Protection of Azidothymidine-Induced Cardiopathology in Mice by Mildronate, a Mitochondria-Targeted Drug

Azidothymidine, a nucleoside-analogue reverse transcriptase inhibitor (NRTI), is a commonly used antiretroviral drug in AIDS treatment, however its use is limited by severe toxic side effects due to its influence on mitochondria that result in myopathy, particularly affecting the cardiac muscle. We suggest that effective protection of azidothymidine- induced cardiopathology can be expected from drugs that are capable of targeting mitochondria. Therefore the present study in mice was carried out with mildronate, a cardioprotective drug of the aza-butyrobetaine class, which previously has been shown to act as a highly potent protector of mitochondrial processes. In our study, saline (control)…

Very low doses of muscimol and baclofen ameliorate cognitive deficits and regulate protein expression in the brain of a rat model of streptozocin-induced Alzheimer's disease.

Recent studies devoted to neuroprotection have focused on the role of the gamma-aminobutyric acid (GABA) system in regulating neuroinflammatory processes which play a key role in the neurodegenerative processes observed in Alzheimer's disease (AD) by inducing glial cell overactivation and impairing neurotransmission. Data on the efficacy of classical GABA-A and GABA-B receptor agonists (muscimol and baclofen, respectively) in animal models of AD are not available. Moreover, no published studies have examined the ability of optimal doses of these compounds to prevent neuroinflammation, the alterations in neurotransmission and cognitive deficits. In the present study, we used a non-transgenic…

The gamma(2)-MSH peptide mediates a central analgesic effect via a GABA-ergic mechanism that is independent from activation of melanocortin receptors.

Using the latency for tail-flick after thermal stimulation we have assessed the effects of alpha-, gamma(1)- and gamma(2)-MSH on nociceptive threshold in the mice. Intracisternal injections of gamma(2)-MSH induced a distinct analgesia, while gamma(1)-MSH in the same doses gave only a minor analgesia. Intracisternal alpha-MSH instead gave a short-term hyperalgesia. The effect of gamma(2)-MSH was not blocked by any of the MC(4)/MC(3)receptor antagonist HS014, naloxone or by the prior intracisternal administrations of gamma(1)-MSH. However, the gamma(2)-MSH analgesic response was completely attenuated by treating animals with the GABA(A)antagonist bicuculline. The gamma(2)-MSH analgesic effect…

γ1- and γ2-melanocyte stimulating hormones induce central anxiogenic effects and potentiate ethanol withdrawal responses in the elevated plus-maze test in mice

Little is known about the endogenous functions of gamma1- and gamma2-melanocyte stimulating hormones (gamma1- and gamma2-MSH). Although gamma-MSHs bind to melanocortin receptor subtypes 3 and 4, we have previously shown that these peptides also influence non-melanocortinergic processes, such as dopaminergic and GABAergic. The aim of this study was to determine the effects of gamma1- and gamma2-MSH (at doses 0.3, 1 and 2 nmol/mouse/5 microl) on the anxiety levels in mice in elevated plus maze. Three experimental paradigms were performed to assess the effects of peptides on: a) ethanol withdrawal; b) acute ethanol-induced anxiolytic action; c) peptides per se. We used ethanol as the model sub…

Synthesis and pharmacological activity of silyl isoxazolines 2

Silyl isoxazolines have been synthesized by [2+3] cycloaddition reaction of nitrile oxides to vinyl- and allylsilanes. The addition of 3-pyridylnitrile oxide to 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane affords 1,3-bis{5-[3-(3-pyridyl)isoxazolin-2-yl]}-1,1,3,3-tetraphenyldisiloxane; the latter exists as a mixture of trans- and cis-isomers.The bond angle of the Si–O–Si fragment in thetrans-isomer equals 180(3)° and in the cis-isomer it is 162(3)°.The pharmacological properties of 4-[3-(5-trimethylsilylisoxazolin-2-yl)]pyridinium-chloride have been studied.

