Advances in drug design based on the amino Acid approach: taurine analogues for the treatment of CNS diseases

Unraveling the Role of miR-200b-3p in Attention-Deficit/Hyperactivity Disorder (ADHD) and Its Therapeutic Potential in Spontaneously Hypertensive Rats (SHR)

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder in children with unknown etiology. Impaired learning ability was commonly reported in ADHD patients and has been associated with dopamine uptake in the striatum of an animal model. Another evidence also indicated that micro-RNA (miR)-200b-3p is associated with learning ability in various animal models. However, the association between miR-200b-3p and ADHD-related symptoms remains unclear. Therefore, the current study investigated the role of miR-200b-3p in ADHD-related symptoms such as inattention and striatal inflammatory cytokines. To verify the influence of miR-200b-3p in ADHD-related symptoms, striatal stereotaxic injection of miR-200b-3p antagomir (AT) was performed on spontaneously hypertensive rats (SHR). The antioxidant activity and expressions of miR-200b-3p, slit guidance ligand 2 (Slit2), and inflammatory cytokines in the striatum of SHR were measured using quantitative real-time polymerase chain reaction (RT-qPCR), immunohistochemistry (IHC), immunoblotting, and enzyme-linked immunosorbent assay (ELISA). The spontaneous alternation of SHR was tested using a three-arm Y-shaped maze. The administration of miR-200b-3p AT or taurine significantly decreased striatal tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in SHR, along with increased super-oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and significantly higher spontaneous alternation. In this paper, we show that miR-200b-3p AT and taurine alleviates ADHD-related symptoms in SHR. These findings provide insights into ADHD's molecular basis and suggest miR-200b-3p as a potential therapeutic target. Concurrently, this study also suggests broad implications for treating neurodevelopmental disorders affecting learning activity such as ADHD.

The Neuropharmacological Evaluation of Seaweed: A Potential Therapeutic Source

The most common neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD) and Parkinson's disease (PD), are the seventh leading cause of mortality and morbidity in developed countries. Clinical observations of NDD patients are characterized by a progressive loss of neurons in the brain along with memory decline. The common pathological hallmarks of NDDs include oxidative stress, the dysregulation of calcium, protein aggregation, a defective protein clearance system, mitochondrial dysfunction, neuroinflammation, neuronal apoptosis, and damage to cholinergic neurons. Therefore, managing this pathology requires screening drugs with different pathological targets, and suitable drugs for slowing the progression or prevention of NDDs remain to be discovered. Among the pharmacological strategies used to manage NDDs, natural drugs represent a promising therapeutic strategy. This review discusses the neuroprotective potential of seaweed and its bioactive compounds, and safety issues, which may provide several beneficial insights that warrant further investigation.

Selective drug delivery to the retinal cells: Biological barriers and avenues

Retinal drug delivery is a challenging, but important task, because most retinal diseases are still without any proper therapy. Drug delivery to the retina is hampered by the anatomical and physiological barriers resulting in minimal bioavailability after topical ocular and systemic administrations. Intravitreal injections are current method-of-choice in retinal delivery, but these injections show short duration of action for small molecules and low target bioavailability for many protein, gene based drugs and nanomedicines. State-of-art delivery systems are based on prolonged retention, controlled drug release and physical features (e.g. size and charge). However, drug delivery to the retina is not cell-specific and these approaches do not facilitate intracellular delivery of modern biological drugs (e.g. intracellular proteins, RNA based medicines, gene editing). In this focused review we highlight biological factors and mechanisms that form the basis for the selective retinal drug delivery systems in the future. Therefore, we are presenting current knowledge related to retinal membrane transporters, receptors and targeting ligands in relation to nanomedicines, conjugates, extracellular vesicles, and melanin binding. These issues are discussed in the light of retinal structure and cell types as well as future prospects in the field. Unlike in some other fields of targeted drug delivery (e.g. cancer research), selective delivery technologies have been rarely studied, even though cell targeted delivery may be even more feasible after local administration into the eye.

