Alteration in the callogenesis, tropane alkaloid formation, and gene expression in Hyoscyamus niger under clinorotation.

This study aimed to investigate the effects of clinorotation induced by 2-D clinostat on the growth, tropane alkaloid production, gene expression, antioxidant capacity, and cellular defense responses in the callus tissue of Hyoscyamus niger. Callus induction was conducted by putting hypocotyl explants in the MS culture medium supplemented with 1 mgL-1 2,4-D and 1 mgL-1 BAP growth regulators. The sub-cultured calli were placed on a clinostat for 0, 3, 7, and 10 days (2.24 × 10-5 g on the edge of the callus ring). Clinorotation significantly increased callus fresh weight, dry weight, protein, carbohydrate, and proline contents compared to the control, and their maximum contents were obtained after 7 and 10 days. H2O2 level enhanced under clinorotation with a 76.3% rise after 10 days compared to control and positively affected the atropine (77.1%) and scopolamine (69.2%) productions. Hyoscyamine 6-beta hydroxylase and putrescine N-methyltransferase gene expression involved in the tropane alkaloid biosynthesis were upregulated markedly with 14.2 and 17.1-folds increase after 10 days of clinorotation, respectively. The expressions of jasmonic acid, mitogen-activated protein kinase, and ethylene-responsive element-binding transcription factor were upregulated, and the activity of peroxidase and catalase showed a 72.7 and 80% rise after 10 days. These findings suggest that microgravity can enhance callogenesis by stimulating the ROS level, which can impact the antioxidant enzymes, tropane alkaloid formation, and gene expression.

Effect of silver nanoparticles on tropane alkaloid production of transgenic hairy root cultures of Hyoscyamus muticus L. and their antimicrobial activity.

The utilization of nanotechnology and biotechnology for enhancing the synthesis of plant bioactive chemicals is becoming increasingly common. The hairy root culture technique can be used to increase secondary metabolites such as tropane alkaloids. Agrobacterium was used to induce hairy roots from various explants of Hyoscyamus muticus. The effect of nano-silver particles (AgNPs) at concentrations of 0, 25, 50, 100, and 200 mg/L on tropane alkaloids synthesis, particularly hyoscyamine and scopolamine, was studied in transgenic hairy root cultures. Different types of explants obtained from 10-day-old seedlings of H. muticus were inoculated with two strains of Agrobacterium rhizogenes (15,834 and A4). The antimicrobial activity of an ethanolic extract of AgNPs-induced hairy root cultures of H. muticus was tested. The frequency of hairy roots was higher in hypocotyl, root, leaf, and stem explants treated with A. rhizogenes strain A4 compared to those treated with strain 15,834. In transgenic hairy root cultures, AgNPs application at a concentration of 100 mg/L resulted in the highest total tropane alkaloid production, which exhibited broad-spectrum antimicrobial activity. The study demonstrated the potential of nano-silver as an elicitor for promoting the production of target alkaloids in Hyoscyamus muticus hairy root cultures, which exhibit high biological activity.

Cytotoxic Activity of Tropane Alkaloides of Species of Erythroxylum.

Erythroxylaceae is a family composed of four genera, with Erythroxylum being the only one represented in the Neotropical region. Chemical studies indicate the presence of alkaloids, terpenes, flavonoids, and phenolic compounds as main compounds. The incorporation of cytotoxic activity assays of natural products using cell cultures assists in the selection of potential chemotherapeutic agents. In this work, we describe a revision of the cytotoxicity evaluation studies performed with extracts or pure substances obtained from Erythroxylum species through an integrative review. We found studies that evaluated the cytotoxic activity of 21 species of Erythroxylum against 45 different cell lines. The analysis of the chemical composition of these species shows that the metabolites present in each species influence their cytotoxic potential, especially the presence of disubstituted tropane alkaloid species with the highest cytotoxic potential. MTT and Sulforrodamine B assays were the main in vitro tests used for the evaluation of the cytotoxic activities. From the total species, less than 10% of the Erythroxylum species have already been evaluated for cytotoxic activity. Four of them showed high cytotoxic activity according to the criteria of the NCI plant screening program. Thus, this genus represents a potential source of natural products with antitumor activity.

