Presence Of Serotonin Research Articles

Vasorelaxant effect of phenylpropanoids: Methyl eugenol and eugenol in human umbilical cord vein

Methyl-eugenol (ME) and eugenol (EUG) are phenylpropanoids with vasodilatory effects. While EUG's vasorelaxant effect in human umbilical artery (HUA) is known, their action in veins is unclear. This study aimed to evaluate ME and EUG in human umbilical vein (HUV). Isolated HUV underwent tension recordings. ME and EUG caused 100 % relaxation in HUV, with EC50 values corresponding to: 174.3 ± 7.3 and 217.3 ± 6.2 µM for ME and EUG respectively in presence of K+; 362.3 ± 5.4 and 227.7 ± 4.9 µM for ME and EUG respectively and in presence of serotonin (5-HT). It was observed that in presence of BaCl2 and CaCl2 evoked contractions, ME (800 and 1000 µM) and EUG (1000 and 1400 µM) prevent the contractions. In presence of K+ channel blockers it was observed that ME promoted relaxation compared to its control, except in presence of 4-AP, suggesting a possible Ca2+-dependent K+ channel activation for this molecule; EUG increased all EC50 in presence of the K+ blockers except in presence of TEA 1 mM. Greater pharmacological potency was observed for ME. This study highlights natural substances' effects on HUV contractile parameters, suggesting ME and EUG as potential vasodilators in maintaining fetal oxygenation and venous flow during gestational hypertensive syndromes.

Serotonin system in tunicates: insight from morphological and molecular approaches

Serotonin (5 hydroxytryptamine, 5-HT) is a biogenic amine of ancient origin that is widespread among animals. It plays multiple roles during development and in adults as neurotransmitter at synaptic level and neuro hormone controlling complex behaviors in both vertebrates and invertebrates. Tunicates occupy a key phylogenetic position to understand the evolution of serotonin functions since they are the sister group of vertebrates. The presence of serotonin in tunicates was first reported in adults of the ascidian Ciona robusta (formerly Ciona intestinalis) in the 1946. Since then, serotonin systems have been in many tunicate species and its functions during embryogenesis and metamorphosis explored. We reviewed the current knowledge about serotonin in these animals first by comparing its presence and localization in larvae and adults of different species. Then, we focused on the model organism Ciona for which data regarding sequences and expression patterns of genes involved in serotonin synthesis and function have been reported. Overall, we provided a comprehensive overview of serotonergic machinery in tunicates and gave hints for future studies in this field.

Serotonin and Interleukin 10 Can Influence the Blood and Urine Viscosity in Gestational Diabetes Mellitus and Pregnancy-Specific Urinary Incontinence.

Serotonin and interleukin 10 (IL-10) may play a role in gestational diabetes mellitus. Hyperglycemic environment, the detrusor musculature of the bladder and pelvic floor muscles may become damaged, leading to urination problems and urine viscosity in pregnant women with gestational diabetes mellitus and pregnancy-specific urinary incontinence. Urine and blood samples were collected from pregnant women between 24 and 28 weeks of gestation. The serotonin concentration and cytokine IL-10 levels were evaluated in plasma and urine. In the total blood and urine, the viscosity was evaluated in the presence and absence of exogenous serotonin and IL-10. The plasma serotonin levels decreased, while the urine serotonin levels increased in the normoglycemic incontinent (NG-I), hyperglycemic continent (GDM-C), and hyperglycemic incontinent (GDM-I) groups. The IL-10 in the plasma decreased in the GDM-I group and was higher in the urine in the NG-I and GDM-I groups. The blood viscosity was higher, independently of urinary incontinence, in the GDM groups. The serotonin increased the blood viscosity from women with GDM-C and urine in the NG-I, GDM-C, and GDM-I groups. Blood and urine in the presence of IL-10 showed a similar viscosity in all groups studied. Also, no difference was observed in the viscosity in either the blood or urine when in the presence of serotonin and IL-10. These findings suggest that serotonin and IL-10 have the potential to reduce blood viscosity in pregnant women with gestational diabetes and specific urinary incontinence, maintaining values similar to those in normoglycemic women's blood.

