Lactobacillus acidophilus supernatant alleviates osteoporosis by upregulating colonic SERT expression.

Aims: To investigate the involvement of serotonin transporter (SERT) in colonic epithelial cells in the anti-osteoporosis role of Lactobacillus acidophilus (LA) supernatant (LAS). Methods: The abundance of fecal LA and bone mineral density (BMD) in patients with osteoporosis (OP) or severe osteoporosis were assessed. The protective role of LA in osteoporosis and the expression of SERT and relative signaling were evaluated. Results: Abundance of fecal LA was decreased in patients with severe OP and was positively correlated with BMD. Supplementing LAS to mice alleviated senile osteoporosis. In vitro, NOD2/RIP2/NF-κB signaling was inhibited by LAS due to increased SERT expression. Conclusion: LAS alleviates OP in mice by producing protective metabolites and upregulating SERT expression and represents a promising therapeutic agent.

Saffron carotenoids reversed the UCMS-induced depression and anxiety in rats: Behavioral and biochemical parameters, and hippocampal BDNF/ERK/CREB and NR2B signaling markers.

BACKGROUND: Depression is a debilitating condition that affects the mind and the individual's body. The improving effects of saffron on depression and anxiety have long been discussed, with limited information about the molecular mechanism of action. HYPOTHESIS/PURPOSE: Investigating the effect of saffron carotenoids, Crocin and Crocetin, on depression and anxiety in rats by emphasizing some signaling pathways involved. STUDY DESIGN: Depression and anxiety were induced in rats via unpredictable chronic mild stress (UCMS). Then different rat groups were treated with Crocin, Crocetin, Fluoxetine, and vehicle. Behavioral tests were done before and after treatment. METHODS: The serum Serotonin and Corticosterone and the expression of some hippocampal signaling proteins were studied. Furthermore, bioinformatics tools were used to predict the interactions of Crocin/ Crocetin with the Serotonin transporter and NMDA receptor subunit NR2B. Then, the patch-clamp was used to study the interaction of Crocetin with the NMDA receptor. RESULTS: Various behavioral tests confirmed the induction of depression and the improvement of depression by these natural carotenoids. In addition, Crocin/ Crocetin significantly increased the decreased serum Serotonin and reduced the increased serum Corticosterone in the depressed groups. They also increased or caused a trend of increase in the CREB, ERK, BAD, BDNF, p11, and 5-HT1B expression in the hippocampus of the depressed groups. In addition, there were an increase or a trend in p-CREB/CREB, p-ERK1/2 /ERK1/2, and p-BAD/BAD ratios in the Crocin/ Crocetin treated depressed groups. However, the NR2B and FOXO3a expression showed a trend of decrease in depressed groups after treatment. The bioinformatics data indicated that Crocin/ Crocetin could bind to the Serotonin transporter (SLC6A4) and NR2B subunit of the NMDA receptor. Both carotenoids bind to the same site as Fluoxetine in the SLC6A4. However, they bound to different sites on the NR2B. So, Crocetin binds to NR2B at the same site as Ifenprodil. But Crocin bound to another site. The whole cell patch-clamp recording on the normal rat hippocampus revealed a significant decrease in the NMDA peak amplitude after Crocetin treatment, indicating its inhibitory effect on this receptor. CONCLUSION: The antidepressant activities of Crocin/ Crocetin are possibly due to their effects on Serotonin and Corticosterone serum concentrations, NR2B expression, and the downstream signaling pathways. Furthermore, these natural carotenoids, like Fluoxetine, induced an increasing tendency in p11 and 5HT1B in depressed rats.

Decreased Expression of KLF4 Leading to Functional Deficit in Pediatric Patients with Intestinal Failure and Potential Therapeutic Strategy Using Decanoic Acid.

Pediatric intestinal failure (IF) is the reduction in gut function to below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. The overall goal in treating IF is to achieve intestinal adaptation; however, the underlying mechanisms have not been fully understood. In this study, by performing single-cell RNA sequencing in pediatric IF patients, we found that decreased Kruppel-Like Factor 4 (KLF4) may serve as the hub gene responsible for the functional deficit in mature enterocytes in IF patients, leading to the downregulation of solute carrier (SLC) family transporters (e.g., SLC7A9) and, consequently, nutrient malabsorption. We also found that inducible KLF4 was highly sensitive to the loss of certain enteral nutrients: in a rodent model of total parenteral nutrition mimicking the deprivation of enteral nutrition, the expression of KLF4 dramatically decreased only at the tip of the villus and not at the bottom of crypts. By using IF patient-derived intestinal organoids and Caco-2 cells as in vitro models, we demonstrated that the supplementation of decanoic acid (DA) could significantly induce the expression of KLF4 along with SLC6A4 and SLC7A9, suggesting that DA may function as a potential therapeutic strategy to promote cell maturation and functional improvement. In summary, this study provides new insights into the mechanism of intestinal adaptation depending on KLF4, and proposed potential strategies for nutritional management using DA.