Aclidinium bromide and formoterol fumarate for the maintenance treatment of chronic obstructive pulmonary disease.

Introduction: Treatment options for COPD have evolved rapidly in the last decade and inhaled bronchodilators have largely supplanted the use of oral bronchodilators because of their increased efficacy and excellent safety with topical delivery to the lung. Recently added to the therapeutic armamentarium are fixed-dose combinations (FDC) of two long acting bronchodilators. LAMAs (long acting muscarinic antagonists) and LABAs (long acting beta agonists) are the main classes available and use different pathways to effectively produce bronchial smooth muscle relaxation.Areas covered: The most recent inhaled FDC LAMA/LABA to come to market is Aclidinium Bromide and Formoterol Fumarate. We searched databases of PubMed, Cochrane Library, and manufacturers' websites and retrieved all the randomized-controlled trials (RCTs) conducted with these drugs up to September 2019.Expert opinion: It is likely that FDCs will become the core of our COPD pharmacotherapy for all but the mildest COPD patients. These individual drugs have excellent efficacy and safety records for the maintenance treatment of COPD. Studies have demonstrated that twice daily treatment with aclidinium/formoterol resulted in significant improvement in lung function and an improved exercise tolerance when compared to placebo. Adverse effects are within the range of what is seen with other LAMA/LABA combinations.

FDA-drug screening identifies deptropine inhibiting hepatitis E virus involving the NF-κB-RIPK1-caspase axis.

Hepatitis E virus (HEV) infection is the leading cause of acute hepatitis worldwide and can develop into chronic infection in immunocompromised patients, promoting the development of effective antiviral therapies. In this study, we performed a screening of a library containing over 1000 FDA-approved drugs. We have identified deptropine, a classical histamine H1 receptor antagonist used to treat asthmatic symptoms, as a potent inhibitor of HEV replication. The anti-HEV activity of deptropine appears dispensable of the histamine pathway, but requires the inhibition on nuclear factor-κB (NF-κB) activity. This further activates caspase mediated by receptor-interacting protein kinase 1 (RIPK1) to restrict HEV replication. Given deptropine being widely used in the clinic, our results warrant further evaluation of its anti-HEV efficacy in future clinical studies. Importantly, the discovery that NF-κB-RIPK1-caspase pathway interferes with HEV infection reveals new insight of HEV-host interactions.

Tropane Alkaloids: Chemistry, Pharmacology, Biosynthesis and Production.

Tropane alkaloids (TA) are valuable secondary plant metabolites which are mostly found in high concentrations in the Solanaceae and Erythroxylaceae families. The TAs, which are characterized by their unique bicyclic tropane ring system, can be divided into three major groups: hyoscyamine and scopolamine, cocaine and calystegines. Although all TAs have the same basic structure, they differ immensely in their biological, chemical and pharmacological properties. Scopolamine, also known as hyoscine, has the largest legitimate market as a pharmacological agent due to its treatment of nausea, vomiting, motion sickness, as well as smooth muscle spasms while cocaine is the 2nd most frequently consumed illicit drug globally. This review provides a comprehensive overview of TAs, highlighting their structural diversity, use in pharmaceutical therapy from both historical and modern perspectives, natural biosynthesis in planta and emerging production possibilities using tissue culture and microbial biosynthesis of these compounds.

A fragment-based approach towards the discovery of N-substituted tropinones as inhibitors of Mycobacterium tuberculosis transcriptional regulator EthR2.

