In vitro effects of the combination of serotonin, selenium, zinc, and vitamins D and E supplementation on human sperm motility and reactive oxygen species production.

Infertility affects 15% of all couples worldwide and 50% of cases of infertility are solely due to male factors. A decrease in motility in the semen is considered one of the main factors that is directly related to infertility. The use of supplementation to improve the overall sperm quality has become increasingly popular worldwide. The purpose of this study was to evaluate whether sperm motility was affected by the combination of serotonin (5-HT), selenium (Se), zinc (Zn), and vitamins D, and E supplementation. Semen samples were incubated for 75 min at 37°C in medium containing varying concentrations of 5-HT, Se, Zn, vitamin D, and E. 5-HT (200 µM), Se (2 µg/ml), Zn (10 µg/ml), vitamin D (100 nM), and vitamin E (2 mmol) have also been shown to increase progressive sperm motility. Three different mixtures of supplements were also tested for their combined effects on sperm motility and reactive oxygen species (ROS) production. While the total motility in the control group was 71.96%, this was found to increase to 82.85% in the first mixture. In contrast the average ROS level was 8.97% in the control group and decreased to 4.23% in the first mixture. Inclusion of a supplement cocktail (5-HT, Se, Zn, vitamins D and E) in sperm processing and culture medium could create an overall improvement in sperm motility while decreasing ROS levels during the incubation period. These molecules may enhance the success of assisted reproduction techniques when present in sperm preparation medium.

The effects of Ellagic acid supplementation on neurotrophic, inflammation, and oxidative stress factors, and indoleamine 2, 3-dioxygenase gene expression in multiple sclerosis patients with mild to moderate depressive symptoms: A randomized, triple-blind, placebo-controlled trial.

BACKGROUND: Depression is one of the most common psychological disorders among multiple sclerosis (MS) patients that characterized as the first symptoms. Ellagic acid is a natural polyphenol that may have neuroprotective properties through antioxidant, anti-inflammatory, and immunomodulatory effects. PURPOSE: The aim of the present study was to investigate the effects of Ellagic acid on circulating levels of brain derived neurotrophic factor (BDNF), interferon-γ (IFN-Æ´), nitric oxide (NO), nuclear factor erythroid-2-related factor 2 (Nrf2), cortisol, serotonergic system, and indoleamine 2, 3-dioxygenase (IDO) gene expression in MS patients with mild to moderate depressive symptoms. STUDY DESIGN: A randomized triple-blind clinical trial. METHODS: The eligible patients according to the inclusion criteria were randomly divided into two groups: either 180 mg Ellagic acid (Axenic company) (n = 25) or 180 mg maltodextrin (n = 25) group for 12 weeks. The Ellagic acid supplement were identical to placebo in shape, color and odor. Serum BDNF, NO, Nrf2, cortisol, serotonin, and IFN-Æ´ were measured by ELISA kit in the baseline and end of the study. Also, demographic characteristics, anthropometric measurements, physical activity, food intake, Beck Depression Inventory-II (BDI-II) and expanding disability status scale (EDSS) questionnaires, as well as IDO gene expression were assessed. SPSS software version 24 was used for statistical analysis. RESULTS: Fifty patients were evaluated, and a significant decrease in BDI-II (p = 0.001), IFN-Æ´ (p = 0.001), NO (p = 0.004), cortisol (p = 0.015), IDO gene expression (p = 0.001) and as well as increased the level of BDNF (p = 0.006) and serotonin (p = 0.019) was observed among those who received 90 mg Ellagic acid twice a day for 12 weeks versus control group. However, there were no significant differences between groups for Nrf2 levels (p>0.05) at the end of study. CONCLUSION: The current study indicates that Ellagic acid intervention has a favorable effect on depression in MS patients. This is achieved by reducing BDI-II scores, as well as levels of NO, cortisol, IFN-Æ´, and IDO gene expression. Furthermore, we found a significant elevation in circulating levels of BDNF and serotonin.

Prophylactic Effects of Hemp Seed Oil on Perimenopausal Depression: A Role of HPA Axis.

