpocetine on Cerebral Hemodynamics and Neuropsychological Performance in Multi-infarct Patients

Vinpocetine (A comprehensive profile)

Vinpocetine (VIN) is a herbal supplement extracted from the periwinkle plant. It is a multi-action agent, which is used to treat various neurological disorders such as Alzheimer's and Parkinson's disease. Vinpocetine has also anti-inflammatory, analgesic, antioxidant property and treats various thinking and memory problems. Currently, vinpocetine is also available in the market as a dietary supplement to enhance cognition and memory. This profile explains the physicochemical properties, methods of preparation, content of related impurities and different spectroscopical behavior of vinpocetine. It also discusses the reported methods of analysis of the drug, which include Compendial Methods, Electrochemical Methods, Spectrophotometric Methods and Chromatographic Methods of analysis. Furthermore, this profile explains the stability of the drug subjected to stress conditions of acid, alkaline and photolytic degradation. In addition, the clinical applications of the drug, its uses, side effects, dosing information, pharmacokinetics and mechanism of action are also discussed.

In Situ Hexosomal Gel as a Promising Tool to Ameliorate the Transnasal Brain Delivery of Vinpocetine: Central Composite Optimization and In Vivo Biodistribution

Vascular dementia is a condition characterized by a wretched cerebral circulation which can lead to memory loss. Vinpocetine showed ability to promote the cerebral circulation and depict neuroprotective impacts. However, it suffers from poor bioavailability and requires frequent daily dosing which is not suitable for dementia patients. In our study, these limitations were overcome by the prolonged direct delivery of vinpocetine to the brain utilizing an intranasal in situ hexosomal gel. A central composite design was utilized and the optimum dispersion (consisting of 15% w/w of oleic acid and 5% w/w of pluronic F127) was loaded in an in situ gel system using gellan gum with 1% w/v. The optimized Formulae achieved a controlled drug release over 24 h and the pharmacokinetic data revealed that the C_max and AUC_0-24 in the rats' brain after the intranasal application of the dispersion and in situ gel were significantly higher relative to the vinpocetine solution applied intravenously at the same dose. The potential of both formulae to deliver vinpocetine to the brain directly through the intranasal route was confirmed by the high BTE% of 370.97% and 480.70% and the high DTP% of 73.04% and 79.19% for the dispersion and in situ gel, respectively.

Influence of angiotensin-converting enzyme inhibition on reversibility of alterations in arterial wall and cognitive performance associated with early hypertension: A follow-up study

The importance of optimal blood pressure control for preventing or reducing the impairment of vascular and cognitive functions is well known. However, the reversibility of early alterations in vascular and cognitive functions through antihypertensive agents is under-investigated. In this study, we evaluated the influence of 3 months of angiotensin-converting enzyme (ACE) inhibition treatment on the morphological and functional arterial wall and cognitive performance changes in 30 newly diagnosed primary hypertensive patients.Common carotid intima-media thickness (IMT) and brachial artery flow-mediated dilatation (FMD) were detected by ultrasonography. Arterial stiffness indicated by augmentation index (AIx) and pulse wave velocity (PWV) was assessed by arteriography. Cognitive functions were assessed by neuropsychological examination.The executive function overall score was significantly higher at 3-month follow-up than at baseline (median, 0.233 (IQR, 0.447) vs -0.038 (0.936); P = .001). Three-month ACE inhibition did not produce significant improvement in IMT, FMD, AIx and PWV values. Significant negative associations were revealed between IMT and complex attention (r = -0.598, P = .0008), executive function (r = -0.617, P = .0005), and immediate memory (r = -0.420, P = .026) overall scores at follow-up. AIx had significant negative correlations with complex attention (r = -0.568, P = .001), executive function (r = -0.374, P = .046), and immediate memory (r = -0.507, P = .005). PWV correlated significantly and negatively with complex attention (r = -0.490, P = .007).Timely and effective antihypertensive therapy with ACE inhibitors has significant beneficial effects on cognitive performance in as few as 3 months. Early ACE inhibition may have an important role in the reversal of initial impairments of cognitive function associated with hypertension-induced vascular alterations.