Tuberculosis (TB) caused by the pathogen Mycobacterium tuberculosis, represents one of the most challenging threat to public health worldwide, and with the increasing resistance to approved TB drugs, it is needed to develop new strategies to address this issue. Ethionamide is one of the most widely used drugs for the treatment of multidrug-resistant TB. It is a prodrug that requires activation by mycobacterial monooxygenases to inhibit the enoyl-ACP reductase InhA, which is involved in mycolic acid biosynthesis. Very recently, we identified that inhibition of a transcriptional repressor, termed EthR2, derepresses a new bioactivation pathway that results in the boosting of ethionamide activation. Herein, we describe the identification of potent EthR2 inhibitors using fragment-based screening and structure-based optimization. A target-based screening of a fragment library using thermal shift assay followed by X-ray crystallography identified 5 hits. Rapid optimization of the tropinone chemical series led to compounds with improved in vitro potency.

The discovery and development of aclidinium bromide for the treatment of chronic obstructive pulmonary disease.

INTRODUCTION: Bronchodilators, including long-acting muscarinic receptor antagonists (LAMAs), are a mainstay of the pharmacological treatment of chronic obstructive pulmonary disease (COPD). LAMAs act as bronchodilators principally by antagonizing airway smooth muscle cells M3 muscarinic receptors. Aclidinium bromide is a twice-daily LAMA which was developed to improve on the efficacy and/or safety of previous LAMAs. Area covered: Herein, the authors present the pharmacotherapeutic role of aclidinium in COPD and point out unmet need in this research area. The following aspects are covered: a) the discovery and medicinal chemistry of aclidinium bromide; b) an overview of the market; c) its mechanism of action; d) its pharmacokinetic/pharmacodynamic profile derived from pre-clinical studies; e) the clinical studies which led to its licensing; f) the evidence from meta-analyses; g) the aclidinium/formoterol fixed dose combination for COPD and h) priorities in this area of research. Expert opinion: Aclidinium bromide has the pharmacological properties, safety and efficacy profile and inhaler characteristics which makes it a valuable therapeutic option for pharmacological management of patients with COPD. Due to its rapid biotransformation into inactive metabolites, aclidinium is potentially one of the safest LAMAs. Further head-to-head randomized clinical trials are required to define efficacy and safety of aclidinium when compared to once-daily LAMAs. The clinical relevance of airway anti-remodeling effects of aclidinium has to be defined.

Symptom variability and control in COPD: Advantages of dual bronchodilation therapy.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disorder characterized by usually progressive development of airflow obstruction that is not fully reversible. While most patients will experience symptoms throughout the day or in the morning upon awakening, many patients do not experience their symptoms as constant but report variability in symptoms during the course of the day or over time. Symptom variability adversely affects patients' health status and increases the risk of COPD exacerbations. METHODS: We examined data from the literature on symptom variability and control in patients with COPD, with focus on the use of inhaled bronchodilator therapy with long-acting muscarinic antagonist agents (LAMA) plus long-acting ß2-agonists (LABA); in particular twice-daily fixed-dose combination LAMA/LABA therapy with aclidinium/formoterol. RESULTS: Correct diagnosis and assessment of COPD requires comprehensive clinical and functional evaluation and consideration of individual needs to support the clinical decisions necessary for effective long-term management. Combining bronchodilators from different and complementary pharmacological classes with distinct mechanisms of action can increase the magnitude of bronchodilation as opposed to increasing the dose of a single bronchodilator. CONCLUSIONS: The use of inhaled bronchodilator therapy with LAMA/LABA fixed-dose combinations in patients with stable COPD is supported by current evidence. This treatment approach provides robust effects on lung function and symptom control and may improve patients' adherence to treatment. Administration of the long-acting bronchodilators aclidinium and formoterol as twice daily fixed-dose aclidinium/formoterol 400/12 µg has the potential to control symptoms throughout the 24 h in patients with stable moderate-to-severe COPD.

Evaluation of antidiabetic effect of total calystegines extracted from Hyoscyamus albus.