The Effect of a New N-hetero Cycle Derivative on Behavior and Inflammation against the Background of Ischemic Stroke

Ischemic stroke triggers a whole cascade of pathological changes in the brain, one of which is postischemic inflammation. Since in such cases thrombolytic therapy is often not possible, methods that modulate inflammation and affect microglia become particularly interesting. We synthesized 3-(2-oxo-4-phenylpyrrolidin-1-yl)propane-1-sulfonate calcium(II) (Compound 4) and studied its anti-inflammatory activity in in vitro and in vivo models of inflammation and ischemia. Macrophage cell line RAW 264.7 was treated with lipopolysaccharides (LPS) and Compound 4 at various dosages to study the cytokine profile using real-time PCR and cytometric bead array (CBA). Stroke in rats was simulated by the middle cerebral artery occlusion method (MCAO). Several tests were performed to characterize the neurological deficit and locomotor activity of the rats, and afterwards, postmortem, the number of astrocytes was counted using immunohistochemistry. Compound 4 in in vitro tests dose-dependently reduced the expression of interleukin-1β (IL1β), and inducible nitric oxide synthase (iNOS) genes in cell culture and increased the concentration of cytokines: interleukin-2, 4, 6 (IL-2, IL-4, and IL-6). In vivo Compound 4 increased the orienting-exploratory behavior, and reduced neurological and motor deficit. The number of astrocytes that promote and support inflammation was lower in the group treated with Compound 4. The stroke volume measured by magnetic resonance imaging (MRI) showed no difference. We have shown that Compound 4 demonstrates anti-inflammatory activity by increasing the synthesis of anti-inflammatory and reducing pro-inflammatory cytokines, and positively affects the neurological deficit in rats. Thus, Compound 4 has a high therapeutic potential in the management of patients after a stroke and requires further study of its neuroprotective properties.

Recyclization of Maleimides by Binucleophiles as a General Approach for Building Hydrogenated Heterocyclic Systems

The building of heterocyclic systems containing hydrogenated fragments is an important step towards the creation of biologically-active compounds with a wide spectrum of pharmacological activity. Among the numerous methods for creating such systems, a special place is occupied by processes using N-substituted maleimides as the initial substrate. This molecule easily reacts in Diels-Alder/retro-Diels-Alder reactions, Michael additions with various nucleophiles, and co-polymerization processes, as have been described in numerous detailed reviews. However, information on the use of maleimides in cascade heterocyclization reactions is currently limited. This study is devoted to a review and analysis of existing literature data on the processes of recyclization of N-substituted maleimides with various C,N-/N,N-/S,N-di- and polynucleophilic agents, such as amidines, guanidines, diamines, aliphatic ketazines, aminouracils, amino- and mercaptoazoles, aminothiourea, and thiocarbomoyl pyrazolines, among others. The significant structural diversity of the recyclization products described in this study illustrates the powerful potential of maleimides as a building block in the organic synthesis of biologically-active compounds with hydrogenated heterocyclic fragments.

Taurine-Derived Compounds Produce Anxiolytic Effects in Rats Following Developmental Lead Exposure

Lead (Pb2+) is a developmental neurotoxicant that disrupts the GABA-shift and subsequently causes alterations in the brain's excitation-to-inhibition (E/I) balance. Taurine is a well-established neuroprotective and inhibitory compound for regulating brain excitability. Since mechanistically taurine can facilitate neuronal inhibition through the GABA-AR, the present study examined the anxiolytic potential of taurine derivatives. Treatment groups consisted of the following developmental Pb2+-exposures: Control (0 ppm) and Perinatal (150 ppm or 1,000 ppm lead acetate in the drinking water). Rats were scheduled for behavioral tests between postnatal days (PND) 36-45 with random drug assignments to either saline, taurine, or taurine-derived compound (TD-101, TD-102, or TD-103) to assess the rats' responsivity to each drug in mitigating the developmental Pb2+-exposure and anxiety-like behaviors through the GABAergic system. Long-Evans hooded rats were assessed using an open field (OF) test for preliminary locomotor assessment. Twenty-four hours later, the same rats were exposed to the elevated plus maze (EPM) and were given an i.p. injection of 43 mg/Kg of the saline, taurine, or TD drugs 15 min prior to testing. Each rat was tested using the triple-blind random assignment method for each drug condition. The OF data revealed that Control female rats had increased locomotor activity over Control male rats, and the Pb2+-exposed males and females had increased locomotor activity when compared to the Control male and female rats. However, in the EPM, the Control female rats exhibited more anxiety-like behaviors over Control male rats, and the Pb2+-exposed male and female rats showed selective responsivity to TD drugs when compared to taurine. For Pb2+-exposed males, TD-101 showed consistent recovery of anxiety-like behaviors similar to that of taurine regardless of Pb2+ dose, whereas in Pb2+-exposed females TD-101 and TD-103 showed greater anxiolytic responses in the EPM. The results from the present psychopharmacological study suggests that taurine and its derivatives are interesting drug candidates to explore sex-specific mechanisms and actions of taurine and the associated GABAergic receptor properties by which these compounds alleviate anxiety as a potential behavioral pharmacotherapy for neurodevelopmental Pb2+ exposure.

