Synaptosomal response to oxidative stress: effect of vinpocetine

Synthesis and pharmacological activity of vinpocetine derivatives

Vinpocetine and its derivatives were extensively employed in the treatment of ischemic stroke, serving as effective cerebrovascular vasodilators. They could also be utilized for neuroprotection, anti-inflammatory purposes, anti-aging interventions, insomnia treatment, and antidepressant effects. However, due to issues such as hepatic first-pass effect, low bioavailability, and poor patient compliance with multiple dosing, the secondary development of Vinpocetine to address these limitations became a prominent area of research. Five primary methodologies were employed for the synthesis of Vinpocetine derivatives. These included substitution on the A ring to modify the 14-ester group, alteration of the 16-ethyl group, simplification of the D and E rings, and modification of the conformation of Vinpocetine. This paper summarized the current synthesis and activity studies of Vinpocetine and its derivatives, with the aim of providing a reference for the discovery of more potent derivatives of Vinpocetine.

New insights on the potential effect of vinpocetine in Parkinson's disease: one of the neglected warden and baffling topics

Vinpocetine (VPN) is an ethyl apovincaminate that has anti-inflammatory and antioxidant effects by inhibiting the expression of nuclear factor kappa B (NF-κB) and phosphodiesterase enzyme 1 (PDE-1). VPN is used in the management of stroke, dementia, and other neurodegenerative brain diseases. VPN may be effective in treating Parkinson's disease (PD). Therefore, this review aimed to clarify the mechanistic role of VPN in the management of PD. VPN has protective and restorative effects against neuronal injury by reducing neuroinflammation, and improvement of synaptic plasticity and cerebral blood flow. VPN protects dopaminergic neurons by reducing oxidative stress, lipid peroxidation, glutamate neurotoxicity, and regulation of Ca+ 2 overloads. VPN can alleviate PD neuropathology through its anti-inflammatory, antioxidant, antiapoptotic and neurogenic effects. VPN through inhibition of PDE1 improves cyclic adenosine monophosphate (cAMP)/cyclic guanosine monophosphate (cGMP) signaling in the dopaminergic neurons of the substantia nigra (SN). VPN improves PD neuropathology through PDE1 inhibition with a subsequent increase of the cAMP/cGMP signaling pathway. Therefore, increasing cAMP leads to antioxidant effects, while augmentation of cGMP by VPN leads to anti-inflammatory effects which reduced neurotoxicity and development of motor severity in PD. In conclusion, this review indicated that VPN could be effective in the management of PD.

Neuroprotective effects of vinpocetine, as a phosphodiesterase 1 inhibitor, on long-term potentiation in a rat model of Alzheimer's disease

BACKGROUND

Vinpocetine (Vin) is known as a phosphodiesterase 1 inhibitor (PDE1-I) drug with multilateral effects, including antioxidant and anti-inflammatory activity. In this research, we investigated the neuroprotective and therapeutic effects of Vin through hippocampal synaptic plasticity on a rat's model of Alzheimer's disease (AD) induced by an intracerebroventricular (ICV) injection of beta-amyloid (Aβ).

METHODS

Sixty adult male Wistar rats were randomly divided into six groups: 1. control, 2. sham, 3. Aβ, 4. pretreatment (Vin + Aβ): Vin (4 mg/kg, gavage) for 30 days and then, inducing an AD model by an ICV injection of Aβ(1-42), 5. treatment (Aβ + Vin): inducing an AD model and then receiving Vin for 30 days by gavage, and 7. pretreatment + treatment (Vin + Aβ + Vin): receiving Vin by gavage for 30 days before and 30 days after the induction of an AD model. After these procedures, via stereotaxic surgery, the stimulating electrodes were placed at the perforant pathway (PP) and the recording electrodes were implanted in the dentate gyrus.

RESULTS

Excitatory postsynaptic potential (EPSP) slope and population spike (PS) amplitude in the Aβ group meaningfully diminished compared to the control group after the induction of long-term potentiation (LTP).

CONCLUSIONS

Vin could significantly prevent the Aβ effects on LTP. It can be concluded that pretreatment and treatment with Vin can be neuroprotective against harmful consequences of Aβ on hippocampal synaptic plasticity.