[Effect of Rehmanniae Radix on depression-like behavior and hippocampal monoamine neurotransmitters of chronic unpredictable mild stress model rats].

To investigate the effect of Rehmanniae Radix on depression-like behavior and monoamine neurotransmitters of chronic unpredictable mild stress(CUMS) model rats. CUMS combined with isolated feeding was used to induce the depression model of rats. The depression-like behavior of rats was evaluated by sucrose preference test, open field test, and forced swim test. Hematoxylin-Eosin(HE) staining was used to investigate the pathological changes of neurons in the CA1 and CA3 area of hippocampus. Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) was used to detect the contents of 5-hydroxytryptamine(5-HT), 5-hydroxyindoleacetic acid(5-HIAA), dopamine(DA), 3,4-dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA), norepinephrine(NE), and 3-methoxy-4-hydroxyphenyl glycol(MHPG) in rats. Western blot was used to detect the protein expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), and monoamine oxidase A(MAO-A) in the hippocampus of rats. Compared with the normal group, depressive-like behavior of rats was obvious in the model group. The arrangements of neurons in the CA1 and CA3 area of hippocampus were loose and disorderly. The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in the hippocampal area were decreased(P<0.01). The protein expression of TPH2 was decreased(P<0.01), but those of SERT and MAO-A were increased(P<0.01). In the Rehmanniae Radix groups with 1.8 g·kg~(-1) and 7.2 g·kg~(-1), the depression-like behavior of CUMS rats and pathological changes of neurons in CA1, CA3 area of hippocampus were improved. The protein expression of TPH2(P<0.05, P<0.01) was increased, and those of SERT and MAO-A were down-regulated(P<0.05, P<0.01). The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in hippocampus were increased(P<0.05, P<0.01). The changes in DA, DOPAC, HVA, DA/(DOPAC +HVA), NE, DHPG, and NE/DHPG were not statistically significant. The results suggested that Rehmanniae Radix improved depression-like behavior of CUMS rats, and the mechanism might be related to the regulation of synthesis, transportation, and metabolism of 5-HT neurotransmitter in the hippocampus.

The response to prolonged fasting in hypothalamic serotonin transporter availability is blunted in obesity.

BACKGROUND AND AIMS: Serotonergic and dopaminergic systems in the brain are essential for homeostatic and reward-associated regulation of food intake and systemic energy metabolism. It is largely unknown how fasting influences these systems or if such effects are altered in humans with obesity. We therefore aimed to evaluate the effects of fasting on hypothalamic/thalamic serotonin transporter (SERT) and striatal dopamine transporter (DAT) availability in lean subjects and subjects with obesity. METHODS: In this randomized controlled cross-over trial, we assessed the effects of 12 vs 24 h of fasting on SERT and DAT availability in the hypothalamus/thalamus and striatum, respectively, using SPECT imaging in 10 lean men and 10 men with obesity. RESULTS: As compared with the 12-h fast, a 24-h fast increased hypothalamic SERT availability in lean men, but not in men with obesity. We observed high inter-individual variation in the effects of fasting on thalamic SERT and striatal DAT, with no differences between lean men and those with obesity. In all subjects, fasting-induced increases in circulating free fatty acid (FFA) concentrations were associated with an increase in hypothalamic SERT availability and a decrease in striatal DAT availability. Multiple regression analysis showed that changes in plasma insulin and FFAs together accounted for 44% of the observed variation in striatal DAT availability. CONCLUSION: Lean men respond to prolonged fasting by increasing hypothalamic SERT availability, whereas this response is absent in men with obesity. Inter-individual differences in the adaptations of the cerebral serotonergic and dopaminergic systems to fasting may, in part, be explained by changes in peripheral metabolic signals of fasting, including FFAs and insulin.

Gastrodin - A potential drug used for the treatment of Tourette Syndrome.

