Harmine is an effective therapeutic small molecule for the treatment of cardiac hypertrophy.

Harmine is a ß-carboline alkaloid isolated from Banisteria caapi and Peganum harmala L with various pharmacological activities, including antioxidant, anti-inflammatory, antitumor, anti-depressant, and anti-leishmanial capabilities. Nevertheless, the pharmacological effect of harmine on cardiomyocytes and heart muscle has not been reported. Here we found a protective effect of harmine on cardiac hypertrophy in spontaneously hypertensive rats in vivo. Further, harmine could inhibit the phenotypes of norepinephrine-induced hypertrophy in human embryonic stem cell-derived cardiomyocytes in vitro. It reduced the enlarged cell surface area, reversed the increased calcium handling and contractility, and downregulated expression of hypertrophy-related genes in norepinephrine-induced hypertrophy of human cardiomyocytes derived from embryonic stem cells. We further showed that one of the potential underlying mechanism by which harmine alleviates cardiac hypertrophy relied on inhibition of NF-κB phosphorylation and the stimulated inflammatory cytokines in pathological ventricular remodeling. Our data suggest that harmine is a promising therapeutic agent for cardiac hypertrophy independent of blood pressure modulation and could be a promising addition of current medications for cardiac hypertrophy.

Twist1 is required for the development of UVB-induced squamous cell carcinoma.

The transcription factor Twist1 has been reported to be essential for the formation and invasiveness of chemically induced tumors in mouse skin. However, the impact of keratinocyte-specific Twist1 deletion on skin carcinogenesis caused by UVB radiation has not been reported. Deletion of Twist1 in basal keratinocytes of mouse epidermis using K5.Cre × Twist1flox/flox mice led to significantly reduced UVB-induced epidermal hyperproliferation. In addition, keratinocyte-specific deletion of Twist1 significantly suppressed UVB-induced skin carcinogenesis. Further analyses revealed that deletion of Twist1 in cultured keratinocytes or mouse epidermis in vivo led to keratinocyte differentiation. In this regard, deletion of Twist1 in epidermal keratinocytes showed significant induction of early and late differentiation markers, including TG1, K1, OVOL1, loricrin, and filaggrin. Similar results were obtained with topical application of harmine, a Harmala alkaloid that leads to degradation of Twist1. In contrast, overexpression of Twist1 in cultured keratinocytes suppressed calcium-induced differentiation. Further analyses using both K5.Cre × Twist1flox/flox mice and an inducible system where Twist1 was deleted in bulge region keratinocytes showed loss of expression of hair follicle stem/progenitor markers, including CD34, Lrig1, Lgr5, and Lgr6. These data support the conclusion that Twist1 has a direct role in maintaining the balance between proliferation and differentiation of keratinocytes and keratinocyte stem/progenitor populations. Collectively, these results demonstrate a critical role for Twist1 early in the process of UVB skin carcinogenesis, and that Twist1 may be a novel target for the prevention of cutaneous squamous cell carcinoma.

The transdermal performance, pharmacokinetics, and anti-inflammatory pharmacodynamics evaluation of harmine-loaded ethosomes.

Harmine (HAR) is a ß-carboline alkaloid with anti-inflammatory and antipruritic effect. However, the low bioavailability and side effects of HAR severely limited its clinical application. The main objective of this study was to develop harmine-loaded ethosomes (HLE) drug delivery system for topical application to treat inflammation. HLE were obtained by ethanol injection method and characterized. The morphology of HLE was evaluated by transmission electron microscopy (TEM). HLE exhibited a good biocompatibility with human embryonic skin fibroblasts and rat skin. The in vitro skin penetration studies showed that HLE had the greatest skin deposition than harmine-loaded liposomes (HLL) and harmine solution (HS). In vivo pharmacokinetic study demonstrated that AUC(0-∞) and Cmax of HLE in subcutaneous tissues were much higher than that of in blood. Moreover, for convenience of fixing on skin, HLE were mixed with gel. HLE gel significantly inhibited the overexpression of inflammation cytokines prostaglandin E2, interleuking (IL)-1ß, nitric oxide, and tumor necrosis factor-alpha (TNF-α) in the inflammation model of rat paw edema compared with HS gel. In short, HLE was promising formulation for topical delivery in treatment of inflammatory diseases.

Harmine-loaded galactosylated pluronic F68-gelucire 44/14 mixed micelles for liver targeting.