Simultaneous Alteration of the Circadian Variation of Memory, Hippocampal Synaptic Plasticity, and Metabolism in a Triple Transgenic Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is characterized by progressive memory deficits accompanied by synaptic and metabolic deficits, namely of mitochondrial function. AD patients also display a disrupted circadian pattern. Thus, we now compared memory performance, synaptic plasticity, and mitochondria function in 24-week-old non-transgenic (non-Tg) and triple transgenic male mice modeling AD (3xTg-AD) at Zeitgeber 04 (ZT-4, inactive phase) and ZT-16 (active phase). Using the Morris water maze test to minimize the influence of circadian-associated locomotor activity, we observed a circadian variation in hippocampus-dependent learning performance in non-Tg mice, which was impaired in 3xTg-AD mice. 3xTg-AD mice also displayed a lack of circadian variation of their performance in the reversal spatial learning task. Additionally, the amplitude of hippocampal long-term potentiation also exhibited a circadian profile in non-Tg mice, which was not observed in 3xTg-AD mice. Moreover, cerebral cortical synaptosomes of non-Tg mice also displayed a circadian variation of FCCP-stimulated oxygen consumption as well as in mitochondrial calcium retention that were blunted in 3xTg-AD mice. In sum, this multidimensional study shows that the ability to maintain a circadian oscillation in brain behavior, synaptic plasticity, and synaptic mitochondria function are simultaneously impaired in 3xTg-AD mice, highlighting the effects of circadian misalignment in AD.

Vinpocetine Effect on the Juncture of Diabetes and Aging: An in-vitro study

BACKGROUND

The rapid-growing population of diabetic patients and the elderly are among the direst challenges that the science of medicine is facing today. Targeting these two challenges can shed light on new means to control and ideally reverse this trend. In this experiment, Vinpocetine's effect on aged pancreatic beta-cell functions in correlation with oxidative stress was studied.

METHODS

Islet cells were isolated from the pancreas of aged rats and exposed to Vinpocetine, dissolved in acetone and RPMI, for 48 h. Then, senescence-associated molecular parameters, including P16 and P38 gene expressions and β-galactosidase activity, were investigated along with diabetic and inflammation markers.

RESULTS

Experimental results showed that Vinpocetine could significantly increase aged islets insulin secretion and also make a meaningful reduction in oxidative stress markers. This drug can also decrease expression levels of P16 and P38, the primary genes responsible for the aging pathway. TNF-α, IL-6, and NF-κB expressions were also reduced noticeably after treatment with Vinpocetine.

CONCLUSION

The current study showed that Vinpocetine, a derivative of the secondary plant metabolite called Vincamine, could break this vicious cycle of oxidative stress and aging by reducing oxidative stress and inflammation, thus inhibiting cellular aging.

Emerging neuroprotective strategies for the treatment of ischemic stroke: An overview of clinical and preclinical studies

Stroke is the leading cause of disability and thesecond leading cause of death worldwide. With the global population aged 65 and over growing faster than all other age groups, the incidence of stroke is also increasing. In addition, there is a shift in the overall stroke burden towards younger age groups, particularly in low and middle-income countries. Stroke in most cases is caused due to an abrupt blockage of an artery (ischemic stroke), but in some instances stroke may be caused due to bleeding into brain tissue when a blood vessel ruptures (hemorrhagic stroke). Although treatment options for stroke are still limited, with the advancement in recanalization therapy using both pharmacological and mechanical thrombolysis some progress has been made in helping patients recover from ischemic stroke. However, there is still a substantial need for the development of therapeutic agents for neuroprotection in acute ischemic stroke to protect the brain from damage prior to and during recanalization, extend the therapeutic time window for intervention and further improve functional outcome. The current review has assessed the past challenges in developing neuroprotective strategies, evaluated the recent advances in clinical trials, discussed the recent initiative by the National Institute of Neurological Disorders and Stroke in USA for the search of novel neuroprotectants (Stroke Preclinical Assessment Network, SPAN) and identified emerging neuroprotectants being currently evaluated in preclinical studies. The underlying molecular mechanism of each of the neuroprotective strategies have also been summarized, which could assist in the development of future strategies for combinational therapy in stroke treatment.

Preconditioning with PDE1 Inhibitors and Moderate-Intensity Training Positively Affect Systemic Redox State of Rats

Taken into consideration that oxidative stress response after preconditioning with phosphodiesterase inhibitors (PDEIs) and moderate physical activity has still not been clarified, the aim of this study was to assess the effects of PDEIs alone or in combination with physical activity, on systemic redox status. The study was carried out on 96 male Wistar albino rats classified into two groups. The first group included animals exposed only to pharmacological preconditioning (PreC) maneuver (sedentary control (CTRL, 1 ml/day saline, n = 12), nicardipine (6 mg/kg/day of NIC, n = 12), vinpocetine (10 mg/kg/day of VIN, n = 12), and nimodipine (NIM 10 mg/kg/day of, n = 12). The second included animals exposed to preconditioning with moderate-intensity training (MIT) on treadmill for 8 weeks. After 5 weeks from the start of training, the animals were divided into four subgroups depending on the medication to be used for pharmacological PreC: moderate-intensity training (MIT+ 1 ml/day saline, n = 12), nicardipine (MIT+ 6 mg/kg/day of NIC, n = 12), vinpocetine (MIT+ 10 mg/kg/day of VIN, n = 12), and nimodipine (MIT+ 10 mg/kg/day of NIM, n = 12). After three weeks of pharmacological preconditioning, the animals were sacrificed. The following oxidative stress parameters were measured spectrophotometrically: nitrites (NO₂⁻), superoxide anion radical (O₂⁻), hydrogen peroxide (H₂O₂), index of lipid peroxidation (TBARS), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). Our results showed that PDE1 and MIT preconditioning decreased the release of prooxidants and improved the activity of antioxidant enzymes thus preventing systemic oxidative stress.

