Dopamine (DA), as a catecholamine neurotransmitter widely distributed in the central nervous system and the peripheral tissues, has attracted a lot of attention. Especially in recent years, DA has been found to regulate the function of the immune system, and the involvement of DA in the intestinal mucosal inflammation-related diseases has become a hot research topic. The digestive tract is an important source of peripheral DA, and DA is not only produced in the enteric nervous system and gastrointestinal epithelium, but also produced by intestinal microorganisms. In addition to the synthetases of DA, the DA contents in body tissues are also affected by the two kinds of metabolic enzymes, monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). This article reviewed the sources, metabolism, and functions of DA in digestive tract, especially focusing on the distribution and function of MAO and COMT, the enzymes degrading DA.
Catechol O-Methyltransferase ; Catechol O-Methyltransferase Inhibitors ; Dopamine ; Gastrointestinal Tract ; Monoamine Oxidase ; Monoamine Oxidase Inhibitors

Isoquiritigenin,one of the active constituents in the Chinese herb liquorice,is found to have moderate inhibitory activity against rat monoamine oxidase B(MAO-B,IC5047. 2 μmol·L-1). However,the structure-activity relationship(SAR) remains unclear until now. In an attempt to reveal the SAR of inhibition by isoquiritigenin,and to identify more potent and selective inhibitors of MAOB,a series of 13 derivatives based on the scaffold of isoquiritigenin were prepared,and their purities and structures were confirmed by UPLC,1 H-NMR,13 C-NMR and HRMS. These compounds were then evaluated for their ability to inhibit the enzymatic activity of human MAO-B. The SAR of inhibition was summarized and a potent compound C8 with high inhibitory activity(IC501. 4 μmol·L-1) and selectivity(>57 folds over MAO-A) was identified. Enzyme kinetics studies suggested that C8 acted as a competitive inhibitor. In addition,C8 showed little cytotoxicity to glial cells in vitro,which could be a promising lead compound for further study.
Animals ; Drugs, Chinese Herbal ; Humans ; Monoamine Oxidase ; Monoamine Oxidase Inhibitors ; Plant Extracts ; Rats ; Structure-Activity Relationship

Tapentadol is a novel oral analgesic with a dual mode of action as an agonist of the µ-opioid receptor (MOR), and as a norepinephrine reuptake inhibitor (NRI) all in a single molecule. Immediate release (IR) tapentadol shows its analgesic effect quickly, at around 30 minutes. Its MOR agonistic action produces acute nociceptive pain relief; its role as an NRI brings about chronic neuropathic pain relief. Absorption is rapid, with a mean maximal serum concentration at 1.25-1.5 h after oral intake. It is present primarily in the form of conjugated metabolites after glucuronidation, and excretes rapidly and completely via the kidneys. The most common adverse reactions are nausea, dizziness, vomiting, and somnolence. Constipation is more common in use of the ER formulation. Precautions against concomitant use of central nervous system depressants, including sedatives, hypnotics, tranquilizers, general anesthetics, phenothiazines, other opioids, and alcohol, or use of tapentadol within 14 days of the cessation of monoamine oxidase inhibitors, are advised. The safety and efficacy have not been established for use during pregnancy, labor, and delivery, or for nursing mothers, pediatric patients less than 18 years of age, and cases of severe renal impairment and severe hepatic impairment. The major concerns for tapentadol are abuse, addiction, seeking behavior, withdrawal, and physical dependence. The presumed problem for use of tapentadol is to control the ratio of MOR agonist and NRI. In conclusion, tapentadol produces both nociceptive and neuropathic pain relief, but with worries about abuse and dependence.
Absorption ; Acute Pain ; Analgesics, Opioid ; Anesthetics, General ; Behavior, Addictive ; Birds* ; Central Nervous System Depressants ; Chronic Pain ; Constipation ; Dizziness ; Drug-Related Side Effects and Adverse Reactions ; Humans ; Hyperalgesia ; Hypnotics and Sedatives ; Kidney ; Monoamine Oxidase Inhibitors ; Mothers ; Nausea ; Neuralgia ; Nociceptive Pain ; Norepinephrine ; Nursing ; Phenothiazines ; Pregnancy ; Receptors, Adrenergic, alpha ; Receptors, Opioid, mu ; Vomiting