Hemp seed, the dried fruit of Cannabis sativa L. (Moraceae), has been extensively documented as a folk source of food due to its nutritional and functional value. This study evaluated the antidepressant effect of hemp seed oil (HSO) during its estrogen-like effect in Perimenopausal depression (PMD) rats induced by ovariectomy combined with chronic unpredictable mild stress (OVX-CUMS). Female SD rats (SPF, 10 weeks, sham operated group, ovariectomy (OVX) model group, ovariectomy - chronic unpredictable mild stress (OVX-CUMS) group, HSO + OVX-CUMS group, fluoxetine (FLU) + OVX-CUMS group, n=8) were subjected to treatment with HSO (4.32 g/kg) or fluoxetine (10 mg/kg) for 28 days (20 mL/kg by ig). Sucrose preference test (SPT), forced swimming test (FST), open field test (OFT), estrogen receptor α (ERα) and estrogen receptor ß (ERß) expression, estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), cortisol (CORT), adrenocorticotropic hormone (ACTH), corticotropin releasing hormone (CRH), norepinephrine (NE), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5HIAA) levels are measured to evaluate the function of the hypothalamic-pituitary-ovarian (HPO) and hypothalamic-pituitary-adrenal (HPA) axis. The results showed that OVX-CUMS significantly decrease sucrose preference rate in SPT, increase immobility time in FST and OFT, and decrease movement distance and stand-up times in OFT. HSO treatment significantly improves depression-like behaviors, upregulates the expression of ERα and ERß, improves HPO axis function by increasing E2 levels and decreasing FSH and LH levels, reverses HPA axis hyperactivation by decreasing CORT, ACTH, and CRH levels, and upregulates NE, 5-HT, and 5HIAA levels in model rats. The findings suggested that HSO could improve depression-like behavior in OVX-CUMS rats by regulating HPO/HPA axis function and neurotransmitter disturbance.

Pharmacological evaluation of the anxiolytic-like effects of an aqueous extract of the Raphanus sativus L. sprouts in mice.

Raphanus sativus L. (Brassicaceae), commonly known as radish, is consumed worldwide as a vegetable. However, its benefits on mental health are unknown. The aim of this study was to evaluate its anxiolytic-like effects and safety using different experimental models. An aqueous extract of R. sativus sprouts (AERSS) was pharmacologically evaluated by intraperitoneal route (i.p.) at 10, 30, and 100 mg/kg and orally (p.o.) at 500 mg/kg on behavior by using open-field and plus-maze tests. In addition, its acute toxicity (LD50) was determined by the Lorke's method. Diazepam (1 mg/kg, i.p.) and buspirone (4 mg/kg, i.p.) were the reference drugs. A significant and anxiolytic-like dosage of AERSS (30 mg/kg, i.p.) resembling the effects of reference drugs was chosen to explore the involvement of GABAA/BDZs site (flumazenil, 5 mg/kg, i.p.) and serotonin 5-HT1A receptors (WAY100635, 1 mg/kg, i.p.) as a possible mechanism of action. A 500 mg/kg, p.o. dosage of AERSS produced an anxiolytic-like response equivalent to 100 mg/kg, i.p. No acute toxicity was observed since a LD50 > 2000 mg/kg, i.p. The phytochemical analysis allowed the identification and quantification of major presence of sulforaphene (2500 µM), sulforaphane (15 µM), iberin (0.75 µM), and indol-3-carbinol (0.75 µM), as major constituents. Both the GABAA/BDZs site and serotonin 5-HT1A receptors were involved in the anxiolytic-like activity of AERSS, depending on the pharmacological parameter or the experimental assay tested. Our results demonstrate that the anxiolytic activity of R. sativus sprouts involves GABAA/BDZs site and serotonin 5-HT1A receptors supporting its health benefits in the treatment of anxiety beyond the satisfaction of basic nutritional needs.

Acupuncture inhibits autophagy and repairs synapses by activating the mTOR pathway in Parkinson's disease depression model rats.