The protective and therapeutic effects of vinpocetine, a PDE1 inhibitor, on oxidative stress and learning and memory impairment induced by an intracerebroventricular (ICV) injection of amyloid beta (aβ) peptide

Alzheimer's disease (AD) is a neurodegenerative disease leading to cognitive and memory impairment. This study aimed at investigating the therapeutic and preserving effects of vinpocetine on amyloid beta (Aβ)-induced rat model of AD. Sixty male adult Wistar rats were randomly divided into 6 groups (n = 10 per group) as follows: 1; control, 2; sham, 3; Aβ, 4; pre-treatment (vinpocetine + Aβ): oral gavage administration of vinpocetine at 4 mg/kg for 30 days followed by intracerebroventricular (ICV) injection of Aβ, 5; treatment (Aβ + vinpocetine): Aβ ICV injection followed by vinpocetine administration for 30 days, 6; pre-treatment + treatment (vinpocetine + Aβ + vinpocetine): vinpocetine administration for 30 days before and 30 days after AD induction. Following treatments, the animals' learning and memory were investigated using passive avoidance learning (PAL) task, Morris water maze (MWM), and novel object recognition (NOR) tests. The results demonstrated that Aβ significantly enhanced escape latency and the distance traveled in the MWM, decreased step-through latency, and increased time spent in the dark compartment in PAL. Vinpocetine ameliorated the Aβ-infused memory deficits in both MWM and PAL tests. Administration of vinpocetine in the Aβ rats increased the discrimination index of the NOR test. It also significantly diminished the nitric oxide and malondialdehyde levels and restored the reduced glutathione (GSH) levels. Vinpocetine can improve memory and learning impairment following Aβ infusion due to its different properties, including antioxidant effects, which indicates that vinpocetine administration can lead to the amelioration of cognitive dysfunction in AD.

Role of vinpocetine in ischemic stroke and poststroke outcomes: A critical review

Vinpocetine (VPN) is a synthetic ethyl-ester derivative of the alkaloid apovincamine from Vinca minor leaves. VPN is a selective inhibitor of phosphodiesterase type 1 (PDE1) that has potential neurological effects through inhibition of voltage-gated sodium channel and reduction of neuronal calcium influx. VPN has noteworthy antioxidant, anti-inflammatory, and anti-apoptotic effects with inhibitory effect on glial and astrocyte cells during and following ischemic stroke (IS). VPN is effective as adjuvant therapy in the management of epilepsy; it reduces seizure frequency by 50% in a dose of 2 mg/kg/day. VPN improves psychomotor performances through modulation of brain monoamine pathway mainly on dopamine and serotonin, which play an integral role in attenuation of depressive symptoms. VPN recover cognitive functions and spatial memory through inhibition of hippocampal and cortical PDE1 with augmentation of cyclic adenosin monophosphate and cyclic guanosin monophosphate ratio, enhancement of cholinergic neurotransmission, and inhibition of neuronal inflammatory mediators. Therefore, VPN is an effective agent in the management of IS and plays an integral role in the prevention and attenuation of poststroke epilepsy, depression, and cognitive deficit through direct cAMP/cGMP-dependent pathway or indirectly through anti-inflammatory and antioxidant effects.

Repurposing of the Nootropic Drug Vinpocetine as an Analgesic and Anti-Inflammatory Agent: Evidence in a Mouse Model of Superoxide Anion-Triggered Inflammation

Clinically active drugs for the treatment of acute pain have their prescription limited due to the significant side effects they induce. An increase in reactive oxygen species (ROS) has been linked to several conditions, including inflammation and pain processing. Therefore, new or repurposed drugs with the ability of reducing ROS-triggered responses are promising candidates for analgesic drugs. Vinpocetine is a clinically used nootropic drug with antioxidant, anti-inflammatory, and analgesic properties. However, the effects of vinpocetine have not been investigated in a model with a direct relationship between ROS, inflammation, and pain. Based on that, we aimed to investigate the effects of vinpocetine in a model of superoxide anion-induced pain and inflammation using potassium superoxide (KO₂) as a superoxide anion donor to trigger inflammation and pain. In the KO₂ model, vinpocetine dose-dependently reduced pain-like behaviors (spontaneous pain and hyperalgesia), paw edema, and neutrophil and mononuclear cell recruitment to the paw skin (assessed by H&E staining, fluorescence, and enzymatic assays) and to the peritoneal cavity. Vinpocetine also restored tissue endogenous antioxidant ability and Nrf2 and Ho-1 mRNA expression and reduced superoxide anion production and gp91^phox mRNA expression. We also observed the inhibition of IκBα degradation by vinpocetine, which demonstrates a reduction in the activation of NF-κB explaining the diminished production of IL-33, IL-1β, and TNF-α. Collectively, our data show that vinpocetine alleviates pain and inflammation induced by KO₂, which is a mouse model with a direct role of ROS in triggering pain and other inflammatory phenomena. Thus, the results suggest the repurposing of vinpocetine as an anti-inflammatory and analgesic drug.