Development of various antidepressants such as monoamine oxidase inhibitors, tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin norepinephrine reuptake inhibitors, and noradrenergic and specific serotonergic antidepressant has led to a tremendous progression of pharmaceutical treatment for depression, but still there are some limitations of current antidepressants, such as treatment-resistant depression and delayed onset of antidepressants. The pathogenesis of depression is unclear because depression is a heterogeneous disease state, and the mechanisms of antidepressants remain uncertain as well. Nevertheless, in an attempt to develop novel antidepressants, some trials have been conducted based on the potential biological mechanism discovered in the numerous research results. This review will provide information about the potential novel antidepressants and the current states of clinical studies using them. In particular, some potential novel antidepressants anti-inflammatory agents, antioxidants, anticholinergics, modulators of Hypothalamic Pituitary Adrenal Axis, glutamate, and opioid systems, as well as some neuropeptides such as susbstance P, neuropeptide Y, and galanin will be discussed.
Anti-Inflammatory Agents ; Antidepressive Agents ; Antidepressive Agents, Tricyclic ; Antioxidants ; Axis, Cervical Vertebra ; Cholinergic Antagonists ; Depression* ; Depressive Disorder ; Drug Therapy ; Galanin ; Glutamic Acid ; Monoamine Oxidase Inhibitors ; Neuropeptide Y ; Neuropeptides ; Norepinephrine ; Serotonin ; Serotonin Uptake Inhibitors

This paper aims to introduce, summarize, and emphasize the importance of the 'Evidence-Based, Pharmacological Treatment Guideline for Depression in Korea, Revised Edition'. The guideline broadly covers most aspects of the pharmacological treatment of patients in Korea diagnosed with moderate to severe major depression according to the DSM-IV TR. The guideline establishment process involved determining and answering a number of key questions, searching and selecting publications, evaluating recommendations, preparing guideline drafts, undergoing external expert reviews, and obtaining approval. A guideline adaptation process was conducted for the revised edition. The guideline strongly recommends pharmacological treatment considered appropriate to the current clinical situation in Korea, and should be considered helpful when selecting the appropriate pharmacological treatment of patients diagnosed with major depressive disorder. Therefore, the wide distribution of this guideline is recommended.
Antidepressive Agents/*therapeutic use ; Antipsychotic Agents/therapeutic use ; Databases, Factual ; Depression/complications/diagnosis/*drug therapy ; Drug Tolerance ; Evidence-Based Practice ; Humans ; Monoamine Oxidase Inhibitors/therapeutic use ; Neurotransmitter Uptake Inhibitors/therapeutic use ; Placebo Effect ; Psychotic Disorders/complications/drug therapy ; Republic of Korea ; Severity of Illness Index

Nowadays newer antidepressants are commonly used in clinical practice, since they are as effective as tricyclic antidepressant, but show less adverse effects. However there are many unexpected adverse effects of these drugs. It is one of the most common causes of treatment failure. I reviewed these adverse effects and pharmacological management focusing on common but under-recognized adverse effects of newer antidepressant. I reviewed newer antidepressant-induced sleep related movement disorder, sweating, tremor, abnormal bleeding. In this paper, newer antidepressants include selective serotonin reuptake inhibitor (fluoxetine, fluvoxamine, citalopram, escitalopram, sertraline, paroxetine), serotonin norepinephrine reuptake inhibitor (venlafaxine, duloxetine), norepinephrine and dopamine reuptake inhibitor (bupropion), noradrenergic and specific serotonergic antidepressant (mirtazapine), and reversible inhibitor of monoamine oxidase A (moclobemide). I suggest that psychiatrists should know not only well-recognized but also under-recognized common adverse effects and their pharmacological management of newer antidepressants, so that it will be helpful to treat patients with psychiatric illness using newer antidepressants and to make better outcome.
Antidepressive Agents* ; Citalopram ; Dopamine ; Fluvoxamine ; Hemorrhage ; Humans ; Monoamine Oxidase Inhibitors ; Movement Disorders ; Norepinephrine ; Psychiatry ; Serotonin ; Sertraline ; Sweat ; Sweating ; Treatment Failure ; Tremor