BACKGROUND: Hyoscyamus albus L. (Solanaceae) an old medicinal plant is a rich source of tropane and nortropane alkaloids which confers to this plant a number of very interesting and beneficial therapeutic effects. PURPOSE: Calystegines that are polyhydroxylated alkaloids and imino-sugars poccess significant glycosidases inhibitory activities and are therefore good candidats for the treatment of diabetes mellitus. STUDY DESIGN: Calystegines extracted from Hyoscyamys albus seeds were tested for teir acute oral toxicity and investigated for their in-vivo antidiabetic effect on Streptozotocine induced diabetes in mice. METHODES: Calystegines were extracted from the seeds plant using an Ion exchange column; the remaining extract was then administrated orally to mice at several single doses for acute toxicity assay. A dose of 130mg/kg streptozotocine was injected to mice to induce diabetes mellitus, and diabetic mice were treated orally during 20days with 10mg/kg and 20mg/kg calystegines and 20mg/kg glibenclamide as the reference drug. RESULTS: Acute oral toxicity showed that calystegines are not toxic up to a dose of 2000mg/kg with absence of any signs of intoxication and damages in Liver and kidney tissues. The nortropane alkaloids markedly reduced blood glucose levels and lipid parameters of diabetic mice to normal concentrations after 20days of treatment at 10mg/kg and 20mg/kg (p<0.05). Histopathological study of diabetic mice pancreas indicated that calystegines of Hyoscyamus albus have minimized streptozotocine damages on ß-cells of islets of langerhans, stimulated ß-cells regeneration and improved with this insulin secretion. CONCLUSION: The findings of this study suggest that calystegines are potent antidiabetic agents with antihyperglicemic and hypolipidemic effects, and a protective fonction on pancreas in streptozotocin induced diabetes in mice.

Evidence of substance P autocrine circuitry that involves TNF-α, IL-6, and PGE2 in endogenous pyrogen-induced fever.

Substance P (SP) is involved in fever that is induced by lipopolysaccharide (LPS) but not by interleukin-1ß or macrophage inflammatory protein-1α. Intracerebroventricular (i.c.v.) administration of the neurokinin-1 (NK1) receptor antagonist SR140333B in rats reduced fever that was induced by an i.c.v. injection of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), corticotropin-releasing factor (CRF), endothelin-1 (ET-1), and morphine (MOR). Furthermore, an i.c.v. injection of SP induced a febrile response that was inhibited by indomethacin concomitant with an increase in PGE2 levels in cerebrospinal fluid. Lipopolysaccharide and PGE2 caused higher expression and internalization of NK1 receptors in the hypothalamus which were prevented by SR140333B. These data suggest that SP is an important mediator of fever, in which it induces a prostaglandin-dependent response and is released after TNF-α, IL-6, PGE2, CRF, endogenous opioids, and ET-1.

Aclidinium bromide inhalation powder for the long-term, maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease including chronic bronchitis and emphysema.

Aclidinium is a twice-daily long-acting muscarinic receptor antagonist (LAMA) with an interesting pharmacological profile. Recent evidence indicates that this LAMA, in addition to causing a significant improvement in lung function and other important supportive outcomes, such as health related quality of life, dyspnea and nighttime/early morning symptoms in patients suffering from COPD, is also able to significantly reduce the rate of exacerbations of any severity, is extremely effective in controlling the COPD symptoms, is able to reduce lung hyperinflation, and has an excellent cardiovascular safety profile. Consequently, aclidinium should be considered a first-line approach at least for the symptomatic treatment of COPD although there are still few head-to-head studies comparing this LAMA with other bronchodilators. In any case, aclidinium can be taken into account in the treatment of different COPD phenotypes (emphysema, chronic bronchitis, exacerbators and patients with overlap COPD asthma).

Combined Effects of Bee Venom Acupuncture and Morphine on Oxaliplatin-Induced Neuropathic Pain in Mice.

