5-hydroxytryphophan mitigates ergot alkaloid-induced suppression of serotonin and feed intake in cattle.

The impact of ergot toxicosis on livestock industries is detrimental and treatments are needed in many countries. The objective of this study was to evaluate the effects of acute exposure to ergot alkaloids and 5-hydroxytryptophan (5-HTP) supplementation on feed intake, serotonin metabolism, and blood metabolites in cattle. Eight Holstein steers (538 ±â€…18 kg) fitted with ruminal cannulas were used in a replicated 4 × 4 Latin Square design experiment with a 2 × 2 factorial treatment structure. The treatments were the combination of 0 (E-) or 15 µg ergovaline/kg BW (E+) and 0 (5HTP-) or 0.5 mg of 5-hydroxy-l-tryptophan/kg BW (5HTP+) administered daily for 6 d. Toxic endophyte-infected tall fescue seed was used to supply the daily dose of ergovaline. Endophyte-free seed was used to equalize seed intake between treatments. Ground seed was placed into the rumen immediately before feeding. The 5-HTP was dissolved in water and infused into the abomasum via the reticulo-omasal orifice. Blood was collected from a jugular vein catheter at 0, 1, 2, 4, 8, and 24 h after treatment administration. Ergovaline without 5-HTP (E+/5HTP-) decreased dry matter intake (DMI) in comparison to steers without ergovaline and 5-HTP (E-/5HTP-). However, 5-HTP infusion in association with ergovaline (E+/5HTP+) normalized the DMI. Although E + did not affect (P > 0.05) the area under the curve (AUC) of serum 5-HTP, 5-hydroxyindoleacetic acid, tryptophan, and kynurenine, serum and plasma serotonin concentrations were decreased (P < 0.05). The infusion of 5-HTP increased (P < 0.05) the AUC of serum 5-HTP, serum and plasma serotonin, and serum 5-hydroxyindoleacetic acid. In conclusion, acute exposure to ergot alkaloids reduced DMI and circulating serotonin in cattle but 5-HTP administration showed potential to normalize both circulating serotonin and feed intake.

Some grass species have a symbiotic relationship with an endophytic fungus that produces toxic ergot alkaloids which have detrimental impacts on herbivores. Ergot alkaloids have a significant impact on livestock production causing annual loss to the livestock industry that likely exceeds $1 billion. Effective treatment for this toxicosis is still needed. The objective of this study was to evaluate the effects of acute exposure to ergot alkaloids and 5-hydroxytryptophan supplementation on feed intake, serotonin metabolism, and blood metabolites in cattle. We found that 5-hydroxytryptophan administration has the potential to normalize both circulating serotonin and feed intake reduced by ergot alkaloid consumption.

Guhan Yangsheng Jing mitigates hippocampal neuronal pyroptotic injury and manifies learning and memory capabilities in sleep deprived mice via the NLRP3/Caspase1/GSDMD signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Guhan Yangsheng Jing (GHYSJ) is a traditional Chinese patent medicine, that has the function of nourishing the kidney and replenishing the essence, invigorating the brain and calming the mind. It is often used to treat dizziness, memory loss, sleep disorders, fatigue, and weakness, etc. However, its mechanism for improving sleep has not yet been determined. AIM OF THE STUDY: This study aims to explore the effects of GHYSJ on Sleep Deprivation (SD)-induced hippocampal neuronal pyroptotic injury, learning and cognitive abilities, and sleep quality in mice. METHODS: In this study, a PCPA-induced SD mouse model was established. We assessed the influence of GHYSJ on sleep quality and mood by using the pentobarbital-induced sleep test (PIST) and sucrose preference test (SPT). The pharmacological effects of GHYSJ on learning and memory impairment were evaluated by the Morris Water Maze (MWM) and Open Field Test (OFT). Pathological changes in the hippocampal tissue of the SD rats were observed via HE staining and Nissl staining. The severity of neuronal damage was evaluated by detecting the expression of the neuronal marker Microtubule-associated protein 2 (MAP2), via immunohistochemistry and immunofluorescence. Furthermore, the levels of neurotransmitter 5-hydroxytryptophan (5-HTP), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), and Glutamic acid (Glu) in hippocampal tissues, as well as the expression of inflammatory factors Interleukin-1ß (IL-1ß) and Interleukin-18 (IL-18) in serum, were determined by ELISA. The expressions of mRNA and protein NOD-like receptor thermal protein domain associated protein 3 (NLRP3), Gasdermin D (GSDMD), Cysteinyl aspartate specific proteinase1 (Caspase1), High mobility group box-1 protein (HMGB1) and Apoptosis-associated speck-like protein containing CARD (ASC) related to the cellular ferroptosis pathway were tested and analyzed by RT-PCR and WB respectively. RESULTS: PCPA significantly diminishes the sleep span of experimental animals by expediting the expenditure of 5-HT, consequently establishing an essentially direct SD model. The intervention of GHYSJ displays remarkable efficacy in mitigating insomnia symptoms, encompassing difficulties in initiating sleep and insufficient sleep duration. Likewise, it ameliorates memory function impairments induced by sleep deprivation, along with symptoms such as fatigue and depletion of vitality. GHYSJ exerts a protective influence on hippocampal neurons facilitated by inhibiting the down regulation of MAP2 and maintaining the equilibrium of neurotransmitters (5-HTP, 5-HT, GABA, and Glu). It diminishes the expression of intracellular pyroptosis-associated inflammatory factors (IL-1ß and IL-18) and curbs the activation of the NLRP3/Caspase1/GSDMD pyroptosis-related signaling pathways, thereby alleviating the damage caused by hippocampal neuronal pyroptosis.