Gastrodin (Gas) represents the major active component of Gastrodia elata, a Chinese herb. Clinically, Gas is widely used for its sedative, anticonvulsive and neuroprotective properties. This work aimed to assess Gas for its efficacy in Tourette Syndrome (TS) treatment. Twenty-four rats were randomized to the blank control (n = 6) and experimental (n = 18) groups. The experimental group was administered continuous injection of 3, 3'-iminodipropionitrile (IDPN) intraperitoneally for 7 days, and subdivided into the IDPN + NS, IDPN + Hal, and IDPN + Gas groups (n = 6). The control and IDPN + NS groups received saline intragastrically, while the IDPN + Hal and IDPN + Gas groups were administered Gas and Haloperidol, respectively, for 8 weeks. Then, micro-positron emission tomography (PET) was performed for measuring the density and brain distribution of dopamine D2 receptors (D2Rs), dopamine transporters (DATs), 5-HT2A receptors (5-HT2ARs) and 5-HT transporters (SERTs). According to stereotypical behavior experiments, IDPN significantly induced abnormal stereotypical behaviors in rats in comparison with control animals. In addition, micro-PET revealed that by reducing the amounts of D2Rs and increasing those of DATs, Gas could significantly reduce stereotypical TS-like behaviors in this rat model system. Furthermore, Gas treatment reduced the density of SERTs, which could indirectly decrease DA release. The current study demonstrated that Gas could be effective in treating TS.

Antidepressant activities and regulative effects on serotonin transporter of Nardostachys jatamansi DC.

ETHNOPHARMACOLOGICAL RELEVANCE: Nardostachys jatamansi (D.Don) DC. (family Caprifoliaceae, NJ) is well-documented and commonly used in the systems of traditional medicine in China, Tibet, Nepal, Bhutan, India and Japan for curing digestive and neuropsychiatric disorders with a long history of medication. However, the possible action mechanisms of antidepressant effects of NJ remain unraveled. AIM OF THE STUDY: The aim of this study was to systematically investigate chemical substances of NJ and their effects on serotonin transporter (SERT) in antidepressant activity. MATERIALS AND METHODS: Antidepressant effects of total methanol extract of NJ were evaluated by tail suspension test (TST) and open field test (OFT). Then the total extract was analyzed by ultra-high-performance liquid chromatography (UHPLC) method, and its effect on SERT activity was evaluated by high content assay (HCA) to determine half maximal effective concentration (EC50). This total extract was subfractioned into twenty subfractions by preparative high-performance liquid chromatography (p-HPLC) method, and 'subfraction-SERT activity' relationship curve was fitted with medians of the retention time of those subfractions and their SERT activity values. Then, the fraction NJFr.01 enriched with SERT enhancers was optimized, prepared and analyzed by UHPLC method. Antidepressant effects of the fraction NJFr.01 were evaluated by TST and OFT. Further, major constituents of the total extract and fraction NJFr.01 were isolated by p-HPLC and identified by extensive nuclear magnetic resonance (NMR) analyses and comparisons with those reported data, and their SERT activities were also evaluated. Finally, antagonistic effects of chlorogenic acid and desoxo-narchinol A against fluoxetine on SERT were evaluated. RESULTS: Results of TST and OFT demonstrated antidepressant effects of toatal extract of NJ. The EC50 of total extract on SERT enhancement was 31.63 µg/mL. The fitted 'subfraction-SERT activity' relationship curve revealed that fraction NJFr.01 was enriched with SERT enhancing constituents. Both total extract and fraction NJFr.01 significantly enhanced SERT activity, while the rest fraction NJFr.02 didn't show any SERT activity. Then, antidepressant effects of fraction NJFr.01 were demonstrated by TST and OFT. Further, phytochemistry investigation and UHPLC analyses confirmed the identification of fourteen constituents in the total extract of NJ, including 7-oxonardinoperoxide (1), desoxo-narchinol A (2), kanshone B (3), narchinol B (4), nardosinonediol (5), kanshone A (6), 1-hydroxylaristolone (7), debilon (8), nardosinone (9), kanshone H (10), 1,8,9,10-tetradehydroaristolan-2-one (11), (-)-aristolone (12), 1(10)-aristolene-2-one (13) and jatamol A (14), and seven constituents in the fraction NJFr.01, including chlorogenic acid (15), 8α-dihydrogeniposide (16), 7-deoxy-8-epi-loganic acid (17), adoxosidic acid (18), 8-epi-loganic acid (19), 8α-6,7-dihydroapodantheroside acetate (20) and 6″-acetylpatrinalloside (21). Their structures were established by NMR analyses and comparisons with those reported data. HCA results of these constituents demonstrated the major components of fraction NJFr.01 enhanced SERT activity. Antagonistic results showed that chlorogenic acid and desoxo-narchinol A reversed inhibition effect of fluoxetine on SERT activity. CONCLUSION: This study first systematically expatiated the roles of SERT activity in antidepressant effects of NJ, including total methanol extract and the water-soluble fraction NJFr.01 enriched with SERT enhancing constituents. This is the first report of natural SERT enhancing extract and fractions with antidepressant potential in NJ.