N-3 polyunsaturated fatty acids and clozapine abrogates poly I: C-induced immune alterations in primary hippocampal neurons

The viral mimetic polyinosinic:polycytidylic acid (poly I:C) is an important tool to study the consequences of viral infection to the development of neuropsychiatric disorders. Here, based on the premise of omega-3 polyunsaturated fatty acids (n3 PUFAs) as supplemental treatment to antipsychotics in schizophrenia, we investigated the involvement of NFkB pathway in the effects of n3 PUFAs or of the atypical antipsychotic clozapine in hippocampal poly I:C-challenged neurons. Primary hippocampal neuronal cultures were exposed to n3 PUFAs (DHA4.35 μM/EPA7.10 μM, DHA 8.7 μM/EPA14.21 μM or DHA17.4 μM/EPA28.42 μM) or clozapine (1.5 or 3 μM) in the presence or absence of poly I:C. MTT assay revealed that poly I:C-induced reduction in cell viability was prevented by n3 PUFAs or clozapine. N3 PUFAs (DHA 8.7 μM/EPA14.21 μM) or clozapine (3 μM) significantly reduced poly I:C-induced increase in iNOS, NFkB (p50/p65), IL-6 and nitrite when compared to non-treated cells. Only n3 PUFAs prevented poly I:C-induced deficits in BDNF. On the other hand, poly I:C caused a marked reduction in DCX immunoexpression, which was prevented only by clozapine. Thus, n3 PUFAs and clozapine exert in vitro neuroprotective effects against poly I:C immune challenge in hippocampal neurons, by mechanisms possibly involving the inhibition of canonical NFkB pathway. The present study adds further evidences to the mechanisms underlying n3 PUFAs and clozapine neuroprotective effects against viral immune challenges. Since n3 PUFAs is a safe strategy for use during pregnancy, our results also add further evidence for the use of this supplement in order to prevent alterations induced by viral hits during this developmental period.

Vinpocetine Ameliorates Acetic Acid-Induced Colitis by Inhibiting NF-κB Activation in Mice

The idiopathic inflammatory bowel diseases (IBD) comprise two types of chronic intestinal disorders: Crohn's disease and ulcerative colitis. Recruited neutrophils and macrophages contribute to intestinal tissue damage via production of ROS and NF-κB-dependent pro-inflammatory cytokines. The introduction of anti-TNF-α therapies in the treatment of IBD patients was a seminal advance. This therapy is often limited by a loss of efficacy due to the development of adaptive immune response, underscoring the need for novel therapies targeting similar pathways. Vinpocetine is a nootropic drug and in addition to its antioxidant effect, it is known to have anti-inflammatory and analgesic properties, partly by inhibition of NF-κB and downstream cytokines. Therefore, the present study evaluated the effect of the vinpocetine in a model of acid acetic-induced colitis in mice. Treatment with vinpocetine reduced edema, MPO activity, microscopic score and macroscopic damage, and visceral mechanical hyperalgesia. Vinpocetine prevented the reduction of colonic levels of GSH, ABTS radical scavenging ability, and normalized levels of anti-inflammatory cytokine IL-10. Moreover, vinpocetine reduced NF-κB activation and thereby NF-κB-dependent pro-inflammatory cytokines IL-1β, TNF-α, and IL-33 in the colon. Thus, we demonstrate for the first time that vinpocetine has anti-inflammatory, antioxidant, and analgesic effects in a model of acid acetic-induced colitis in mice and deserves further screening to address its suitability as an approach for the treatment of IBD.

Protective effect of vinpocetine against neurotoxicity of manganese in adult male rats