Neuroprotective action of diazepam at very low and moderate doses in Alzheimer's disease model rats

Abstract Early manifestations of Alzheimer's disease (AD) include neuroinflammation, disrupted neurotransmission and cognitive deficits. Impairment of the GABAergic system is essentially involved in the pathogenesis of AD. Traditionally, agonists of GABAA receptors at doses above 1 mg/kg are known to possess memory impairing effects. However, we have previously found that GABAA receptor GABA site ligand muscimol at very low doses acted contrary – enhanced spatial learning/memory, as well as prevented neuroinflammation and augmented neurotransmission in AD model rats. Therefore, in the present study we focused on the assessment of the effects of non-sedative – very low (0.05 mg/kg) and moder…

Taurine and tauropyrone: Comparative neuropharmacological studies of small doses

Opposite effects of γ1- and γ2-melanocyte stimulating hormone on regulation of the dopaminergic mesolimbic system in rats

By use of the brain microdialysis technique we show that administration of gamma(1)-melanocyte stimulating hormone (gamma(1)-MSH) into the ventral tegmental area of anaesthetized rats causes an increase in the release of extracellular dopamine and its metabolite 3,4-dihydroxyphenylacetic acid in the nucleus accumbens, while gamma(2)-MSH causes the opposite effect. Moreover, gamma(2)-MSH pre-treatment considerably reduced the gamma(1)-MSH-induced effects. Our findings suggest an opposing action of two gamma-MSH-activated pathways on the mesolimbic dopaminergic system, which could be important in the maintenance of a balanced psychoactivation state.

GABA-containing compound gammapyrone protects against brain impairments in Alzheimer's disease model male rats and prevents mitochondrial dysfunction in cell culture.

Neuroinflammation, oxidative stress, decreased glucose/energy metabolism, and disrupted neurotransmission are changes that occur early in sporadic Alzheimer's disease (AD), manifesting as mild cognitive impairment. Recently, the imbalanced function of the gamma-aminobutyric acid (GABA) system was identified as a critical factor in AD progression. Thus, maintaining balance among neurotransmitter systems, particularly the GABA system, can be considered a beneficial strategy to slow AD progression. The present study investigated the effects of the compound gammapyrone, a molecule containing three GABA moieties: "free" moiety attached to the position 4 of the 1,4-dihydropyridine (DHP) ring, and…

Intra-Nasally Administered Oligopeptide Lunasin Acts as a Possible Anti-Psychotic Agent in Mice Models

Background and Objectives: Previously we have shown that synthetic lunasin, a 43 amino acid residue-containing peptide, after its central (intracisternal) administration in mice demonstrated antagonism against dopaminergic drug behavioural effects, indicating a putative antipsychotic/anti-schizophrenic profile of lunasin. The aims of the present studies were: to test whether lunasin would show an influence on the dopaminergic system after intranasal administration, and to examine the effect(s) of lunasin on serotonin and glutamatergic systems, which could play an essential role in antipsychotic action. Materials and Methods: Lunasin was administered intra-nasally at doses 0.1 and 1 nmol/mou…

Comparative study of taurine and tauropyrone: GABA receptor binding, mitochondrial processes and behaviour.

Abstract Objectives Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo. Methods The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial p…

Mildronate enhances learning/memory and changes hippocampal protein expression in trained rats.

Previously we demonstrated that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a representative of the aza-butyrobetaine class of compounds, protects mitochondrial metabolism under conditions such as ischemia. Mildronate also acted as a neuroprotective agent in an azidothymidine-induced mouse model of neurotoxicity, as well as in a rat model of Parkinson's disease. These observations suggest that mildronate may stimulate processes involved in cell survival and change expression of proteins involved in neurogenic processes. The present study investigated the influence of mildronate on learning and memory in the passive avoidance response (PAR) test and the active condition…

The differential influences of melanocortins on nociception in the formalin and tail flick tests

Melanocortins exert multiple physiological effects that include the modulation of immune responses, inflammation processes, and pain transmission. In the present study we investigated the peripheral activity of natural melanocortins - alpha-, beta-, gamma1- and gamma2-melanocyte stimulating hormone (MSH) - and melanocortin receptor subtypes 3 and 4 (MC3/4 receptor) antagonist HS014 in pain (formalin and tail flick) tests after peptide subcutaneous administration in mice. In the formalin test, among all substances tested only alpha-MSH (1 micromol/kg) statistically significantly inhibited the formalin-induced first phase pain response, however, all tested peptides (except gamma1-MSH) at the …