The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.

BACKGROUND & AIMS: Sleep quality is a pivotal part of health and there is growing evidence on the association between gut microbiota composition and sleep quality. 5-Hydroxytryptophan (5-HTP) is known as a precursor of the sleep regulating neurotransmitter and hormone. However, efficacy of 5-HTP supplementation for improving sleep quality in older adults is unclear. Hence, the aim of this study is to assess the impact of 5-HTP supplementation on sleep quality and gut microbiota composition in older adults. METHODS: This is a single-blinded, 12-week parallel randomized controlled trial. Thirty older adults (66 ± 3 years) in Singapore were randomly assigned to either consume or not consume 100 mg 5-HTP daily. Every 4 weeks, sleep quality was assessed via both subjective (Pittsburg Sleep Quality Index) and objective (actigraphy watch) measures. A global sleep score (GSS) was obtained from the PSQI, where a GSS>5 defines as poor sleeper while a GSS≤5 defines as good sleeper. Blood serotonin level, urine melatonin concentration, gut microbiota composition and stool short chain fatty acids (SCFA) content were assessed at week 0 and 12. This study was registered in clinicaltrials.gov as NCT04078724 (https://clinicaltrials.gov/ct2/show/NCT04078724). RESULTS: 5-HTP supplementation showed an overall favorable effect on certain sleep quality components and an increase in serum serotonin concentration. In particular, at week 12, not good sleepers but poor sleepers with 5-HTP supplementation were able to significantly improve subjective GSS (ΔSL5-HTP: -2.80 ± 1.10 min, p-value = 0.005). In addition, they showed an increase in microbiota diversity (Simpson5-HTP vs. SimpsonControl: 0.037 ± 0.032 a.u. vs. -0.007 ± 0.022 a.u.; pinteraction: 0.013) and relative abundance of SCFA producing bacteria in the gut. CONCLUSIONS: 5-HTP supplementation can improve certain sleep quality components in older adults and this benefit was more prominently observed in poor sleepers. 5-HTP was also able to improve the gut microbiota composition in poor sleepers.

The differential sensitivity of the hypothalamic-hypophysial-ovarian axis to 5-hydroxytryptophan alters the secretion of estradiol.

Serotonin [5-hydroxytryptamine (5-HT)] modulates ovarian function. The precursor of 5-HT, 5-hydroxytryptophan (5-HTP), has been used to treat depression. However, the effects of 5-HTP on ovarian and reproductive physiology remain unknown. In this research, we analysed the impact of 5-HTP on the monoaminergic system and its interactions with the reproductive axis and ovarian estradiol secretion when administered by distinct routes. Female rats 30 days of age were injected with 5-HTP i.p. (100 mg/kg), into the ovarian bursa (1.5 µg/40 µL) or into the median raphe nucleus (20 µg/2.5 µL) and were killed 60 or 120 min after injection. As controls, we used rats of the same age injected with vehicle (0.9% NaCl). Monoamine, gonadotrophin and steroid ovarian hormone concentrations were measured. The injection of 5-HTP either i.p. or directly into the ovarian bursa increased the concentrations of 5-HT and the metabolite 5-hydroxyindole-3-acetic acid in the ovary. For both routes of administration, the serum concentration of estradiol increased. After i.p. injection of 5-HTP, the concentrations of luteinizing hormone were decreased and follicle-stimulating hormone increased after 120 min. Micro-injection of 5-HTP into the median raphe nucleus increased the concentrations of 5-HT in the anterior hypothalamus and dopamine in the medial hypothalamus after 120 min. Our results suggest that the administration of 5-HTP either i.p. or directly into the ovarian bursa enhances ovarian estradiol secretion.