A Novel Electrochemical Sensor Based on Multi Walled Carbon Nano Tubes/Poly (Evans Blue) Composite for the Determination of Dopamine in Presence of 5-HT and FA

A new sensor was fabricated by electrochemical polymerization of Evans blue (EB) followed by deposition of multi walled carbon nano tubes (MWCNTs) on glassy carbon electrode (GCE). The developed electrode was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed for analyzing neurotransmitter Dopamine (DA) drug and its simultaneous determination in presence of serotonin (5-HT) and folic acid (FA) with the help of differential pulse voltammetry (DPV) technique. The effect of pH of phosphate buffer solution (PBS) was studied and pH - 5.0 was found to be an optimum pH value. In the present investigation the kinetic parameters, such as charge transfer coefficient, number of electrons and rate constant values were evaluated. The voltammetric peak currents showed a linear response for DA concentrations from 0.5 to 100 µM and from the linear relationship the limit of detection (LOD) and limit of quantification (LOQ), values were as evaluated as 0.54 µM and 1.8 µM respectively. The fabricated electrode showed good stability, reproducibility and sensitivity. The practical application of the developed sensor in determining DA levels in pharmaceutical formulation was successfully monitored.

Differences in responses of premotor interneurons to serotonin and 5-hydroxytryptophan, a precursor for serotonin synthesis, in naive and trained snails

This study investigated the responses of premotor interneurons LPa3 and RPa3 of the snails to applications of serotonin and 5-hydroxytryptophan (5-HTP), a precursor for serotonin synthesis, as ingredients of the broth that bathes the central nervous system of naive snails and snails after the formation of long-term sensitization. Measurements of the electrical characteristics have shown that a membrane potential of interneurons LPa3 and RPa3 in naive snails was significantly depolarized (3.7 mV) in the presence of serotonin, while the threshold potential was increased (unsupported hypothesis). The similar pattern was observed in the presence of 5-hydroxytryptophan: true depolarization to 3.1 mV occurred in interneurons until reaching the unreliable rise in the threshold potential inducing an action potential. It was found that application of serotonin causes a significant decrease in the membrane potential of interneurons LPa3 and RPa3 of trained snails (depolarization to 4.6 mV) and the unreliable increase in the threshold potential of premotor interneurons (0.9 mV). In contrast, application of 5-hydroxytryptophan causes an unreliable increase (2.5 mV) of the membrane potential and also an unreliable increase (0.8 mV) in the threshold potential.

Comparative morphology of serotonin-immunoreactive neurons innervating the central complex in the brain of dicondylian insects.

Serotonin (5-hydroxytryptamine) acts as a widespread neuromodulator in the nervous system of vertebrates and invertebrates. In insects, it promotes feeding, enhances olfactory sensitivity, modulates aggressive behavior, and, in the central complex of Drosophila, serves a role in sleep homeostasis. In addition to a role in sleep-wake regulation, the central complex has a prominent role in spatial orientation, goal-directed locomotion, and navigation vector memory. To further understand the role of serotonergic signaling in this brain area, we analyzed the distribution and identity of serotonin-immunoreactive neurons across a wide range of insect species. While one bilateral pair of tangential neurons innervating the central body was present in all species studied, a second type was labeled in all neopterans but not in dragonflies and firebrats. Both cell types show conserved major fiber trajectories but taxon-specific differences in dendritic targets outside the central body and axonal terminals in the central body, noduli, and lateral accessory lobes. In addition, numerous tangential neurons of the protocerebral bridge were labeled in all studied polyneopteran species except for Phasmatodea, but not in Holometabola. Lepidoptera and Diptera showed additional labeling of two bilateral pairs of neurons of a third type. The presence of serotonin in systems of columnar neurons apparently evolved independently in dragonflies and desert locusts. The data suggest distinct evolutionary changes in the composition of serotonin-immunolabeled neurons of the central complex and provides a promising basis for a phylogenetic study in a wider range of arthropod species.