Harmine (HM), a phytoconstituent has wide range of pharmacological activities including antimicrobial, antifungal, antioxidative, and anticancer. HM has shown promising anticancer activity against liver cancer cells. However, poor aqueous solubility, multidrug pump P-gp efflux, extensive in vivo metabolism, and rapid elimination due to glucuronidation/sulfation limit clinical utility of HM. In order to overcome the drawbacks of HM, the current work reports preparation of HM-loaded galactosylated pluronic F-68 (PF68)-Gelucire® 44/14 (GL44) mixed micelles (HM-MM). 32 factorial design was used to investigate the effect of formulation variables on formation HM-loaded mixed micelles. Solvent evaporation method was used for preparation of HM-MM. The optimized HM-MM was evaluated for size, percent drug entrapped (EE), in vitro HM release, oral bioavailability, and biodistribution in rats. HM-MM with an average size 277.5 ± 3.24 nm had an EE of 86.5 ± 1.51% w/w. HM-MM released HM in a controlled manner. Additionally, HM-MM showed significant enhancement in oral bioavailability (around six-folds) of HM when compared to HM alone. Further, HM-MM showed around sevenfold higher amount of HM in the liver when compared to HM alone revealing efficient drug targeting capability. Such significant improvement in oral bioavailability of HM when formulated into mixed micelles could be attributed to solubilization of hydrophobic HM into micellar core along with P-gp inhibition effect of both galactosylated PF68 and GL44. Thus, the present work highlights galactosylated PF68 and GL44 mixed micelles as an efficient carrier system having drug targeting capability and potential to enhance bioavailability of BCS class II drugs.

Combination of doxorubicin with harmine-loaded liposomes exerting synergistic antitumor efficacy.

CONTEXT: Long-circulation (PEGLip), pH-sensitive (PEOzLip), and active targeted liposomes (PEG-TATLip)-loading doxorubicin (DOX) and harmine (HM) were prepared. Their physicochemical properties and antitumor effect were investigated. OBJECTIVES: The aims of the present study were to evaluate synergistic antitumor efficacy. MATERIALS AND METHODS: Liposomes were prepared by using thin-film dispersion, active drug-loading and target post-insertion method. Subsequently physiochemical properties including particle size distribution, zeta potential, entrapment efficiency (EE), drug-loading content and in-vitro release were determined. Besides, the in vitro cytotoxicity of free drugs and drug-loaded liposomes was explored by using a Sulforhodamine-B Staining assay and the combination index values (CI Value) were calculated. Finally, the cellular uptake experiments by MCF-7cells were carried out via flow cytometry. RESULTS AND DISCUSSION: All liposomes enhanced the antitumor effect significantly compared to free drugs. Among liposomes, PEG-TATLip enhanced the antitumor effect significantly compared to others. DOX and HM had moderate synergism with CI Value 0.85 for free drugs, 0.81 for PEGLip, 0.72 for PEOzLip, and 0.84 for PEG-TATLip respectively when the weight ratio of two drugs was 1:2. Moreover, the similarity between DOX and HM such as physicochemical properties, in vitro release modes and in vitro uptake kinetics characteristics when they were in the same formulations proved it possible for them to be delivered together. CONCLUSION: Active targeting liposomes were the most effective delivery system as compared with pH-sensitive and long circulation liposomes. Additionally, DOX and HM could be co-delivered in liposomes and they could play moderate synergism effect in antitumor efficacy.

In vitro and in vivo anti-malarial activity of novel harmine-analog heat shock protein 90 inhibitors: a possible partner for artemisinin.