Acupuncture is a good treatment for depression in Parkinson's disease (DPD), so the possible mechanism of acupuncture in the treatment of DPD was explored in this study. Firstly, observing the behavioral changes of the DPD rat model, the regulation of monoamine neurotransmitters dopamine (DA) and 5-hydroxytryptamine (5-HT) in the midbrain, the change of α-synuclein (α-syn) in the striatum, the efficacy of acupuncture in the treatment of DPD was discussed. Secondly, autophagy inhibitors and activators were selected to judge the effect of acupuncture on autophagy in the DPD rat model. Finally, an mTOR inhibitor was used to observe the effect of acupuncture on the mTOR pathway in the DPD rat model. The results showed that acupuncture could improve the motor and depressive symptoms of DPD model rats, increase the content of DA and 5-HT, and decrease the content of ɑ-syn in the striatum. Acupuncture inhibited the expression of autophagy in the striatum of DPD model rats. At the same time, acupuncture upregulates p-mTOR expression, inhibits autophagy, and promotes synaptic protein expression. Therefore, we concluded that acupuncture might improve the behavior of DPD model rats by activating the mTOR pathway, inhibiting autophagy from removing α-syn and repairing synapses.

Theabrownin inhibits obesity and non-alcoholic fatty liver disease in mice via serotonin-related signaling pathways and gut-liver axis.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) with obesity seriously threats public health. Our previous studies showed that dark tea had more potential on regulating lipid metabolism than other teas, and theabrownin (TB) was considered to be a main contributor to the bioactivity of dark tea. OBJECTIVES: This in vivo study aims to reveal the effects and molecular mechanisms of TB on NAFLD and obesity, and the role of the gut-liver axis is explored. METHODS: The histopathological examinations, biochemical tests, and nuclear magnetic resonance were applied to evaluate the effects of TB on NAFLD and obesity. The untargeted metabolomics was used to find the key molecule for further exploration of molecular mechanisms. The 16S rRNA gene sequencing was used to assess the changes in gut microbiota. The antibiotic cocktail and fecal microbiota transplant were used to clarify the role of gut microbiota. RESULTS: TB markedly reduced body weight gain (67.01%), body fat rate (62.81%), and hepatic TG level (51.35%) in the preventive experiment. Especially, TB decreased body weight (32.16%), body fat rate (42.56%), and hepatic TG level (42.86%) in the therapeutic experiment. The mechanisms of action could be the improvement of fatty acid oxidation, lipolysis, and oxidative stress via the regulation of serotonin-related signaling pathways. Also, TB increased the abundance of serotonin-related gut microbiota, such as Akkermansia, Bacteroides and Parabacteroides. Antibiotics-induced gut bacterial dysbiosis disrupted the regulation of TB on serotonin-related signaling pathways in liver, whereas the beneficial regulation of TB on target proteins was regained with the restoration of gut microbiota. CONCLUSION: We find that TB has markedly preventive and therapeutic effects on NAFLD and obesity by regulating serotonin level and related signaling pathways through gut microbiota. Furthermore, gut microbiota and TB co-contribute to alleviating NAFLD and obesity. TB could be a promising medicine for NAFLD and obesity.

Injected serotonin decreases foraging aggression in black widow spiders (Latrodectus hesperus), but dopamine has no effect.

A fundamental goal of animal behavior research is to discover the proximate mechanisms driving individual behavioral differences. Biogenic amines are known to mediate various aspects of behavior across many species, including aggression, one of the most commonly measured behavioral traits in animals. Arthropods provide an excellent system to manipulate biogenic amines and quantify subsequent behavioral changes. Here, we investigated the role of dopamine (DA) and serotonin (5-HT) on foraging aggression in western black widow spiders (Latrodectus hesperus), as measured by the number of attacks on a simulated prey animal in the web. We injected spiders with DA or 5-HT and then quantified subsequent changes in behavior over 48 h. Based on previous work on insects and spiders, we hypothesized that increasing DA levels would increase aggression, while increasing 5-HT would decrease aggression. We found that injection of 5-HT did decrease black widow foraging aggression, but DA had no effect. This could indicate that the relationship between DA and aggression is complex, or that DA may not play as important a role in driving aggressive behavior as previously thought, at least in black widow spiders. Aggressive behavior is likely also influenced by other factors, such as inter-individual differences in genetics, metabolic rates, environment, and other neurohormonal controls.

Quinonoid dihydropteridine reductase, a tetrahydrobiopterin-recycling enzyme, contributes to 5-hydroxytryptamine-associated platelet aggregation in mice.