Zinc Phosphate-Incorporated Niobium Carbide as an Effective Electrocatalyst for Ultrasensitive and Selective Monitoring of Monoamine Neurotransmitter

The earth-abundant, cost-effective, easier preparation of zinc phosphate eases its diverse implications in recent applications. We have synthesized two-dimensional niobium carbide (NbC)-encapsulated zinc phosphate Zn2P2O7. The physicochemical characteristics were determined, which demonstrate pure crystallinity and good integration of the composite samples. To improve and develop a sustainable environment, the Zn2P2O7/NbC composite will be an efficient material. The detection of pharmaceutical compounds is highly preferable in clinical approaches. The importance of serotonin (SER) has empowered sensor development with the fabricated Zn2P2O7-based electrode. The synergistic action prevailing in the composite material endowed the active sites with improved electrocatalytic activity. The increased addition of SER was acquired with two linear ranges from 0.019 to 563.68 μM. The lower detection limit was obtained as 0.0055 μM toward the exposed SER addition at a lower concentration, and the sensitivity was about 7.72 μA μM–1 cm–2. Analyses of other parameters such as repeatability, reproducibility, and stability indicate the excellent performance of the electrode. The presence of SER in human urine and blood serum samples can be identified very easily, and hence, analysis of real samples was performed. The as-obtained recovery results stated the excellent performance of the fabricated sensor.

Construction of the Embedded Li4Ti5O12-MWCNTs Nanocomposite Electrode for Diverse Applications in Electrochemical Sensing and Rechargeable Battery

Here, a facile and cost-effective hydrothermal method was used to synthesize lithium titanate (Li4Ti5O12, (LTO))-multiwalled carbon nanotubes (MWCNTs) nanocomposite for the bifunctional property of sensing and energy storage applications. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used to confirm the formation of LTO-MWCNTs nanocomposite. The electrochemical sensing of Dopamine (DA) at LTO-MWCNTs modified glassy carbon electrode (GCE) was studied. The modified electrode demonstrated remarkable sensitivity, with a detection limit of 1.54 µM of DA. Moreover, the modified electrode was used for the selective measurement of DA in presence of 5-hydroxytryptamine (5-HT) and folic acid (FA) without interfering with their respective potentials. The modified electrode was used to quantify the DA in commercial DA injection sample with satisfactory recoveries. The modified LTO-MWCNTs/GCE electrode showed acceptable reproducibility and excellent stability. In addition, LTO-MWCNTs nanocomposite electrode delivered a high initial discharge capacity of 176 mAh g− 1 at a charge-discharge rate of 1 C in a constant-current charge-discharge experiment, which proved its efficacy as a rechargeable battery anode material.

Gold nanoparticle assimilated polymer layer on carbon nanotube matrices for sensitive detection of serotonin in presence of dopamine in-vitro

A biosensor has been developed based on simple electrodeposition of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) and gold nanoparticles (nAu) on functionalized carbon nanotube (f-CNT) coated glassy carbon electrode for sensitive detection of an important neurotransmitter, serotonin (5-HT). The glassy carbon electrode was coated with f-CNT, and then deposition of a thin layer of poly-AMT (pAMT) followed by nAu was electrochemically carried out by applying an oxidation potential first and then a reduction potential. The fabricated sensor has been characterized by scanning electron microscopy (SEM) and EDX to realize the sensor system’s surface morphological and chemical properties. Electrochemical responses of serotonin at nAu/pAMT/f-CNT/GCE sensor were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV) and i-t amperometric analysis. The fabricated nAu/pAMT/f-CNT electrode showed high electrocatalytic performance towards the oxidation of 5-HT compared to pAMT/f-CNT and bare GCE, and it exhibited the highest oxidation peak current. At the optimized conditions of SWV, a linear calibration plot was achieved between the peak current against 5-HT concentration, and the detection limit was as low as 7.8 nM. The nAu/pAMT incorporated f-CNT electrode has been investigated for selectivity towards 5-HT in presence of an important electroactive interferent, dopamine (DA). We determined 5-HT from human serum for the practical utility of the sensor and have observed good recovery limits of 96.3 to 103.6 %.

