Piracetam and TRH analogues antagonise inhibition by barbiturates, diazepam, melatonin and galanin of human erythrocyte D-glucose transport

Pharmacokinetic Drug-Drug Interactions among Antiepileptic Drugs, Including CBD, Drugs Used to Treat COVID-19 and Nutrients

Anti-epileptic drugs (AEDs) are an important group of drugs of several generations, ranging from the oldest phenobarbital (1912) to the most recent cenobamate (2019). Cannabidiol (CBD) is increasingly used to treat epilepsy. The outbreak of the SARS-CoV-2 pandemic in 2019 created new challenges in the effective treatment of epilepsy in COVID-19 patients. The purpose of this review is to present data from the last few years on drug–drug interactions among of AEDs, as well as AEDs with other drugs, nutrients and food. Literature data was collected mainly in PubMed, as well as google base. The most important pharmacokinetic parameters of the chosen 29 AEDs, mechanism of action and clinical application, as well as their biotransformation, are presented. We pay a special attention to the new potential interactions of the applied first-generation AEDs (carbamazepine, oxcarbazepine, phenytoin, phenobarbital and primidone), on decreased concentration of some medications (atazanavir and remdesivir), or their compositions (darunavir/cobicistat and lopinavir/ritonavir) used in the treatment of COVID-19 patients. CBD interactions with AEDs are clearly defined. In addition, nutrients, as well as diet, cause changes in pharmacokinetics of some AEDs. The understanding of the pharmacokinetic interactions of the AEDs seems to be important in effective management of epilepsy.

Changes in thyroid hormones, leptin, ghrelin and, galanin following oral melatonin administration in intact and castrated dogs: a preliminary study

Background

Melatonin regulates metabolism and metabolism related hormones in mammalians. Castration has some adverse effects on the metabolic hormones of dog. This study was conducted to determine the effects of oral melatonin administration on metabolic hormones, as well as to compare changes of these hormones after administration of melatonin in castrated and intact dogs. Twenty healthy mixed breed mature male dogs were divided randomly into four groups (n = 5): melatonin (3 mg/10 kg(, castrated, castrated and melatonin treated, and negative control. Blood sample was collected from jugular vein weekly for 1 month.

Results

T3 and T4 hormones had a significant decrease within 1 month following administration of melatonin. No significant change was observed in concentration of FT3 and FT4 hormones. Leptin and ghrelin hormones also had a significant decrease in this period. Leptin and ghrelin had a more significant decrease in “non-castrated and melatonin treated” group compared to “castrated and melatonin treated” group. Galanin had a significant decrease but this neurotransmitter had no significant change in “non-castrated and melatonin treated” group in comparison to “castrated and melatonin treated” group.

Conclusions

It seems that daily administration of melatonin capsule in all dogs can probably decrease concentration of T3 and T4 hormones and balance other metabolic hormones following castration.

Methods

The dogs underwent castration, melatonin treatment and blood sampling.

Diagnosing Glucose Transporter 1 Deficiency at Initial Presentation Facilitates Early Treatment

OBJECTIVE

To profile the initial clinical events of glucose transporter 1 deficiency syndrome (Glut1 DS) in order to facilitate the earliest possible diagnosis.

STUDY DESIGN

We retrospectively reviewed 133 patients with Glut1 DS from a single institution. Family interviews and medical record reviews identified the first clinical event(s) reported by the caregivers.

RESULTS

Average age of the first event was 8.15 ± 11.9 months (range: 0.01-81). Ninety-one patients experienced the first symptom before age 6 months (68%). Thirty-three additional patients (25%) presented before age 2 years. Only 9 patients (7%), reported the first event after age 2 years. Seizures were the most common first event (n = 81, 61%), followed by eye movement abnormalities (n = 51, 38%) and changes in muscle strength and tone (n = 30, 22%). Eye movement abnormalities, lower cerebrospinal fluid glucose values, and lower Columbia Neurological Scores correlated with earlier onset of the first event (r: -0.17, 0.22, and 0.25 respectively, P < .05). There was no correlation with age of first event and red blood cell glucose uptake or mutation type.

CONCLUSIONS

Glut1 DS is a treatable cause of infantile onset encephalopathy. Health care providers should recognize the wide spectrum of paroxysmal events that herald the clinical onset of Glut1 DS in early infancy to facilitate prompt diagnosis, immediate treatment, and improved long-term outcome.

Unifi nootropics from the lab to the web: a story of academic (and industrial) shortcomings

This paper is a review of the work of my former academic group of research in the past 15 years, in the field of cognition enhancers (also called nootropics) that identified two very potent molecules: Unifiram and Sunifiram that for a variety of reasons were not protected by a patent. Some 12 years after their disclosure (2000) I casually found that on the web, there were dozens of sites offering Unifiram and Sunifiram as drugs that improve cognition in healthy individuals even if only few preclinical studies were done and their long-term toxicity was unknown.