Targeting the Mitochondria by Novel Adamantane-Containing 1,4-Dihydropyridine Compounds

Linda Klimaviciusa1, Maria A. S. Fernandes2, Nelda Lencberga1, Marta Pavasare1, Joaquim A. F. Vicente2, Antonio J. M. Moreno2, Maria S. Santos3, Catarina R. Oliveira4, Imanta Bruvere5, Egils Bisenieks5, Brigita Vigante5 and Vija Klusa1 1Department of Pharmacology, Faculty of Medicine, University of Latvia, Riga 2IMAR-CMA, Department of Life Sciences, University of Coimbra, Coimbra 3CNC, Department of Life Sciences, University of Coimbra, Coimbra 4CNC, Faculty of Medicine, University of Coimbra, Coimbra 5Laboratory of Membrane Active and beta-Diketone Compounds, Latvian Institute of Organic Synthesis, Riga 2,3,4Portugal 1,5Latvia

Synthesis and studies of calcium channel blocking and antioxidant activities of novel 4-pyridinium and/or N-propargyl substituted 1,4-dihydropyridine derivatives

The novel 1,4-dihydropyridine derivatives containing the cationic pyridine moiety at the position 4, and the N-propargyl group as a substituent at position 1 of the 1,4-DHP cycle were designed, synthesised, and assessed in biological tests. Among all the novel compounds, the 4-(N-dodecyl) pyridinium group-containing compounds 11 (without the N-propargyl group) and 12 (with the N-propargyl group) demonstrated the highest calcium antagonistic properties against neuroblastoma SH-SY5Y (IC50 about 5–14 mM) and the vascular smooth muscle A7r5 cell (IC50 – 0.6–0.7 mM) lines, indicating that they predominantly target the L-type calcium channels. These compounds showed a slight total antioxidant act…

Anti-Neurotoxic Effects of Tauropyrone, a Taurine Analogue

Lunasin-induced behavioural effects in mice: Focus on the dopaminergic system

The present study for the first time is devoted to identify central effects of synthetic lunasin, a 43 amino acid peptide. A markedly expressed neuroleptic/cataleptic effect was observed at low (0.1-10 nmol/mouse) centrally administered doses in male C57Bl/6 mice. Lunasin considerably reduced the amphetamine hyperlocomotion but weakly apomorphine climbing behaviour. No influence on ketamine and bicuculline effects was observed. Binding assay studies demonstrated modest affinity of lunasin for the dopamine D₁ receptor (Ki=60 ± 15 μM). In a functional assay of cAMP accumulation on live cells lunasin antagonised apomorphine effect on D₁ receptor activation (pEC₅₀=6.1 ± 0.3), but had no effect …

3,4-trans-4-Aryl-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolates—new group of potential cardiotonic drugs

Abstract 3,4- trans -4-Aryl-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolates 6 – 11 were prepared by a Michael reaction of N -acetonylpyridinium chloride with 3-aryl-2-cyanothioacrylamides or by a one-pot three-carbon condensation of N -acetonylpyridinium chloride, aromatic aldehyde and 2-cyanothioacetamide, and their cardiotonic properties were studied. 3,4- trans -5-cyano-2-hydroxy-2-methyl-4-(3-nitrophenyl)-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolate 8 was considered as a lead compound in this series since it in vitro experiments (spontaneously beating rat atria) showed a cardiotonic activity similar to that of milrinone 2 , however compound 8 induced activity at lover co…

Neuroprotective properties of mildronate, a mitochondria-targeted small molecule.

Mildronate, a representative of the aza-butyrobetaine class of drugs with proven cardioprotective efficacy, was recently found to prevent dysfunction of complex I in rat liver mitochondria. The present study demonstrates that mildronate also acts as a neuroprotective agent. In a mouse model of azidothymidine (anti-HIV drug) neurotoxicity, mildronate reduced the azidothymidine-induced alterations in mouse brain tissue: it normalized the increase in caspase-3, cellular apoptosis susceptibility protein (CAS) and iNOS expression assessed by quantitative and semi-quantitative analysis. Mildronate also normalized the changes in cytochrome c oxidase (COX) expression, reduced the expression of glia…

The effects of glutamate receptor antagonists on cerebellar granule cell survival and development.