Decreased serotonin transporter activity in the mitral valve contributes to progression of degenerative mitral regurgitation.

Degenerative mitral valve (MV) regurgitation (MR) is a highly prevalent heart disease that requires surgery in severe cases. Here, we show that a decrease in the activity of the serotonin transporter (SERT) accelerates MV remodeling and progression to MR. Through studies of a population of patients with MR, we show that selective serotonin reuptake inhibitor (SSRI) use and SERT promoter polymorphism 5-HTTLPR LL genotype were associated with MV surgery at younger age. Functional characterization of 122 human MV samples, in conjunction with in vivo studies in SERT-/- mice and wild-type mice treated with the SSRI fluoxetine, showed that diminished SERT activity in MV interstitial cells (MVICs) contributed to the pathophysiology of MR through enhanced serotonin receptor (HTR) signaling. SERT activity was decreased in LL MVICs partially because of diminished membrane localization of SERT. In mice, fluoxetine treatment or SERT knockdown resulted in thickened MV leaflets. Similarly, silencing of SERT in normal human MVICs led to up-regulation of transforming growth factor β1 (TGFβ1) and collagen (COL1A1) in the presence of serotonin. In addition, treatment of MVICs with fluoxetine not only directly inhibited SERT activity but also decreased SERT expression and increased HTR2B expression. Fluoxetine treatment and LL genotype were also associated with increased COL1A1 expression in the presence of serotonin in MVICs, and these effects were attenuated by HTR2B inhibition. These results suggest that assessment of both 5-HTTLPR genotype and SERT-inhibiting treatments may be useful tools to risk-stratify patients with MV disease to estimate the likelihood of rapid disease progression.

Health advisory: melatonin use in children.

