Harmine inhibits the proliferation and migration and promotes the apoptosis of colon cancer cells via inhibition of the FAK/AKT and ERK1/2/CREB signaling pathways.

Harmine is present in a variety of medicinal plants, and its effects on colon cancer cells remain unclear. Here, we found that harmine exhibited significant inhibitory effects on the proliferation of colon cancer cells by inhibiting the phosphorylation levels of the FAK/AKT and ERK1/2/CREB. Furthermore, harmine also inhibited the migration of colon cancer cells and suppressed the expression levels of MMP-2, MMP-9, and VEGF. Additionally, harmine-induced apoptosis in colon cancer cells by regulating the expression of Bcl-2 and Bax. In conclusion, our findings suggest that harmine exerts a significant inhibitory effect on the development of colon cancer cells.

Harmine inhibits pulmonary fibrosis through regulating DNA damage repair-related genes and activation of TP53-Gadd45α pathway.

BACKGROUND: Harmine has many pharmacological activities and has been found to significantly inhibit the fibrosis of keloid fibroblasts. DNA damage repair (DDR) is essential to prevent fibrosis. This study aimed to investigate the effects of harmine on pulmonary fibrosis and its underlying mechanisms. METHODS: Bleomycin and TGF-ß1 were used to construct pulmonary fibrosis models in vivo and in vitro, then treated with harmine to explore harmine's effects in treating experimental pulmonary fibrosis and its related mechanisms. Then, RNA sequencing was applied to investigate further the crucial DDR-related genes and drug targets of harmine against pulmonary fibrosis. Finally, the expression levels of DDR-related genes were verified by real-time quantitative PCR (RT-qPCR) and western blot. RESULTS: Our in vivo experiments showed that harmine treatment could improve weight loss and lung function and reduce tissue fibrosis in mice with pulmonary fibrosis. The results confirmed that harmine could inhibit the viability and migration of TGF-ß1-induced MRC-5 cells, induce their apoptosis, and suppress the F-actin expression, suggesting that harmine could suppress the phenotypic transition from lung fibroblasts to lung myoblasts. In addition, RNA sequencing identified 1692 differential expressed genes (DEGs), and 10 DDR-related genes were screened as critical DDR-related genes. RT-qPCR and western blotting showed that harmine could down-regulate the expression of CHEK1, ERCC1, ERCC4, POLD1, RAD51, RPA1, TOP1, and TP53, while up-regulate FEN1, H2AX and GADD45α expression. CONCLUSIONS: Harmine may inhibit pulmonary fibrosis by regulating DDR-related genes and activating the TP53-Gadd45α pathway.

Unraveling the mechanistic interplay of mediators orchestrating the neuroprotective potential of harmine.

Neurodegenerative diseases (NDDs) encompass a range of conditions characterized by the specific dysfunction and continual decline of neurons, glial cells, and neural networks within the brain and spinal cord. The majority of NDDs exhibit similar underlying causes, including oxidative stress, neuroinflammation, and malfunctioning of mitochondria. Elevated levels of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), alongside decreased expression of brain-derived neurotrophic factor (BDNF) and glutamate transporter subtype 1 (GLT-1), constitute significant factors contributing to the pathogenesis of NDDs. Additionally, the dual-specificity tyrosine phosphorylation-regulated kinase 1 A (DYRK1A) gene has emerged as a significant target for the treatment of NDDs at the preclinical level. It significantly contributes to developmental brain defects, early onset neurodegeneration, neuronal loss, and dementia in Down syndrome. Moreover, an impaired ubiquitin-proteosome system (UPS) also plays a pathological role in NDDs. Malfunctioning of UPS leads to abnormal protein buildup or aggregation of α-synuclein. α-Synuclein is a highly soluble unfolded protein that accumulates in Lewy bodies and Lewy neurites in Parkinson's disease and other synucleinopathies. Recent research highlights the promising potential of natural products in combating NDDs relative to conventional therapies. Alkaloids have emerged as promising candidates in the fight against NDDs. Harmine is a tricyclic ß-carboline alkaloid (harmala alkaloid) with one indole nucleus and a six-membered pyrrole ring. It is extracted from Banisteria caapi and Peganum harmala L. and exhibits diverse pharmacological properties, encompassing neuroprotective, antioxidant, anti-inflammatory, antidepressant, etc. Harmine has been reported to mediate its neuroprotective via reducing the level of inflammatory mediators, NADPH oxidase, AChE, BChE and reactive oxygen species (ROS). Whereas, it has been observed to increase the levels of BDNF, GLT-1 and anti-oxidant enzymes, along with protein kinase-A (PKA)-mediated UPS activation. This review aims to discuss the mechanistic interplay of various mediators involved in the neuroprotective effect of harmine.