Corydalis yanhusuo Polysaccharides Ameliorate Chronic Stress-Induced Depression in Mice through Gut Microbiota-Derived Short-Chain Fatty Acid Activation of 5-Hydroxytryptamine Signaling.

Depression, a prevalent psychiatric disorder, presents a serious health risk to humans. Increasing evidence suggested that the gut microbiota and the 5-hydroxytryptamine (5-HT) pathway both contribute significantly to depression. This research aimed to investigate how Corydalis yanhusuo polysaccharides (CYP) could potentially alleviate depression induced by chronic unpredictable mild stress in mice, as well as its underlying mechanism. The sucrose preference test, tail suspension test, and forced swimming test were employed to evaluate the behavior of mice. Enzyme-linked immunosorbent assay and PCR techniques were utilized to measure depression-related factors (dopamine [DA], 5-HT, norepinephrine [NE], brain-derived neurotrophic factor [BDNF], tryptophan hydroxylase 2 [TPH-2], 5-hydroxytryptophan [5-HTP], and tryptophan hydroxylase [TPH-1] levels). Hematoxylin and eosin staining and Nissl staining were conducted to observe histopathological changes in the hippocampus, the differences in the diversity of gut flora between groups were analyzed using 16S rRNA sequencing, and gas chromatography-mass spectrometry metabolomics was utilized to evaluate short-chain fatty acid (SCFA) concentrations. The findings indicated that CYP treatment increased the sucrose preference index, decreased the immobility time, and improved neuropathological injury. In depressed mice, CYP improved the dysregulation of the gut microbiota, and increased the SCFA levels. In addition, CYP enhanced the DA, 5-HT, NE, BDNF, and TPH-2 levels in the brain and the expression of 5-HTP and TPH-1 in the colon, while SCFAs were positively correlated with these levels. In summary, our study suggested that CYP may mitigate depression by ameliorating gut microbiota dysregulation, promoting the generation of SCFAs, and activation of 5-HT signaling expression.

Corylin ameliorates chronic ulcerative colitis via regulating the gut-brain axis and promoting 5-hydroxytryptophan production in the colon.

BACKGROUND: Chronic ulcerative colitis (UC) is a lifelong disease, patients with chronic UC have a high prevalence of common mental disorders. The increasing interest in the role of gut-brain axis is seen in inflammatory bowel diseases. PURPOSE: Corylin is a representative flavonoid compound isolated from the Psoraleae Fructus. This study aimed to identify the effects and mechanism of corylin on the inflammation interactions and 5-HT synthesis between the gut and brain in chronic UC. METHODS: Dextran sulfate sodium (DSS) induced chronic UC mouse model was established to assess the therapeutic effect of corylin on chronic UC symptoms. The expression of inflammatory cytokines was detected in the colon and brain. The expression of tight junction (TJ) proteins of intestinal mucosal barrier and blood-brain barrier (BBB) and the ionized calcium-binding adaptor molecule 1 (Iba1) in the hippocampus were determined by western blotting and immunofluorescence staining. In addition, several tryptophan (Trp) metabolites and related neurotransmitters in faeces, colon, serum, and brain were detected by UPLC-MS/MS. The interaction between corylin and 5-hydroxytryptophan decarboxylase (5-HTPDC) was performed by molecular docking and surface plasmon resonance (SPR). Finally, the changes of gut microbiota composition were analyzed by 16S rRNA sequencing. RESULTS: Corylin significantly alleviated colitis symptoms and inhibited inflammatory response in the colon and brain of DSS-induced chronic UC mice. The TJ proteins of intestinal mucosal barrier and BBB were improved and the expression of Iba1 in the hippocampus was normalized after corylin treatment. In addition, corylin treatment increased the expression of neurotransmitters in the brain, especially 5-hydroxytryptamine (5-HT) and 5-hydroxytryptophan (5-HTP), but the expression of 5-HT in the colon was inhibited. Further study firstly proved that corylin could bind to the 5-HTDPC, and then inhibit the expression of 5-HTDPC and VB6, resulting in the 5-HT reduction and 5-HTP accumulation in the colon. Moreover, the intake of corylin transformed the diversity and composition of intestinal microbiota, Bacteroides, Escherichia-Shigella, and Turicibacter were decreased but Dubosiella, Enterorhabdus, and Candidatus_Stoquefichus were increased. CONCLUSION: Corylin administration ameliorated DSS-induced colitis and inhibited intestinal inflammation and neuroinflammation via regulating the inflammation interactions across gut-brain axis and increasing 5-HTP generation in the colon.

