Monoaminergic system is implicated in the antidepressant-like effect of hyperoside and protocatechuic acid isolated from Impatiens glandulifera Royle in mice.

We have recently demonstrated that the hydroethanolic extracts of Impatiens glandulifera Royle (Balsaminaceae) have antianxiety effect in mice. The present study was aimed to investigate an antidepressant activity of hyperoside (HYP) and protocatechuic acid (PCA), two polyphenols isolated from the aerial parts of this plant, using the forced swimming test (FST) and tail suspension test (TST) in mice. The implication of the monoaminergic system in this effect was assessed and brain-derived neurotrophic factor (BDNF) expression was measured. At doses 1.875, 3.75 and 7.5 mg/kg, HYP and PCA significantly reduced immobility in the FST and TST, without affecting locomotor activity of mice. Pretreatment with p-chlorophenylalanine (PCPA 100 mg/kg, a serotonin synthesis inhibitor) or α-methyl-DL-tyrosine (AMPT 100 mg/kg, a catecholamine synthesis inhibitor) was able to prevent antidepressant-like effect of HYP and PCA (3.75 mg/kg). Sub-effective doses of fluoxetine (5 mg/kg) or reboxetine (2 mg/kg) were capable of potentiating the effect of a sub-effective dose of HYP (0.94 mg/kg) in the FST. Co-administration of sub-effective dose of PCA (0.94 mg/kg) and reboxetine (2 mg/kg) resulted in reducing immobility in the FST. The antidepressant-like effect of HYP and PCA was also prevented by the administration of sulpiride (50 mg/kg), a D2 antagonist. In addition, HYP (3.75 and 7.5 mg/kg) and PCA (7.5 mg/kg) improved the expression of hippocampal BDNF of mice subjected to TST. Altogether, our findings suggest that HYP and PCA exert antidepressant-like effects in mice, which was possibly mediated by monoaminergic system and the upregulation of BDNF level.

The Impact of Carvacrol on Ammonia and Biogenic Amine Production by Common Foodborne Pathogens.

The impact of carvacrol at different levels (0.1%, 0.5%, and 1%) on ammonia (AMN) and biogenic amines (BAs) production by 8 common foodborne pathogens (FBPs) (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Listeria monocytogenes, Aeromonas hydrophila, and Salmonella Paratyphi A) was studied using a rapid high-performance liquid chromatography method. Significant differences among bacteria (P < 0.05) in AMN and BA production were observed using a tyrosine decarboxylase broth. Tyramine, dopamine, agmatine, spermine, and putrescine were the main amines produced by the bacteria. Tyramine production by P. aeruginosa was the highest (967 mg/L), whereas K. pneumoniae was the poorest tyramine producer (6.42 mg/L). AMN and BA production varied significantly depending on carvacrol levels and the specific bacterial strains. Tyramine production for all bacterial strains was significantly suppressed by addition of carvacrol at levels of 0.5% and 1%, but not 0.1%. Consequently, the effect of carvacrol on BA and AMN formation by FBP was dependent on bacterial strain as well as carvacrol level.

Mountain cedar pollen induces IgE-independent mast cell degranulation, IL-4 production, and intracellular reactive oxygen species generation.

Cedar pollens cause severe allergic disease throughout the world. We have previously characterized allergenic pollen glycoproteins from mountain cedar (Juniperus ashei) that bind to allergen-specific immunoglobulin E (IgE). In the present report, we investigated an alternative pathway of mast cell activation by mountain cedar pollen extract through IgE-independent mechanisms. We show that mountain cedar pollen directly induces mast cell serotonin and IL-4 release and enhances release induced by IgE cross-linking. Concomitant with mediator release, high levels of intracellular reactive oxygen species (ROS) were generated, and both ROS and serotonin release were inhibited by anti-oxidants. These findings suggest that alternative mechanisms exist whereby pollen exposure enhances allergic inflammatory mediator release through mechanisms that involve ROS. These mechanisms have the potential for enhancing the allergenic potency of pollens.

Targeting polyamines and biogenic amines by green tea epigallocatechin-3-gallate.

Biogenic amines and polyamines are organic polycations derived from aromatic or cationic amino acids. They exert pleiotropic effects, more related to intercellular communication in the case of biogenic amines, and to intracellular signaling in the case of polyamines. The bioactive compound epigallocatechin-3-gallate (EGCG), a major component of green tea, has been shown to target key enzyme of biogenic amine and polyamine metabolic pathways. Herein, we review the specific effects of EGCG on concrete molecular targets of both biogenic amine and polyamine metabolic pathways, and discuss the relevance of these data to support the potential therapeutic interest of this compound.