N-Methyl-d-aspartate (NMDA) receptor stimulation promotes neuronal survival and differentiation under both in vitro and in vivo conditions. We studied the effects of various NMDA receptor antagonists acting at different NMDA receptor binding sites and non-NMDA receptor antagonists on the development and survival of cerebellar granule cell (CGC) culture. Only three of the drugs tested induced neurotoxicity-MK-801 (non-competitive NMDA channel blocking antagonist), ifenprodil (an antagonist of the NR2B site and polyamine site of the NMDA receptor) and L-701.324 (full antagonist at glycine site), while CGP-37849 (a competitive NMDA antagonist), (+)-HA-966 (a partial agonist of the glycine site…

A Novel 1,4-Dihydropyridine Derivative Improves Spatial Learning and Memory and Modifies Brain Protein Expression in Wild Type and Transgenic APPSweDI Mice.

Ca2+ blockers, particularly those capable of crossing the blood-brain barrier (BBB), have been suggested as a possible treatment or disease modifying agents for neurodegenerative disorders, e.g., Alzheimer's disease. The present study investigated the effects of a novel 4-(N-dodecyl) pyridinium group-containing 1,4-dihydropyridine derivative (AP-12) on cognition and synaptic protein expression in the brain. Treatment of AP-12 was investigated in wild type C57BL/6J mice and transgenic Alzheimer's disease model mice (Tg APPSweDI) using behavioral tests and immunohistochemistry, as well as mass spectrometry to assess the blood-brain barrier (BBB) penetration. The data demonstrated the ability …

Mildronate as a Regulator of Protein Expression in a Rat Model of Parkinson’s Disease

Background. Mildronate (3-[2,2,2-trimethylhydrazinium] propionate dihydrate) traditionally is a well-known cardioprotective drug. However, our recent studies convincingly demonstrated its neuroprotective properties. The aim of the present study was to evaluate the influence of mildronate on the expression of proteins that are involved in the differentiation and survival of the nigrostriatal dopaminergic neurons in the rat model of Parkinson’s disease (PD). The following biomarkers were used: heat shock protein 70 (Hsp70, a molecular chaperone), glial cell line-derived nerve growth factor (GDNF, a growth factor promoting neuronal differentiation, regeneration, and survival), and neural cell …

Neuroprotective Properties of Mildronate, a Small Molecule, in a Rat Model of Parkinson’s Disease

Previously, we have found that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a small molecule with charged nitrogen and oxygen atoms, protects mitochondrial metabolism that is altered by inhibitors of complex I and has neuroprotective effects in an azidothymidine-neurotoxicity mouse model. In the present study, we investigated the effects of mildronate in a rat model of Parkinson’s disease (PD) that was generated via a unilateral intrastriatal injection of the neurotoxin 6-hydroxydopamine (6‑OHDA). We assessed the expression of cell biomarkers that are involved in signaling cascades and provide neural and glial integration: the neuronal marker TH (tyrosine hydroxylase); …

Neuroprotective potential of antihyperglycemic drug metformin in streptozocin-induced rat model of sporadic Alzheimer's disease.

Abstract The earliest hallmarks of sporadic Alzheimer's disease (sAD) are impaired glucose metabolism, chronic neuroinflammation, diminished synaptic plasticity and subsequent cognitive decline. The safest antidiabetic drug metformin has shown both glucose metabolism-improving and cognition-enhancing action in type 2 diabetes patients and diabetic model animals. However, metformin has not been previously studied in intracerebroventricular streptozocin (STZ)-induced model of sAD. Therefore, our aim was to assess the preventive action of metformin in sAD model-rats. Firstly, the actions of metformin (75 and 100 mg/kg) on cognitive functions and sociability were examined. Secondly, we wanted t…

Neuroinflammation and acetylcholinesterase overexpression as the main targets for low doses of GABA-A receptor agonists in Alzheimer's disease rat model