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.

L-5-hydroxytryptophan promotes antitumor immunity by inhibiting PD-L1 inducible expression.

BACKGROUND: The repression or downregulation of programmed death-ligand 1 (PD-L1) can release its inhibition of T cells and activate antitumor immune responses. Although PD-1 and PD-L1 antibodies are promising treatments for diverse tumor types, their inherent disadvantages and immune-related adverse events remain significant issues. The development of small molecule inhibitors targeting the interaction surface of PD-1 and PD-L1 has been reviving, yet many challenges remain. To address these issues, we aimed to find small molecules with durable efficacy and favorable biosafety that alter PD-L1 surface expression and can be developed into a promising alternative and complementary therapy for existing anti-PD-1/PD-L1 therapies. METHODS: Cell-based screen of 200 metabolic molecules using a high-throughput flow cytometry assay of PD-L1 surface expression was conducted, and L-5-hydroxytryptophan (L-5-HTP) was found to suppress PD-L1 expression induced by interferon gamma (IFN-γ). Inhibition of PD-L1 induction and antitumor effect of L-5-HTP were evaluated in two syngeneic mouse tumor models. Flow cytometry was performed to investigate the change in the tumor microenvironment caused by L-5-HTP treatment. RESULTS: We discovered that L-5-HTP suppressed IFN-γ-induced PD-L1 expression in tumor cells transcriptionally, and this effect was directly due to itself. Mechanistically, L-5-HTP inhibited IFN-γ-induced expression of RTK ligands and thus suppressed phosphorylation-mediated activation of RTK receptors and the downstream MEK/ERK/c-JUN signaling cascade, leading to decreased PD-L1 induction. In syngeneic mouse tumor models, treatment with 100 mg/kg L-5-HTP (intraperitoneal) inhibited PD-L1 expression and exhibited antitumor effect. L-5-HTP upregulated the ratio of granzyme B+ CD8+ activated cytotoxic T cells. An intact immune system and PD-L1 expression was critical for L-5-HTP to exert its antitumor effects. Furthermore, L-5-HTP acted synergistically with PD-1 antibody to improve anticancer effect. CONCLUSION: Our study illustrated L-5-HTP's inhibitory effect on PD-L1 induction stimulated by IFN-γ in tumor cells and also provided insight into repurposing L-5-HTP for use in tumor immunotherapy.

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.

Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn.

Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray-dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons.

Tryptophan-enriched diet or 5-hydroxytryptophan supplementation given in a randomized controlled trial impacts social cognition on a neural and behavioral level.

Understanding of emotions and intentions are key processes in social cognition at which serotonin is an important neuromodulator. Its precursor is the essential amino acid tryptophan (TRP). Reduced TRP availability leads to weaker impulse control ability and higher aggression, while TRP supplementation promotes confidence. In a double-blind placebo-controlled fMRI study with 77 healthy adults, we investigated the influence of a 4 week TRP enriched diet and an acute 5-hydroxytryptophan (5-HTP) intake on two social-cognitive tasks, a moral evaluation and an emotion recognition task. With 5-HTP, immoral behavior without negative consequences was rated as more reprehensible. Additionally, during story reading, activation in insula and supramarginal gyrus was increased after TRP intake. No significant effects of TRP on emotion recognition were identified for the whole sample. Importantly, emotion recognition ability decreased with age which was for positive emotions compensated by TRP. Since the supramarginal gyrus is associated with empathy, pain and related information integration results could be interpreted as reflecting stricter evaluation of negative behavior due to better integration of information. Improved recognition of positive emotions with TRP in older participants supports the use of a TRP-rich diet to compensate for age related decline in social-cognitive processes.

Histological and transcriptomic analysis of adipose and muscle of dairy calves supplemented with 5-hydroxytryptophan.