Discovery of harmiprims, harmine-primaquine hybrids, as potent and selective anticancer and antimalarial compounds.

Although cancer and malaria are not etiologically nor pathophysiologically connected, due to their similarities successful repurposing of antimalarial drugs for cancer and vice-versa is known and used in clinical settings and drug research and discovery. With the growing resistance of cancer cells and Plasmodium to the known drugs, there is an urgent need to discover new chemotypes and enrich anticancer and antimalarial drug portfolios. In this paper, we present the design and synthesis of harmiprims, hybrids composed of harmine, an alkaloid of the ß-carboline type bearing anticancer and antiplasmodial activities, and primaquine, 8-aminoquinoline antimalarial drug with low antiproliferative activity, covalently bound via triazole or urea. Evaluation of their antiproliferative activities in vitro revealed that N-9 substituted triazole-type harmiprime was the most selective compound against MCF-7, whereas C1-substituted ureido-type hybrid was the most active compound against all cell lines tested. On the other hand, dimeric harmiprime was not toxic at all. Although spectrophotometric studies and thermal denaturation experiments indicated binding of harmiprims to the ds-DNA groove, cell localization showed that harmiprims do not enter cell nucleus nor mitochondria, thus no inhibition of DNA-related processes can be expected. Cell cycle analysis revealed that C1-substituted ureido-type hybrid induced a G1 arrest and reduced the number of cells in the S phase after 24 h, persisting at 48 h, albeit with a less significant increase in G1, possibly due to adaptive cellular responses. In contrast, N-9 substituted triazole-type harmiprime exhibited less pronounced effects on the cell cycle, particularly after 48 h, which is consistent with its moderate activity against the MCF-7 cell line. On the other hand, screening of their antiplasmodial activities against the erythrocytic, hepatic, and gametocytic stages of the Plasmodium life cycle showed that dimeric harmiprime exerts powerful triple-stage antiplasmodial activity, while computational analysis showed its binding within the ATP binding site of PfHsp90.

Research progress on the antitumor effects of harmine.

Harmine is a naturally occurring ß-carboline alkaloid originally isolated from Peganum harmala. As a major active component, harmine exhibits a broad spectrum of pharmacological properties, particularly remarkable antitumor effects. Recent mechanistic studies have shown that harmine can inhibit cancer cell proliferation and metastasis through epithelial-to-mesenchymal transition, cell cycle regulation, angiogenesis, and the induction of tumor cell apoptosis. Furthermore, harmine reduces drug resistance when used in combination with chemotherapeutic drugs. Despite its remarkable antitumor activity, the application of harmine is limited by its poor solubility and toxic side effects, particularly neurotoxicity. Novel harmine derivatives have demonstrated strong clinical application prospects, but further validation based on drug activity, acute toxicity, and other aspects is necessary. Here, we present a review of recent research on the action mechanism of harmine in cancer treatment and the development of its derivatives, providing new insights into its potential clinical applications and strategies for mitigating its toxicity while enhancing its efficacy.

Harmine alleviated STZ-induced rat diabetic nephropathy: A potential role via regulating AMPK/Nrf2 pathway and deactivating ataxia-telangiectasia mutated (ATM) signaling.