The Fundamental Role of Melanocortins in Brain Processes

The discoveries of the latest ten years have shed new light in understanding the roles of melanocortins and their receptors in brain functions and in the development of different pathologies. Since 1992 when genes encoded melanocortin receptor five subtypes were identified, cloned and characterized, the molecular mechanisms underlying different effects such as skin darkening, behaviour, food intake, anti-inflammatory action, analgesia have been clarified. The contribution of melanocortins and their receptors in the physiological control of organism homeostasis has become as the background for the search of agonists and antagonists of separate receptor subtypes, that can be targeted to the m…

Carnitine congener mildronate protects against stress- and haloperidol-induced impairment in memory and brain protein expression in rats.

The present study investigates the efficacy of mildronate, a carnitine congener, to protect stress and haloperidol-induced impairment of memory in rats and the expression of brain protein biomarkers involved in synaptic plasticity, such as brain-derived neurotrophic factor (BDNF), acetylcholine esterase and glutamate decarboxylase 67 (GAD67). Two amnesia models were used: 2h immobilization stress and 3-week haloperidol treatment. Stress caused memory impairment in the passive avoidance test and induced a significant 2-fold BDNF elevation in hippocampal and striatal tissues that was completely inhibited by mildronate. Mildronate decreased the level of GAD67 (but not acetylcholine esterase) e…

Search for Stroke-Protecting Agents in Endothelin-1-Induced Ischemic Stroke Model in Rats

Background and Objective. Ischemic stroke may initiate a reperfusion injury leading to brain damage cascades where inflammatory mechanisms play a major role. Therefore, the necessity for the novel stroke-protecting agents whose the mechanism of action is focused on their anti-inflammatory potency is still on the agenda for drug designers. Our previous studies demonstrated that cerebrocrast (a 1,4-dihydropyridine derivative) and mildronate (a representative of the aza-butyrobetaine class) possessed considerable anti-inflammatory and neuroprotective properties in different in vitro and in vivo model systems. The present study investigated their stroke-protecting ability in an endothelin-1 (ET…

Atypical 1,4-dihydropyridine derivatives, an approach to neuroprotection and memory enhancement

This mini review is devoted to the design and pharmacological studies of novel atypical 1,4-dihydropyridine (DHP) derivatives which differ to a great extent from the traditional DHPs either by lack of neuronal calcium channel blocking activity and/or inability to protect mitochondrial processes. About 100 new DHP derivatives were screened and the mostly active were selected for detailed studies. The compounds of the series of the amino acid ("free" plus "crypto")-containing DHPs and lipophilic di-cyclic DHPs demonstrated long-lasting neuroprotective and/or memory-enhancing action, particularly at low doses (0.005-0.05mg/kg) in different neurodeficiency rat or mice models, and exerted neurot…

Pilot study to evaluate the assessment methods of the basic pharmacology course at the Faculty of Medicine of the University of Latvia

Mildronate improves cognition and reduces amyloid-β pathology in transgenic Alzheimer's disease mice

Mildronate, a carnitine congener drug, previously has been shown to provide neuroprotection in an azidothymidine-induced mouse model of neurotoxicity and in a Parkinson's disease rat model. The aim of this study was to investigate the effects of mildronate treatment on cognition and pathology in Alzheimer's disease (AD) model mice (APP(SweDI)). Mildronate was administered i.p. daily at 50 or 100 mg/kg for 28 days. At the end of treatment, the animals were behaviorally and cognitively tested, and brains were assessed for AD-related pathology, inflammation, synaptic markers, and acetylcholinesterase (AChE). The data show that mildronate treatment significantly improved animal performance in w…

Potato (Solanum tuberosum) Juice Exerts an Anticonvulsant Effect in Mice through Binding to GABA Receptors