Synthesis and Biological Evaluation of Novel Benzhydrylpiperazine-Coupled Nitrobenzenesulfonamide Hybrids

A series of novel benzhydryl piperazine-coupled nitrobenzenesulfonamide hybrids were synthesized with good to excellent yields. They were tested for in vitro inhibition of mycobacterial activity against the Mycobacterium tuberculosis H37Rv strain, in vitro cytotoxicity MTT (RAW 264.7cells) assay, nutrient starvation (H37Rv strain), and ability to block Cav3.2 T-type calcium channels. Novel hybrids did not inhibit T-type calcium channels, whereas they showed excellent antituberculosis (TB) activity and low cytotoxicity with a selectivity index of >30. A direct impact of the amino acid linker was not observed. Studied hybrids exhibited good inhibition activities, and the 2,4-dinitrobenzenesulfonamide group emerged as a promising scaffold for further drug design by hybridization approaches for anti-TB therapy.

Sulfur-containing therapeutics in the treatment of Alzheimer's disease

Sulfur is widely existent in natural products and synthetic organic compounds as organosulfur, which are often associated with a multitude of biological activities. OBenzothiazole, in which benzene ring is fused to the 4,5-positions of the thiazolerganosulfur compounds continue to garner increasing amounts of attention in the field of medicinal chemistry, especially in the development of therapeutic agents for Alzheimer's disease (AD). AD is a fatal neurodegenerative disease and the primary cause of age-related dementia posing severe societal and economic burdens. Unfortunately, there is no cure for AD. A lot of research has been conducted on sulfur-containing compounds in the context of AD due to their innate antioxidant potential and some are currently being evaluated in clinical trials. In this review, we have described emerging trends in the field, particularly the concept of multi-targeting and formulation of disease-modifying strategies. SAR, pharmacological targets, in vitro/vivo ADMET, efficacy in AD animal models, and applications in clinical trials of such sulfur compounds have also been discussed. This article provides a comprehensive review of organosulfur-based AD therapeutic agents and provides insights into their future development.

Quantitative Protein Expression in the Human Retinal Pigment Epithelium: Comparison Between Apical and Basolateral Plasma Membranes With Emphasis on Transporters

Purpose

Retinal pigment epithelium (RPE) limits the xenobiotic entry from the systemic blood stream to the eye. RPE surface transporters can be important in ocular drug distribution, but it has been unclear whether they are expressed on the apical, basal, or both cellular surfaces. In this paper, we provide quantitative comparison of apical and basolateral RPE surface proteomes.

Methods

We separated the apical and basolateral membranes of differentiated human fetal RPE (hfRPE) cells by combining apical membrane peeling and sucrose density gradient centrifugation. The membrane fractions were analyzed with quantitative targeted absolute proteomics (QTAP) and sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) to reveal the membrane protein localization on the RPE cell surfaces. We quantitated 15 transporters in unfractionated RPE cells and scaled their expression to tissue level.

Results

Several proteins involved in visual cycle, cell adhesion, and ion and nutrient transport were expressed on the hfRPE plasma membranes. Most drug transporters showed similar abundance on both RPE surfaces, whereas large neutral amino acids transporter 1 (LAT1), p-glycoprotein (P-gp), and monocarboxylate transporter 1 (MCT1) showed modest apical enrichment. Many solute carriers (SLC) that are potential prodrug targets were present on both cellular surfaces, whereas putative sodium-coupled neutral amino acid transporter 7 (SNAT7) and riboflavin transporter (RFT3) were enriched on the basolateral and sodium- and chloride-dependent neutral and basic amino acid transporter (ATB0+) on the apical membrane.

Conclusions

Comprehensive quantitative information of the RPE surface proteomes was reported for the first time. The scientific community can use the data to further increase understanding of the RPE functions. In addition, we provide insights for transporter protein localization in the human RPE and the significance for ocular pharmacokinetics.