Phosphodiesterase 1: A Unique Drug Target for Degenerative Diseases and Cognitive Dysfunction

The focus of this chapter is on the cyclic nucleotide phosphodiesterase 1 (PDE1) family. PDE1 is one member of the 11 PDE families (PDE 1-11). It is the only phosphodiesterase family that is calcium/calmodulin activated. As a result, whereas other families of PDEs 2-11 play a dominant role controlling basal levels of cyclic nucleotides, PDE1 is involved when intra-cellular calcium levels are elevated and, thus, has an "on demand" or activity-dependent involvement in the control of cyclic nucleotides in excitatory cells including neurons, cardiomyocytes and smooth muscle. As a Class 1 phosphodiesterase, PDE1 hydrolyzes the 3' bond of 3'-5'-cyclic nucleotides, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Here, we review evidence for this family of enzymes as drug targets for development of therapies aimed to address disorders of the central nervous system (CNS) and of degenerative diseases. The chapter includes sections on the potential for cognitive enhancement in mental disorders, as well as a review of PDE1 enzyme structure, enzymology, tissue distribution, genomics, inhibitors, pharmacology, clinical trials, and therapeutic indications. Information is taken from public databases. A number of excellent reviews of the phosphodiesterase family have been written as well as reviews of the PDE1 family. References cited here are not comprehensive, rather pointing to major reviews and key publications.

DNA Damage: A Main Determinant of Vascular Aging

Vascular aging plays a central role in health problems and mortality in older people. Apart from the impact of several classical cardiovascular risk factors on the vasculature, chronological aging remains the single most important determinant of cardiovascular problems. The causative mechanisms by which chronological aging mediates its impact, independently from classical risk factors, remain to be elucidated. In recent years evidence has accumulated that unrepaired DNA damage may play an important role. Observations in animal models and in humans indicate that under conditions during which DNA damage accumulates in an accelerated rate, functional decline of the vasculature takes place in a similar but more rapid or more exaggerated way than occurs in the absence of such conditions. Also epidemiological studies suggest a relationship between DNA maintenance and age-related cardiovascular disease. Accordingly, mouse models of defective DNA repair are means to study the mechanisms involved in biological aging of the vasculature. We here review the evidence of the role of DNA damage in vascular aging, and present mechanisms by which genomic instability interferes with regulation of the vascular tone. In addition, we present potential remedies against vascular aging induced by genomic instability. Central to this review is the role of diverse types of DNA damage (telomeric, non-telomeric and mitochondrial), of cellular changes (apoptosis, senescence, autophagy), mediators of senescence and cell growth (plasminogen activator inhibitor-1 (PAI-1), cyclin-dependent kinase inhibitors, senescence-associated secretory phenotype (SASP)/senescence-messaging secretome (SMS), insulin and insulin-like growth factor 1 (IGF-1) signaling), the adenosine monophosphate-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR)-nuclear factor kappa B (NFκB) axis, reactive oxygen species (ROS) vs. endothelial nitric oxide synthase (eNOS)-cyclic guanosine monophosphate (cGMP) signaling, phosphodiesterase (PDE) 1 and 5, transcription factor NF-E2-related factor-2 (Nrf2), and diet restriction.