New insights on Saccus vasculosus evolution: a developmental and immunohistochemical study in elasmobranchs.

The saccus vasculosus (SV) is a circumventricular organ of the hypothalamus of many jawed fishes whose functions have not yet been clarified. It is a vascularized neuroepithelium that consists of coronet cells, cerebrospinal fluid-contacting (CSF-c) neurons and supporting cells. To assess the organization, development and evolution of the SV, the expression of glial fibrillary acidic protein (GFAP) and the neuronal markers gamma-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD; the GABA synthesizing enzyme), neuropeptide Y (NPY), neurophysin II (NPH), tyrosine hydroxylase (TH; the rate-limiting catecholamine-synthesizing enzyme) and serotonin (5-HT), were investigated by immunohistochemistry in developing and adult sharks. Coronet cells showed GFAP immunoreactivity from embryos at stage 31 to adults, indicating a glial nature. GABAergic CSF-c neurons were evidenced just when the primordium of the SV becomes detectable (at stage 29). Double immunolabeling revealed colocalization of NPY and GAD in these cells. Some CSF-c cells showed TH immunoreactivity in postembryonic stages. Saccofugal GABAergic fibers formed a defined SV tract from the stage 30 and scattered neurosecretory (NPH-immunoreactive) and monoaminergic (5-HT- and TH-immunoreactive) saccopetal fibers were first detected at stages 31 and 32, respectively. The early differentiation of GABAergic neurons and the presence of a conspicuous GABAergic saccofugal system are shared by elasmobranch and teleosts (trout), suggesting that GABA plays a key function in the SV circuitry. Monoaminergic structures have not been reported in the SV of bony fishes, and were probably acquired secondarily in sharks. The existence of saccopetal monoaminergic and neurosecretory fibers reveals reciprocal connections between the SV and hypothalamic structures which have not been previously detected in teleosts.

Biogenic amines in restructured beef steaks as affected by added walnuts and cold storage.

This article evaluates changes in biogenic amines and how these relate to microbiological growth in chilled, fresh restructured beef steaks containing transglutaminase as a cold binding agent and different amounts of walnut. Added walnut and chilling favored higher total and lactic acid bacteria counts during storage, whereas Enterobacteriaceae were not affected. The highest initial biogenic amine concentrations were identified as spermidine, spermine, and tyramine. Both added walnut and cold storage generally favored the formation of amines (tyramine, histamine, putrescine, and cadaverine), which was more obviously apparent by the end of the storage period. Agmatine, on the other hand, was not generally affected by the walnut.

Effect of enhanced proteolysis on formation of biogenic amines by lactobacilli during Gouda cheese ripening.

The effect of enhanced proteolysis on amine formation by amino acid decarboxylase positive Lactobacillus sp. during Gouda cheese ripening was examined. A commercial proteolytic enzyme preparation was added to pasteurized milk prior to cheese preparation. The effect of this manipulation on the formation of putrescine, histamine and tyramine was investigated in the presence and absence of amino acid decarboxylase-positive strains during a 12-week ripening period. Four batches were supplemented with a proteolytic enzyme. Batch I contained the proteolytic enzyme only, whereas batches II-IV were additionally supplemented with Lactobacillus delbrueckii LTH 1260 (batch II), Lactobacillus buchneri LTH 1388 (batch III) or Lactobacillus brevis LTH 2560 (batch IV). In batch I putrescine was detected with 4 mg/kg, in batch II, 42 mg/kg putrescine, 238 mg/kg histamine and 636 mg/kg tyramine were found. Batch III contained 13 mg/kg putrescine and 418 mg/kg histamine, whereas in batch IV, 26 mg/kg putrescine and 776 mg/kg tyramine were present. Batch V was supplemented with all three lactobacilli but did not contain the proteolytic enzyme. In this experiment, 4 mg/kg putrescine, 179 mg/kg histamine and 337 mg/kg tyramine were detected. A control cheese batch (VI) without addition of amine forming lactobacilli or a proteolytic enzyme was produced and only 4 mg/kg putrescine were detected. An increase in amine concentration during cheese ripening under conditions of enhanced proteolysis in the presence of starter and spoilage lactobacilli was evident from the experiments.

Benzodiazepine prevention of swim stress-induced sensitization of cortical biogenic amines: an in vivo microdialysis study.