In mammals, peripheral serotonin is involved in regulating energy balance. Herein, we characterized the transcriptomic profile and microstructure of adipose and muscle in pre-weaned calves with increased circulating serotonin. Holstein bull calves (21 ± 2 days old) were fed milk replacer supplemented with saline (CON, 8 mL/day n = 4) or 5-hydroxytryptophan (5-HTP, 90 mg/day, n = 4) for 10 consecutive days. Calves were euthanized on d10 to harvest adipose and muscle for RNA-Sequencing and histological analyses. Twenty-two genes were differentially expressed in adipose, and 33 in muscle. Notably, Interferon gamma inducible protein-47 was highly expressed and upregulated in muscle and adipose (avg. log FC = 6.5). Enriched pathways in adipose tissue revealed serotonin's participation in lipid metabolism and PPAR signaling. In muscle, enriched pathways were related to histone acetyltransferase binding, Jak-STAT signaling, PI3K-Akt signaling and cell proliferation. Supplementation of 5-HTP increased cell proliferation and total cell number in adipose and muscle. Adipocyte surface area was smaller and muscle fiber area was not different in the 5-HTP group. Manipulating the serotonin pathway, through oral supplementation of 5-HTP, influences signaling pathways and cellular processes in adipose and muscle related to endocrine and metabolic functions which might translate into improvements in calf growth and development.

From forest to pharmacy: Should we be depressed about a sustainable Griffonia simplicifolia (Fabaceae) seed supply chain?

ETHNOPHARMACOLOGICAL RELEVANCE: Griffonia simplicifolia D.C (Baill.) (Fabaceae) seeds are unusually high (6-20% wet weight) in 5-HTP (5-Hydroxytryptophan), a serotonin precursor widely used to treat depression. Consequently, this species is regarded as a herbal "Prozac®". Contemporary use as an anti-depressant contrasts with traditional uses for insecticides, arachnicides, fodder, dyes, mordants and chewing-sticks. G. simplicifolia seeds are wild-harvested for the export trade. Over the past 15 years, use of 5-HTP extracted from G. simplicifolia in cosmetics has added to global demand. Wild populations in West Africa are the sole commercial source of G. simplicifolia seed. AIMS OF THE STUDY: Were to (i) assess the scale of the global trade in G. simplicifolia seeds and (ii) produce a synthesis of the challenges facing sustainable harvest of G. simplicifolia. MATERIALS AND APPROACH: Firstly, we analysed global trade data for G. simplicifolia, taking into account historical trends over the past 40 years. Secondly, we reviewed published studies on the distribution, population biology and harvest impacts of wild G. simplicifolia populations. RESULTS AND CONCLUSION: s: Wild G. simplicifolia populations have been the focus of commercial harvest of their pods (for seeds) for international trade from West Africa for almost 50 years. In the late 1980's, when Ghana exported 75-80 metric tonnes (MT) of G. simplicifolia seed to Europe, this species was already Ghana's main medicinal plant export. Currently, 5 West African countries export G. simplicifolia seeds (Cote d'Ivoire, Ghana, Liberia, Nigeria and Togo). Although in the 1980's, most seed exports were to Europe, today China is the main importer of G. simplicifolia seed. These seeds are value-added for production of 5-HTP extracts, and then re-exported, particularly to North America (c.48% of exports). The low habitat specificity and vigorous re-sprouting of G. simplicifolia after cutting, plus its occurrence in forest reserves and national parks confer some resilience on wild populations. Sustaining future supply chains faces six future challenges, however: (1) Rapid loss of forest habitats; (2) Declining populations of understorey birds and disruption of G. simplicifolia pollination in this bird pollinated species; (3) Negative effects of introduced invasive plant species (Broussonetia papyrifera, Chromolaena odorata) on G. simplicifolia regeneration; (4) Grazing by livestock and use of G. simplicifolia leaves as forage; (5) The long-term impact of industrial scale seed "predation": Over a 9-year period (2005-2013), G. simplicifolia exports from Ghana totalled at least 5550 metric tonnes (or between 9.1 billion to 13.5 billion seeds). This could affect the long-term population dynamics of this species, which produces a low number of seeds per pod (1-4 seeds) and has short distance (ballistic) seed dispersal; and (6) Destructive harvest methods, when plants are cut to harvest get the seed pods. Improved resource management, monitoring, quality control and careful pricing are important if supply chains from wild stocks are to be maintained. If wild populations decline, then 5-HTP biosynthesis may compete with low G. simplicifolia seed yields, leading to loss of income to West African harvesters and traders.