Quinonoid dihydropteridine reductase (QDPR) regenerates tetrahydrobiopterin (BH4), which is an essential cofactor for catecholamine and serotonin (5-hydroxytryptamine, 5-HT) biosynthesis. Serotonin is known as an important platelet agonist, but its role under BH4-synthesizing or recycling enzymes deficiency is unknown. In the present study, we evaluated the effect of Qdpr gene disruption on platelet aggregation using knockout (Qdpr-/-) mice. Platelet aggregation was monitored by light transmission aggregometry using adenosine diphosphate (ADP) and collagen as agonists. We also assessed how platelet aggregation was modified by 5-HT recovery through supplementation with 5-hydroxytryptophan (5-HTP), a 5-HT precursor, or by blocking the serotonin 5-HT2A receptor. Platelet aggregation in the Qdpr-/- mice was significantly suppressed in comparison with that in wild-type (Qdpr+/+) mice, particularly at the maintenance phase of aggregation. 5-HT storage was decreased in Qdpr-/- platelets, and 5-HTP supplementation recovered not only the intraplatelet 5-HT levels but also platelet aggregation. In addition, 5-HT signal blockade using sarpogrelate suppressed platelet aggregation in Qdpr+/+ mice, and platelets in Qdpr-/- mice were hardly affected. Our results indicate that QDPR deficiency suppresses platelet aggregation by impairing 5-HT biosynthesis in mice.

Perillyl alcohol attenuates chronic restraint stress aggravated dextran sulfate sodium-induced ulcerative colitis by modulating TLR4/NF-κB and JAK2/STAT3 signaling pathways.

BACKGROUND: Ulcerative colitis (UC) is the most prevalent chronic inflammatory immune bowel disease. The modernization of lifestyle accompanied by the stress to cope with the competition has resulted in a new range of complications where stress became a critical contributing factor for many diseases, including UC. Hence there is an urgent need to develop a dual role in curtailing both systemic and neuroinflammation. Perillyl alcohol (POH) is a natural essential oil found in lavender, peppermint, cherries etc and has been widely studied for its strong anti-inflammatory, antioxidant and anti-stress properties. HYPOTHESIS/PURPOSE: POH regulates the various inflammatory signaling cascades involved in chronic inflammation by inhibiting farnesyltransferase  enzyme. Several studies reported that POH could inhibit the phosphorylation of  NF-κB, STAT3 and promote the endogenous antioxidant enzymes like Nrf2 via farnesyltransferase enzyme inhibition.  Also, the effects of POH against UC is not known yet. Thus, this study aims to explore the anti-ulcerative properties of POH on stress aggravated ulcerative colitis in C57BL/6 mice. METHODS: Ulcerative colitis was induced by duel exposure of chronic restraint stress (day 1 to day 28) and 2.5% dextran sulphate sodium (day8 to day14) in mice. POH treatment 100 and 200 mg/kg was administred from day14 ti day28 following oral route of administration. Disease activity index, colonoscopy, western blot analysis and histological analysis, neurotransmitter analysis and Gene expression studies were perofomerd to asses the anti-colitis effects of POH. RESULTS: The treatment reversed the oxidative stress and inflammatory response by inhibiting TLR4/NF-kB pathway, and IL-6/JAK2/STAT3 pathway in both isolated mice colons and brains. The inhibition of these pathways resulted in a decrease in pro-inflammatory cytokines like IL-6, IL-1ß and TNF-α. The treatment improved the physiological and histological changes with decreased ulcerations as examined by colonic endoscopy and Haematoxylin and Eosin staining. The treatment also improved the behavior response as it increased mobility time which was reduced by chronic restrained stress. This was due to increased satiety neurotransmitters like dopamine and serotonin and decreased cortisol in mice brains. CONCLUSION: These results infer that POH has significant anti-colitis activity on chronic restraint stress aggravated DSS-induced UC in mice.

The Small Molecule PPARγ Agonist GL516 Induces Feeding-Stimulatory Effects in Hypothalamus Cells Hypo-E22 and Isolated Hypothalami.