BACKGROUND: The emergence of artemisinin-resistant Plasmodium falciparum strains poses a serious challenge to the control of malaria. This necessitates the development of new anti-malarial drugs. Previous studies have shown that the natural beta-carboline alkaloid harmine is a promising anti-malarial agent targeting the P. falciparum heat-shock protein 90 (PfHsp90). The aim of this study was to test the anti-malarial activity of harmine analogues. METHODS: Forty-two harmine analogues were synthesized and the binding of these analogues to P. falciparum heat shock protein 90 was investigated. The in vitro anti-malarial activity of two of the analogues, 17A and 21A, was evaluated using a 72-h growth inhibition assay. The in vivo anti-malarial activity was tested in Plasmodium berghei infection of BALB/c mice. The potential of 21A for a combination treatment with artemisinin was evaluated using in vivo combination study with dihydro-artemisinin in BALB/c mice. Cytotoxicity of the harmine analogues was tested in vitro using HepG2 and HeLa cell lines. RESULTS: 17A and 21A bound to PfHsp90 with average IC50 values of 12.2 ± 2.3 and 23.1 ± 8.8 µM, respectively. They also inhibited the P. falciparum W2 strain with average IC50 values of 4.2 ± 1.3 and 5.7 ± 1.7 µM, respectively. In vivo, three daily injections of P. berghei-infected BALB/c mice with 100 mg/kg of either 17A or 21A showed significant reduction in parasitaemia with a 51.5 and 56.1% reduction, respectively. Mice treated with 17A and 21A showed a median survival time of 11 and 14 days, respectively, while the vehicle control mice survived a median of only 8.5 days. A dose-ranging experiment with 21A showed that the compound has a dose-dependent anti-malarial effect. Furthermore, treatment of infected mice with a combination of 21A and dihydroartemisinin (DHA) showed a dramatic reduction in parasitaemia compared to treatment with DHA alone. CONCLUSION: A novel and non-toxic harmine analogue has been synthesized which binds to PfHsp90 protein, inhibits P. falciparum in vitro at micromolar concentration, reduces parasitaemia and prolongs survival of P. berghei-infected mice with an additive anti-malarial effect when combined with DHA.

Pharmacokinetic study of harmane and its 10 metabolites in rat after intravenous and oral administration by UPLC-ESI-MS/MS.

Context The ß-carboline alkaloid harmane is widely distributed in common foods, beverages and hallucinogenic plants. Harmane exerts potential in therapies for Alzheimer's and depression diseases. However, little information on its dynamic metabolic profiles and pharmacokinetics in vivo is currently available. Objective This study investigates the dynamic metabolic profiles and pharmacokinetic properties of harmane and its metabolites in rats in vivo. Materials and methods A highly selective, sensitive and rapid ultra-performance liquid chromatography combined with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and well-validated for simultaneous quantitative determination of harmane and its uncertain endogenous metabolite harmine, as well as for semiquantitative determination of 10 harmane metabolites in rats after intravenous injection and oral administration of harmane at 1.0 and 30.0 mg/kg, respectively. Results The calibration curves of harmane and harmine showed excellent linearity within the concentration range of 1-2000 ng/mL with acceptable accuracy, precision, selectivity, recovery, matrix effect and stability. Ten metabolites, including harmane but not harmine, were detected and identified after intravenous and oral administration of harmane. The absolute bioavailability of harmane following an oral dose was 19.41 ± 3.97%. According to the AUC0-t values of all the metabolites, the metabolic levels of phase II metabolites were higher than those of phase I metabolites, and the sulphation pathways were the dominant metabolic routes for harmane in both routes of administration. Discussion and conclusion The pharmacokinetic properties of harmane and its 10 metabolites in rats were determined. Sulphate conjugation was the predominant metabolic process of harmane in rats.

Evaluation of monoamine oxidase A and B type enzyme occupancy using non-radiolabelled tracers in rat brain.

Monoamine oxidase (MAO) enzymes, type A and B metabolise the amine neurotransmitters of the body. Selective inhibition of either enzyme is an approach for treating neurodegenerative and stress-induced disorders, and inhibition of an enzyme is proportional to the binding of the MAO inhibitor. Conventionally, the binding of test compounds to enzymes is assessed by radiolabelled ligands in ex vivo and in vivo occupancy assays. Regulatory restrictions and turnaround time are the limitations of the methods that use radiolabelled ligands. But the use of non-radiolabelled tracers and sensitive mass spectrometry (LC-MS/MS) based assays accelerated the determination of target occupancy in pre-clinical species. A report on use of non-radiolabelled ligand in in vivo MAO occupancy assay is not available. The objectives of the present study were to optimise non-radiolabelled harmine and deprenyl as selective tracers in MAO-A and MAO-B occupancy assays and evaluate MAO occupancy of test compounds in rat brain. Tracer optimisation resulted in a detectable, stable, and low ratio (<3.0) of tracer concentrations between any two brain tissues. In occupancy assay, tracer was intravenously administered (10 µg/kg, harmine or 60 µg/kg, L-deprenyl) after the treatment with test compound (clorgyline or tranylcypromine or pargyline or phenelzine or thioperamide). Specific brain tissues were isolated at a defined interval and tracer concentrations were quantified using LC-MS/MS method. Pre-treatment with MAO inhibitors resulted in a decrease (maximum, 80-85%) in harmine or an increase (maximum, 85-300%) in L-deprenyl concentrations. But we considered the change in tracer concentration, relative to the vehicle and positive control groups to calculate MAO occupancy. The observed selectivity and ratio of occupancies (ED50) of test compound towards MAO-A and MAO-B are comparable with the results from in vitro radiolabelled ligand-based inhibition assay. The results demonstrated the application of these non-radiolabelled tracers as suitable pre-clinical tools to determine MAO occupancy.