Effect of diet on serotonergic neurotransmission in depression

Depression is characterized by sadness, purposelessness, irritability, and impaired body functions. Depression causes severe symptoms for several weeks, and dysthymia, which may cause chronic, low-grade symptoms. Treatment of depression involves psychotherapy, medications, or phototherapy. Clinical and experimental evidence indicates that an appropriate diet can reduce symptoms of depression. The neurotransmitter, serotonin (5-HT), synthesized in the brain, plays an important role in mood alleviation, satiety, and sleep regulation. Although certain fruits and vegetables are rich in 5-HT, it is not easily accessible to the CNS due to blood brain barrier. However the serotonin precursor, tryptophan, can readily pass through the blood brain barrier. Tryptophan is converted to 5-HT by tryptophan hydroxylase and 5-HTP decarboxylase, respectively, in the presence of pyridoxal phosphate, derived from vitamin B(6). Hence diets poor in tryptophan may induce depression as this essential amino acid is not naturally abundant even in protein-rich foods. Tryptophan-rich diet is important in patients susceptible to depression such as certain females during pre and postmenstrual phase, post-traumatic stress disorder, chronic pain, cancer, epilepsy, Parkinson's disease, Alzheimer's disease, schizophrenia, and drug addiction. Carbohydrate-rich diet triggers insulin response to enhance the bioavailability of tryptophan in the CNS which is responsible for increased craving of carbohydrate diets. Although serotonin reuptake inhibitors (SSRIs) are prescribed to obese patients with depressive symptoms, these agents are incapable of precisely regulating the CNS serotonin and may cause life-threatening adverse effects in the presence of monoamine oxidase inhibitors. However, CNS serotonin synthesis can be controlled by proper intake of tryptophan-rich diet. This report highlights the clinical significance of tryptophan-rich diet and vitamin B(6) to boost serotonergic neurotransmission in depression observed in various neurodegenerative diseases. However pharmacological interventions to modulate serotonergic neurotransmission in depression, remains clinically significant. Depression may involve several other molecular mechanisms as discussed briefly in this report.

A novel CaV2.2 channel inhibition by piracetam in peripheral and central neurons

No mechanistic actions for piracetam have been documented to support its nootropic effects. Voltage-gated calcium channels have been proposed as a promising pharmacological target of nootropic drugs. In this study, we investigated the effect of piracetam on Ca(V)2.2 channels in peripheral neurons, using patch-clamp recordings from cultured superior cervical ganglion neurons. In addition, we tested if Ca(V)2.2 channel inhibition could be related with the effects of piracetam on central neurons. We found that piracetam inhibited native Ca(V)2.2 channels in superior cervical ganglion neurons in a dose-dependent manner, with an IC(50) of 3.4 μmol/L and a Hill coefficient of 1.1. GDPβS dialysis did not prevent piracetam-induced inhibition of Ca(V)2.2 channels and G-protein-coupled receptor activation by noradrenaline did not occlude the piracetam effect. Piracetam altered the biophysical characteristics of Ca(V)2.2 channel such as facilitation ratio. In hippocampal slices, piracetam and ω-conotoxin GVIA diminished the frequency of excitatory postsynaptic potentials and action potentials. Our results provide evidence of piracetam's actions on Ca(V)2.2 channels in peripheral neurons, which might explain some of its nootropic effects in central neurons.

Quercetin-iron chelates are transported via glucose transporters

Flavonoids are well-known antioxidants and free radical scavengers. Their metal-binding activity suggests that they could be effective protective agents in pathological conditions caused by both extracellular and intracellular oxidative stress linked to metal overload. Quercetin is both a permeant ligand via glucose transport proteins (GLUTs) and a high-affinity inhibitor of GLUT-mediated glucose transport. Chelatable "free iron" at micromolar concentrations in body fluids is a catalyst of hydroxyl radical (OH(•)) production from hydrogen peroxide. A number of flavonoids, e.g., quercetin, luteolin, chrysin, and 3,6-dihydroxyflavone, have been demonstrated to chelate intracellular iron and suppress OH(•) radical production in Madin Darby canine kidney cells. The most effective chelation comes from the flavonone B ring catechol found in both quercetin and luteolin. We show here that quercetin concentrations of <1μM can facilitate chelatable iron shuttling via GLUT1 in either direction across the cell membrane. These siderophoric effects are inhibited by raised quercetin concentrations (>1μM) or GLUT inhibitors, e.g., phloretin or cytochalasin B, and iron efflux is enhanced by impermeant extracellular iron chelators, either desferrioxamine or rutin. This iron shuttling property of quercetin might be usefully harnessed in chelotherapy of iron-overload conditions.