Gut bacteria-derived 5-hydroxyindole is a potent stimulant of intestinal motility via its action on L-type calcium channels.

Microbial conversion of dietary or drug substrates into small bioactive molecules represents a regulatory mechanism by which the gut microbiota alters intestinal physiology. Here, we show that a wide variety of gut bacteria can metabolize the dietary supplement and antidepressant 5-hydroxytryptophan (5-HTP) to 5-hydroxyindole (5-HI) via the tryptophanase (TnaA) enzyme. Oral administration of 5-HTP results in detection of 5-HI in fecal samples of healthy volunteers with interindividual variation. The production of 5-HI is inhibited upon pH reduction in in vitro studies. When administered orally in rats, 5-HI significantly accelerates the total gut transit time (TGTT). Deciphering the underlying mechanisms of action reveals that 5-HI accelerates gut contractility via activation of L-type calcium channels located on the colonic smooth muscle cells. Moreover, 5-HI stimulation of a cell line model of intestinal enterochromaffin cells results in significant increase in serotonin production. Together, our findings support a role for bacterial metabolism in altering gut motility and lay the foundation for microbiota-targeted interventions.

The effects of 5-hydroxytryptophan on carrageenan-induced mouse paw oedemas / Efeito de 5-hidroxitriptofano no edema de pata de camundongo induzido por carragenina

ABSTRACT Objective 5-Hydroxytryptophan is the precursor compound of serotonin biosynthesis. The oral absorption of 5-Hydroxytryptophan is close to 100% and, unlike serotonin, it crosses the blood-brain barrier freely. 5-Hydroxytryptophan has been used as a food supplement for many years to treat anxiety and depression. Recent studies have shown that 5-Hydroxytryptophan suppresses the pro-inflammatory mediators and is effective in some inflammatory diseases, such as arthritis and allergic asthma. However, the role of 5-Hydroxytryptophan supplements on acute peripheral inflammation has not been investigated yet. In this study, the in vivo anti-inflammatory activity of 5-Hydroxytryptophan was evaluated with a carrageenan-induced paw oedema test in mice. Methods For the investigation of the acute antiinflammatory activity, single oral doses of 5-Hydroxytryptophan (1.5, 5 and 20mg/kg) were given to mice 1.5 hours prior to the carrageenan test. For chronic activity, the same oral doses were administered daily for two weeks prior to the carrageenan test on the 14th day. To induce inflammation, 0.01mL of 2% carrageenan was injected into the paws of mice. Results Supplementation with 5-Hydroxytryptophan significantly reduced inflammation in a dose-independent manner which was irrespective of the duration of exposure (per cent inhibition in acute experiments was 35.4%, 20.9%, 24.0%, and per cent inhibition in chronic experiments was 29.5%, 35.3%, 40.8% for the doses of 1.5, 5, and 20mg/kg, respectively). Conclusion Our findings demonstrate for the first time that 5-HTP supplements have the potential of suppressing the measures of acute peripheral inflammation. It is suggested that, apart from several diseases where serotonin is believed to play an important role, including depression, patients with inflammatory conditions may also benefit from 5-HTP.

RESUMO Objetivo O 5-hidroxitriptofano (5-HTP) é o composto precursor da biossíntese da serotonina. A absorção oral do 5-HTP é próxima a 100% e, ao contrário da serotonina, atravessa a barreira hematoencefálica livremente. O 5-HTP tem sido usado como suplemento alimentar por muitos anos na ansiedade e na depressão. Estudos recentes demonstraram que o 5-HTP suprime os mediadores pró-inflamatórios e é eficaz em algumas doenças inflamatórias, como artrite e asma alérgica. No entanto, o papel dos suplementos de 5-HTP na inflamação periférica aguda ainda não foi investigado. Neste estudo, a atividade anti-inflamatória in vivo do 5-HTP foi avaliada por meio do teste de edema de pata induzido por carragenina em ratos. Métodos Para a atividade aguda, doses orais únicas de 5 -HTP (1,5, 5 e 20 mg/kg) foram dados aos ratos 1,5 horas antes do teste da carragenina. Para a atividade crônica, as mesmas doses orais foram dadas cada dia durante duas semanas antes do teste da carragenina no 14º dia. 0,01ml da carragenina a 2% foi injetado nas patas dos ratos a fim de induzir a inflamação. Resultados A suplementação com 5-HTP reduziu significativamente a inflamação de uma maneira independente da dose, que foi independente da duração da exposição (por cento de inibição em experimentos agudos; 35,4%, 20,9%, 24,0% e por cento de inibição em experimentos crônicos; 29,5%, 35,3%, 40,8% para as doses de 1.5, 5 e 20 mg/kg respectivamente). Conclusão Nossas conclusões demonstram pela primeira vez que os suplementos de 5-HTP têm potencial para suprimir os sintomas de inflamação periférica aguda. É sugerido que, além de várias doenças em que se acredita que a serotonina tem uma função importante, incluindo a depressão, os pacientes com doenças inflamatórias também podem se beneficiar do 5-HTP.