Oxaliplatin, a chemotherapeutic drug for colorectal cancer, induces severe peripheral neuropathy. Bee venom acupuncture (BVA) has been used to attenuate pain, and its effect is known to be mediated by spinal noradrenergic and serotonergic receptors. Morphine is a well-known opioid used to treat different types of pain. Here, we investigated whether treatment with a combination of these two agents has an additive effect on oxaliplatin-induced neuropathic pain in mice. To assess cold and mechanical allodynia, acetone and von Frey filament tests were used, respectively. Significant allodynia signs were observed three days after an oxaliplatin injection (6 mg/kg, i.p.). BVA (0.25, 1, and 2.5 mg/kg, s.c., ST36) or morphine (0.5, 2, and 5 mg/kg, i.p.) alone showed dose-dependent anti-allodynic effects. The combination of BVA and morphine at intermediate doses showed a greater and longer effect than either BVA or morphine alone at the highest dose. Intrathecal pretreatment with the opioidergic (naloxone, 20 µg) or 5-HT3 (MDL-72222, 15 µg) receptor antagonist, but not with α2 adrenergic (idazoxan, 10 µg) receptor antagonist, blocked this additive effect. Therefore, we suggest that the combination effect of BVA and morphine is mediated by spinal opioidergic and 5-HT3 receptors and this combination has a robust and enduring analgesic action against oxaliplatin-induced neuropathic pain.

Aclidinium/formoterol fixed-dose combination for the treatment of chronic obstructive pulmonary disease.

This review will be focused on the development of aclidinium bromide/formoterol fumarate (ACLI/FORM) fixed-dose combinations (FDC) that have been granted marketing authorization by the European Commission to be used as a maintenance bronchodilator treatment to relieve symptoms in adult patients with chronic obstructive pulmonary disease (COPD). ACLI/FORM FDC has been studied in 2 pivotal trials involving over 3,400 patients with COPD, in which it was compared with ACLI alone, FORM alone and placebo. The addition of FORM to ACLI resulted in greater bronchodilation than FORM or ACLI alone. ACLI/FORM FDC was also shown to increase the percentage of patients who had an improvement in symptoms and health-related quality of life compared with monotherapies. The frequency of side effects reported with ACLI/FORM FDC was low and their nature did not raise any major safety concern.

Serotonergic mechanism of the relieving effect of bee venom acupuncture on oxaliplatin-induced neuropathic cold allodynia in rats.

BACKGROUND: Oxaliplatin, an important chemotherapy drug for advanced colorectal cancer, often induces peripheral neuropathy, especially cold allodynia. Our previous study showed that bee venom acupuncture (BVA), which has been traditionally used in Korea to treat various pain symptoms, potently relieves oxaliplatin-induced cold allodynia in rats. However, the mechanism for this anti-allodynic effect of BVA remains poorly understood. We investigated whether and how the central serotonergic system, a well-known pathway for acupuncture analgesia, mediates the relieving effect of BVA on cold allodynia in oxaliplatin-injected rats. METHODS: The behavioral signs of cold allodynia in Sprague-Dawley (SD) rats were induced by a single injection of oxaliplatin (6 mg/kg, i.p.). Before and after BVA treatment, the cold allodynia signs were evaluated by immersing the rat's tail into cold water (4°C) and measuring the withdrawal latency. For BVA treatment, a diluted BV (0.25 mg/kg) was subcutaneously administered into Yaoyangguan (GV3) acupoint, which is located between the spinous processes of the fourth and the fifth lumbar vertebra. Serotonin was depleted by a daily injection of DL-p-chlorophenylalanine (PCPA, 150 mg/kg, i.p.) for 3 days. The amount of serotonin in the spinal cord was measured by ELISA. Serotonergic receptor antagonists were administered intraperitoneally or intrathecally before BVA treatment. RESULTS: The serotonin levels in the spinal cord were significantly increased by BVA treatment and such increase was significantly reduced by PCPA. This PCPA pretreatment abolished the relieving effect of BVA on oxaliplatin-induced cold allodynia. Either of methysergide (mixed 5-HT1/5-HT2 receptor antagonist, 1 mg/kg, i.p.) or MDL-72222 (5-HT3 receptor antagonist, 1 mg/kg, i.p) blocked the anti-allodynic effect of BVA. Further, an intrathecal injection of MDL-72222 (12 µg) completely blocked the BVA-induced anti-allodynic action, whereas NAN-190 (5-HT1A receptor antagonist, 15 µg, i.t.) or ketanserin (5-HT2A receptor antagonist, 30 µg, i.t.) did not. CONCLUSIONS: These results suggest that BVA treatment alleviates oxaliplatin-induced acute cold allodynia in rats via activation of the serotonergic system, especially spinal 5-HT3 receptors. Thus, our findings may provide a clinically useful evidence for the application of BVA as an alternative therapeutic option for the management of peripheral neuropathy, a dose-limiting side effect that occurs after an administration of oxaliplatin.