Acute administration of levetiracetam in tonic pain model modulates gene expression of 5HT1A and 5HT7 receptors in the thalamus of rats (Rattus norvergicus).

The nociceptive effect of Levetiracetam (LEV) on the expression of 5-HT1A and 5-HT7 receptors found in the thalamus was evaluated. Thirty-six male rats (Wistar) were randomized into six groups: in the Control group without treatment; LEV50 group LEV was administered in a single dose of 50 mg/kg i.g.; in the LEV300 group LEV dose of 300 mg/kg i.g.; in the FORMALIN group the formalin test was performed; in the LEV50/FORMALIN group LEV dose of 50 mg/kg i.g and the formalin test was performed; in the LEV300/FORMALIN group LEV dose of 300 mg/kg i.g and the formalin test was performed, subsequently the thalamus was dissected in all groups. In the formalin tests LEV exhibited an antinociceptive effect in the LEV300/FORMALIN group (p < 0.05) and a pronociceptive effect in the LEV50/FORMALIN group (p < 0.001). The results obtained by Real-time PCR confirmed the expression of the 5-HT1A and 5-HT7 receptors in the thalamus, 5-HT1A receptors increased significantly in the FORMALIN group and the LEV300/FORMALIN group (p < 0.05). 5-HT7 receptors are only over expressed at a dose of 300 mg/Kg of LEV with formalin (p < 0.05). This suggests that LEV modulates the sensation of pain by controlling the expression of 5-HT1A and 5-HT7 in a tonic pain model, and that changes in the expression of 5-HT1A and 5-HT7 receptors are associated with the sensation of pain, furthermore its possibility to be used in clinical treatments for pain.

Effects of Paeonia lactiflora Extract on Estrogen Receptor ß, TPH2, and SERT in Rats with PMS Anxiety.

This study is to investigate the effect of Paeonia lactiflora extract on PMS anxiety and on expression of estrogen receptor ß (ERß), tryptophan hydroxylase-2 (TPH2), and serotonin transporter (SERT) in the premenstrual syndrome (PMS) anxiety model rats. The vaginal smear and open field test were used to screen rats in nonreception phase of estrus cycle with similar macroscopic behaviors and regular estrus cycle. PMS anxiety model rats were prepared by electrical stimulation. RT-PCR and immunofluorescence were used to measure the expression of ERß, TPH2, and SERT. Compared with normal rats, the total distance in the open field test of the model rats was significantly increased (P < 0.05). The model rats showed nervous alertness, irritability, and sensitivity to external stimuli. After treatment with the Paeonia lactiflora extract, the total distance of rats was significantly reduced (P < 0.05). In reception stage, there was no significant difference in the mRNA and protein expression of ERß, TPH2, and SERT. In nonreception stage, the expression of ERß and TPH2 in the model group was significantly decreased (P < 0.05) as compared with the control group, but not SERT. Abnormal changes of the above indicators were reversed after the administration of the Paeonia lactiflora extract. In conclusion, Paeonia lactiflora extract can increase the expression of ERß and TPH2 and decrease SERT in PMS model rats, which may be one of the mechanisms underlying the effect of Paeonia lactiflora extract on PMS.

An integrative analysis of 5HTT-mediated mechanism of hyperactivity to non-threatening voices.

The tonic model delineating the serotonin transporter polymorphism's (5-HTTLPR) modulatory effect on anxiety points towards a universal underlying mechanism involving a hyper-or-elevated baseline level of arousal even to non-threatening stimuli. However, to our knowledge, this mechanism has never been observed in non-clinical cohorts exhibiting high anxiety. Moreover, empirical support regarding said association is mixed, potentially because of publication bias with a relatively small sample size. Hence, how the 5-HTTLPR modulates neural correlates remains controversial. Here we show that 5-HTTLPR short-allele carriers had significantly increased baseline ERPs and reduced fearful MMN, phenomena which can nevertheless be reversed by acute anxiolytic treatment. This provides evidence that the 5-HTT affects the automatic processing of threatening and non-threatening voices, impacts broadly on social cognition, and conclusively asserts the heightened baseline arousal level as the universal underlying neural mechanism for anxiety-related susceptibilities, functioning as a spectrum-like distribution from high trait anxiety non-patients to anxiety patients.