PPARγ agonists are implicated in the regulation of diabetes and metabolic syndrome and have therapeutic potential in brain disorders. PPARγ modulates appetite through its central effects, especially on the hypothalamic arcuate nucleus (ARC). Previous studies demonstrated that the small molecule GL516 is a PPARγ agonist able to reduce oxidative stress and apoptosis with a potential neuroprotective role. Herein, we investigated the effects of GL516, in vitro and ex vivo, on the levels of hypothalamic dopamine (DA) and serotonin (5-HT). The gene expressions of neuropeptide Y, CART, AgRP, and POMC, which play master roles in the neuroendocrine regulation of feeding behavior and energy balance, were also evaluated. HypoE22 cells were treated with H2O2 (300 µM) for 2 h e 30' and with different concentrations of GL516 (1 nM-100 µM). The cell viability was evaluated after 24 and 48 h of culturing using the MTT test. DA and 5-HT levels in the HypoE22 cell supernatants were analyzed through HPLC; an ex vivo study on isolated hypothalamic specimens challenged with scalar concentrations of GL516 (1-100 µM) and with pioglitazone (10 µM) was carried out. The gene expressions of CART, NPY, AgRP, and POMC were also determined by a quantitative real-time PCR. The results obtained showed that GL516 was able to reduce DA and 5-HT turnover; moreover, it was effective in stimulating NPY and AgRP gene expressions with a concomitant reduction in CART and POMC gene expressions. These results highlight the capability of GL516 to modulate neuropeptide pathways deeply involved in appetite control suggesting an orexigenic effect. These findings emphasize the potential use of GL516 as a promising candidate for therapeutical applications in neurodegenerative diseases associated with the reduction in food intake and stimulation of catabolic pathways.

An ABA-serotonin module regulates root suberization and salinity tolerance.

Suberin in roots acts as a physical barrier preventing water/mineral losses. In Arabidopsis, root suberization is regulated by abscisic acid (ABA) and ethylene in response to nutrient stresses. ABA also mediates coordination between microbiota and root endodermis in mineral nutrient homeostasis. However, it is not known whether this regulatory system is common to plants in general, and whether there are other key molecule(s) involved. We show that serotonin acts downstream of ABA in regulating suberization in rice and Arabidopsis and negatively regulates suberization in rice roots in response to salinity. We show that ABA represses transcription of the key gene (OsT5H) in serotonin biosynthesis, thus promoting root suberization in rice. Conversely, overexpression of OsT5H or supplementation with exogenous serotonin represses suberization and reduces tolerance to salt stress. These results identify an ABA-serotonin regulatory module controlling root suberization in rice and Arabidopsis, which is likely to represent a general mechanism as ABA and serotonin are ubiquitous in plants. These findings are of significant importance to breeding novel crop varieties that are resilient to abiotic stresses and developing strategies for production of suberin-rich roots to sequestrate more CO2 , helping to mitigate the effects of climate change.

Consumption of Dietary Fiber with Different Physicochemical Properties during Late Pregnancy Alters the Gut Microbiota and Relieves Constipation in Sow Model.

Constipation is a common problem in sows and women during late pregnancy. Dietary fiber has potential in the regulation of intestinal microbiota, thereby promoting intestinal motility and reducing constipation. However, the effects of fibers with different physicochemical properties on intestinal microbe and constipation during late pregnancy have not been fully explored. In this study, a total of 80 sows were randomly allocated to control and one of three dietary fiber treatments from day 85 of gestation to delivery: LIG (lignocellulose), PRS (resistant starch), and KON (konjaku flour). Results showed that the defecation frequency and fecal consistency scores were highest in PRS. PRS and KON significantly increased the level of gut motility regulatory factors, 5-hydroxytryptamine (5-HT), motilin (MTL), and acetylcholinesterase (AChE) in serum. Moreover, PRS and KON promoted the IL-10 level and reduced the TNF-α level in serum. Furthermore, maternal PRS and KON supplementation significantly reduced the number of stillborn piglets. Microbial sequencing analysis showed that PRS and KON increased short-chain fatty acids (SCFAs)-producing genera Bacteroides and Parabacteroides and decreased the abundance of endotoxin-producing bacteria Desulfovibrio and Oscillibacter in feces. Moreover, the relative abundance of Turicibacter and the fecal butyrate concentration in PRS were the highest. Correlation analysis further revealed that the defecation frequency and serum 5-HT were positively correlated with Turicibacter and butyrate. In conclusion, PRS is the best fiber source for promoting gut motility, which was associated with increased levels of 5-HT under specific bacteria Turicibacter and butyrate stimulation, thereby relieving constipation. Our findings provide a reference for dietary fiber selection to improve intestinal motility in late pregnant mothers.