Diabetic nephropathy (DN) is a serious kidney disorder driven by diabetes and affects people all over the world. One of the mechanisms promoting NF-κB-induced renal inflammation and injury has been theorized to be ATM signaling. On the other hand, AMPK, which can be activated by the naturally occurring alkaloid harmine (HAR), has been proposed to stop that action. As a result, the goal of this study was to evaluate the therapeutic effectiveness of HAR against streptozotocin (STZ)-induced DN in rats through AMPK-mediated inactivation of ATM pathways. Twenty male Wistar rats were grouped into 4 groups, as follow: CONT, DN, HAR (10 mg/kg), DN + HAR, where HAR was daily administered I.P. once for 2 weeks. The renal AMPK and PGC-1α expressions, as well as Sirt1 levels, were assessed. To ascertain the oxidative reactions, renal Nrf2 expression, HO-1, MDA, and TAC concentrations were measured. As parts of ATM pathways, ATM and p53 expressions, in addition to GSK-3ß levels were determined. Renal expression of NEMO, TNF-α, and IL-6 levels were also estimated. Moreover, histopathological and immunohistochemical detection of Bcl-2, Bax, and caspase 3 were reported. Results indicated that HAR intake notably alleviated STZ-induced kidney damage by triggering AMPK and Sirt1, which in turn boosted PGC-1α, improved NRf2/HO-1 axis, and lowered ROS production. As a consequence, HAR blocked the ATM-triggered renal inflammation and minimized caspase-3 expression by repressing the Bax/Bcl2 ratio. Because of its ability to activate AMPK/Nrf2 axis, HAR may represent an emerging avenue for future DN therapy by blocking ATM pathways.

Harmine ameliorates CCl4-induced acute liver injury through suppression of autophagy and inflammation.

CCl4-induced acute liver injury (ALI) is characterized by heightened autophagy, inflammation, and oxidative damage. Accumulating evidence suggests that harmine exerts beneficial effects in countering CCl4-induced ALI by mitigating inflammation and oxidative stress. However, the impact of autophagy on CCl4-induced ALI and the protective role of harmine remain unclear. This study aimed to investigate the potential protective effects of harmine against CCl4-induced ALI in mice by suppressing autophagy and inflammation. Male Kunming mice were orally administered harmine or bifendate for seven days. Subsequently, one hour after the final administration, the model group and treatment groups were intraperitoneally injected with CCl4 to induce ALI. The findings revealed that harmine significantly reduced the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, and ameliorated the liver histopathological changes induced by CCl4. Furthermore, harmine diminished the levels of TNF-α and IL-6, restored the levels of glutathione (GSH) and superoxide dismutase (SOD), and suppressed the production of nitric oxide (NO) and malondialdehyde (MDA) in the liver. Mechanistically, harmine down-regulated LC3B II/I, p38 MAPK, TLR4, and NF-κB levels, while upregulating p62, Bcl-2, Beclin1, ULK1, and p-mTOR expression. In conclusion, harmine mitigated CCl4-induced ALI by inhibiting autophagy and inflammation through the p38 MAPK/mTOR autophagy pathway, the Bcl-2/Beclin1 pathway, and the TLR4/NF-κB pathway.

Ayahuasca and its major component harmine promote antinociceptive effects in mouse models of acute and chronic pain.