Early life stress induced by maternal separation during lactation alters the eating behavior and serotonin system in middle-aged rat female offspring.

Stressful events occurring during early life have been related to behavioral and neurochemical disturbances. Maternal separation during the first two weeks of life is a traumatic event that strongly affects the feeding behavior and serotonergic system of the progeny in adulthood. As this system modulates the feeding behavior, the present study aimed at investigating the effects of maternal separation-induced stress on both the feeding behavior and serotonergic system of the middle-aged female rats by manipulating this system using fluoxetine, a selective serotonin transporter inhibitor. Lactating Wistar rats were separated from their litters from postnatal day 2 (PND 2) to PND 14 for 3 h in the dark phase of the circadian cycle. The maternally separated (MS) and control (C) groups were distinguished from each other based on the incidence or absence of maternal separation (early life stress). All the analyses were done on the female offspring from one-year of age. Maternal separation anticipated the satiety point in these females. This anticipation was linked to lower food intake, meal duration and meal size. These results mirrored the effects of fluoxetine in the control animals. Furthermore, maternal separation was associated with 5ht1b serotonin receptor hyperexpression in the hypothalamus. These findings demonstrate that maternal separation has long-lasting effects on the eating behavior and serotonergic system and that this system could be responsible for mediating these behavioral outcomes.

Network Pharmacology-based Research of Active Components of Albiziae Flos and Mechanisms of Its Antidepressant Effect.

Albiziae Flos (AF) has been experimentally proven to have an antidepressant effect. However, due to the complexity of botanical ingredients, the exact pharmacological mechanism of action of AF in depression has not been completely deciphered. This study used the network pharmacology method to construct a component-target-pathway network to explore the active components and potential mechanisms of action of AF. The methods included collection and screening of chemical components, prediction of depression-associated targets of the active components, gene enrichment, and network construction and analysis. Quercetin and 4 other active components were found to exert antidepressant effects mainly via monoaminergic neurotransmitters and cAMP signaling and neuroactive ligand-receptor interaction pathways. DRD2, HTR1A, and SLC6A4 were identified as important targets of the studied bioactive components of AF. This network pharmacology analysis provides guidance for further study of the antidepressant mechanism of AF.

Early weaning modulates eating behavior and promotes hypofunction of the serotonergic (5HT) system in juvenile male rats.

Early life stress (ELS) has been associated with developmental impairments. Early weaning (EW) is a postnatal stress model consisting of interruption of lactation and maternal care. The 5HT-system has been associated with neurobehavioral modulations promoted by ELS. Thus, the present work aims to investigate the effects of early weaning on feeding behavior and serotonergic system of juvenile male rats. For this, rats were submitted to early (PND15) or natural (PND30) weaning and had the body weight, food intake in circadian phases, and food intake in response to fenfluramine assessed. mRNA expression of serotoninergic receptors (5HT1A and 5HT2C) and transporter (SERT) was assessed in the hypothalamus and brainstem, as well as NPY and POMC mRNA expression in hypothalamus. The results show that early weaning promoted changes in the percentage of weight gain during lactation period and increase in body weight at PND40. It was also observed that EW promoted increase and decrease in food intake in light and dark phase, respectively, and leads to a decreased action of fenfluramine on inhibition of food intake. In addition, early weaning promoted increased NPY and SERT mRNA expression in the hypothalamus and 5HT2C in the brainstem. Together, the data indicate that the stress caused by early weaning impairs the eating behavior of juvenile male rats through hypofunction of the 5HT-system.

Early weaning leads to disruption of homeostatic and hedonic eating behaviors and modulates serotonin (5HT) and dopamine (DA) systems in male adult rats.