Aclidinium bromide/formoterol fumarate fixed-dose combination for the treatment of chronic obstructive pulmonary disease.

INTRODUCTION: Combining a long-acting ß(2)-agonist (LABA) and a long-acting antimuscarinic agent (LAMA) is potentially a good pharmacological approach to improve clinical results in stable moderate chronic obstructive pulmonary disease (COPD) patients when symptoms are not adequately controlled with tiotropium monotherapy. Consequently, there is a strong interest in developing a LABA/LAMA fixed-dose combination therapy in an attempt to simplify the treatment. AREAS COVERED: An aclidinium bromide/formoterol fumarate fixed-dose combination is under development. The few clinical data at our disposal suggest that the addition of formoterol fumarate to aclidinium bromide results in greater bronchodilation than formoterol fumarate or aclidinium bromide alone. However, a large Phase III program is involving a huge number of patients with moderate-to-severe COPD and consists of large long-term (from 24 to 52 weeks) pivotal clinical trials that have been designed to fulfil both European Medicines Agency (EMA) and Food and Drug Administration (FDA) requirements and are evaluating the efficacy and safety of this fixed-dose combination. EXPERT OPINION: Studies assessing the impact of aclidinium bromide/formoterol fumarate fixed-dose combination on COPD exacerbations, exercise capacity and hospitalisations are clearly needed to better detect its potential effects of disease modification in COPD. Moreover, it seems pragmatic to proceed with its introduction in the market at a highly competitive price.

The potential for aclidinium bromide, a new anticholinergic, in the management of chronic obstructive pulmonary disease.

Long-acting muscarinic antagonists (LAMAs) play a central role in the management of chronic obstructive pulmonary disease (COPD). Previously, only one LAMA (tiotropium) was available for the treatment of COPD, necessitating the development of other therapeutic options due to the heterogeneity of COPD and patient responses to treatment. This article reviews the COPD management potential of aclidinium bromide, a LAMA administered twice daily (BID) by a multidose dry powder inhaler that is indicated for maintenance treatment of COPD. Aclidinium possesses kinetic selectivity for the M(3) versus M(2) receptor and is rapidly hydrolyzed in plasma to two major inactive metabolites, resulting in a low and transient systemic exposure and minimizing the potential for systemic side effects. A pharmacokinetic study with multiple doses of twice-daily aclidinium demonstrated the short half-life of aclidinium in plasma, suggesting that a steady state may be reached as early as the second day postdose. In a phase II study, twice-daily aclidinium 400 µg provided 24-hour bronchodilation, with significant improvements versus tiotropium during the second half of the day. In two phase III studies (ACCORD I and ATTAIN), both aclidinium 200 µg and 400 µg BID provided statistically significant improvements in trough forced expiratory volume in 1 second (FEV(1)) and other related lung function measurements. Improvements in peak FEV(1) on day 1 were comparable to those at study end, demonstrating that aclidinium provides maximal bronchodilation after the first dose that is maintained over time. Health status was significantly improved and dyspnea, nighttime and morning symptoms of COPD were likewise significantly reduced with aclidinium. Numerically greater improvements in efficacy were observed with the 400 µg dose compared with the lower dose, with similar safety profiles between the two doses and a low incidence of anticholinergic side effects. The approved therapeutic dose of aclidinium 400 µg BID is thus an effective new treatment option for patients with COPD.