Naturally occurring benzodiazepines have been identified in regular food such as wheat and potato, but there is still no evidence that potato extracts can affect CNS responses in vivo. Here we found that undiluted potato juice and potato juice diluted with saline 1 : 2 administered 10 min intracisternally ( I. C.) and 30 min per os before bicuculline exerted significant anticonvulsant activity in the bicuculline-induced seizure threshold test in mice. In vitro, potato juice from different harvests at dilution series from 10 % to 0.000001 %, diluted 100,000-fold, displaced 50 % of gamma-aminobutyric acid (GABA) receptor ligand [ (3)H]GABA and diluted 40-fold displaced 50 % of [(3)H]flunitraz…

Intranasal Administration of Extracellular Vesicles Derived from Human Teeth Stem Cells Improves Motor Symptoms and Normalizes Tyrosine Hydroxylase Expression in the Substantia Nigra and Striatum of the 6-Hydroxydopamine-Treated Rats.

Abstract Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting millions of people worldwide. At present, there is no effective cure for PD; treatments are symptomatic and do not halt progression of neurodegeneration. Extracellular vesicles (EVs) can cross the blood–brain barrier and represent promising alternative to the classical treatment strategies. In the present study, we examined therapeutic effects of intranasal administration of EVs derived from human exfoliated deciduous teeth stem cells (SHEDs) on unilateral 6-hydroxydopamine (6-OHDA) medial forebrain bundle (MFB) rat model of PD. CatWalk gait tests revealed that EVs effectively suppressed 6-OHDA-…

Distinct influence of atypical 1,4-dihydropyridine compounds in azidothymidine-induced neuro- and cardiotoxicity in mice ex vivo.

This study demonstrates the effective protection by compounds of atypical 1,4-dihydropyridine (DHP) series cerebrocrast, glutapyrone and tauropyrone against neuro- and cardiotoxicity caused by the model compound azidothymidine, a well-known mitochondria-compromising anti-HIV drug. In previous in vitro experiments, we have demonstrated distinct effects of these DHP compounds to influence mitochondrial functioning. In the present in vivo experiments, DHP compounds were administered intraperitoneally in mice daily for 2 weeks, per se and in combinations with azidothymidine at doses: azidothymidine 50 mg/kg; cerebrocrast 0.1 mg/kg; glutapyrone 1 mg/kg; and tauropyrone 1 mg/kg. At the end of the…

GABAA agonist muscimol ameliorates learning/memory deficits in streptozocin-induced Alzheimer’s disease non-transgenic rat model

Background: GABAergic inhibitory action regulates learning/memory processes and contributes to neurotransmission (Gong et al., 2009). Existing evidence suggests GABAergic system is involved in pathophysiology of Alzheimer’s disease (AD) via inhibitory interneuron deficits (Verret et al., 2012) and decrease in functional GABAA receptors (Limon et al., 2012). In vitro, GABA and muscimol (GABAA receptor agonist) blocked neuronal death induced by Aβ in rat hippocampal and cortical neurons (Paula-Lima et al., 2005). Our concept: low doses of muscimol may prevent learning/memory deficits in intracerebroventricular (icv) streptozocin (STZ)-induced AD non-transgenic rat model. Methods. Wistar male …

Betulin binds to gamma-aminobutyric acid receptors and exerts anticonvulsant action in mice.

The lupane type pentacyclic triterpenes: lupeol, betulin, and betulinic acid are widely distributed natural compounds. Recently, pharmaceutical compositions from plant extracts (family Marcgraviaceae) containing betulinic acid, have been patented as anxiolytic remedies. To extend our knowledge of the CNS effects of the triterpenes, we suggest here that the chemically related lupeol, betulin and betulinic acid may interact with the brain neurotransmitter gamma-aminobutyric acid (GABA) receptors in vitro and in vivo. Using radioligand receptor-binding assay, we showed that only betulin bound to the GABA(A)-receptor sites in mice brain in vitro and antagonised the GABA(A)-receptor antagonist b…

Anti-inflammatory effects of cerebrocrast in a model of rat paw edema and on mononuclear THP-1 cells.