Free AccessLetters to the EditorHealth advisory: melatonin use in children Muhammad Adeel Rishi, MD, Seema Khosla, MD, Shannon S. Sullivan, MD, for the Public Safety and the Public Awareness Advisory Committees of the American Academy of Sleep Medicine Muhammad Adeel Rishi, MD Address correspondence to: Muhammad Adeel Rishi, MD, Indiana University School of Medicine, 340 W. 10th St, Indianapolis, IN 46077; Email: E-mail Address: [email protected] Indiana University School of Medicine, Indianapolis, Indiana; Search for more papers by this author , Seema Khosla, MD North Dakota Center for Sleep, Fargo, North Dakota; Search for more papers by this author , Shannon S. Sullivan, MD Division of Pulmonary, Asthma, and Sleep Medicine, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California Search for more papers by this author , for the Public Safety and the Public Awareness Advisory Committees of the American Academy of Sleep Medicine Search for more papers by this author Published Online:February 1, 2023https://doi.org/10.5664/jcsm.10332SectionsPDF ShareShare onFacebookTwitterLinkedInRedditEmail ToolsAdd to favoritesDownload CitationsTrack Citations AboutINTRODUCTIONAmong US adults and children, melatonin supplement consumption significantly increased from 1999 to 2020.1,2 The growing use of melatonin in children has occurred despite incomplete safety and efficacy data, reports demonstrating inconsistent dose labeling, and an increase in accidental pediatric melatonin ingestions.2,3While the perception may be that melatonin is natural and therefore safe, a recent analysis published in Morbidity and Mortality Weekly Report indicates that the annual pediatric ingestions of melatonin have risen from 8,000 in 2012 to more than 52,000 in 2021, and 15% of children with overdoses were hospitalized.2Adding to the misperception of safety, melatonin is marketed as a dietary supplement, with reduced regulatory oversight compared with pharmaceuticals.4 Variation in melatonin content is reported to be −83% to +478% of labeled content,5 with the most variability found in chewable tablets, such as those in pediatric formulations. Additionally, these supplements may be candy-like and colorful, appealing to children in particular. Melatonin is also relatively inexpensive and widely available, from grocery stores to warehouse stores where it may be sold in large quantities.With this background, the Public Safety Committee and Public Awareness Advisory Committee of the American Academy of Sleep Medicine developed a health advisory addressing the use of melatonin in children.6 The Academy advises that melatonin should be handled as any other medication and kept out of reach of children, and importantly, before starting melatonin or any supplement for their children, that parents discuss this with a pediatric health care professional to assess whether behavioral strategies may be more appropriate. Finally, if melatonin is used, a practical suggestion is to look for products with the US Pharmacopeia verified (USP verified) mark, which indicates that product was produced in a facility following Good Manufacturing Practice (GMP) standards.As the use and misuse of melatonin increases, it is important to emphasize that nonpharmacologic management techniques have been well studied and are considered safe and effective for pediatric insomnia.7 We also call for ongoing public and provider education about the appropriate role for melatonin use, and we encourage health care providers to engage with their patients about usage of melatonin.DISCLOSURE STATEMENTAll authors have seen and approved this manuscript. The authors report no conflicts of interest.REFERENCES1. Li J, Somers VK, Xu H, Lopez-Jimenez F, Covassin N. Trends in use of melatonin supplements among US adults, 1999–2018. JAMA. 2022;327(5):483–485 . CrossrefGoogle Scholar2. Lelak K, Vohra V, Neuman MI, Toce MS, Sethuraman U. Pediatric melatonin ingestions—United States, 2012–2021. MMWR Morb Mortal Wkly Rep. 2022;71(22):725–729 . CrossrefGoogle Scholar3. Lelak KA, Vohra V, Neuman MI, Farooqi A, Toce MS, Sethuraman U. COVID-19 and pediatric ingestions. Pediatrics. 2021;148(1):e2021051001 . CrossrefGoogle Scholar4. Grigg-Damberger MM, Ianakieva D. Poor quality control of over-the-counter melatonin: what they say is often not what you get. J Clin Sleep Med. 2017;13(2):163–165 . LinkGoogle Scholar5. Erland LA, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med. 2017;13(2):275–281 . LinkGoogle Scholar6. American Academy of Sleep Medicine. Health Advisory: Melatonin Use in Children and Adolescents. Adopted September 9, 2022. https://aasm.org/advocacy/position-statements/melatonin-use-in-children-and-adolescents-health-advisory/. Accessed September 20, 2022. Google Scholar7. Mindell JA, Emslie G, Blumer J, et al.. Pharmacologic management of insomnia in children and adolescents: consensus statement. Pediatrics. 2006;117(6):e1223–e1232 . CrossrefGoogle Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 19 • Issue 2 • February 1, 2023ISSN (print): 1550-9389ISSN (online): 1550-9397Frequency: Monthly Metrics History Submitted for publicationSeptember 22, 2022Submitted in final revised formSeptember 30, 2022Accepted for publicationOctober 3, 2022Published onlineFebruary 1, 2023 Information© 2023 American Academy of Sleep MedicinePDF download

Evaluation of biogenic amines, phenolic and antioxidant compounds in “Senatore Cappelli” durum wheat products

“Senatore Cappelli” durum wheat products have attracted much interest in recent years because of their nutritional and quality characteristics, as they are a source of different bioactive compounds (i.e., polyphenols, serotonin, etc.). This study examines the content of biogenic amines (BAs), ß-phenylethylamine, putrescine, cadaverine, histamine, tyramine, serotonin and spermine, total polyphenols content (TPC) and antioxidant capacity (AC) of different products of the “Senatore Cappelli” durum wheat chain (SCDW): seeds, chaff, flour, and pasta. BAs were detected and quantified by HPLC-RF. While UV-Vis spectrophotometer was applied for the determination of TPC and AC. All BAs investigated were found in the samples analyzed at different concentrations. Particularly, the presence of serotonin (21.71 ± 0.15 - 42.66 ±0 .03 mg/kg), an BA with positive effects on human health, was found in all SCDW products. In addition, a higher concentration in SCDW pasta of histamine (36.37 ± 0.01 mg/kg) and cadaverine (11.43 ± 0.36 mg/kg), which are the main BAs involved in allergic processes, compared to the other SCDW products was found.

Histamine/H1 receptor signaling in the parafacial region increases activity of chemosensitive neurons and respiratory activity in rats.