Manganese (Mn) is required for many essential biological processes as well as in the development and functioning of the brain. Extensive accumulation of Mn in the brain may cause central nervous system dysfunction known as manganism, a motor disorder associated with cognitive and neuropsychiatric deficits similar to parkinsonism. Vinpocetine, a synthetic derivative of the alkaloid vincamine, is used to improve the cognitive function in cerebrovascular diseases. It possesses antioxidant and antiinflammatory properties. The present work was designed to explore the potential neuroprotective mechanisms exerted by vinpocetine in the Mn-induced neurotoxicity in rats. Rats were allocated into four groups. First group was given saline. The other three groups were given MnCl₂; two of them were treated with either L-dopa, the gold standard antiparkinsonian drug, or vinpocetine. Rats receiving MnCl₂ exhibited lengthened catalepsy duration in the grid and bar tests, motor impairment in the open-field test and short-term memory deficit in the Y-maze test. Additionally, histological examination revealed structural alterations and degeneration in different brain regions. Besides, striatal monoamines and mitochondrial complex I contents were declined, apoptotic biomarker caspase-3 expression and acetylcholinesterase activity were elevated. Moreover, oxidative stress and inflammation were detected in the striata. L-dopa or vinpocetine exerted protective effects against MnCl₂-induced neurotoxicity. It could be hypothesized that modulation of monoamines, upregulation of mitochondrial complex I, antioxidant, antiinflammatory, and antiapoptotic activities are significant mechanisms underlying the neuroprotective effect of vinpocetine in the Mn-induced neurotoxicity model in rats.

An update on vinpocetine: New discoveries and clinical implications

Vinpocetine, a derivative of the alkaloid vincamine, has been clinically used in many countries for treatment of cerebrovascular disorders such as stroke and dementia for more than 30 years. Currently, vinpocetine is also available in the market as a dietary supplement to enhance cognition and memory. Due to its excellent safety profile, increasing efforts have been put into exploring the novel therapeutic effects and mechanism of actions of vinpocetine in various cell types and disease models. Recent studies have revealed a number of novel functions of vinpocetine, including anti-inflammation, antagonizing injury-induced vascular remodeling and high-fat-diet-induced atherosclerosis, as well as attenuating pathological cardiac remodeling. These novel findings may facilitate the repositioning of vinpocetine for preventing or treating relevant disorders in humans.

Vinpocetine mitigates proteinuria and podocytes injury in a rat model of diabetic nephropathy

Podocyte injury and glomerular basement membrane thickening have been considered as essential pathophysiological events in diabetic nephropathy. The aim of this study was to investigate the possible beneficial effects of vinpocetine on diabetes-associated renal damage. Male Wistar rats were made diabetic by injection of streptozotocin (STZ). Diabetic rats were treated with vinpocetine in a dose of 20mg/kg/day for 6 weeks. Treatment with vinpocetine resulted in a marked decrease in the levels of blood glucose, glycosylated haemoglobin, creatinine, blood urea nitrogen, urinary albumin and albumin/creatinine ratio along with an elevation in creatinine clearance rate. The renal contents of advanced glycation end-products, interleukin-10, tissue growth factor-β, nuclear factor (NF)-κB and Ras-related C3 botulinum toxin substrate 1 (Rac 1) were decreased. Renal nephrin and podocin contents were increased and their mRNA expressions were replenished in vinpocetine-treated rats. Moreover, administration of vinpocetine showed improvements in oxidative status as well as renal glomerular and tubular structures. The current investigation revealed that vinpocetine ameliorated the STZ-induced renal damage. This beneficial effect could be attributed to its antioxidant and antihyperglycemic effects parallel to its ability to inhibit NF-κB which eventually modulated cytokines production as well as nephrin and podocin proteins expression.

Vinpocetine reduces diclofenac-induced acute kidney injury through inhibition of oxidative stress, apoptosis, cytokine production, and NF-κB activation in mice

Acute kidney injury (AKI) represents a complex clinical condition associated with significant morbidity and mortality. Approximately, 19-33% AKI episodes in hospitalized patients are related to drug-induced nephrotoxicity. Although, considered safe, non-steroidal anti-inflammatory drugs such as diclofenac have received special attention in the past years due to the potential risk of renal damage. Vinpocetine is a nootropic drug known to have anti-inflammatory properties. In this study, we investigated the effect and mechanisms of vinpocetine in a model of diclofenac-induced AKI. We observed that diclofenac increased proteinuria and blood urea, creatinine, and oxidative stress levels 24h after its administration. In renal tissue, diclofenac also increased oxidative stress and induced morphological changes consistent with renal damage. Moreover, diclofenac induced kidney cells apoptosis, up-regulated proinflammatory cytokines, and induced the activation of NF-κB in renal tissue. On the other hand, vinpocetine reduced diclofenac-induced blood urea and creatinine. In the kidneys, vinpocetine inhibited diclofenac-induced oxidative stress, morphological changes, apoptosis, cytokine production, and NF-κB activation. To our knowledge, this is the first study demonstrating that diclofenac-induced AKI increases NF-κB activation, and that vinpocetine reduces the nephrotoxic effects of diclofenac. Therefore, vinpocetine is a promising molecule for the treatment of diclofenac-induced AKI.