Early weaning is associated with disruption of eating behavior. However, little is known about the mechanisms behind it. 5HT and DA systems are key regulators of homeostatic and hedonic eating behaviors, respectively. Thus, this study aims to evaluate the effects of early weaning on feeding behavior and 5HT and DA systems. For this, rats were submitted to regular (PND30) or early weaning (PND15) and between PND250 and PND300 were evaluated food intake of standard diet in response to 4 h food deprivation, during the 24 h period and per phase of the circadian cycle, in addition to the palatable food intake. Additionally, body mass and mRNA expression of 5HT1B, 5HT2C, SERT, DRD1 and DRD2 were evaluated in the hypothalamus and brainstem. The results demonstrate that early weaning promoted an increase in standard food intake in response to a 4 h food deprivation in the 24 h period and in the dark phase of the circadian cycle, in addition to an increased palatable food intake. No differences in body mass between regular or early weaning were observed. In the hypothalamus, increased mRNA expression of SERT and DRD1 was observed, but decreased 5HT1B mRNA expression. In the brainstem, the expression of 5HT1B, SERT, 5HT2C, DRD1 and DRD2 was increased in early weaned rats. In a nutshell, the stress promoted by early weaning has programmed the animals to be hyperphagic and to increase their palatable food intake, which was associated with modulation of 5HT and DA systems.

D-578, an orally active triple monoamine reuptake inhibitor, displays antidepressant and anti-PTSD like effects in rats.

Significant unmet needs exist for development of better pharmacotherapeutic agents for major depressive disorder (MDD) and post-traumatic stress disorder (PTSD) as the current drugs are inadequate. Our goal in this study is to investigate behavioral pharmacological characterization of a novel triple reuptake inhibitor (TRI) D-578 which exhibits nanomolar potency at all three monoamine transporters (Ki; 16.2. 16.2, 3.23 nM, and 29.6, 20.6, 6.10 nM for the rat brain and cloned human dopamine, serotonin and norepinephrine transporters, respectively) and exhibited little to no affinity for other off-target CNS receptors. In a rat forced swim test, compound D-578 upon oral administration displayed high efficacy and not stimulating in locomotor behavior. The effects of D-578 and paroxetine were next evaluated in a rat model for traumatic stress exposure - the single prolonged stress (SPS) model - which has been shown to have construct, predictive, and behavioral validity in modeling aspects of PTSD. Our results show that SPS had no effect on the acquisition of conditioned fear, but impaired extinction learning and extinction retention of fear behavior compared to sham treatment. D-578, but not paroxetine, attenuated the extinction and extinction-retention deficit induced by SPS. These findings suggest that D-578 has greater efficacy in normalizing traumatic stress-induced extinction-retention learning in a model for PTSD compared to paroxetine. Overall these results suggest that D-578, in addition to producing a robust and efficacious antidepressant effect, may attenuate maladaptive retention of fearful memories and support further testing of this agent for the pharmacotherapy of depression and PTSD.

Uncovering pharmacological mechanisms of Zhi-Zi-Hou-Po decoction in chronic unpredictable mild stress induced rats through pharmacokinetics, monoamine neurotransmitter and neurogenesis.

ETHNOPHARMACOLOGICAL RELEVANCE: Zhi-Zi-Hou-Po decoction (ZZHPD), a classical Chinese prescription, has been reported to improve depressive behaviors in clinic. However, definite pharmacological effects and mechanisms of ZZHPD on monoaminergic system and hippocampal neurogenesis are ambiguous. It need to be further illuminated. AIM OF THE STUDY: Our study is designed to reveal pharmacological mechanisms of ZZHPD on depression through pharmacokinetics, monoamine neurotransmitters and neurogenesis. MATERIALS AND METHODS: Chronic unpredictable mild stress (CUMS) is used to establish rats model of depression. Then, the antidepressant effects of ZZHPD are evaluated by detecting body weight, sucrose preference and forced swimming test. The regulatory functions of ZZHPD on monoaminergic system are assessed by measuring monoamine neurotransmitters, neurotransmitter precursor substances, synthesized rate-limiting enzymes and transporters. Finally, potential molecular mechanism of ZZHPD on hippocampal neurogenesis is evaluated by investigating newborn immature neuron and newborn mature neuron. RESULTS: Our results show that ZZHPD remarkably normalizes CUMS-induced decline in weight gain, decrease of sucrose consumption rate in sucrose preference test and increase of immobility time in forced swimming test. Moreover, ZZHPD significantly reverses CUMS-induced reduction of 5-hydroxytryptamine (5-HT), dopamine (DA), tryptophan (Trp), tyrosine (Tyr), tryptophan hydroxylase2 (TPH2) and tyrosine hydroxylase (TH), whereas decreases level of serotonin transporter (SERT) in CUMS-induced rats. Finally, ZZHPD obviously improves CUMS-induced decrease of newborn immature neuron and newborn mature neuron in dentate gyrus of hippocampus. CONCLUSION: This study demonstrates that ZZHPD can alleviate CUMS-induced depression-like behaviors. It is probably attributed to the fact that ZZHPD could enhance monoaminergic system and hippocampal neurogenesis. Our findings provide the new perspectives on molecular targets of ZZHPD, and it will facilitate its clinical application.