Mitochondrial dysfunction: common final pathway in brain aging and Alzheimer's disease--therapeutic aspects

As a fully differentiated organ, our brain is very sensitive to cumulative oxidative damage of proteins, lipids, and DNA occurring during normal aging because of its high energy metabolism and the relative low activity of antioxidative defense mechanisms. As a major consequence, perturbations of energy metabolism including mitochondrial dysfunction, alterations of signaling mechanisms and of gene expression culminate in functional deficits. With the increasing average life span of humans, age-related cognitive disorders such as Alzheimer's disease (AD) are a major health concern in our society. Age-related mitochondrial dysfunction underlies most neurodegenerative diseases, where it is potentiated by disease-specific factors. AD is characterized by two major histopathological hallmarks, initially intracellular and with the progression of the disease extracellular accumulation of oligomeric and fibrillar beta-amyloid peptides and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. In this review, we focus on findings in AD animal and cell models indicating that these histopathological alterations induce functional deficits of the respiratory chain complexes and therefore consecutively result in mitochondrial dysfunction and oxidative stress. These parameters lead synergistically with the alterations of the brain aging process to typical signs of neurodegeneration in the later state of the disease, including synaptic dysfunction, loss of synapses and neurites, and finally neuronal loss. We suggest that mitochondrial protection and subsequent reduction of oxidative stress are important targets for prevention and long-term treatment of early stages of AD.

The metabolic enhancer piracetam ameliorates the impairment of mitochondrial function and neurite outgrowth induced by beta-amyloid peptide

BACKGROUND AND PURPOSE

beta-Amyloid peptide (Abeta) is implicated in the pathogenesis of Alzheimer's disease by initiating a cascade of events from mitochondrial dysfunction to neuronal death. The metabolic enhancer piracetam has been shown to improve mitochondrial dysfunction following brain aging and experimentally induced oxidative stress.

EXPERIMENTAL APPROACH

We used cell lines (PC12 and HEK cells) and murine dissociated brain cells. The protective effects of piracetam in vitro and ex vivo on Abeta-induced impairment of mitochondrial function (as mitochondrial membrane potential and ATP production), on secretion of soluble Abeta and on neurite outgrowth in PC12 cells were investigated.

KEY RESULTS

Piracetam improves mitochondrial function of PC12 cells and acutely dissociated brain cells from young NMRI mice following exposure to extracellular Abeta(1-42). Similar protective effects against Abeta(1-42) were observed in dissociated brain cells from aged NMRI mice, or mice transgenic for mutant human amyloid precursor protein (APP) treated with piracetam for 14 days. Soluble Abeta load was markedly diminished in the brain of those animals after treatment with piracetam. Abeta production by HEK cells stably transfected with mutant human APP was elevated by oxidative stress and this was reduced by piracetam. Impairment of neuritogenesis is an important consequence of Abeta-induced mitochondrial dysfunction and Abeta-induced reduction of neurite growth in PC12 cells was substantially improved by piracetam.

CONCLUSION AND IMPLICATIONS

Our findings strongly support the concept of improving mitochondrial function as an approach to ameliorate the detrimental effects of Abeta on brain function.

Piracetam improves mitochondrial dysfunction following oxidative stress

1.--Mitochondrial dysfunction including decrease of mitochondrial membrane potential and reduced ATP production represents a common final pathway of many conditions associated with oxidative stress, for example, hypoxia, hypoglycemia, and aging. 2.--Since the cognition-improving effects of the standard nootropic piracetam are usually more pronounced under such pathological conditions and young healthy animals usually benefit little by piracetam, the effect of piracetam on mitochondrial dysfunction following oxidative stress was investigated using PC12 cells and dissociated brain cells of animals treated with piracetam. 3.--Piracetam treatment at concentrations between 100 and 1000 microM improved mitochondrial membrane potential and ATP production of PC12 cells following oxidative stress induced by sodium nitroprusside (SNP) and serum deprivation. Under conditions of mild serum deprivation, piracetam (500 microM) induced a nearly complete recovery of mitochondrial membrane potential and ATP levels. Piracetam also reduced caspase 9 activity after SNP treatment. 4.--Piracetam treatment (100-500 mg kg(-1) daily) of mice was also associated with improved mitochondrial function in dissociated brain cells. Significant improvement was mainly seen in aged animals and only less in young animals. Moreover, the same treatment reduced antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in aged mouse brain only, which are elevated as an adaptive response to the increased oxidative stress with aging. 5.--In conclusion, therapeutically relevant in vitro and in vivo concentrations of piracetam are able to improve mitochondrial dysfunction associated with oxidative stress and/or aging. Mitochondrial stabilization and protection might be an important mechanism to explain many of piracetam's beneficial effects in elderly patients.

Pharmacological characterization of DM232 (unifiram) and DM235 (sunifiram), new potent cognition enhancers

DM232 (unifiram) and DM235 (sunifiram) are potent cognition-enhancers, which are four order of magnitude more potent than piracetam. These compounds, although not showing affinity in binding studies for the most important central receptors or channels, are able to prevent amnesia induced by modulation of several neurotransmission systems. These compounds are able to increase the release of acetylcholine from rat cerebral cortex, and, as far as unifiram is concerned, to increase the amplitude of fEPSP in rat hippocampal slices. In vitro experiments, performed on hippocampal slices, also supported the hypothesis of a role of the AMPA receptors for the cognition-enhancing properties of unifiram and sunifiram.