Complexation with ß-cyclodextrin enhances apoptosis-mediated cytotoxic effect of harman in chemoresistant BRAF-mutated melanoma cells.

Harman, a natural ß-carboline alkaloid, has recently gained considerable interest due to its anticancer properties. However, its physicochemical characteristics and poor oral bioavailability have been limiting factors for its pharmaceutical development. In this paper, we described the complexation of harman (HAR) with ß-cyclodextrin (ßCD) as a promising alternative to improve its solubility and consequently its cytotoxic effect in chemoresistant melanoma cells (A2058 cell line). Inclusion complexes (ßCD-HAR) were prepared using a simple method and then characterized by FTIR, NMR and SEM techniques. Through in silico studies, the mechanism of complexation of HAR with ßCD was elucidated in detail. Both HAR and ßCD-HAR promoted cytotoxicity, apoptosis, cell cycle arrest and inhibition of cell migration in melanoma cells. Interestingly, complexation of HAR with ßCD enhanced its pro-apoptotic effect by increasing of caspase-3 activity (p < 0.05), probably due to an improvement in HAR solubility. In addition, HAR and ßCD-HAR sensitized A2058 cells to vemurafenib, dacarbazine and 5FU treatments, potentializing their cytotoxic activity. These findings suggest that complexation of HAR with natural polymers such as ßCD can be useful to improve its bioavailability and antimelanoma activity.

Chronic harmine treatment has a delayed effect on mobility in control and socially defeated rats.

INTRODUCTION: Depression is characterized by behavioral, cognitive and physiological changes, imposing a major burden on the overall wellbeing of the patient. Some evidence indicates that social stress, changes in growth factors (e.g., brain-derived neurotrophic factor (BDNF)), and neuroinflammation are involved in the development and progression of the disease. The monoamine oxidase A inhibitor drug harmine was suggested to have both antidepressant and anti-inflammatory properties and may, therefore, be a potential candidate for treatment of depression. AIM: The goal of this study was to assess the effects of harmine on behavior, brain BDNF levels, and microglia activation in control rats and a rat model of social stress. MATERIAL AND METHODS: Rats were submitted to 5 consecutive days of repeated social defeat (RSD) or control conditions. Animals were treated daily with harmine (15 mg/kg) or vehicle from day 3 until the end of the experiment. To assess the effects of harmine treatment on behavior, the sucrose preference test (SPT) was performed on days 1, 6, and 15, the open field test (OFT) on days 6 and 14, and the novel object recognition test (NOR) on day 16. Brain microgliosis was assessed using [11C]PBR-28 PET on day 17. Animals were terminated on day 17, and BDNF protein concentrations in the hippocampus and frontal cortex were analyzed using ELISA. RESULTS: RSD significantly decreased bodyweight and increased anxiety and anhedonia-related parameters in the OFT and SPT on day 6, but these behavioral effects were not observed anymore on day 14/15. Harmine treatment caused a significant reduction in bodyweight gain in both groups, induced anhedonia in the SPT on day 6, and significantly reduced the mobility and exploratory behavior of the animals in the OFT mainly on day 14. PET imaging and the NOR test did not show any significant effects on microglia activation and memory, respectively. BDNF protein concentrations in the hippocampus and frontal cortex were not significantly affected by either RSD or harmine treatment. DISCUSSION: Harmine was not able to reverse the acute effects of RSD on anxiety and anhedonia and even aggravated the effect of RSD on bodyweight loss. Moreover, harmine treatment caused unexpected side effects on general locomotion, both in RSD and control animals, but did not influence glial activation status and BDNF concentrations in the brain. In this model, RSD-induced stress was not strong enough to induce long-term effects on the behavior, neuroinflammation, or BDNF protein concentration. Thus, the efficacy of harmine treatment on these delayed parameters needs to be further evaluated in more severe models of chronic stress.

Bioactive ß-Carbolines in Food: A Review.