Histaminergic neurons of the tuberomammillary nucleus (TMN) are pH sensitive and contribute to CO2/H+-dependent behaviors including arousal and respiratory activity. TMN neurons project to several respiratory centers including the ventral parafacial region (pF), where the chemosensitive retrotrapezoid (RTN) neurons are located, and since RTN neurons are an important source of CO2/H+-dependent respiratory drive, we wondered whether histamine contributes to RTN chemoreception. To test this, we characterized effects of histamine on mean arterial pressure (MAP) and diaphragm muscle activity (DIAEMG) in urethane-anesthetized, vagotomized, and artificially ventilated male Wistar rats. Unilateral injection of histamine in the pF (25 mM) increased DIAEMG amplitude without changing DIAEMG frequency and MAP. Bilateral injections of the H1 receptor antagonist diphenhydramine hydrochloride (DPH; 0.5 mM) into the pF decreased baseline DIAEMG amplitude and frequency and MAP. Despite the strong inhibitory effect of DPH on baseline breathing, the hypercapnic ventilatory response was preserved under these experimental conditions. At the cellular level, chemosensitive RTN neurons showed a dose-dependent excitatory response to histamine that was blunted by DPH and mimicked by H1 receptor agonist 2-pyridylethylamine dihydrochloride (2PYEA) both under control conditions and when fast neurotransmitter receptors were blocked. We also tested effects of 2PYEA in the presence of serotonin, another wake-on neurotransmitter that activates RTN chemoreceptors partly by activation of Gq-coupled receptors. We found that the response to 2PYEA was diminished in serotonin, suggesting that RTN neurons have a limited capacity to respond to multiple Gq-coupled modulators. These results suggest that histamine can modulate breathing at the pF level by a mechanism involving H1 receptors.NEW & NOTEWORTHY Histamine/H1 receptor signaling activates retrotrapezoid (RTN) neurons under control conditions and to a lesser extent in the presence of serotonin. These results suggest that RTN neurons have a limited capacity to respond to simultaneous activation of multiple Gq-coupled receptors.

Experimental silicon intake with drinking water affects the serotonin supply in the digestive tract of laboratory rats

Serotonin plays an important role in the function of the gastrointestinal tract. Currently, the dietary supplementation containing silicon becomes very popular trend, even for the long‐time reception. The effect of dietary silicon intake on serotonin level in small intestine (SI) and liver are not well understood. In this study we checked the impact of water‐soluble silicon compounds intake on the serotonin supply in structures of SI and liver.The study was curry out on 2‐months‐old male rats, which were divided on two groups: control group (n=10) received ad libitum drinking water; experimental group (n=10) received ad libitum the same water containing sodium metasilicate (Na2SiO3x9H2O, 10 mg/liter) for 2 and 9 months. Five animals from each group were sacrificed 2 months after beginning of the experiment, the rest – 9 months later. All manipulations with experimental animals were performed in accordance with the Regulations on Animal Experiments and in Compliance with European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes. The liver and pieces of small intestine (10 sm below the hepatoduodenal ligament) were isolated after decapitation and immediately frozen for the luminescence‐histochemical study. The presence of serotonin was detected on 10 µm cryosections using Falck‐Hillarp method modified by Krokhina (1982). The sections were examined under the Leica D1000 fluorescent microscope (360 nm of exciting light length, 525 nm of emission wavelength). Spectrofluorimetry was used to identify and quantify the serotonin levels in cytoplasm of follow structures: epithelial cells of mucous membrane, in the macrophages of the lamina propria of SI, in hepatocytes and luminescent granular cells (LGC) of liver.There are no significant differences in intensity of serotonin fluorescence in investigates structures of SI between control and experimental groups were detected after 2 months from the beginning of experiments. However, in liver the value of serotonin fluorescence intensity in the wall of the central veins and hepatocytes of rats in experimental group was elevated in 1.2 times, in LGC and their microenvironment – 1.5 times (р < 0,05) compared to the control group.The 9‐months silicon supplementation leads to the up‐regulation of serotonin fluorescence intensity in structures of SI: in cytoplasm of epithelial cells of the mucous membrane, in macrophages of the lamina propria and in their microenvironment, by 1.2 and 1.4 times, respectively (p < 0.05). The intensity of serotonin value in cytoplasm of hepatocytes and in the wall of the central veins of liver increased by 1.2 and 1.1 times, respectively (p < 0.05), in LGC and their microenvironment – by 1.3 and 1.7 times, respectively (p < 0.05).We concluded that (i) the liver is a little more sensitive to the intake of silicon with drinking water than the structures of SI; (ii) the silicon supplementation generally increases the intensity of serotonin content in structures of liver and SI, which can be explained by age‐related changes in these organs.