Antidepressant Effect of Water Extract of Royal Sun Medicinal Mushroom, Agaricus brasiliensis (Agaricomycetes), in Mice Exposed to Chronic Unpredictable Mild Stress.

Our study aimed to investigate whether Agaricus brasiliensis water extract (AWE) possesses antidepressant activity. Depression as a result of chronic unpredictable mild stress (CUMS) was established in mice. The AWE group was administered 3.0 g/kg of AWE. The tail suspension test (TST) was conducted 1 h after the last administration. Then after fasting for 12 h, the mice were sacrificed by euthanasia and the brain and organs (liver, spleen, kidney, and thymus) were collected immediately. Biochemical indexes, including serotonin (5-HT), norepinephrine (NE), and dopamine (DA), were analyzed with biochemical reagent kits. In addition, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, inhibition of hydroxyl radical activity, and total antioxidant capacity were used to evaluate the antioxidant activity of AWE. The organ index analysis indicated that AWE had no adverse effect on mice at feeding time. The results suggested that AWE administration could significantly shorten the immobility time of mice in the TST. Particularly, the levels of 5-HT and NE appeared to increase significantly (P < 0.05) after AWE administration. At the same time, in vitro antioxidant experiments also revealed that AWE displayed better antioxidant activity. Collectively, these results suggest that AWE possesses good antidepressant activity, and these effects may be mediated by enhancing monoamine neurotransmitter content in the brain or antioxidant capacity to improve depression.

Serotonin mediates stress-like effects on responses to non-nociceptive stimuli in the medicinal leech Hirudo verbana.

Noxious stimuli can elicit stress in animals that produce a variety of adaptations including changes in responses to nociceptive and non-nociceptive sensory input. One example is stress-induced analgesia that may be mediated, in part, by the endocannabinoid system. However, endocannabinoids can also have pro-nociceptive effects. In this study, the effects of electroshock, one experimental approach for producing acute stress, were examined on responses to non-nociceptive mechanical stimuli and nociceptive thermal stimuli in the medicinal leech (Hirudo verbana). The electroshock stimuli did not alter the leeches' responses to nociceptive stimuli, but did cause sensitization to non-nociceptive stimuli, characterized by a reduction in response threshold. These experiments were repeated with drugs that either blocked synthesis of the endocannabinoid transmitter 2-arachidonoylglycerol (2-AG) or transient receptor potential vanilloid (TRPV) channel, which is known to act as an endocannabinoid receptor. Surprisingly, neither treatment had any effect on responses following electroshock. However, the electroshock stimuli reliably increased serotonin (5-hydroxytryptamine or 5HT) levels in the H. verbana CNS. Injection of 5HT mimicked the effects of the electroshocks, sensitizing responses to non-nociceptive stimuli and having no effect on responses to nociceptive stimuli. Injections of the 5HT receptor antagonist methysergide reduced the sensitization effect to non-nociceptive stimuli after electroshock treatment. These results indicate that electroshocks enhance response to non-nociceptive stimuli but do not alter responses to nociceptive stimuli. Furthermore, while 5HT appears to play a critical role in this shock-induced sensitizing effect, the endocannabinoid system seems to have no effect.

Hyperthermia and Serotonin: The Quest for a "Better Cyproheptadine".

Fine temperature control is essential in homeothermic animals. Both hyper- and hypothermia can have deleterious effects. Multiple, efficient and partly redundant mechanisms of adjusting the body temperature to the value set by the internal thermostat exist. The neural circuitry of temperature control and the neurotransmitters involved are reviewed. The GABAergic inhibitory output from the brain thermostat in the preoptic area POA to subaltern neural circuitry of temperature control (Nucleus Raphe Dorsalis and Nucleus Raphe Pallidus) is a function of the balance between the (opposite) effects mediated by the transient receptor potential receptor TRPM2 and EP3 prostaglandin receptors. Activation of TRPM2-expressing neurons in POA favors hypothermia, while inhibition has the opposite effect. Conversely, EP3 receptors induce elevation in body temperature. Activation of EP3-expressing neurons in POA results in hyperthermia, while inhibition has the opposite effect. Agonists at TRPM2 and/or antagonists at EP3 could be beneficial in hyperthermia control. Activity of the neural circuitry of temperature control is modulated by a variety of 5-HT receptors. Based on the theoretical model presented the "ideal" antidote against serotonin syndrome hyperthermia appears to be an antagonist at the 5-HT receptor subtypes 2, 4 and 6 and an agonist at the receptor subtypes 1, 3 and 7. Very broadly speaking, such a profile translates in a sympatholytic effect. While a compound with such an ideal profile is presently not available, better matches than the conventional antidote cyproheptadine (used off-label in severe serotonin syndrome cases) appear to be possible and need to be identified.