5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology.

L-5-hydroxytryptophan (5-HTP) is both a drug and a natural component of some dietary supplements. 5-HTP is produced from tryptophan by tryptophan hydroxylase (TPH), which is present in two isoforms (TPH1 and TPH2). Decarboxylation of 5-HTP yields serotonin (5-hydroxytryptamine, 5-HT) that is further transformed to melatonin (N-acetyl-5-methoxytryptamine). 5-HTP plays a major role both in neurologic and metabolic diseases and its synthesis from tryptophan represents the limiting step in serotonin and melatonin biosynthesis. In this review, after an look at the main natural sources of 5-HTP, the chemical analysis and synthesis, biosynthesis and microbial production of 5-HTP by molecular engineering will be described. The physiological effects of 5-HTP are discussed in both animal studies and human clinical trials. The physiological role of 5-HTP in the treatment of depression, anxiety, panic, sleep disorders, obesity, myoclonus and serotonin syndrome are also discussed. 5-HTP toxicity and the occurrence of toxic impurities present in tryptophan and 5-HTP preparations are also discussed.

Increasing serotonin bioavailability alters gene expression in peripheral leukocytes and lymphoid tissues of dairy calves.

Dairy calves are born with a naïve immune system, making the pre-weaning phase a critical window for immune development. In the U.S., 40-60% of dairy farms feed milk replacer to pre-weaned calves, which are devoid of bioactive factors with immunological roles. Serotonin is a bioactive factor with immunoregulatory properties naturally produced by the calf and present in milk. Human and rodent immune cells express the serotonin machinery, but little is known about the role of serotonin in the bovine immune system. Supplementing milk replacer with 5-hydroxytryptophan (serotonin precursor) or fluoxetine (reuptake inhibitor) increases serotonin bioavailability. We hypothesized that increased serotonin bioavailability promotes serotonergic signaling and modulates the expression of immune related genes in peripheral leukocytes and immune-related tissues of dairy calves. The present experiment targeted candidate genes involved in serotonin production, metabolism, transport, signaling and immune regulation. We established that bovine peripheral leukocytes express all known serotonin receptors, and can synthesize, uptake and degrade serotonin due to the expression of serotonin metabolism-related genes. Indeed, we showed that increasing serotonin bioavailability alters gene expression of serotonin receptors and immune-related genes. Further research will determine whether manipulation of the serotonin pathway could be a feasible approach to bolster dairy calves' immune system.

Rumen-Protected 5-Hydroxytryptophan Improves Sheep Melatonin Synthesis in the Pineal Gland and Intestinal Tract.

BACKGROUND Based on the extensive biological effects of melatonin (MLT), it is beneficial to increase the MLT content in the bodies of animals at a specific physiological stage. This study was conducted to investigate the effect of a diet supplemented with rumen-protected (RP) 5-hydroxytryptophan (5-HTP) on the pineal gland and intestinal tract MLT synthesis of sheep. MATERIAL AND METHODS Eighteen Kazakh sheep were assigned randomly to 3 diet groups: control group (CT, corn-soybean meal basal diet), CT+111 group (111 mg/kg BW RP 5-HTP), and CT+222 group (222 mg/kg BW RP 5-HTP). The gene expressions of aromatic amino acid decarboxylase (AADC), arylalkylamine N-acetyltransferase (AA-NAT), hydroxyindole-O-methyltransferase (HIOMT), monoamine oxidase A (MAOA), and the intermediates of MLT synthesis were observed from the pineal gland and intestinal tract by the reverse transcription (RT)-PCR method. The 5-HTP, 5-HT, N-acetylserotonin (NAS), MLT, and 5-hydroxyindole acetic acid (5-HIAA) contents in the pineal gland and intestinal tract were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry. RESULTS The study showed that the pineal gland HIOMT expression (P<0.05), MLT (P<0.05) and 5-HIAA (P<0.05) levels in the 222 mg/kg group significantly increased compared to those in the CT and CT+111 mg/kg groups. In addition, the AADC (P<0.01) and AA-NAT (P<0.05) gene expression levels in the duodenum and jejunum were increased by the supplementation of RP 5-HTP. CONCLUSIONS Rumen-protected 5-hydroxytryptophan promoted melatonin synthesis in the pineal gland and intestinal tract during the natural light period.