ETHNOPHARMACOLOGICAL RELEVANCE: Ayahuasca (AYA) is a psychedelic brew used in religious ceremonies. It is broadly used as a sacred medicine for treating several ailments, including pain of various origins. AIM OF THE STUDY: To investigate the antinociceptive effects of AYA and its mechanisms in preclinical models of acute and chronic pain in mice, in particular during experimental neuropathy. MATERIALS AND METHODS: The antinociceptive effects of AYA administered orally were assessed in the following models of pain: formalin test, Complete Freund's Adjuvant (CFA)-induced inflammation, tail flick test, and partial sciatic nerve ligation model of neuropathic pain. Antagonism assays and Fos immunohistochemistry in the brain were performed. AYA-induced toxicity was investigated. AYA was chemically characterized. The antinociceptive effect of harmine, the major component present in AYA, was investigated. RESULTS: AYA (24-3000 µL/kg) dose-dependently reduced formalin-induced pain-like behaviors and CFA-induced mechanical allodynia but did not affect CFA-induced paw edema or tail flick latency. During experimental neuropathy, single treatments with AYA (24-3000 µL/kg) reduced mechanical allodynia; daily treatments once or twice a day for 14 days promoted consistent and sustained antinociception. The antinociceptive effect of AYA (600 µL/kg) was reverted by bicuculline (1 mg/kg) and methysergide (5 mg/kg), but not by naloxone (5 mg/kg), phaclofen (2 mg/kg), and rimonabant (10 mg/kg), suggesting the roles of GABAA and serotonergic receptors. AYA increased Fos expression in the ventrolateral periaqueductal gray and nucleus raphe magnus after 1 h, but not after 6 h or 14 days of daily treatments. AYA (600 µL/kg) twice a day for 14 days did not alter mice's motor function, spontaneous locomotion, body weight, food and water intake, hematological, biochemical, and histopathological parameters. Harmine (3.5 mg/kg) promoted consistent antinociception during experimental neuropathy. CONCLUSIONS: AYA promotes consistent antinociceptive effects in different mouse models of pain without inducing detectable toxic effects. Harmine is at least partially accountable for the antinociceptive properties of AYA.

Evaluation of the Therapeutic Effects of Harmine on Anaplastic Thyroid Cancer Cells.

Anaplastic thyroid carcinoma (ATC) is an extremely difficult disease to tackle, with an overall patient survival of only a few months. The currently used therapeutic drugs, such as kinase inhibitors or immune checkpoint inhibitors, can prolong patient survival but fail to eradicate the tumor. In addition, the onset of drug resistance and adverse side-effects over time drastically reduce the chances of treatment. We recently showed that Twist1, a transcription factor involved in the epithelial mesenchymal transition (EMT), was strongly upregulated in ATC, and we wondered whether it might represent a therapeutic target in ATC patients. To investigate this hypothesis, the effects of harmine, a ß-carboline alkaloid shown to induce degradation of the Twist1 protein and to possess antitumoral activity in different cancer types, were evaluated on two ATC-derived cell lines, BHT-101 and CAL-62. The results obtained demonstrated that, in both cell lines, harmine reduced the level of Twist1 protein and reverted the EMT, as suggested by the augmentation of E-cadherin and decrease in fibronectin expression. The drug also inhibited cell proliferation and migration in a dose-dependent manner and significantly reduced the anchorage-independent growth of both ATC cell lines. Harmine was also capable of inducing apoptosis in BHT-101 cells, but not in CAL-62 ones. Finally, the activation of PI3K/Akt signaling, but not that of the MAPK, was drastically reduced in treated cells. Overall, these in vitro data suggest that harmine could represent a new therapeutic option for ATC treatment.

Identification of functional biomarkers of Peganum harmala and Hypericum perforatum using PCA-constructed secondary metabolite maps.

Peganum harmala L. (P. harmala), also known as Espand, Harmel, or Syrian rue, and Hypericum perforatum L. (H. perforatum), commonly known as St. John's wort, are two of the widely cultivated industrial crops and used worldwide in antihepatoma-related products. However, their main functional substances are still not clear, thus impeding the efficacy evaluations and quality controls of relative products around the world. In this work, the anti-hepatoma biomarkers of P. harmala and H. perforatum were clarified through the development of principal components analysis (PCA)-HPLC secondary metabolite mapping models. The chemical fingerprints of plant extracts were profiled by HPLC and then mapped to produce the secondary metabolite models using PCA. The models correlated the chemical information with the anti-hepatoma activities of plant extracts, thus indicating the functional inhibitors of P. harmala and H. perforatum against hepatoma cells. The activities of the identified compounds were validated by cytotoxic and apoptotic assays. The major inhibitors of P. harmala and H. perforatum against human hepatoma were determined to be harmine and quercetin, respectively. The IC50 values and the induced apoptotic rate of harmine on HepG2 cells were 20.7 ± 2.8 µM and 46.7 ± 3.5 %, respectively. The IC50 values and the induced apoptotic rate of quercetin on HepG2 cells were 49.5 ± 6.6 µM and 38.7 ± 2.6 %, respectively. In conclusion, the results significantly expanded the understanding of the biochemical foundations of P. harmala and H. perforatum, thus evidently supporting their current applications around the world. Moreover, harmine and quercetin could be used as biomarkers to evaluate the efficacy and quality of related products of industrial crops in therapeutic and health-improving applications.