Harman and norharman, two neuroactive ß-carbolines, are present in several plants and in thermally processed foods. They exhibited a wide spectrum of biological and pharmacological effects, including antioxidant, neuroprotective, and anti-inflammatory effects. In this article, we review the progress of recent research on the presence of these compounds in food, as well as their various biological and neuroactive properties. Our findings strongly suggest that some foods, especially coffee, can act as a rich source of ß-carbolines, which may possibly be associated with a reduced risk for serious neurodegenerative diseases, such as Parkinson's and Alzheimer's.

Harmine induces anticancer activity in breast cancer cells via targeting TAZ.

Harmine (HM) is a ß­carboline alkaloid found in multiple medicinal plants. It has been used in folk medicine for anticancer therapy; however, the molecular mechanism of HM on human breast cancer remains unclear. Transcriptional co­activator with PDZ­binding motif (TAZ), also known as WW domain­containing transcription regulator 1, serves an important role in the carcinogenesis and progression of breast cancer. The aim of the present study was to elucidate the potential anticancer activity and mechanism of HM in breast cancer, in vitro and in vivo. Cell proliferation was measured using a CCK­8 assay, apoptotic activity was detected by flow cytometry and DAPI staining, and cell migration was examined using a wound healing assay. The expression of proteins, including extracellular signal­regulate kinase (Erk), phosphorylated (p­) Erk, protein kinase B (Akt), p­Akt, B­cell lymphoma 2 (Bcl­2) and Bcl­2­associated X protein (Bax), were determined by western blotting. The mRNA expression of TAZ was detected using reverse transcription­quantitative polymerase chain reaction analysis. The expression of proteins in mouse tumor tissues were examined by immunohistochemistry. HM significantly suppressed cellular proliferation and migration, promoted apoptosis in vitro and inhibited tumor growth in vivo. In addition, HM significantly decreased the expression of TAZ, p­Erk, p­Akt and Bcl­2, but increased that of Bax. The overexpression of TAZ in breast cancer cells inhibited the antitumor effect of HM. In conclusion, HM was found to induce apoptosis and prevent the proliferation and migration of human breast cancer cell lines, possibly via the downregulation of TAZ.

Dietary epidemiology of essential tremor: meat consumption and meat cooking practices.

BACKGROUND/AIM: Harmane [1-methyl-9H-pyrido(3,4-b)indole] is a tremor-producing neurotoxin. Blood harmane concentrations are elevated in essential tremor (ET) patients for unclear reasons. Potential mechanisms include increased dietary harmane intake (especially through well-cooked meat) or genetic-metabolic factors. We tested the hypothesis that meat consumption and level of meat doneness are higher in ET cases than in controls. METHODS: Detailed data were collected using the Lawrence Livermore National Laboratory Meat Questionnaire. RESULTS: Total current meat consumption was greater in men with than without ET (135.3 +/- 71.1 vs. 110.6 +/- 80.4 g/day, p = 0.03) but not in women with versus without ET (80.6 +/- 50.0 vs. 79.3 +/- 51.0 g/day, p = 0.76). In an adjusted logistic regression analysis in males, higher total current meat consumption was associated with ET (OR = 1.006, p = 0.04, i.e., with 10 additional g/day of meat, odds of ET increased by 6%). Male cases had higher odds of being in the highest than lowest quartile of total current meat consumption (adjusted OR = 21.36, p = 0.001). Meat doneness level was similar in cases and controls. CONCLUSION: This study provides evidence of a dietary difference between male ET cases and male controls. The etiological ramifications of these results warrant additional investigation.

Effects of ayahuasca on psychometric measures of anxiety, panic-like and hopelessness in Santo Daime members.

The use of the hallucinogenic brew ayahuasca, obtained from infusing the shredded stalk of the malpighiaceous plant Banisteriopsis caapi with the leaves of other plants such as Psychotria viridis, is growing in urban centers of Europe, South and North America in the last several decades. Despite this diffusion, little is known about its effects on emotional states. The present study investigated the effects of ayahuasca on psychometric measures of anxiety, panic-like and hopelessness in members of the Santo Daime, an ayahuasca-using religion. Standard questionnaires were used to evaluate state-anxiety (STAI-state), trait-anxiety (STAI-trait), panic-like (ASI-R) and hopelessness (BHS) in participants that ingested ayahuasca for at least 10 consecutive years. The study was done in the Santo Daime church, where the questionnaires were administered 1h after the ingestion of the brew, in a double-blind, placebo-controlled procedure. While under the acute effects of ayahuasca, participants scored lower on the scales for panic and hopelessness related states. Ayahuasca ingestion did not modify state- or trait-anxiety. The results are discussed in terms of the possible use of ayahuasca in alleviating signs of hopelessness and panic-like related symptoms.