Pre-treatment with vinpocetine protects against retinal ischemia

Vinpocetine has been shown to have beneficial effects for tissues of the central nervous system subjected to ischemia and other related metabolic insults. We recently showed vinpocetine promotes glucose availability, prevents unregulated cation channel permeability and regulates glial reactivity when present during retinal ischemia. Less is known however about the ability of vinpocetine to protect against future ischemic insults. This study explores the effect of vinpocetine when used as a pre-treatment in an ex vivo model for retinal ischemia using cation channel permeability of agmatine (AGB) combined with immunohistochemistry as a measure for cell functionality. We found that vinpocetine pre-treatment reduced cation channel permeability and apoptotic marker immunoreactivity in the GCL and increased parvalbumin immunoreactivity of inner retinal neurons in the inner nuclear layer following ischemic insult. Vinpocetine pre-treatment also reduced Müller cell reactivity following ischemic insults of up to 120 min compared to untreated controls. Many of vinpocetine's effects however were transient in nature suggesting the drug can protect retinal neurons against future ischemic damage but may have limited long-term applications.

Anti-inflammatory effects of vinpocetine in atherosclerosis and ischemic stroke: a review of the literature

Immune responses play an important role in the pathophysiology of atherosclerosis and ischemic stroke. Atherosclerosis is a common condition that increases the risk of stroke. Hyperlipidemia damages endothelial cells, thus initiating chemokine pathways and the release of inflammatory cytokines—this represents the first step in the inflammatory response to atherosclerosis. Blocking blood flow in the brain leads to ischemic stroke, and deprives neurons of oxygen and energy. Damaged neurons release danger-associated molecular patterns, which promote the activation of innate immune cells and the release of inflammatory cytokines. The nuclear factor κ-light-chain-enhancer of activated B cells κB (NF-κB) pathway plays a key role in the pathogenesis of atherosclerosis and ischemic stroke. Vinpocetine is believed to be a potent anti-inflammatory agent and has been used to treat cerebrovascular disorders. Vinpocetine improves neuronal plasticity and reduces the release of inflammatory cytokines and chemokines from endothelial cells, vascular smooth muscle cells, macrophages, and microglia, by inhibiting the inhibitor of the NF-κB pathway. This review clarifies the anti-inflammatory role of vinpocetine in atherosclerosis and ischemic stroke.

Effects of vinpocetine and ozagrel on behavioral recovery of rats after global brain ischemia

Brain ischemia leads to severe disruption of the nervous system and recovery is often prolonged. Rehabilitative post-ischemia pharmacological treatment may therefore be important for behavioral recovery, especially for cognition and motor behavior. The present study investigated the effects of combined vinpocetine and ozagrel administration on the behavioral recovery of rats from global brain ischemia. The results suggest that the combined treatment leads to significantly better improvement compared to single drug administration. We conclude that the combined use of vinpocetine and ozagrel may provide beneficial effects to patients suffering from brain ischemia.

Vinpocetine protects liver against ischemia-reperfusion injury

Hepatic ischemia-reperfusion (IR) injury is a clinical problem that leads to cellular damage and organ dysfunction mediated mainly via production of reactive oxygen species and inflammatory cytokines. Vinpocetine has long been used in cerebrovascular disorders. This study aimed to explore the protective effect of vinpocetine in IR injury to the liver. Ischemia was induced in rats by clamping the common hepatic artery and portal vein for 30 min followed by 30 min of reperfusion. Serum transaminases and liver lactate dehydrogenase (LDH) activities, liver inflammatory cytokines, oxidative stress biomarkers, and liver histopathology were assessed. IR resulted in marked histopathology changes in liver tissues coupled with elevations in serum transaminases and liver LDH activities. IR also increased the production of liver lipid peroxides, nitric oxide, and inflammatory cytokines interleukin-1β and interleukin-6, in parallel with a reduction in reduced glutathione and interleukin-10 in the liver. Pretreatment with vinpocetine protected against liver IR-induced injury, in a dose-dependent manner, as evidenced by the attenuation of oxidative stress as well as inflammatory and liver injury biomarkers. The effects of vinpocetine were comparable with that of curcumin, a natural antioxidant, and could be attributed to its antioxidant and anti-inflammatory properties.

Vinpocetine suppresses pathological vascular remodeling by inhibiting vascular smooth muscle cell proliferation and migration