Sub-chronic taurine administration induces behavioral sensitization but does not influence ethanol-induced dopamine release in the nucleus accumbens

Preclinical studies have shown that the amino acid taurine is of importance for the dopamine elevating properties of ethanol. Taurine intake has escalated over the last decade due to increased consumption of taurine-containing energy drinks and dietary supplements. Whether long-term intake of large amounts of taurine induces adaptations affecting ethanol-induced dopamine elevation is not clear. Thus the aim of the present studies was to explore the impact of repeated administration of large amounts of taurine on ethanol-induced behavior and dopamine neurotransmission. Repeated daily systemic administration of taurine increased taurine-induced locomotor activity and rearing. Acute administration of taurine and ethanol in naïve animals produced an additive effect on extracellular taurine but no alteration of the ethanol-induced dopamine elevation, as measured by in vivo microdialysis. Sub-chronic administration of taurine did not modify the taurine- or dopamine-elevating properties of ethanol. Daily taurine treatment also failed to change the mRNA expression of the taurine transporter and GABA_A- and glycine-receptor subunits, as measured by qPCR in nucleus accumbens tissue. We conclude that systemic administration of taurine may have long lasting central effects, here displayed as behavioral sensitization. However, repeated daily exposure to taurine does not appear to influence the dopamine elevating properties of ethanol.

Anxiolytic Action of Taurine via Intranasal Administration in Mice

Taurine has a number of beneficial pharmacological actions in the brain such as anxiolytic and neuroprotective actions. We explored to test whether taurine could be transported to the central nervous system through the intranasal route. Following intranasal administration of taurine in mice, elevated plus maze test, activity cage test and rota rod test were carried out to verify taurine's effect on anxiety. For the characterization of potential mechanism of taurine's anti-anxiety action, mouse convulsion tests with strychnine, picrotoxin, yohimbine, and isoniazid were employed. A significant increase in the time spent in the open arms was observed when taurine was administered through the nasal route in the elevated plus maze test. In addition, vertical and horizontal activities of mice treated with taurine via intranasal route were considerably diminished. These results support the hypothesis that taurine can be transported to the brain through intranasal route, thereby inducing anti-anxiety activity. Taurine's anti-anxiety action may be mediated by the strychnine-sensitive glycine receptor as evidenced by the inhibition of strychnine-induced convulsion.

Age-dependent effects of (+)-MK801 treatment on glutamate release and metabolism in the rat medial prefrontal cortex

NMDAR antagonist treatments in adolescent/young adult rodents are associated with augmented glutamate (Glu) release and perturbed Glu/glutamine (Gln) metabolism in the medial prefrontal cortex (mPFC) resembling those found in first-episode schizophrenia. Few studies, however, investigated NMDAR antagonist-induced changes in the adult mPFC and whether there is an age-dependence to this end. In this study, the effects of acute/repeated (+)-MK801 treatment on Glu release/metabolism were measured in the mPFC of male adolescent (postnatal day 30) and adult (14 weeks) rats. Acute (+)-MK801 treatment at 0.5 mg/kg body weight induced an approximately 4-fold increase of extracellular Glu concentration in the adolescent rats, and repeated treatment for 6 consecutive days significantly increased the levels of Glu + Gln (Glx) and glial metabolites 7 days after the last dose. Histologically (+)-MK801 treatments induced reactive astrocytosis and elevated oxidative stress in the mPFC of adolescent rats, without causing evident neuronal degeneration in the region. All (+)-MK801-induced changes observed in the mPFC of adolescent rats were not present or evident in the adult rats, suggesting that the treatments might have caused less disinhibition in the adult mPFC than in the adolescent mPFC. In conclusion, the effects of (+)-MK801 treatments on the Glu release/metabolism in the mPFC were found to be age-dependent; and the adult mPFC is likely equipped with more robust neurobiological mechanisms to preserve excitatory-inhibitory balance in response to NMDAR hypofunction.

Taurine and its analogs in neurological disorders: Focus on therapeutic potential and molecular mechanisms

Taurine is a sulfur-containing amino acid and known as semi-essential in mammals and is produced chiefly by the liver and kidney. It presents in different organs, including retina, brain, heart and placenta and demonstrates extensive physiological activities within the body. In the several disease models, it attenuates inflammation- and oxidative stress-mediated injuries. Taurine also modulates ER stress, Ca2+ homeostasis and neuronal activity at the molecular level as part of its broader roles. Different cellular processes such as energy metabolism, gene expression, osmosis and quality control of protein are regulated by taurine. In addition, taurine displays potential ameliorating effects against different neurological disorders such as neurodegenerative diseases, stroke, epilepsy and diabetic neuropathy and protects against injuries and toxicities of the nervous system. Several findings demonstrate its therapeutic role against neurodevelopmental disorders, including Angelman syndrome, Fragile X syndrome, sleep-wake disorders, neural tube defects and attention-deficit hyperactivity disorder. Considering current biopharmaceutical limitations, developing novel delivery approaches and new derivatives and precursors of taurine may be an attractive option for treating neurological disorders. Herein, we present an overview on the therapeutic potential of taurine against neurological disorders and highlight clinical studies and its molecular mechanistic roles. This article also addresses the neuropharmacological potential of taurine analogs.