A First-in-Class TWIST1 Inhibitor with Activity in Oncogene-Driven Lung Cancer.

TWIST1, an epithelial-mesenchymal transition (EMT) transcription factor, is critical for oncogene-driven non-small cell lung cancer (NSCLC) tumorigenesis. Given the potential of TWIST1 as a therapeutic target, a chemical-bioinformatic approach using connectivity mapping (CMAP) analysis was used to identify TWIST1 inhibitors. Characterization of the top ranked candidates from the unbiased screen revealed that harmine, a harmala alkaloid, inhibited multiple TWIST1 functions, including single-cell dissemination, suppression of normal branching in 3D epithelial culture, and proliferation of oncogene driver-defined NSCLC cells. Harmine treatment phenocopied genetic loss of TWIST1 by inducing oncogene-induced senescence or apoptosis. Mechanistic investigation revealed that harmine targeted the TWIST1 pathway through its promotion of TWIST1 protein degradation. As dimerization is critical for TWIST1 function and stability, the effect of harmine on specific TWIST1 dimers was examined. TWIST1 and its dimer partners, the E2A proteins, which were found to be required for TWIST1-mediated functions, regulated the stability of the other heterodimeric partner posttranslationally. Harmine preferentially promoted degradation of the TWIST1-E2A heterodimer compared with the TWIST-TWIST1 homodimer, and targeting the TWIST1-E2A heterodimer was required for harmine cytotoxicity. Finally, harmine had activity in both transgenic and patient-derived xenograft mouse models of KRAS-mutant NSCLC. These studies identified harmine as a first-in-class TWIST1 inhibitor with marked anti-tumor activity in oncogene-driven NSCLC including EGFR mutant, KRAS mutant and MET altered NSCLC.Implications: TWIST1 is required for oncogene-driven NSCLC tumorigenesis and EMT; thus, harmine and its analogues/derivatives represent a novel therapeutic strategy to treat oncogene-driven NSCLC as well as other solid tumor malignancies. Mol Cancer Res; 15(12); 1764-76. ©2017 AACR.

Interaction between harmane, a class of ß-carboline alkaloids, and the CA1 serotonergic system in modulation of memory acquisition.

This study set to assess the involvement of dorsal hippocampus (CA1) serotonergic system on harmane induced memory acquisition deficit. We used one trial step-down inhibitory avoidancetask to evaluate memory retention and then, open field test to evaluate locomotor activity in adult male NMRI mice. The results showed that pre-training intra-peritoneal (i.p.) administration of harmane (12mg/kg) induced impairment of memory acquisition. Pre-training intra-CA1 administration of 5-HT1B/1D receptor agonist (CP94253; 0.5 and 5ng/mouse) and 5-HT2A/2B/2C receptor agonist (α-methyl 5-HT; 50ng/mouse) impaired memory acquisition. Furthermore, intra-CA1 administration of 5-HT1B/1D receptor antagonist (GR127935; 0.5ng/mouse) and 5-HT2 receptor antagonist (cinancerine; 5ng/mouse) improved memory acquisition. In addition, pre-training intra-CA1 injection of sub-threshold dose of CP94253 (0.05ng/mouse) and α-methyl 5-HT (5ng/mouse) potentiated impairment of memory acquisition induced by harmane (12mg/kg, i.p.). On the other hand, pre-training intra-CA1 infusion of sub-threshold dose of GR127935 (0.05ng/mouse) and cinancerine (0.5ng/mouse) with the administration of harmane (12mg/kg, i.p.) weakened impairment of memory acquisition. Moreover, all above doses of drugs did not change locomotor activity. The present findings suggest that there is an interaction between harmane and the CA1 serotonergic system in modulation of memory acquisition.