Discovery of novel harmine derivatives as GSK-3ß/DYRK1A dual inhibitors for Alzheimer's disease treatment.

Multitarget-directed ligands (MTDLs) have recently attracted significant interest due to their superior effectiveness in multifactorial Alzheimer's disease (AD). Combined inhibition of two important AD targets, glycogen synthase kinase-3ß (GSK-3ß) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), may be a breakthrough in the treatment of AD. Based on our previous work, we have designed and synthesized a series of novel harmine derivatives, investigated their inhibition of GSK-3ß and DYRK1A, and evaluated a variety of biological activities. The results of the experiments showed that most of these compounds exhibited good activity against GSK-3ß and DYRK1A in vitro. ZLQH-5 was selected as the best compound due to the most potent inhibitory effect against GSK-3ß and DYRK1A. Molecular docking studies demonstrated that ZLQH-5 could form stable interactions with the ATP binding pocket of GSK-3ß and DYRK1A. In addition, ZLQH-5 showed low cytotoxicity against SH-SY5Y and HL-7702, good blood-brain barrier permeability, and favorable pharmacokinetic properties. More importantly, ZLQH-5 also attenuated the tau hyperphosphorylation in the okadaic acid SH-SY5Y cell model. These results indicated that ZLQH-5 could be a promising dual-target drug candidate for the treatment of AD.

Active natural compounds perturb the melanoma risk-gene network.

Cutaneous melanoma is an aggressive type of skin cancer with a complex genetic landscape caused by the malignant transformation of melanocytes. This study aimed at providing an in silico network model based on the systematic profiling of the melanoma-associated genes considering germline mutations, somatic mutations, and genome-wide association study signals accounting for a total of 232 unique melanoma risk genes. A protein-protein interaction network was constructed using the melanoma risk genes as seeds and evaluated to describe the functional landscape in which the melanoma genes operate within the cellular milieu. Not only were the majority of the melanoma risk genes able to interact with each other at the protein level within the core of the network, but this showed significant enrichment for genes whose expression is altered in human melanoma specimens. Functional annotation showed the melanoma risk network to be significantly associated with processes related to DNA metabolism and telomeres, DNA damage and repair, cellular ageing, and response to radiation. We further explored whether the melanoma risk network could be used as an in silico tool to predict the efficacy of anti-melanoma phytochemicals, that are considered active molecules with potentially less systemic toxicity than classical cytotoxic drugs. A significant portion of the melanoma risk network showed differential expression when SK-MEL-28 human melanoma cells were exposed to the phytochemicals harmine and berberine chloride. This reinforced our hypothesis that the network modeling approach not only provides an alternative way to identify molecular pathways relevant to disease but it may also represent an alternative screening approach to prioritize potentially active compounds.

Design, synthesis, and biological evaluation of harmine derivatives as topoisomerase I inhibitors for cancer treatment.