Cerebrocrast (IOS 1.1212; 4-[2-(difluoromethoxy)phenyl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid di(2-propoxyethyl) diester) is a novel derivative of 1,4-dihydropyridine, which does not antagonize Ca(2+) influx in neuronal tissues. Since several classical dihydropyridines possess anti-inflammatory properties, we first studied the effects of cerebrocrast in a model of rat paw edema induced by carrageenan. Cerebrocrast had a preventative effect in this model of inflammation, with maximal activity (32-45% inhibition) in the 0.1-0.25 mg kg(-1) range. It was ineffective when added after the injection of carrageenan. Subsequent in vitro experiments showed that cerebrocrast in the mi…

Memory-enhancing and brain protein expression-stimulating effects of novel calcium antagonist in Alzheimer’s disease transgenic female mice

The prevalence of Alzheimer's disease (AD) is higher in females than in males, and causes more severe cognitive, memory and behavioral impairments. Previously, in male transgenic (Tg) APPSweDI mice, we reported that the novel lipophilic 1,4-dihydropyridine (DHP) derivative AP-12 crossed the blood-brain barrier, blocked neuronal and vascular calcium channels, changed brain protein expression and improved behavior. In this study, we used female Tg APPSweDI mice to assess the effects of AP-12 on behavior, and brain protein expression, with a particular focus on those of the GABAergic system. The results showed that in female Tg mice, similar to male Tg mice, AP-12 improved spatial learning/mem…

Distinct effects of atypical 1,4-dihydropyridines on 1-methyl-4-phenylpyridinium-induced toxicity.

Our previous data obtained from in vivo experiments demonstrated high neuroprotective effects of three novel atypical neuronal non-calcium antagonistic 1,4-dihydropyridine (DHP) derivatives cerebrocrast, glutapyrone and tauropyrone. The present studies were carried out in vitro to clarify, at least in part, their mechanism of action in primary culture of cerebellar granule cells by use of 1-methyl-4-phenylpyridinium (MPP+) as a neurotoxic agent which causes dramatic oxidative stress. Cerebrocrast (highly lipophilic, with a classical two-ring structure) dose-dependently (0.01-10.0 microM, EC50 = 13 nM) reduced MPP+-induced cell death. At the same time, the calcium antagonist nimodipine (refe…

Mildronate and its neuroregulatory mechanisms: targeting the mitochondria, neuroinflammation, and protein expression.

This review for the first time summarizes the data obtained in the neuropharmacological studies of mildronate, a drug previously known as a cardioprotective agent. In different animal models of neurotoxicity and neurodegenerative diseases, we demonstrated its neuroprotecting activity. By the use of immunohistochemical methods and Western blot analysis, as well as some selected behavioral tests, the new mechanisms of mildronate have been demonstrated: a regulatory effect on mitochondrial processes and on the expression of nerve cell proteins, which are involved in cell survival, functioning, and inflammation processes. Particular attention is paid to the capability of mildronate to stimulate…

Characterization of the transporterB0AT3 (Slc6a17) in the rodent central nervous system.

Abstract Background The vesicular B0AT3 transporter (SLC6A17), one of the members of the SLC6 family, is a transporter for neutral amino acids and is exclusively expressed in brain. Here we provide a comprehensive expression profile of B0AT3 in mouse brain using in situ hybridization and immunohistochemistry. Results We confirmed previous expression data from rat brain and used a novel custom made antibody to obtain detailed co-labelling with several cell type specific markers. B0AT3 was highly expressed in both inhibitory and excitatory neurons. The B0AT3 expression was highly overlapping with those of vesicular glutamate transporter 2 (VGLUT2) and vesicular glutamate transporter 1 (VGLUT1…

Mitochondria as the target for mildronate's protective effects in azidothymidine (AZT)-induced toxicity of isolated rat liver mitochondria

Previously mildronate, an aza-butyrobetaine derivative, was shown to be a cytoprotective drug, through its mechanism of action of inhibition of carnitine palmitoyltransferase-1, thus protecting mitochondria from long-chain fatty acid accumulation and subsequent damage. Recently in an azidothymidine (AZT)-induced cardiotoxicity model in vivo (in mice), we have found mildronate's ability of protecting heart tissue from nuclear factor kappaB abnormal expression. Preliminary data also demonstrate cerebro- and hepatoprotecting properties of mildronate in AZT-toxicity models. We suggest that mildronate may target its action predominantly to mitochondria. The present study in isolated rat liver mi…