Phosphodiesterase 1 regulation is a key mechanism in vascular aging

Reduced nitric oxide (NO)/cGMP signalling is observed in age-related vascular disease. We hypothesize that this disturbed signalling involves effects of genomic instability, a primary causal factor in aging, on vascular smooth muscle cells (VSMCs) and that the underlying mechanism plays a role in human age-related vascular disease. To test our hypothesis, we combined experiments in mice with genomic instability resulting from the defective nucleotide excision repair gene ERCC1 (Ercc1(d/-) mice), human VSMC cultures and population genome-wide association studies (GWAS). Aortic rings of Ercc1(d/-) mice showed 43% reduced responses to the soluble guanylate cyclase (sGC) stimulator sodium nitroprusside (SNP). Inhibition of phosphodiesterase (PDE) 1 and 5 normalized SNP-relaxing effects in Ercc1(d/-) to wild-type (WT) levels. PDE1C levels were increased in lung and aorta. cGMP hydrolysis by PDE in lungs was higher in Ercc1(d/-) mice. No differences in activity or levels of cGMP-dependent protein kinase 1 or sGC were observed in Ercc1(d/-) mice compared with WT. Senescent human VSMC showed elevated PDE1A and PDE1C and PDE5 mRNA levels (11.6-, 9- and 2.3-fold respectively), which associated with markers of cellular senescence. Conversely, PDE1 inhibition lowered expression of these markers. Human genetic studies revealed significant associations of PDE1A single nucleotide polymorphisms with diastolic blood pressure (DBP; β=0.28, P=2.47×10(-5)) and carotid intima-media thickness (cIMT; β=-0.0061, P=2.89×10(-5)). In summary, these results show that genomic instability and cellular senescence in VSMCs increase PDE1 expression. This might play a role in aging-related loss of vasodilator function, VSMC senescence, increased blood pressure and vascular hypertrophy.

Inhibitory effects of vinpocetine on the progression of atherosclerosis are mediated by Akt/NF-κB dependent mechanisms in apoE-/- mice

BACKGROUND

Recent studies have found additional roles for vinpocetine, a potent phosphodiesterase type I inhibitor, in anti-proliferation and anti-inflammation of vascular smooth muscle cells and cancer cells via different mechanisms. In this study, we attempted to investigate whether vinpocetine protected against atherosclerotic development in apoE(-/-) mice and explore the underlying anti-atherogenic mechanisms in macrophages.

METHODOLOGY/PRINCIPAL FINDINGS

Vinpocetine markedly decreased atherosclerotic lesion size in apoE(-/-) mice measured by oil red O. Masson's trichrome staining and immunohistochemical analyses revealed that vinpocetine significantly increased the thickness of fibrous cap, reduced the size of lipid-rich necrotic core and attenuated inflammation. In vitro experiments exhibited a significant decrease in monocyte adhesion treated with vinpocetine. Further, active TNF-α, IL-6, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 expression induced by ox-LDL were attenuated by vinpocetine in a dose-dependent manner. Similarly, ox-LDL-induced reactive oxygen species were significantly repressed by vinpocetine. Both western blot and luciferase activity assay showed that vinpocetine inhibited the enhanced Akt, IKKα/β, IκBα phosphorylation and NF-κB activity induced by ox-LDL, and the inhibition of NF-κB activity was partly caused by Akt dephosphorylation. However, knockdown of PDE1B did not affect Akt, IKKα/β and IκBα phosphorylation.

CONCLUSIONS

These results suggest that vinpocetine exerts anti-atherogenic effects through inhibition of monocyte adhesion, oxidative stress and inflammatory response, which are mediated by Akt/NF-κB dependent pathway but independent of PDE1 blockade in macrophages.

Role of phosphodiesterases in adult-onset pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by increased mean pulmonary artery pressure (mPAP) due to vasoconstriction and structural changes in the small pulmonary arteries (PAs); proliferation of pulmonary artery smooth muscle cells (PASMCs) contributes to the remodeling. The abnormal pathophysiology in the pulmonary vasculature relates to decreased cyclic nucleotide levels in PASMCs. Phosphodiesterases (PDEs) catalyze the hydrolysis of cAMP and cGMP, thereby PDE inhibitors are effective in vasodilating the PA and decreasing PASMC proliferation. Experimental studies support the use of PDE3, PDE5, and PDE1 inhibitors in PAH. PDE5 inhibitors such as sildenafil are clinically approved to treat different forms of PAH and lower mPAP, increase functional capacity, and decrease right ventricular hypertrophy, without decreasing systemic arterial pressure. New evidence suggests that the combination of PDE inhibitors with other therapies for PAH may be beneficial in treating the disease. Furthermore, inhibiting PDEs in the heart and the inflammatory cells that infiltrate the PA may offer new targets to reduce right ventricular hypertrophy and inhibit inflammation that is associated with and contributes to the development of PAH. This chapter summarizes the advances in the area and the future of PDEs in PAH.