In vivo microdialysis was used to determine the effect of diazepam, flumazenil and FG-7142 upon the biogenic amine response to acute and repeated swim stress in the medial prefrontal cortex of the rat. Acute swim stress increased norepinephrine levels, although dopamine and serotonin levels remained stable. Upon re-exposure to swim stress twenty-four hours later, sustained increases (200-300% of baseline) in all three biogenic amines were detected. This enhanced response to re-stress was not seen in rats pretreated with either a benzodiazepine: agonist (diazepam, 2 mg/kg), an antagonist (flumazenil, 10 mg/kg), or an inverse agonist (FG-7142, 10 mg/kg) given prior to the first swim stress. Therefore, the sensitization of biogenic amine response to re-stress may be prevented by compounds which differ in their activity at the benzodiazepine receptor.

Increase in dopamine turnover and tyrosine hydroxylase enzyme in hippocampus of rats fed on low selenium diet.

We have studied the turnover of dopamine, noradrenaline, and serotonin and their metabolites in hippocampus of adult female rats that were fed control or selenium-deficient diets during 15 days. Under these circumstances, there was an increase of dopamine turnover (4-fold) in rats fed with selenium-deficient diet with respect to controls and also an increase in the tyrosine hydroxylase activity (75.8%), which was the result of the increase of the amount of the enzyme (2-fold), without significant change in the phosphorylation of the tyrosine hydroxylase. In addition the glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase activities have been studied. After selenium-deficient diet, the enzymatic activities of superoxide dismutase and catalase did not show change with respect to the controls; however glutathione reductase and glutathione peroxidase significantly decreased 15% and 29%, respectively. It is concluded that the increase in dopamine turnover seems to be associated with the induction of tyrosine hydroxylase enzyme. In these conditions the decrease in antioxidant capacity may produce a cascade of events, which accelerates the degenerative process, since the increase in dopamine turnover produces an increase in oxygen radical by monoamine oxidase activity.

Age-related changes in biogenic amines, opiate, and steroid receptors in the prepubertal bull calf.

Events leading to the increase in pulsatile LH secretion during prepubertal development in the bull calf may include removal of inhibitory or the development of stimulatory mechanisms affecting the hypothalamic release of GnRH. To examine possible contributing systems, serial blood samples were collected from Holstein bull calves at 2, 5, and 10 wk of age one day prior to receiving either no treatment (controls) or two injections of alpha-methyl-p-tyrosine (alpha-MPT), an inhibitor of catecholamine synthesis. Blood was sampled every 10 min for 5 h and serum was analyzed for LH by RIA. Following treatment, animals were killed and hypothalamic and pituitary tissues were removed for analysis of total opiate receptors, mu-opiate receptors, estrogen and androgen receptors and concentrations of monoamines: dopamine, the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DO-PAC), norepinephrine, serotonin, and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA). Pulses of LH increased from non-detectable at 2 wk to nearly 1.5 pulses per sampling period at 10 wk. Pulse height rose to 0.95 +/- 0.16 ng/ml at 10 wk. Total opiate receptor number as determined by binding to naloxone was unchanged in all tissues between 2 and 10 wk. In contrast, mu-opiate receptors (DAGO binding) increased 2-fold in the preoptic-anterior hypothalamic area between 5 and 10 wk. No age-related changes in estrogen receptor concentrations were observed in any tissue except the anterior pituitary in which binding increased 3.2-fold between 2 and 10 wk. A similar increase was not noted for androgen receptors in the pituitary; however, testosterone binding in the preoptic-anterior hypothalamic area was 4.6-fold higher at 5 wk compared to levels at 2 and 10 wk.(ABSTRACT TRUNCATED AT 250 WORDS)

Oestradiol increases the extracellular levels of amine metabolites in the ewe hypothalamus during anoestrus: a microdialysis study.