Monoamine oxidase inhibitors (MAOI) have been widely used as antidepressants. Recently, there has been renewed interest in MAO inhibitors. The activity-guided fractionation of extracts from Angelica keiskei Koidzumi (A. keiskei K.) led to the isolation of two prenylated chalcones, xanthoangelol and 4-hydroxyderricin and a flavonoid, cynaroside. These three isolated compounds are the major active ingredients of A. keiskei K. to inhibit the MAOs and DBH activities. Xanthoangelol is a nonselective MAO inhibitor, and a potent dopamine beta-hydroxylase (DBH) inhibitor. IC50 values of xanthoangelol to MAO-A and MAO-B were calculated to be 43.4 microM, and 43.9 microM. These values were very similar to iproniazid, which is a nonselective MAO inhibitor used as a drug against depression. The IC50 values of iproniazid were 37 microM, and 42.5 microM in our parallel examination. Moreover, IC50 value of xanthoangelol to DBH was calculated 0.52 microM. 4-Hydroxyderricin is a potent selective MAO-B inhibitor and also mildly inhibits DBH activity. The IC50 value of 4-hydroxyderricin to MAO-B was calculated to be 3.43 microM and this value was higher than that of deprenyl (0.046 microM) used as a positive control for selective MAO-B inhibitor in our test. Cynaroside is a most potent DBH inhibitor. The IC50 value of cynaroside to DBH was calculated at 0.0410 microM. Results of this study suggest that the two prenylated chalcones, xanthoangelol and 4-hydroxyderricin isolated from A. keiskei K., are expected for potent candidates for development of combined antidepressant drug. A. keiskei K. will be an excellent new bio-functional food material that has the combined antidepressant effect.
Angelica* ; Antidepressive Agents ; Chalcones ; Depression ; Dopamine beta-Hydroxylase ; Inhibitory Concentration 50 ; Iproniazid ; Monoamine Oxidase ; Monoamine Oxidase Inhibitors ; Oxidoreductases* ; Selegiline

Present anti-PD and -AD drugs have limited symptomatic activity and devoid of neuroprotective and neurorestorative property that is needed for disease modifying action. The complex pathology of PD and AD led us to develop several multi-target neuroprotective and neurorestorative drugs with several CNS targets with the ability for possible disease modifying activity. Employing the pharmacophore of our anti-parkinson drug rasagiline (Azilect, N-propagrgyl-1-R-aminoindan), we have developed a series of novel multi-functional neuroprotective drugs (A) [TV-3326 (N-propargyl-3R-aminoindan-5yl)-ethyl methylcarbamate)], with both cholinesterase-butyrylesterase and brain selective monoamine-oxidase (MAO) A/B inhibitory activities and (B) the iron chelator-radical scavenging-brain selective monoamine oxidase (MAO) A/B inhibitor and M30 possessing the neuroprotective and neurorescuing propargyl moiety of rasagiline, as potential treatment of AD, DLB and PD with dementia. Another series of multi-target drugs (M30, HLA-20 series) which are brain permeable iron chelators and potent selective brain MAO inhibitors were also developed. These series of drugs have the ability of regulating and processing amyloid precursor protein (APP) since APP and alpha-synuclein are metaloproteins (iron-regulated proteins), with an iron responsive element 5"UTR mRNA similar to transferring and ferritin. Ladostigil inhibits brain acetyl and butyrylcholinesterase in rats after oral doses. After chronic but not acute treatment, it inhibits MAO-A and -B in the brain. Ladostigil acts like an anti-depressant in the forced swim test in rats, indicating a potential for anti-depressant activity. Ladostigil prevents the destruction of nigrostriatal neurons induced by infusion of neurotoxin MPTP in mice. The propargylamine moiety of ladostigil confers neuroprotective activity against cytotoxicity induced by ischemia and peroxynitrite in cultured neuronal cells. The multi-target iron chelator M30 has all the properties of ladostigil and similar neuroprotective activity to ladostigil, but is not a ChE inhibitor. M30 has a neurorestorative activity in post-lesion of nigrostriatal dopamine neurons in MPTP, lacatcystin and 6-hydroxydopamine animal models of PD. The neurorestorative activity is related to the ability of the drug to activate hypoxia inducing factor (HIF) which induces the production of such neurotrophins as brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF) and erythropoietin as well as glia-derived neurotrophic factor (GDNF). The unique multiple actions of ladostigil and M30 make the potentially useful drugs for the treatment of dementia with Parkinsonian-like symptoms and depression.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; alpha-Synuclein ; Amyloid ; Animals ; Anoxia ; Brain ; Brain-Derived Neurotrophic Factor ; Butyrylcholinesterase ; Chelating Agents ; Dementia ; Depression ; Dopamine ; Erythropoietin ; Ferritins ; Indans ; Iron ; Ischemia ; Mice ; Models, Animal ; Monoamine Oxidase ; Monoamine Oxidase Inhibitors ; Nerve Growth Factors ; Neurons ; Neuroprotective Agents ; Oxidopamine ; Pargyline ; Peroxynitrous Acid ; Propylamines ; Rats ; RNA, Messenger ; Vascular Endothelial Growth Factor A