Bioactivities of serotonin transporter mediate antidepressant effects of Acorus tatarinowii Schott.

ETHNOPHARMACOLOGICAL RELEVANCE: Acrorus tatarinowii Schott has been widely used in the treatments of neuropsychiatric and digestive disorders in clinical practices of traditional Chinese medicine for thousands of years. Both clinical and preclinical studies demonstrated antidepressant effects of A. tatarinowii. However, the possible action mechanisms of antidepressant effects of A. tatarinowii remain unraveled. AIM OF THE STUDY: The present study aimed to investigate the roles of serotonin transporter (SERT) in antidepressant effects of A. tatarinowii. MATERIALS AND METHODS: Antidepressant effects of water extract of A. tatarinowii were evaluated by forced swimming test (FST), tail suspension test (TST) and locomotor activity test. The water extract was analyzed by ultra high performance liquid chromatography (UPLC) method. Two major fractions of A. tatarinowii, petroleum ether extract and water extract after petroleum ether processed, were prepared and analyzed by UPLC method. Further, volatile oil extracted by ether extraction, solid phase micro-extraction (SPME) and hydro-distillation were compared and analyzed by gas chromatography-mass spectrometer (GC-MS) method. Finally, major constituents of water extract of A. tatarinowii were isolated by preparative high performance liquid chromatography (HPLC) and identified by extensive spectroscopic analyses. Effects of all of the above mentioned samples on SERT activity were tested by a high content assay (HCA). RESULTS: Results of FST, TST and locomotor activity confirmed that water extract of A. tatarinowii significantly decreased mice immobility time but did not change mice locomotor activity. UPLC analysis results revealed that the water extract contained trace amount of ß-asarone (0.0004206%) and α-asarone (0.0001918%). HCA results demonstrated that the water extract significantly enhanced SERT activity at 100 µg/mL. Further, GC-MS and UPLC analyses revealed that petroleum ether extract contained high content of ß-asarone (45.63%) and α-asarone (12.50%). GC-MS analysis results demonstrated that the volatile oil extracted by ether extraction, SPME and hydro-distillation contained similar major components. HCA results verified that the petroleum ether extract significantly enhanced SERT activity at 1.56 µg/mL. Moreover, UPLC analysis of water extract after petroleum ether processed did not show any characteristic peaks. HCA results demonstrated that this extract significantly inhibited SERT activity at 50-100 µg/mL. Finally, phytochemistry investigation on the water extract of A. tatarinowii afforded seven constituents including veratric acid (9), anisic acid (7), 3,4,5-trimethoxybenzoic acid (3), trans-isoferulic acid (2), 2,4,5-trimethoxybenzoic acid (11), 4-hydroxybenzoic acid (6) and syringic acid (13). Their structures were established on the basis of nuclear magnetic resonance (NMR) and mass spectrometer (MS) data and comparative UPLC analyses. HCA results demonstrated the major components of the water extract of A. tatarinowii demonstrated SERT enhancement/inhibition activities. CONCLUSIONS: This study first systematically demonstrated the roles of SERT activity in antidepressant effects of A. tatarinowii, including water extract, major fractions and main constituents. These results revealed that A. tatarinowii could regulate SERT activities in bidirectional ways.

Dose-dependent effects of the selective serotonin reuptake inhibitor citalopram: A combined SPECT and phMRI study.