Taurine attenuates acrylamide-induced axonal and myelinated damage through the Akt/GSK3β-dependent pathway

Acrylamide (ACR), formed during the Maillard reaction induced by high temperature in food processing, is one of the main causes of neurodegenerative diseases. Taurine, a free intracellular β-amino acid, is characterized by many functions, including antioxidation, anti-inflammatory, and neuroprotective properties. This promotes its application in the treatment of neurodegenerative diseases. In this study, the neuroprotective effects of taurine against ACR-induced neurotoxicity and the potential underlying mechanisms were explored. Rats were intoxicated with ACR and injected with taurine in different groups for totally 2 weeks between January and July 2017. Electron microscopic analysis was used to observe the changes in tissues of the rats. Meanwhile, the levels of proteins including p-Akt, p-GSK3β, SIM312, and MBP were detected by Western blot. Furthermore, the GSK3β phosphorylation in taurine-treated dorsal root ganglion (DRG) with ACR was examined in the presence of the Akt inhibitor, MK-2206. The analysis of behavioral performances and electron micrographs indicated that taurine treatment significantly attenuated the toxic manifestations induced by ACR and stimulated the growth of axons and the medullary sheath, which was associated with the activation of the Akt/GSK3β signaling pathway. Mechanistically, it was found that taurine activated GSK3β, leading to significant recovery of the damage in ACR-induced sciatic nerves. Furthermore, MK-2206, an inhibitor of Akt, was applied in DRG cells, suggesting that taurine-induced GSK3β phosphorylation was Akt dependent. Our findings demonstrated that taurine attenuated ACR-induced neuropathy in vivo, in an Akt/GSK3β-dependent manner. This confirmed the treatment with taurine to be a novel strategy against ACR-induced neurotoxicity.

Taurine supplementation in high-fat diet fed male mice attenuates endocrine pancreatic dysfunction in their male offspring

Obesity in fathers leads to DNA damage and epigenetic changes in sperm that may carry potential risk factors for metabolic diseases to the next generation. Taurine (TAU) supplementation has demonstrated benefits against testicular dysfunction and pancreatic islet impairments induced by obesity, but it is not known if these protective actions prevent the propagation of metabolic disruptions to the next generation; as such, we hypothesized that paternal obesity may increase the probability of endocrine pancreatic dysfunction in offspring, and that this could be prevented by TAU supplementation in male progenitors. To test this, male C57Bl/6 mice were fed on a control diet (CTL) or a high-fat diet (HFD) without or with 5% TAU in their drinking water (CTAU and HTAU) for 4 months. Subsequently, all groups of mice were mated with CTL females, and the F1 offspring were identified as: CTL-F1, CTAU-F1, HFD-F1, and HTAU-F1. HFD-fed mice were normoglycemic, but glucose intolerant and their islets hypersecreted insulin. However, at 90 days of age, HFD-F1 offspring displayed normal glucose homeostasis and adiposity, but reduced glucose-induced insulin release. HFD-F1 islets also exhibited β- and α-cell hypotrophy, and lower δ-cell number per islet. Paternal TAU supplementation prevented the decrease in glucose-induced insulin secretion and normalized β-cell size and δ-cell number, and increased α-cell size/islet in HTAU-F1 mice. In conclusion, HFD consumption by male founders decreases β-cell secretion and islet-cell distribution in their offspring. TAU attenuates the deleterious effects of paternal obesity on insulin secretion and islet-cell morphology in F1 offspring.

Taurine potentiates the anticonvulsive effect of the GABAA agonist muscimol and pentobarbital in the immature mouse hippocampus

OBJECTIVE

The high incidence of epileptic seizures in neonates and their frequent refractoriness to pharmacologic therapies require identification of new therapeutical options. Therefore, we investigated whether the modulatory effect of taurine on γ-aminobutyric acid (GABA)_A receptors can enhance the anticonvulsive potential of the GABA_A receptor agonist muscimol and of the barbiturate pentobarbital.