A series of ß-carboline derivatives were designed and synthesized by introducing the chalcone moiety into the harmine. The synthesized derivatives were evaluated their anti-proliferative activities against six human cancer cell lines (MCF-7, MDA-MB-231, HepG2, HT29, A549, and PC-3) and one normal cell line (L02). Among them, compound G11 exhibited the potent anti-proliferative activity against MCF-7 cell line, with an IC50 value of 0.34 µM. Further biological studies revealed that compound G11 inhibited colony formation of MCF-7 cells, suppressed MCF-7 cell migration by downregulating migration-associated protein MMP-2. In addition, it could induce apoptosis of MCF-7 cells by downregulating Bcl-2 and upregulating Cleaved-PARP, Bax, and phosphorylated Bim proteins. Furthermore, compound G11 can act as a Topo I inhibitor, affecting DNA synthesis and transcription, thereby inhibiting cancer cell proliferation. Moreover, compound G11 inhibited tumor growth in 4T1 syngeneic transplant mice with an inhibition rate of 43.19 % at a dose of 10 mg/kg, and 63.87 % at 20 mg/kg, without causing significant toxicity to the mice or their organs, achieving the goal of reduced toxicity and increased efficacy. All these results indicate of G11 has enormous potential as an anti-tumor agent and merits further investigation.

Overcoming the clinical challenges of traditional ayahuasca: a first-in-human trial exploring novel routes of administration of N,N-Dimethyltryptamine and harmine.

Recently, the Amazonian plant medicine "ayahuasca"-containing the psychedelic compound N,N-dimethyltryptamine (DMT) and numerous ß-carboline alkaloids, such as harmine-has been suggested to exhibit beneficial effects in patients with affective and other mental health disorders. Although ayahuasca ingestion is considered safe, its pharmacokinetics/pharmacodynamics and tolerability profile pose some challenges and may limit the clinical applicability in vulnerable patient populations. While overdosing and the admixture of intolerable plant constituents may explain some of the common adverse reactions, the peroral route of administration may represent another relevant source of gastro-intestinal intolerabilities and unpredictable pharmacokinetics across users. To overcome these challenges, the present work aimed at creating ayahuasca-analogue formulations with improved pharmacokinetics and tolerability profiles. To this end, we developed peroral formulas and compared them with parenteral formulas specifically designed to circumvent the gastro-intestinal tract. In more detail, peroral administration of a capsule (containing purified DMT and harmine) was tested against a combined administration of an oromucosal harmine tablet and an intranasal DMT spray at two dose levels in an open-label within-subject study in 10 healthy male subjects. Pharmacokinetic and pharmacodynamic profiles were assessed by means of continuous blood sampling, vital sign monitoring, and psychometric assessments. Common side effects induced by traditional herbal ayahuasca such as nausea, vomiting, and diarrhea were significantly attenuated by our DMT/harmine formulations. While all preparations were well tolerated, the combined buccal/intranasal administration of harmine and DMT yielded substantially improved pharmacokinetic profiles, indicated by significantly reduced variations in systemic exposure. In conclusion, the combined buccal/intranasal administration of harmine and DMT is an innovative approach that may pave the way towards a safe, rapid-acting, and patient-oriented administration of DMT/harmine for the treatment of affective disorders. Clinical Trial Registration: clinicaltrials.gov, identifier NCT04716335.

Synthesis, antiproliferative and antiplasmodial evaluation of new chloroquine and mefloquine-based harmiquins.

Here we present the synthesis and evaluation of the biological activity of new hybrid compounds, ureido-type (UT) harmiquins, based on chloroquine (CQ) or mefloquine (MQ) scaffolds and ß-carboline alkaloid harmine against cancer cell lines and Plasmodium falciparum. The hybrids were prepared from the corresponding amines by 1,1'-carbonyldiimidazole (CDI)-mediated synthesis. In vitro evaluation of the biological activity of the title compounds revealed two hit compounds. Testing of the antiproliferative activity of the new UT harmiquins, and previously prepared triazole-(TT) and amide-type (AT) CQ-based harmiquins, against a panel of human cell lines, revealed TT harmiquine 16 as the most promising compound, as it showed pronounced and selective activity against the tumor cell line HepG2 (IC 50 = 5.48 ± 3.35 µmol L-1). Screening of the antiplasmodial activities of UT harmiquins against erythrocytic stages of the Plasmodium life cycle identified CQ-based UT harmiquine 12 as a novel antiplasmodial hit because it displayed low IC 50 values in the submicromolar range against CQ-sensitive and resistant strains (IC 50 0.06 ± 0.01, and 0.19 ± 0.02 µmol L-1, respectively), and exhibited high selectivity against Plasmodium, compared to mammalian cells (SI = 92).