Abnormal vascular smooth muscle cell (SMC) activation is associated with various vascular disorders such as atherosclerosis, in-stent restenosis, vein graft disease, and transplantation-associated vasculopathy. Vinpocetine, a derivative of the alkaloid vincamine, has long been used as a cerebral blood flow enhancer for treating cognitive impairment. However, its role in pathological vascular remodeling remains unexplored. Herein, we show that systemic administration of vinpocetine significantly reduced neointimal formation in carotid arteries after ligation injury. Vinpocetine also markedly decreased spontaneous remodeling of human saphenous vein explants in ex vivo culture. In cultured SMCs, vinpocetine dose-dependently suppressed cell proliferation and caused G1-phase cell cycle arrest, which is associated with a decrease in cyclin D1 and an increase in p27Kip1 levels. In addition, vinpocetine dose-dependently inhibited platelet-derived growth factor (PDGF)-stimulated SMC migration as determined by the two-dimensional migration assays and three-dimensional aortic medial explant invasive assay. Moreover, vinpocetine significantly reduced PDGF-induced type I collagen and fibronectin expression. It is noteworthy that PDGF-stimulated phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), but not protein kinase B, was specifically inhibited by vinpocetine. Vinpocetine powerfully attenuated intracellular reactive oxidative species (ROS) production, which largely mediates the inhibitory effects of vinpocetine on ERK1/2 activation and SMC growth. Taken together, our results reveal a novel function of vinpocetine in attenuating neointimal hyperplasia and pathological vascular remodeling, at least partially through suppressing ROS production and ERK1/2 activation in SMCs. Given the safety profile of vinpocetine, this study provides insight into the therapeutic potential of vinpocetine in proliferative vascular disorders.

Brain trace element concentration of rats treated with the plant alkaloid, vincamine

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.

Amelioration of intracerebroventricular streptozotocin induced cognitive dysfunction and oxidative stress by vinpocetine -- a PDE1 inhibitor

Enhancing cyclic nucleotides signaling by inhibition of phosphodiesterases (PDEs) is known to be beneficial in disorders associated with cognitive decline. The present study was designed to investigate the effect of vinpocetine (PDE1 inhibitor) on intracerebroventricular (i.c.v.) streptozotocin induced experimental sporadic dementia of Alzheimer's type. Infusion of streptozotocin impaired learning and memory, increased oxidative-nitritive stress and induced cholinergic hypofunction in rats. Chronic treatment with vinpocetine (5, 10 and 20 mg/kg i.p.) for 21 days following first i.c.v. streptozotocin infusion significantly improved learning and memory in Morris water maze and passive avoidance paradigms. Further, vinpocetine significantly reduced the oxidative-nitritive stress, as evidenced by decrease in malondialdehyde (MDA) and nitrite levels, and restored the reduced glutathione (GSH) levels. Significant increase in acetylcholinesterase activity and lactate dehydrogenase levels was observed in the present model indicating cholinergic hypofunction and increase in neuronal cell damage. Chronic treatment with vinpocetine also reduced significantly the increase in acetylcholinesterase activity and lactate dehydrogenase levels indicating restorative capacity of vinpocetine with respect to cholinergic functions and preventing the neuronal damage. The observed beneficial effects of vinpocetine on spatial memory may be due to its ability to favorably modulate cholinergic functions, prevent neuronal cell damage and possibly through its antioxidant mechanism also.

New insights into nitroglycerin effects and tolerance: role of calcitonin gene-related peptide

It has been shown that calcitonin gene-relate peptide plays an extensive role in cardiovascular system. CGRP is a potent vasodilator and plays an important role in mediation of nitroglycerin-induced vascular relaxation. Recently, calcitonin gene-relate peptide is emerging as a potential player in nitroglycerin tolerance. There is increasing evidence that the decreased depressor effect of nitroglycerin in tolerant states is closely related to a decrease in calcitonin gene-relate peptide release. The reduced release of calcitonin gene-relate peptide in nitroglycerin tolerance is associated with the decreased nitroglycerin biotransformation due to the mitochondrial dysfunction. Recent work has been shown that the inhibited activity of mitochondrial isoform of aldehyde dehydrogenase and the upregulation of phosphodiesterase 1A1 are the key factors that lead to the decreased nitroglycerin biotransformation in nitroglycerin tolerance, with a subsequently reduced release of calcitonin gene-relate peptide.

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.

Autoradiographic evaluation of [11C]vinpocetine binding in the human postmortem brain

The main objective ofthe study was to evaluate with autoradiographic technique whether or not [11C]vinpocetine, a compound widely used in the prevention and treatment of cerebrovascular diseases (Cavinton, Gedeon Richter Ltd., Budapest), binds to specific sites in the human brain in post mortem human brain sections. Binding was assessed under four conditions: the incubation was performed using Tris-HCl buffer with or without the addition of salts (0.1% (weight/vol) ascorbic acid, 120 mM NaCl, 5 mM KCl, 2 mM CaCl2 and 1 mM MgCl2), with or without the addition of excess (10 microM) unlabelled vinpocetine. Measurements on digitized autoradiograms indicated that [11C]vinpocetine labelled all grey matter areas in the human brain to a similar extent and no significantly heterogeneous binding could be demonstrated among cortical or subcortical regions. The addition of excess unlabelled vinpocetine lowered the binding slightly in all regions. Although these results indicate that [11C]vinpocetine does not bind to human brain transmitter receptors or transporters with a high affinity (Ki < 10 nM), it cannot be ruled out that the compound binds to receptors and/or transporters with lower affinity.