Advances in the synthesis of calystegines and related products and their biochemical properties.

The revision of the structures and properties of Calystegines shows that they can be regarded as carbohydrate mimics, with related biological activities and peculiar characteristics. Not only they can be isolated from food plants, but they can be obtained from a variety of monosaccharide derivatives and of non-carbohydrate products. Although several synthetic calystegine analogs have been reported as glycosidase inhibitors, new, more potent and effective inhibitors are required.

Molecular mechanism of serotonin transporter inhibition elucidated by a new flexible docking protocol.

The two main groups of antidepressant drugs, the tricyclic antidepressants (TCAs) and the selective serotonin reuptake inhibitors (SSRIs), as well as several other compounds, act by inhibiting the serotonin transporter (SERT). However, the binding mode and molecular mechanism of inhibition in SERT are not fully understood. In this study, five classes of SERT inhibitors were docked into an outward-facing SERT homology model using a new 4D ensemble docking protocol. Unlike other docking protocols, where protein flexibility is not considered or is highly dependent on the ligand structure, flexibility was here obtained by side chain sampling of the amino acids of the binding pocket using biased probability Monte Carlo (BPMC) prior to docking. This resulted in the generation of multiple binding pocket conformations that the ligands were docked into. The docking results showed that the inhibitors were stacked between the aromatic amino acids of the extracellular gate (Y176, F335) presumably preventing its closure. The inhibitors interacted with amino acids in both the putative substrate binding site and more extracellular regions of the protein. A general structure-docking-based pharmacophore model was generated to explain binding of all studied classes of SERT inhibitors. Docking of a test set of actives and decoys furthermore showed that the outward-facing ensemble SERT homology model consistently and selectively scored the majority of active compounds above decoys, which indicates its usefulness in virtual screening.

Effects of neurotoxin - anatoxin-a on common carp (Cyprinus carpio L.) innate immune cells in vitro.

OBJECTIVES: The aim of this study was to determine if cyanoneurotoxin - anatoxin-a (ANTX-a) alters the essential functions of innate immune cells such as free radicals generation in phagocytic cells and phagocytosis. DESIGN: In the experiments pure ANTX-a was used at concentrations of 0.01, 0.05, 0.1 and 1 µg/ml RPMI-1640 medium. Phagocytes were isolated from carp blood and pronephros. Relative changes in intracellular total free radical presence in fish phagocytes were monitored using a fluorescent probe, dichlorodihydrofluorescin DiOxyQ (DCFH-DiOxyQ) which detects hydrogen peroxide (H2O2), nitric oxide (NO), peroxyl radical and peroxynitrite anion. Phagocytic activity of fish leukocytes was analyzed with a Vybrant phagocytosis assay kit. RESULTS: The H2O2 level generated in response to ANTX-a at the highest used concentration was significantly suppressed in pronephros but not in blood phagocytes. Moreover, it was observed that generation of superoxide radicals and nitrite formation was significantly increased in blood and pronephros phagocytes after incubation with lower concentrations of the neurotoxin. The phagocytosis of fish leukocytes was significantly reduced at the two highest used toxin concentrations (0.1 and 1 µg/ml medium). CONCLUSION: This findings suggests that ANTX-a could change innate immunity and reduced adaptive immunity after stress induced by cyanobacterial blooms.