BACKGROUND: Serotonin transporter blockers, like citalopram, dose-dependently bind to the serotonin transporter. Pharmacological magnetic resonance imaging (phMRI) can be used to non-invasively monitor effects of serotonergic medication. Although previous studies showed that phMRI can measure the effect of a single dose of serotoninergic medication, it is currently unclear whether it can also detect dose-dependent effects. AIMS: To investigate the dose-dependent phMRI response to citalopram and compared this with serotonin transporter occupancy, measured with single photon emission computed tomography (SPECT). METHODS: Forty-five healthy females were randomized to pre-treatment with placebo, a low (4 mg) or clinically standard (16 mg) oral citalopram dose. Prior to citalopram, and 3 h after, subjects underwent SPECT scanning. Subsequently, a phMRI scan with a citalopram challenge (7.5 mg intravenously) was conducted. Change in cerebral blood flow in response to the citalopram challenge was assessed in the thalamus and occipital cortex (control region). RESULTS: Citalopram dose-dependently affected serotonin transporter occupancy, as measured with SPECT. In addition, citalopram dose-dependently affected the phMRI response to intravenous citalopram in the thalamus (but not occipital cortex), but phMRI was less sensitive in distinguishing between groups than SPECT. Serotonin transporter occupancy showed a trend-significant correlation to thalamic cerebral blood flow change. CONCLUSION: These results suggest that phMRI likely suffers from higher variation than SPECT, but that these techniques probably also assess different functional aspects of the serotonergic synapse; therefore phMRI could complement positron emission tomography/SPECT for measuring effects of serotonergic medication.

Striatal DAT and extrastriatal SERT binding in early-stage Parkinson's disease and dementia with Lewy bodies, compared with healthy controls: An 123I-FP-CIT SPECT study.

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are thought to be part of a spectrum: both have a clinical profile including symptoms associated with dopaminergic and serotonergic loss, yet few imaging studies have focused on serotonergic neurodegeneration in both disorders. We aimed to study degeneration of terminals with dopamine and serotonin transporter (DAT and SERT, respectively) in patients with early-stage PD and DLB relative to healthy controls, using 123I-N-ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl)nortropane (123I-FP-CIT) single photon emission computed tomography (SPECT). We conducted region of interest (ROI) and voxel-based analyses on 123I-FP-CIT SPECT scans. Using the cerebellum as a reference region, we determined binding ratios (BRs) for bilateral ROIs in the DAT-rich striatum (head of the caudate nucleus and posterior putamen) and SERT-rich extrastriatal brain regions (thalamus, hypothalamus and hippocampus). We compared BRs in PD and DLB patients with BRs in healthy controls (all groups: n = 16). Both PD and DLB patients had lower striatal 123I-FP-CIT BRs than healthy controls for the bilateral caudate head (PD-left: F(1,29) = 28.778, P < .001, ω2 = 0.35; right: F(1,29) = 35.338, P < .001, ω2 = 0.42; DLB-left: F(1,29) = 28.241, P < .001, ω2 = 0.31; right: F(1,29) = 18.811, P < .001, ω2 = 0.26) and bilateral posterior putamen (PD-left: F(1,29) = 107.531, P < .001, ω2 = 0.77; right: F(1,29) = 87.525, P < .001, ω2 = 0.72; DLB-left: F(1,29) = 39.910, P < .001, ω2 = 0.48; right: F(1,29) = 26.882, P < .001, ω2 = 0.38). DLB patients had lower hypothalamic 123I-FP-CIT BRs than healthy controls (F(1,29) = 6.059, P = .020, ω2 = 0.12). In the voxel-based analysis, PD and DLB patients had significantly lower striatal binding than healthy controls. Both PD patients in the early disease stages and DLB patients have reduced availability of striatal DAT, and DLB patients lower hypothalamic SERT compared with healthy controls. These observations add to the growing body of evidence that PD and DLB are not merely dopaminergic diseases, thereby providing additional clinicopathological insights.

Post-Weaning Social Isolation Disturbs Gene Expression in Rat Brain Structures.

Post-weaning social isolation of male Wistar rats for 10 weeks led to an increase of their aggressiveness, sensorimotor reactivity, and cognitive deficiency, manifesting in training disorders evaluated by the acoustic startle response (amplitude of the response decreasing). Expression of gene encoding serine protease prolyl endopeptidase (EC 3.4.21.26) in the frontal cortex was higher than in control rats kept in groups, while the level of mRNA of the gene encoding dipeptidyl peptidase IV (EC 3.4.14.5) did not differ from the control in any of the brain structures. The levels of serotonin transporter gene mRNA in the striatum and hypothalamus were higher than in the control. No appreciable changes in the expression of genes encoding tryptophan hydroxylase-2 and monoaminoxidase A and B in the frontal cortex, striatum, amygdala, hypothalamus, and hippocampus were detected. The data indicated the involvement of genes associated with the serotoninergic system in the mechanisms of mental disorders induced by post-weaning social isolation and suggest the gene encoding prolyl endopeptidase as a candidate gene involved in the pathogenesis of these disorders.