Chemical Characterization and DNA Fingerprinting of Griffonia simplicifolia Baill.

BACKGROUND: Griffonia simplicifolia Baill. (Caesalpiniaceae) is a medicinal plant whose seeds are widely used in traditional medicine for their high content of 5-hydroxy-l-tryptophan (5-HTP), a direct precursor and enhancer of the activity of the brain hormone serotonin (5-HT). The plant extracts are used in dietary supplements aimed to alleviate serotonin-related disorders. METHODS: In order to characterize the chemical components of G. simplicifolia seeds and their identity, we used a combined methodology by using HPLC-DAD-ESI-MS/MS for the qualitative and quantitative determination of the N-containing compounds, GC-FID and GC-MS for the characterization of the major fatty acids, and DNA fingerprinting based on PCR⁻RFLP for the unequivocal identification of the plant. RESULTS: 5-HTP was the most representative compound, followed by lower percentages of the ß-carboline alkaloid derivative griffonine and other alkaloids. Fatty acids were dominated by the unsaturated fatty acids linoleic acid and oleic acid, followed by the saturated fatty acids stearic and palmitic acids. PCR analysis of the internal transcribed spacer amplified sequence showed a major band at about 758 bp, whereas the PCR⁻RFLP analysis of this sequence using three different restriction enzymes (MspI, HhaI, and HaeIII) generated a specific fingerprinting useful for the plant identification. CONCLUSIONS: The combined chemical and molecular analysis of G. simplicifolia provided an interesting integrated approach for the unequivocal identification of commercial G. simplicifolia seeds.

High-fat simple carbohydrate (HFSC) diet impairs hypothalamic and corpus striatal serotonergic metabolic pathway in metabolic syndrome (MetS) induced C57BL/6J mice.

OBJECTIVES: To study the effect of specially formulated high-fat simple carbohydrate diet (HFSC) on the serotonin metabolic pathway in male C57BL/6J mice. METHODS: Previous studies from our laboratory have shown that specially formulated HFSC induces metabolic syndrome in C57BL/6J mice. In the present investigation, 5-hydroxytryptophan, serotonin and 5-hydroxyindoleacetic acid were analyzed in two brain regions (hypothalamus, corpus striatum), urine and plasma of HFSC-fed mice on a monthly basis up to 5 months using high-performance liquid chromatography fitted with electrochemical detector. The data were analyzed using Graph pad Prism v7.3 by two-way ANOVA and post hoc Tukey's test (to assess the effect of time on the serotonergic metabolic pathway). RESULTS: HFSC feed was observed to lower the hypothalamic serotonergic tone as compared to the age-matched control-fed C57BL/6J mice. Although the hypothalamic serotonergic tone was unaltered over time due to consumption of diet per se, hypothalamic 5-HTP levels were observed to be lower on consumption of HFSC feed over duration of 5 months as compared to 1st month of consumption of HFSC feed. The striatal 5-HTP levels were lowered in the HFSC-fed mice after 4 months of feeding as compared to the age-matched control-fed mice. The striatal 5-HTP levels were also lower in both control and HFSC-fed mice due to consumption of the respective diet over a duration of 5 months. Increased plasma 5-HTP levels were observed due to consumption of HFSC feed over duration of 5 months in the HFSC-fed group. However, higher breakdown of serotonin was observed in both the plasma and urine of HFSC-fed C57BL/6J mice as per the turnover studies. DISCUSSION: The central and peripheral serotonergic pathway is affected differentially by both the type of diet consumed and the duration for which the diet is consumed. The hypothalamic, striatal and plasma serotonergic pathway were altered both by the type of feed consumed and the duration of feeding. The urine serotonergic pathway was affected by mainly the duration for which a particular diet was consumed. These findings may have implications in the feeding behavior, cognitive decline and depression associated with metabolic syndrome patients.