Phosphodiesterase inhibition increases CREB phosphorylation and restores orientation selectivity in a model of fetal alcohol spectrum disorders

Background

Fetal alcohol spectrum disorders (FASD) are the leading cause of mental retardation in the western world and children with FASD present altered somatosensory, auditory and visual processing. There is growing evidence that some of these sensory processing problems may be related to altered cortical maps caused by impaired developmental neuronal plasticity.

Methodology/Principal Findings

Here we show that the primary visual cortex of ferrets exposed to alcohol during the third trimester equivalent of human gestation have decreased CREB phosphorylation and poor orientation selectivity revealed by western blotting, optical imaging of intrinsic signals and single-unit extracellular recording techniques. Treating animals several days after the period of alcohol exposure with a phosphodiesterase type 1 inhibitor (Vinpocetine) increased CREB phosphorylation and restored orientation selectivity columns and neuronal orientation tuning.

Conclusions/Significance

These findings suggest that CREB function is important for the maturation of orientation selectivity and that plasticity enhancement by vinpocetine may play a role in the treatment of sensory problems in FASD.

Alternative medicine and Alzheimer disease

BACKGROUND

Complimentary and alternative medicine has an extensive worldwide history and is commonly used by older patients. A number of different alternative medicines are used by patients having Alzheimer disease. It is both desirable and expected for clinicians to be acquainted with these medications.

REVIEW SUMMARY

This paper discusses the available clinical trial evidence regarding 8 agents commonly used by people having Alzheimer disease. We provide an overview of the history and basic scientific evidence available for each agent, followed by a critical analysis of the evidence available from clinical trials, including the number of participants, trial duration, and specific outcomes evaluated.

CONCLUSION

Although many of these compounds have been associated with interesting basic science, none has shown clear clinical benefit to date. Data available for some, such as Ginkgo biloba, curcumin, and huperzine A, suggest that further evaluation is warranted. Familiarity with this literature will allow clinicians to provide meaningful recommendations to patients who wish to use these agents.

Vinpocetine for acute ischaemic stroke

BACKGROUND

Vasoactive and neuroprotective drugs such as vinpocetine are used to treat stroke in some countries.

OBJECTIVES

To assess the effect of vinpocetine in acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched February 2007), MEDLINE (1966 to February 2007) and Scopus (1960 to February 2007). We also searched the Internet Stroke Center Stroke Trials Registry, Google Scholar, the science-specific search engine Scirus and Wanfang Data, the leading information provider in China. We contacted researchers in the field and four pharmaceutical companies that manufacture vinpocetine. Searches were complete to February 2007.

SELECTION CRITERIA

Unconfounded randomised trials of vinpocetine compared with placebo, or any other reference treatment, in people with acute ischaemic stroke. We included trials if treatment started no later than 14 days after stroke onset.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria. One review author extracted the data, which was then checked by the second review author. We assessed trial quality. The primary outcome measure was death or dependency.

MAIN RESULTS

We included two trials, involving a total of 70 participants. Data for 63 participants were reported in the two trials combined. The rate of death or dependency did not differ between the treatment and placebo groups at one and three months. The 95% confidence intervals for the outcome measures were wide and included the possibility of both significant benefit and significant harm. No adverse effects were reported.

AUTHORS' CONCLUSIONS

There is not enough evidence to evaluate the effect of vinpocetine on survival or dependency in patients with acute ischaemic stroke.