OBJECTIVES: The aim of this study was to demonstrate the recommendations for antidepressant treatment strategy of dose increment, switching, combination, and augmentation therapy derived from Evidence-Based Korean Pharmacological Treatment Guideline for Depression, Revised Edition. METHODS: The guideline was developed through adaptation of 12 domestic and foreign clinical guidelines for depression, with key questions concerning pharmacotherapy of depression, and drawing of recommendations. RESULTS: The guideline strongly recommended dose increment, switching, and combination and augmentation therapy of antidepressant when patients with depression showed inadequate treatment outcomes from initial antidepressant treatment. The dose increment was strongly recommended when the patients had insufficient response from treatment with tricyclic antidepressants (TCAs), monoamine oxidase inhibitors, selective serotonin reuptake inhibitors (SSRIs), and serotonin and norepinephrine reuptake inhibitors (SNRIs). Switching from SSRI to non-SSRI was also strongly recommended. The combination of initial medication and other classes of antidepressants could benefit from treatment with TCAs, SSRIs, SNRIs, and noradrenergic and specific serotonergic antidepressants. Combination with norepinephrine and dopamine reuptake inhibitors or serotonin-2 antagonist/reuptake inhibitors was weakly recommended. The guideline strongly recommended use of the augmentation strategy of adding lithium or benzodiazepine to initial antidepressants. Augmentation of lamotrigine, T3, methylphenidate, and modafinil was weakly recommended. CONCLUSION: If the initial outcomes of antidepressant therapy are unsatisfactory to the patients the next-step strategies of dose increment, switching, combination and augmentation of antidepressants should be considered after rechecking the patients' drug compliance, dose, and diagnosis.
Antidepressive Agents ; Antidepressive Agents, Tricyclic ; Benzhydryl Compounds ; Benzodiazepines ; Compliance ; Depression* ; Depressive Disorder, Major ; Dopamine Uptake Inhibitors ; Drug Therapy ; Humans ; Lithium ; Methylphenidate ; Monoamine Oxidase Inhibitors ; Norepinephrine ; Serotonin ; Serotonin Uptake Inhibitors ; Triazines

OBJECTIVES: The purpose of this study was to suggest recommendations of antidepressant efficacy compared with placebo, difference in efficacy of antidepressants, and appropriate time of efficacy judgment in antidepressant therapy. METHODS: Using recommendations from 12 international and domestic clinical practice guidelines for depression, drawing of recommendation drafts, and peer review, the executive committee developed the guideline. RESULTS: Tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOI), selective serotonin reuptake inhibitors (SSRI), serotonin and norepinephrine reuptake inhibitors (SNRIs), norepinephrine and specific serotonergic antidepressants (NaSSAs), norepinephrine and dopamine reuptake inhibitors (NDRIs), and serotonin antagonist and reuptake inhibitors (SARIs) were strongly recommended as having antidepressant efficacy compared with placebo. Difference in efficacy of antidepressants was as follows. TCAs, MAOI, SSRI, SNRIs, and NaSSAs were strongly recommended, however, NDRIs, SARIs were weakly recommended. If there was no or minimal improvement with treatment, appropriate time of efficacy judgment in antidepressant therapy was estimated to be after two to four weeks. CONCLUSION: We hope that the results of this study will be helpful in encouraging the optimal treatment by understanding antidepressant efficacy compared with placebo, difference in efficacy of antidepressants, and appropriate time of efficacy judgment in antidepressant therapy.
Antidepressive Agents* ; Antidepressive Agents, Tricyclic ; Depression* ; Depressive Disorder, Major ; Dopamine Uptake Inhibitors ; Judgment* ; Monoamine Oxidase Inhibitors ; Norepinephrine ; Peer Review ; Serotonin ; Serotonin Uptake Inhibitors