In vitro effects of 5-Hydroxy-L-tryptophan supplementation on primary bovine mammary epithelial cell gene expression under thermoneutral or heat shock conditions.

Serotonin (5-HT) is an autocrine-paracrine molecule within the mammary gland regulating homeostasis during lactation and triggering involution after milk stasis. Exposure of dairy cows to hyperthermia during the dry period alters mammary gland involution processes leading to reduced subsequent yields. Herein, primary bovine mammary epithelial cells (pBMEC) under thermoneutral (TN, 37 °C) or heat shock (HS, 41.5 °C) conditions were cultured with either 0, 50, 200, or 500 µM 5-Hydroxy-L-tryptophan (5-HTP; 5-HT precursor) for 8-, 12- or 24-h. Expression of 95 genes involved in 5-HT signaling, involution and tight junction regulation were evaluated using a Multiplex RT-qPCR BioMark Dynamic Array Circuit. Different sets of genes were impacted by 5-HTP or temperature, or by their interaction. All 5-HT signaling genes were downregulated after 8-h of HS and then upregulated after 12-h, relative to TN. After 24-h, apoptosis related gene, FASLG, was upregulated by all doses except TN-200 µM 5-HTP, and cell survival gene, FOXO3, was upregulated by HS-50, 200 and 500 µM 5-HTP, suggesting 5-HTP involvement in cell turnover under HS. Supplementing 5-HTP at various concentrations in vitro to pBMEC modulates the expression of genes that might aid in promoting epithelial cell turn-over during involution in dairy cattle under hyperthermia.

Mismatch negativity as an index of target engagement for excitation/inhibition-based treatment development: a double-blind, placebo-controlled, randomized, single-dose cross-over study of the serotonin type-3 receptor antagonist CVN058.

Serotonin type-3 receptor (5-HT3R) antagonists show potential as a treatment for cognitive deficits in schizophrenia. CVN058, a brain-penetrant, potent and selective 5-HT3R antagonist, shows efficacy in rodent models of cognition and was well-tolerated in Phase-1 studies. We evaluated the target engagement of CVN058 using mismatch negativity (MMN) in a randomized, double-blind, placebo-controlled, cross-over study. Subjects were stable outpatients with schizophrenia or schizoaffective disorder treated with antipsychotics. Subjects were not permitted to use other 5-HT3R modulators or serotonin reuptake inhibitors. Each subject received a high (150 mg) and low (15 mg or 75 mg) oral dose of CVN058 and placebo in a randomized order across 3 single-day treatment visits separated by at least 1 week. The primary pre-registered outcome was amplitude of duration MMN. Amplitude of other MMN deviants (frequency, intensity, frequency modulation, and location), P50, P300 and auditory steady-state response (ASSR) were exploratory endpoints. 19 of 22 randomized subjects (86.4%) completed the study. Baseline PANSS scores indicated moderate impairment. CVN058 150 mg led to significant improvement vs. placebo on the primary outcome of duration MMN (p = 0.02, Cohen's d = 0.48). A significant treatment effect was also seen in a combined analysis across all MMN deviants (p < 0.001, d = 0.57). Effects on location MMN were independently significant (p < 0.007, d = 0.46). No other significant effects were seen for other deviants, doses or EEG measures. There were no clinically significant treatment related adverse effects. These results show MMN to be a sensitive target engagement biomarker for 5-HT3R, and support the potential utility of CVN058 in correcting the excitatory/inhibitory imbalance in schizophrenia.

Sex-specific effects of psychedelics on prepulse inhibition of startle in 129S6/SvEv mice.