Novel harmine derivatives as potent acetylcholinesterase and amyloid beta aggregation dual inhibitors for management of Alzheimer's disease.

In this study, a series of potential ligands for the treatment of AD were synthesised and characterised as novel harmine derivatives modified at position 9 with benzyl piperazinyl. In vitro studies revealed that the majority of the derivatives exhibited moderate to potent inhibition against hAChE and Aß1 - 42 aggregation. Notably, compounds 13 and 17d displayed potent drug - likeness and ADMET properties, demonstrating remarkable inhibitory activities towards AChE (IC50 = 58.76 nM and 89.38 nM, respectively) as well as Aß aggregation (IC50 = 9.31 µM and 13.82 µM, respectively). More importantly, compounds 13 and 17d showed exceptional neuroprotective effects against Aß1 - 42-induced SH - SY5Y damage, while maintaining low toxicity in SH - SY5Y cells. Further exploration of the mechanism through kinetic studies and molecular modelling confirmed that compound 13 could interact with both the CAS and the PAS of AChE. These findings suggested that harmine derivatives hold great potential as dual - targeted candidates for treating AD.

Harmine and Kaempferol treatment enhances NFATC1 and FOXP3 mediated regulatory T-cells' suppressive capacity in generalized vitiligo.

BACKGROUND: Generalized vitiligo (GV) is an autoimmune disease characterized by the progressive loss of melanocytes. OBJECTIVES: Current study was undertaken to assess in-vitro therapeutic potential of Harmine and Kaempferol for GV. METHODS: Calcium, calcineurin, NFATC1 levels, cell proliferation were assessed by various kits and ORAI1, PEIZO1, Calcineurin, GSK3B, DYRK1A transcripts and IFN-γ,IL-10,TGF-ß protein levels were assessed by qPCR and ELISA in blood and skin biopsy samples from Tregs of 52 patients and 50 controls. RESULTS: Harmine and Kaempferol treatment enhances Treg suppressive capacity, NFATs and FOXP3 expression in blood and skin Tregs of GV patients (p < 0.05). Furthermore, Harmine and Kaempferol treatment in Tregs increased calcineurin and NFATC1 activity and decreased DYRK1A transcripts in blood and skin Tregs of GV patients(p < 0.05). In-silico analysis revealed that Harmine and Kaempferol might boost Treg suppressive capacity by increasing calcineurin dephosphorylation activity leading to increase NFATs activation and also increase nuclear retention of NFATs by inhibiting DYRK1a phosphorylation activity. Moreover, calcineurin and NFATC1 activity in Tregs were positively correlated with Treg suppressive capacity, NFATC1 and FOXP3 expression (p < 0.05), whereas, DYRK1A transcripts were negatively correlated with Treg suppressive capacity, NFATC1 and FOXP3 expression (p < 0.05). These compounds significantly increased melanocytes' survival and proliferation in Treg:CD4+/CD8+:SK-Mel-28 cell line co-culture system from GV patients (p < 0.0001). CONCLUSIONS: For the first time the study suggests that Harmine and Kaempferol treated Tregs could control the CD8+ and CD4+T-cells' proliferation and IFN-γ production, leading to melanocytes' survival and proliferation. These compounds may serve as novel Treg-based therapeutics for GV; however, in vivo studies are warranted to assess the safety and efficacy of these compounds.

A pilot study of cerebral metabolism and serotonin 5-HT2A receptor occupancy in rats treated with the psychedelic tryptamine DMT in conjunction with the MAO inhibitor harmine.

Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely ß-carboline alkaloids such as harmine. However, there is lacking biochemical evidence to substantiate this pharmacokinetic potentiation of DMT in brain via systemic MAO-A inhibition. Objectives: We measured the pharmacokinetic profile of harmine and/or DMT in rat brain, and tested for pharmacodynamic effects on brain glucose metabolism and DMT occupancy at brain serotonin 5-HT2A receptors. Methods: We first measured brain concentrations of harmine and DMT after treatment with harmine and/or DMT at low sub-cutaneous doses (1 mg/kg each) or harmine plus DMT at moderate doses (3 mg/kg each). In the same groups of rats, we also measured ex vivo the effects of these treatments on the availability of serotonin 5-HT2A receptors in frontal cortex. Finally, we explored effects of DMT and/or harmine (1 mg/kg each) on brain glucose metabolism with [18F]FDG-PET. Results: Results confirmed that co-administration of harmine inhibited the formation of the DMT metabolite indole-3-acetic acid (3-IAA) in brain, while correspondingly increasing the cerebral availability of DMT. However, we were unable to detect any significant occupancy by DMT at 5-HT2A receptors measured ex vivo, despite brain DMT concentrations as high as 11.3 µM. We did not observe significant effects of low dose DMT and/or harmine on cerebral [18F]FDG-PET uptake. Conclusion: These preliminary results call for further experiments to establish the dose-dependent effects of harmine/DMT on serotonin receptor occupancy and cerebral metabolism.

Design, synthesis and antiplasmodial evaluation of new amide-, carbamate-, and ureido-type harmicines.

Malaria, one of the oldest parasitic diseases, remains a global health threat, and the increasing resistance of the malaria parasite to current antimalarials is forcing the discovery of new, effective drugs. Harmicines, hybrid compounds in which harmine/ß-carboline alkaloids and cinnamic acid derivatives are linked via an amide bond or a triazole ring, represent new antiplasmodial agents. In this work, we used a multiple linear regression technique to build a linear quantitative structure-activity relationship (QSAR) model, based on a group of 40 previously prepared amide-type (AT) harmicines and their antiplasmodial activities against erythrocytic stage of chloroquine-sensitive strain of P. falciparum (Pf3D7). After analysing the QSAR model, new harmicines were designed and synthesized: six amide-type, eleven carbamate-type and two ureido-type harmicines at the N-9 position of the ß-carboline core. Subsequently, we evaluated the antiplasmodial activity of the new harmicines against the erythrocytic and hepatic stages of the Plasmodium life cycle in vitro and their antiproliferative activity against HepG2 cells. UT harmicine (E)-1-(2-(7-methoxy-1-methyl-9H-pyrido[3,4-b]indol-9-yl)ethyl)-3-(3-(3-(trifluoromethyl)phenyl)allyl)urea at the N-9 position of the ß-carboline ring exhibited pronounced antiplasmodial activity against both the erythrocytic and the hepatic stages of the Plasmodium life cycle, accompanied by good selectivity towards Plasmodium.

A screening identifies harmine as a novel antibacterial compound against Ralstonia solanacearum.

Ralstonia solanacearum, the causal agent of bacterial wilt, is a devastating plant pathogenic bacterium that infects more than 450 plant species. Until now, there has been no efficient control strategy against bacterial wilt. In this study, we screened a library of 100 plant-derived compounds for their antibacterial activity against R. solanacearum. Twelve compounds, including harmine, harmine hydrochloride, citral, vanillin, and vincamine, suppressed bacterial growth of R. solanacearum in liquid medium with an inhibition rate higher than 50%. Further focus on harmine revealed that the minimum inhibitory concentration of this compound is 120 mg/L. Treatment with 120 mg/L of harmine for 1 and 2 h killed more than 90% of bacteria. Harmine treatment suppressed the expression of the virulence-associated gene xpsR. Harmine also significantly inhibited biofilm formation by R. solanacearum at concentrations ranging from 20 mg/L to 60 mg/L. Furthermore, application of harmine effectively reduced bacterial wilt disease development in both tobacco and tomato plants. Collectively, our results demonstrate the great potential of plant-derived compounds as antibacterial agents against R. solanacearum, providing alternative ways for the efficient control of bacterial wilt.