Detection of Serotonin, Melatonin, and Their Metabolites in Honey.

Melatonin and serotonin, products of tryptophan metabolism, are endogenous neurotransmitters and hormones. We have identified and quantified these metabolites in natural honey from Australia, USA, and Poland using a Xevo G2 XS qTof LC-MS. To help ensure correct product identification, some samples were prepurified by RP-HPLC based on the retention times of standards, prior to LC-MS. The concentrations of the metabolites of interest depended on the source of the honey. For Australian honey, levels for melatonin and 2-hydroxymelatonin were 0.91 and 0.68 ng/g, respectively. Melatonin was detected in one brand of US commercial honey at 0.48 ng/g, while a second brand contained serotonin at 88.2 ng/g. In Polish natural honey, 20.6 ng/g of serotonin and 40.8 ng/g of N-acetylserotonin (NAS) were detected, while in Polish commercial honey 25.9 ng/g of serotonin and 7.30 ng/g of NAS were present. We suggest that addictive and health-related properties of honey may be in part dependent on the presence of serotonin, melatonin, and their metabolites, and that these compounds may play a role in the colony activities of bees.

Pico Molar Sensing of Dopamine in Presence of Serotonin Using BaMnO3/Carbon Nanostructures

A novel electrochemical sensor for dopamine (DA) in the presence of serotonin (ST) was fabricated by modifying a glassy carbon electrode with BaMnO3 and super P carbon black. The modifier, BaMnO3 was synthesized by a co-precipitation method and subsequent calcination. The formation of a pure crystalline form of BaMnO3 was ensured during synthesis and verified by characterization techniques such as powder X-ray diffraction, infrared spectroscopy, Raman, thermogravimetry, Ultraviolet–visible spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray analysis. 5 mg of BaMnO3 was sufficient to allow sensor development. The sensor was characterized by electrochemical impedance spectra and cyclic voltammetry studies. The mechanism of oxidation of DA and ST at the sensor is proposed based on experimental findings. Trace level determination of DA and ST was successfully carried out using the sensor. The electrochemical oxidation of DA and ST are completely independent. The limit of detection of DA and ST are 50 pM and 5 nM respectively. The DA has a linear dynamic range (LDR) of 0.1 to 300 nM and ST has a LDR of 10 to 2300 nM. The practical utility of the sensor was demonstrated by calculating the recovery of DA in human blood serum and urine.

The Synergistic role of serotonin and melatonin during temperature stress in promoting cell division, ethylene and isoflavones biosynthesis in Glycine max

Serotonin (SER) and melatonin (MEL) are signalling molecules involved in signalling in various stress response mechanisms in plants. However, their role and molecular mechanism in the accumulation of isoflavones and biomass under temperature stress are not clearly defined. To explicate their function, SER and MEL at different ratios were applied to the in vitro cultures of soybean at 16, 24, and 32 °C and were analyzed for the accumulation of bioactive compounds, isoflavones content, and culture biomass followed by transcript levels of cell division, isoflavones, and ethylene biosynthesis genes. An increase in biomass, total phenolics, total flavonoids, and different forms of isoflavones content was evident in the treatments. The expression level of critical genes of isoflavone (chalcone synthase, chalcone reductase, chalcone isomerase, and isoflavone synthase), ethylene (s-adenosyl methionine and 1-aminocyclopropane-1-carboxylic acid oxidase), cell division (cyclin and cyclin-dependent kinase), and MEL biosynthesis genes (acetyl serotonin O-methyltransferase and serotonin N-acetyltransferase) and transcription factors (melatonin 2 hydroxylase, myeloblastosis like protein) were co-expressed during temperature stress in the presence of SER and MEL. At 32 °C, the SER and MEL application showed maximum biomass and isoflavones content and was substantiated with the corresponding gene expression. We hypothesize that the SER and MEL ratio may play a role in increasing the biomass and isoflavones content under temperature stress in soybean cell culture.