Effects of beta-carboline alkaloids on the object recognition task in mice.

beta-carboline alkaloids are found in several medicinal plants and display a variety of actions on the central nervous, muscular and cardiovascular systems. The aim of the present study was to evaluate the effects of systemic administration of beta-carboline alkaloids on object recognition in mice. Adult Swiss mice received an intra-peritoneal injection (i.p.) of alkaloids (1.0, 2.5 or 5.0 mg/kg) 30 min before training in an object recognition task. The fully aromatic beta-carbolines, harmine and harmol, induced an enhancement of short-term memory (STM) at all doses tested when compared to controls. Harmaline, a dihydro beta-carboline and inverse agonist of the MK-801 binding site on the N-methyl-d-aspartate (NMDA) receptor, also induced an enhancement of both short-term memory (STM) and long-term memory (LTM). These results demonstrate that systemic administration of beta-carboline alkaloids can improve object recognition memory in mice.

Neurochemical mechanisms of the dorsal pallidum in the antiaversive effects of anxiolytics in various models of anxiety.

In conditions in which rats had a free choice between dark and light chambers, microinjections of glutamic acid, serotonin, and campiron into the globus pallidus showed that these agents have antiaversive properties in a threatening situation test but not in an illuminated area test. Dopamine, apomorphine, GABA, chlordiazepoxide, phenibut, and indoter injected locally into this formation of the basal ganglia had no effect on the mechanisms of voluntary movement but counteracted anxiety states in both behavioral models. These results provide evidence that the monoaminergic and aminoacidergic systems of the dorsal pallidum have different functional roles in the operative regulation of behavior for aversive stimuli of different modalities. Prior intraperitoneal administration of functional antagonists of these synaptotropic substances and subsequent microinjection of transmitter monoamines and amino acids and their agonists into the globus pallidus demonstrated the selective involvement of the neurotransmitter systems of the dorsal pallidum in the antiaversive effects of anxiosedative and anxioselective substances.

Elevated Monoamine Oxidase-A Distribution Volume in Borderline Personality Disorder Is Associated With Severity Across Mood Symptoms, Suicidality, and Cognition.

BACKGROUND: Monoamine oxidase-A (MAO-A) is a treatment target in neurodegenerative illness and mood disorders that increases oxidative stress and predisposition toward apoptosis. Increased MAO-A levels in prefrontal cortex (PFC) and anterior cingulate cortex (ACC) occur in rodent models of depressive behavior and human studies of depressed moods. Extreme dysphoria is common in borderline personality disorder (BPD), especially when severe, and the molecular underpinnings of severe BPD are largely unknown. We hypothesized that MAO-A levels in PFC and ACC would be highest in severe BPD and would correlate with symptom magnitude. METHODS: [(11)C] Harmine positron emission tomography measured MAO-A total distribution volume (MAO-A VT), an index of MAO-A density, in severe BPD subjects (n = 14), moderate BPD subjects (n = 14), subjects with a major depressive episode (MDE) only (n = 14), and healthy control subjects (n = 14). All subjects were female. RESULTS: Severe BPD was associated with greater PFC and ACC MAO-A VT compared with moderate BPD, MDE, and healthy control subjects (multivariate analysis of variance group effect: F6,102 = 5.6, p < .001). In BPD, PFC and ACC MAO-A VT were positively correlated with mood symptoms (PFC: r = .52, p = .005; ACC: r = .53, p = .004) and suicidality (PFC: r = .40, p = .037; ACC: r = .38, p = .046), while hippocampus MAO-A VT was negatively correlated with verbal memory (r = -.44, p = .023). CONCLUSIONS: These results suggest that elevated MAO-A VT is associated with multiple indicators of BPD severity, including BPD symptomatology, mood symptoms, suicidality, and neurocognitive impairment.

Harmine Induces Adipocyte Thermogenesis through RAC1-MEK-ERK-CHD4 Axis.

Harmine is a natural compound possessing insulin-sensitizing effect in db/db diabetic mice. However its effect on adipose tissue browning is unknown. Here we reveal that harmine antagonizes high fat diet-induced adiposity. Harmine-treated mice gained less weight on a high fat diet and displayed increased energy expenditure and adipose tissue thermogenesis. In vitro, harmine potently induced the expression of thermogenic genes in both brown and white adipocytes, which was largely abolished by inhibition of RAC1/MEK/ERK pathway. Post-transcriptional modification analysis revealed that chromodomain helicase DNA binding protein 4 (CHD4) is a potential downstream target of harmine-mediated ERK activation. CHD4 directly binds the proximal promoter region of Ucp1, which is displaced upon treatment of harmine, thereby serving as a negative modulator of Ucp1. Thus, here we reveal a new application of harmine in combating obesity via this off-target effect in adipocytes.