Giving a subcutaneous oestradiol implant during anoestrus to ovariectomized ewes inhibits pulsatile LH secretion. This effect results from an increased negative feedback of oestradiol and depends on the synthesis of biogenic amines, mainly from the mediobasal hypothalamus. In the present study, we examined the effect of oestradiol on the extracellular levels of amines and their metabolites. Eight ewes were sampled by microdialysis from the lateral retrochiasmatic area, including the dopaminergic A15 nucleus, during inhibition of LH secretion by long days. Two dialysis sessions were carried out on each ewe; one after a 10-day oestradiol treatment and the other one after 10 days without oestradiol treatment. Half of the ewes were first oestradiol-treated then untreated, the other half received the treatment in the reverse order. Oestradiol caused a decline in pulsatile LH secretion without affecting the secretion of prolactin. This steroid also led to a significant increase in the levels of amine metabolites: 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid in the extracellular medium. These results demonstrate the effect of oestradiol on aminergic activity as related to changes in hormonal secretions during long days (16 h of light per 24 h). Thus our data support the hypothesis that amines inhibit gonadotrophic secretion during anoestrus in the ewe and suggest that there is an activation of the aminergic neurones from the retrochiasmatic area in this regulatory mechanism.

Reduced aminergic synthesis in the hypothalamus of the infertile, genetically diabetic (C57BL/KsJ-db/db) male mouse.

Diabetes mellitus is commonly associated with reproductive neuroendocrinopathy in both humans and animal models for the disease. Diabetes-associated reproductive failure in the male is a result of multilevel dysfunction within the hypothalamo-pituitary-testicular axis. In view of the known effects of diabetes on hypothalamic gonadotropin-releasing hormone (GnRH) and gonadotropins in chemically-induced animal models for diabetes, we examined hypothalamic aminergic activities (important to the regulation of GnRH release), circulating gonadotropin levels and testicular morphology in the infertile, genetically diabetic (C57BL/KsJ-db/db) male mouse. Groups of 2-5 month old (average age: 3.4 months) and 6-11 month old (average age: 8.8 months) diabetic mice were compared with age-matched non-diabetic (C57BL/KsL(-)+/?) male mice. Diabetic mice in both age groups were markedly obese and hyperglycemic. Hypothalamic serotonin synthesis was inhibited in the preoptic area-anterior hypothalamus (POA-AH) in both 2-5 month old and 6-11 month old diabetic mice as well as in the mediobasal hypothalamus-median eminence (MBH-ME) of 6-11 month old diabetic mice. Catecholamine synthesis (norepinephrine and dopamine) was reduced in the POA-AH of 2-5 month old diabetic mice and in the MBH-ME of 6-11 month old mice. These aminergic changes were associated in 2-5 month old diabetic mice with reduced circulating levels of LH and in 6-11 month old diabetic mice, of both LH and FSH. In 6-11 month old diabetic mice, testes were characterized by a thickened tunica albuginea, numerous Sertoli cells and the near absence of any spermatogenic cells. The epididymis from these diabetic mice was devoid of spermatozoa.(ABSTRACT TRUNCATED AT 250 WORDS)

A disorder of biogenic amines in dihydropteridine reductase deficiency.

A severe deficiency of dihydropteridine reductase (DHPR) in liver, brain, and cultured skin fibroblasts was demonstrated in a child with hyperphenylalaninemia and an atypical form of phenylketonuria. DHPR is required for regeneration of the cofactor, tetrahydrobiopterin. The cofactor is essential in hydroxylation of aromatic amino acid precursors in the biosynthesis of neurotransmitters, serotonin, dopamine, and norepinephrine. In gray tissue at brain biopsy, dopamine was low at 3 ng per gram of tissue, serotonin was barely detected, and norepinephrine appeared high at 1600 ng per gram. In cerebrospinal fluid, homovanillic acid (HVA) was low normal at 33 ng/ml, 5-hydroxyindoleacetic acid (5-HIAA) was low at 4.2 ng/ml, and after a high dose of oral probenecid there was impaired accumulation of HVA to 128 ng/ml and 5-HIAA to 22.4 ng/ml. When the patient was 22 months of age, treatment with hydroxylated aromatic amino acid precursors was initiated, and after three months HVA and 5-HIAA levels were increased in CSF. The apparent restoration of biogenic amines in brain appears to have delayed the rate of neurological deterioration. DHPR activity in cultured skin fibroblasts of children with persistent hyperphenylalaninemia should permit early diagnosis and early treatment of this disorder.

Biogenic amine response to whole body irradiation. Prevention by APTH.

60Co whole body irradiation with 154.8 mC/kg (600 R) resulted in a mortality of 50 per cent within two weeks. Administration of 1-acetyl-3-phenylamidine thiocarbamide hydrochloride (APTH) 30 min before irradiation prevented this mortality. Irradiation eliminated neurosecretory material from the perikaryons of the supraoptic and paraventricular neurons, whereas APTH counteracted this action. APTH also increased the synthesis of bioamines (5-hydroxytryptamine, catecholamine and acetylcholine).