METHODS

We performed field potential recordings in in toto hippocampus preparations of immature (postnatal days 4-7) C57Bl/6 mouse pups. Spontaneous epileptiform activity was induced by the continuous presence of the potassium channel blocker 4-aminopyridine and the glycinergic antagonist strychnine in Mg²⁺ -free solutions.

RESULTS

Bath application of 0.1 μmol/L muscimol increases the occurrence of recurrent epileptiform discharges, whereas they are significantly attenuated in a dose-dependent manner by muscimol in concentrations between 0.5 and 5 μmol/L. Taurine at concentrations between 0.1 and 0.5 mmol/L induces a proconvulsive effect, but upon coapplication, it significantly augments the anticonvulsive effect of moderate muscimol doses (0.5-1 μmol/L). In addition, the anticonvulsive effect of 100 and 200 μmol/L pentobarbital is increased significantly in the presence of 0.5 μmol/L taurine.

SIGNIFICANCE

These observations demonstrate that taurine can indeed enhance the anticonvulsive effects of muscimol and pentobarbital, suggesting that taurine may act as a positive modulator on GABA_A receptors. Thus, interfering with the modulatory taurine binding site of GABA_A receptors or the interstitial taurine concentration may provide new therapeutical options for anticonvulsive therapies in neonates.

Hypotaurine evokes a malignant phenotype in glioma through aberrant hypoxic signaling

Metabolomics has shown significant potential in identifying small molecules specific to tumor phenotypes. In this study we analyzed resected tissue metabolites using capillary electrophoresis-mass spectrometry and found that tissue hypotaurine levels strongly and positively correlated with glioma grade. In vitro studies were conducted to show that hypotaurine activates hypoxia signaling through the competitive inhibition of prolyl hydroxylase domain-2. This leads to the activation of hypoxia signaling as well as to the enhancement of glioma cell proliferation and invasion. In contrast, taurine, the oxidation metabolite of hypotaurine, decreased intracellular hypotaurine and resulted in glioma cell growth arrest. Lastly, a glioblastoma xenograft mice model was supplemented with taurine feed and exhibited impaired tumor growth. Taken together, these findings suggest that hypotaurine is an aberrantly produced oncometabolite, mediating tumor molecular pathophysiology and progression. The hypotaurine metabolic pathway may provide a potentially new target for glioblastoma diagnosis and therapy.

Understanding taurine CNS activity using alternative zebrafish models

Taurine is a highly abundant "amino acid" in the brain. Despite the potential neuroactive role of taurine in vertebrates has long been recognized, the underlying molecular mechanisms related to its pleiotropic effects in the brain remain poorly understood. Due to the genetic tractability, rich behavioral repertoire, neurochemical conservation, and small size, the zebrafish (Danio rerio) has emerged as a powerful candidate for neuropsychopharmacology investigation and in vivo drug screening. Here, we summarize the main physiological roles of taurine in mammals, including neuromodulation, osmoregulation, membrane stabilization, and antioxidant action. In this context, we also highlight how zebrafish models of brain disorders may present interesting approaches to assess molecular mechanisms underlying positive effects of taurine in the brain. Finally, we outline recent advances in zebrafish drug screening that significantly improve neuropsychiatric translational researches and small molecule screens.

Isolation and Total Synthesis of Stolonines A-C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera

Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A-C (1-3), belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A-C (1-3), respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells.

[Pharmaconutrition: pharmacological approach to nutrition therapy]

Reviewing the literature of nutrition therapy one can conclude that during the last decade the pharmacological action of several nutrients has been demonstrated. However, research activity is still at the beginning and it could be verified in a restricted number of nutrients only that in which conditions (illnesses), dose and duration we can expect therapeutic effect in addition to nutrition. The examples of glutamine, arginine, taurine, leucine, ω-3 fatty acids, however, support the possibility that complex reactions and treatment results observed in certain patients are not purely due to nutritional support but the consequence of additional pharmacological action as well. Evaluation of results of therapeutic intervention is especially difficult because in the everyday practice physicians try to use several therapeutic modalities that can be beneficial for the patient. Therefore, retrospective separation of beneficial components of the therapeutic agents is almost impossible. Only well designed, randomized and multicentric studies can verify specific therapeutic action of certain ingredients ie. nutrients.