PET studies on the brain uptake and regional distribution of [11C]vinpocetine in human subjects

OBJECTIVES

Vinpocetine is a compound widely used in the prevention and treatment of cerebrovascular diseases. It is still not clear whether the drug has a direct and specific effect on neurotransmission or its effects are due to extracerebral actions, such as changes in cerebral blood flow. The main objective of the present investigation was to determine the global uptake and regional distribution of radiolabelled vinpocetine in the human brain in order to explore whether it may have direct central nervous system effects.

MATERIAL AND METHODS

Three healthy subjects were examined with positron emission tomography and [11C]vinpocetine. The regional uptake was determined in anatomically defined volumes-of-interest. The fractions of [11C]vinpocetine and labelled metabolites in plasma were determined using high pressure liquid chromatography.

RESULTS

The uptake of [11C]vinpocetine in brain was rapid and 3.7% (mean; n = 4) of the total radioactivity injected was in brain 2 min after radioligand administration. The uptake was heterogeneously distributed among brain regions. When compared with the cerebellum, an a priori reference region, the highest regional uptake was in the thalamus, upper brain stem, striatum and cortex. Following an initial peak, the total concentration of radioactivity in blood was relatively stable with time, whereas the concentration of the unchanged compound decreased with time in an exponential manner.

CONCLUSION

Vinpocetine, administered intravenously in humans, readily passes the blood-brain barrier and enters the brain. Its regional uptake and distribution in the brain is heterogeneous, indicating binding to specific sites. The brain regions showing increased uptake in the human brain correspond to those in which vinpocetine has been shown to induce elevated metabolism and blood flow. These observations support the hypothesis that vinpocetine has direct neuronal actions in the human brain.

Brain and liver mitochondria isolated from diabetic Goto-Kakizaki rats show different susceptibility to induced oxidative stress

BACKGROUND

Increased oxidative stress and changes in antioxidant capacity observed in both clinical and experimental diabetes mellitus have been implicated in the etiology of chronic diabetic complications. Many authors have shown that hyperglycemia leads to an increase in lipid peroxidation in diabetic patients and animals reflecting a rise in reactive oxygen species production. The aim of the study was to compare the susceptibility of mitochondria from brain and liver of Goto-Kakizaki (12-month-old diabetic) rats (GK rats), a model of non-insulin dependent diabetes mellitus, to oxidative stress and antioxidant defenses.

METHODS

Brain and liver mitochondrial preparations were obtained by differential centrifugation. Oxidative damage injury was induced in vitro by the oxidant pair ADP/Fe(2+) and the extent of membrane oxidation was assessed by oxygen consumption, malondialdehyde (MDA) and thiobarbituric acid reactive substances (TBARS) formation. Coenzyme Q and alpha-tocopherol contents were measured by high-performance liquid chromatography (HPLC).

RESULTS

Brain mitochondria isolated from 12-month-old control rats displayed a higher susceptibility to lipid peroxidation, as assessed by oxygen consumption and formation of MDA and TBARS, compared to liver mitochondria. In GK rats, mitochondria isolated from brain were more susceptible to in vitro oxidative damage than brain mitochondria from normal rats. In contrast, liver mitochondria from diabetic rats were less susceptible to oxidative damage than mitochondria from normal rats. This decreased susceptibility was inversely related to their alpha-tocopherol and coenzyme Q (CoQ) content.

CONCLUSIONS

The present results indicate that the diabetic state can result in an elevation of both alpha-tocopherol and CoQ content in liver, which may be involved in the elimination of mitochondrially generated reactive oxygen species. The difference in the antioxidant defense mechanisms in the brain and liver mitochondrial preparations of moderately hyperglycemic diabetic GK rats may correspond to a different adaptive response of the cells to the increased oxidative damage in diabetes.

Role of sodium channel inhibition in neuroprotection: effect of vinpocetine

Vinpocetine (ethyl apovincaminate) discovered during the late 1960s has successfully been used in the treatment of central nervous system disorders of cerebrovascular origin for decades. The increase in the regional cerebral blood flow in response to vinpocetine administration is well established and strengthened by new diagnostical techniques (transcranial Doppler, near infrared spectroscopy, positron emission tomography). The latest in vitro studies have revealed the effect of the compound on Ca(2+)/calmodulin dependent cyclic guanosine monophosphate-phosphodiesterase 1, voltage-operated Ca(2+) channels, glutamate receptors and voltage dependent Na(+)-channels; the latest being especially relevant to the neuroprotective action of vinpocetine. The good brain penetration profile and heterogenous brain distribution pattern (mainly in the thalamus, basal ganglia and visual cortex) of labelled vinpocetin were demonstrated by positron emission tomography in primates and man. Multicentric, randomized, placebo-controlled clinical studies proved the efficacy of orally administered vinpocetin in patients with organic psychosyndrome. Recently positron emission tomography studies have proved that vinpocetine is able to redistribute regional cerebral blood flow and enhance glucose supply of brain tissue in ischemic post-stroke patients.