Altered Membrane Mechanics Provides a Receptor-Independent Pathway for Serotonin Action.

Serotonin, an important signaling molecule in humans, has an unexpectedly high lipid membrane affinity. The significance of this finding has evoked considerable speculation. Here we show that membrane binding by serotonin can directly modulate membrane properties and cellular function, providing an activity pathway completely independent of serotonin receptors. Atomic force microscopy shows that serotonin makes artificial lipid bilayers softer, and induces nucleation of liquid disordered domains inside the raft‐like liquid‐ordered domains. Solid‐state NMR spectroscopy corroborates this data at the atomic level, revealing a homogeneous decrease in the order parameter of the lipid chains in the presence of serotonin. In the RN46A immortalized serotonergic neuronal cell line, extracellular serotonin enhances transferrin receptor endocytosis, even in the presence of broad‐spectrum serotonin receptor and transporter inhibitors. Similarly, it increases the membrane binding and internalization of oligomeric peptides. Our results uncover a mode of serotonin–membrane interaction that can potentiate key cellular processes in a receptor‐independent fashion.

Serotonin contributes to the in vitro production of a biomimetic enamel-like material from reprogrammed oral epithelial keratinocytes.

To evaluate the role of serotonin in the development of a biomimetic enamel-like material in vitro. Immortalized murine oral keratinocytes raised from adult mouse mucosa were cultured in vitro. In addition, specimens incorporating molar tooth buds harvested from mice were included in our studies. We used cell-based scaffold-free tissue engineering to assemble three-dimensional (3D) organoids into complex tissue constructs that closely emulate the complexity of adult enamel. We also analysed mouse molar specimens using immunohistochemistry for serotonin expression as well as its cognate receptor. TGF-β1-reprogrammed murine oral keratinocytes formed organoids that laid down an amelogenin-rich protein matrix when grown as three-dimensional (3D) cultures in the presence of serotonin. Following mineralization, the newly formed crystals were densified under pressure and vacuum to produce a biomimetic enamel-like material that demonstrated parallel alignment of hydroxyapatite crystals with some interspaced residual organoid matter into enamel prism-like structures conferring size, mechanical properties comparable to tooth enamel, including light translucency. Serotonin expression was localized by immunohistochemistry proximal to the enamel organ of developing molar buds. Moreover, serotonin HTRb2 receptor expression was localized on ameloblasts within the enamel organ proximal to the area where serotonin was immunolocalized. Our results demonstrate that serotonin is inductive in the development of a biomimetic enamel-like material from reprogrammed oral epithelial keratinocytes in vitro. The facileness of harvesting adult somatic cells together with the versatility of our approach offers exciting opportunities to address regenerative challenges linked to lost enamel.

Covalent organic frameworks (COF-300-AR) with unique catalytic performance in luminol chemiluminescence for sensitive detection of serotonin

The covalent organic frameworks (COFs), as excellently desirable nanomaterials for catalytic applications, used in the chemiluminescence (CL) system is far from fully developed. Herein, in this work, the COF-300-AR as a catalyst notably increasing the CL intensity of luminol system in alkaline solution with no extra oxidants were first put forward. The presence of serotonin can dramatically decrease the CL of luminol-COF-300-AR system, thus causing the concentration-dependent change of the quenching efficiency (I0/IS). By utilizing these phenomena, the excellent CL sensing method was established for the detection of serotonin by coupling with flow injection analysis (FIA). Under the optimum conditions, the CL quenching efficiency had a linear increase with the concentration of serotonin ranging from 10 nM to 800 nM, and the limit of detection was 2.3 nM (S/N = 3). The method was utilized for the detection of serotonin in rat serum sample with satisfactory results.