BACKGROUND: Prepulse inhibition (PPI) of startle is a sensorimotor gating phenomenon perturbed in a variety of neuropsychiatric conditions. Psychedelics disrupt PPI in rats and humans, but their effects and involvement of the serotonin 5-HT2A receptor (5-HT2AR) in mice remain unexplored. METHODS: We tested the effect of the psychedelic 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (0.5 mg/kg, i.p.) on startle amplitude and %PPI in response to acoustic stimuli under up to four different experimental conditions that included changes in background and stimulus intensity, prepulse and pulse duration, and interstimulus interval in male and female 129S6/SvEv mice. We also evaluated the effect of the 5-HT2AR antagonist M100,907 (1 mg/kg, i.p.) on DOI-induced startle amplitude and %PPI, as well as the effect of the psychedelic LSD (0.24 mg/kg, i.p.) and the dopamine agonists apomorphine (5 mg/kg, s.c.) and SKF-82,958 (0.5 mg/kg, i.p.) in male 129S6/SvEv mice. RESULTS: DOI altered startle amplitude with either pulse alone or prepulse + pulse presentations in all PPI conditions, and increased %PPI in three out of four PPI conditions in male mice - an effect that was prevented by M100,907. In female mice, DOI increased %PPI without affecting startle amplitude. %PPI was positively correlated with startle amplitude in males while being negatively correlated in female mice. In male mice, LSD also increased %PPI, although it did not affect startle amplitude, whereas apomorphine and SKF-82,958 induced decreases in %PPI. CONCLUSION: Our findings highlight a distinct effect of the psychedelic DOI on PPI in 129S6/SvEv mice, suggesting 5-HT2AR-dependent PPI improvement in a paradigm-dependent and sex-dependent manner.

Gαi/o-coupled Htr2c in the paraventricular nucleus of the hypothalamus antagonizes the anorectic effect of serotonin agents.

The anorexigenic effect of serotonergic compounds has largely been attributed to activation of serotonin 2C receptors (Htr2cs). Using mouse genetic models in which Htr2c can be selectively deleted or restored (in Htr2c-null mice), we investigate the role of Htr2c in forebrain Sim1 neurons. Unexpectedly, we find that Htr2c acts in these neurons to promote food intake and counteract the anorectic effect of serotonergic appetite suppressants. Furthermore, Htr2c marks a subset of Sim1 neurons in the paraventricular nucleus of the hypothalamus (PVH). Chemogenetic activation of these neurons in adult mice suppresses hunger, whereas their silencing promotes feeding. In support of an orexigenic role of PVH Htr2c, whole-cell patch-clamp experiments demonstrate that activation of Htr2c inhibits PVH neurons. Intriguingly, this inhibition is due to Gαi/o-dependent activation of ATP-sensitive K+ conductance, a mechanism of action not identified previously in the mammalian nervous system.

A Cornflower Extract Containing N-Feruloylserotonin Reduces Inflammation in Human Skin by Neutralizing CCL17 and CCL22 and Inhibiting COX-2 and 5-LOX.

Thymus and Activation-Regulated Chemokine (TARC/CCL17) and Macrophage-Derived Chemokine (MDC/CCL22) are two key chemokines exerting their biological effect via binding and activating a common receptor CCR4, expressed at the surface of type 2 helper T (Th2) cells. By recruiting Th2 cells in the dermis, CCL17 and CCL22 promote the development of inflammation in atopic skin. The aim of this research was to develop a plant extract whose biological properties, when applied topically, could be beneficial for people with atopic-prone skin. The strategy which was followed consisted in identifying ligands able to neutralize the biological activity of CCL17 and CCL22. Thus, an in silico molecular modeling and a generic screening assay were developed to screen natural molecules binding and blocking these two chemokines. N-Feruloylserotonin was identified as a neutraligand of CCL22 in these experiments. A cornflower extract containing N-feruloylserotonin was selected for further in vitro tests: the gene expression modulation of inflammation biomarkers induced by CCL17 or CCL22 in the presence or absence of this extract was assessed in the HaCaT keratinocyte cell line. Additionally, the same cornflower extract in another vehicle was evaluated in parallel with N-feruloylserotonin for cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) enzymatic cellular inhibition. The cornflower extract was shown to neutralize the two chemokines in vitro, inhibited COX-2 and 5-LOX, and demonstrated anti-inflammatory activities due mainly to the presence of N-feruloylserotonin. Although these findings would need to be confirmed in an in vivo study, the in vitro studies lay the foundation to explain the benefits of the cornflower extract when applied topically to individuals with atopic-prone skin.