Design and optimization of novel Tetrahydro-ß-carboline-based HDAC inhibitors with potent activities against tumor cell growth and metastasis.

Histone deacetylases (HDACs) are validated drug targets for various therapeutic applications. A series of Tetrahydro-ß-carboline-based hydroxamate derivatives, designed as HDAC inhibitors (HDACis), were synthesized. Compound 11g exhibited strong inhibitory activity against HDAC1 and the A549 cancer cell line. Additionally, this compound increased the levels of acetylated histone H3 and H4. Notably, 11g effectively arrested A549 cells in the G2/M phase and also increased ROS production and DNA damage, thereby inducing apoptosis. Further molecular docking experiments illustrated the potential interactions between compound 11g and HDAC1. These findings suggested that the novel Tetrahydro-ß-carboline-based HDACis could serve as a promising framework for further optimization as anticancer agents.

1-Acetyl-ß-Carboline from a Jeju Gotjawal Strain Lentzea sp. JNUCC 0626 and Its Melanogenic Stimulating Activity in B16F10 Melanoma Cells.

The genus Lentzea is a prolific source of bioactive and structurally diverse secondary metabolites. We isolated a novel strain, Lentzea sp. JNUCC 0626, from Hwasun Gotjawal on Jeju Island, Korea. Based on 16S rRNA partial gene sequence analysis, strain JNUCC 0626 is closely related to Lentzea isolaginshaensis NX62 (99.41% similarity), Lentzea pudingi DHS C021 (99.31%), and Lentzea cavernae SYSU K10001 (99.26%). From the fermentation broth of JNUCC 0626, we isolated 1-acetyl-ß-carboline, whose structure was established using IR, HR-ESI-MS, and 1D- and 2D-NMR techniques. 1-acetyl-ß-carboline was found to activate melanogenesis in mouse B16F10 cells without cytotoxicity at concentrations up to 50 µM. At this concentration, the compound increased melanin content by 27.44% and tyrosinase activity by 240.64% compared to the control, by upregulating key melanogenic enzymes, including tyrosinase, TRP-1, TRP-2, and microphthalmia-associated transcription factor (MITF), a central regulator of melanogenesis. In addition, 1-acetyl-ß-carboline significantly inhibited ERK phosphorylation, reducing it by 20.79% at a concentration of 12.5 µM and by 25.63% at 25 µM. This inhibition supports the hypothesis that 1-acetyl-ß-carboline enhances melanin synthesis by upregulating MITF and melanogenic enzymes via the ERK signaling pathway. This study aimed to isolate and identify 1-acetyl-ß-carboline from a novel strain of Lentzea sp. JNUCC 0626, discovered in Gotjawal, Jeju Island, and to evaluate its effect on melanin production in B16F10 melanoma cells. Skin irritation tests on 32 subjects confirmed its safety for topical use, and the findings suggest that 1-acetyl-ß-carboline, which enhances melanogenesis without cytotoxicity, holds promise as a therapeutic agent for hypopigmentation-related conditions or as a cosmetic ingredient.

Synthesis, pharmacological evaluation, and modeling of novel quaternary ammonium salts derived from ß-carboline containing an imidazole moiety as angiogenesis inhibitors.

In this study, a series of novel ß-carboline condensed imidazolium derivatives (7a-7y) were designed and synthesized by incorporating imidazolium salt structures into ß-carboline. The cytotoxicity of compounds 7a-7y was evaluated in various cancer cell lines, including lung cancer (A549), gastric cancer (BGC-823), mouse colon cancer (CT-26), liver cancer (Bel-7402), and breast cancer (MCF-7), using the MTT assay. Most compounds exhibited significant activity against one or more of the cancer cell lines. Notably, compounds 7 g, 7o, 7r, 7 s, 7u, 7v, 7x, and 7w showed the highest cytotoxic activity (IC50 < 2 µM) in the tested tumor cell lines. Compound 7x demonstrated cytotoxic activities of 1.3 ± 0.3 µM (for BGC-823), 2.4 ± 0.4 µM (against A549), 7.8 ± 0.9 µM (for Bel-7402), and 9.8 ± 1.4 µM (against CT-26). The chick chorioallantoic membrane assay revealed significant anti-angiogenic potential of compound 7x. Molecular imprinting studies suggested the anti-angiogenic effect of compound 7x might be attributed to inhibition of VEGFR2 kinase. Molecular docking and molecular dynamics further indicate that its activity may be primarily associated with the potential inhibition of VEGFR2. Our research outcomes have provided valuable lead compounds for the development of novel antitumor drugs and have offered beneficial insights for subsequent drug design and optimization.

Evaluation of the in vivo acute toxicity and in vitro genotoxicity and mutagenicity of synthetic ß-carboline alkaloids with selective cytotoxic activity against ovarian and breast cancer cell lines.

The aim of this study was to evaluate the in vitro cytotoxic, genotoxic, and mutagenic potential and to determine the in silico ADME parameters of two synthetic ß-carboline alkaloids developed as prototypes of antitumor agents (NQBio-06 and NQBio-21). Additionally, acute toxicity of the compounds was evaluated in mice. The results from the MTT assay showed that NQBio-06 presented higher cytotoxicity in the ovarian cancer cell line TOV-21 G (IC50 = 2.5 µM, selectivity index = 23.7). NQBio-21 presented an IC50 of 6.9 µM and a selectivity index of 14.5 against MDA-MB-231 breast cancer cells. Comet assay results showed that NQBio-06 did not induce chromosomal breaks in vitro, but NQBio-21 was genotoxic with and without metabolic activation (S9 fraction). Micronucleus assay showed that both compounds were mutagenic. In addition, metabolic activation enhanced this effect in vitro. The in silico predictions showed that the compounds met the criteria set by Lipinski's rules, had strong prediction for intestinal absorption, and were possible substrates for P-glycoprotein. The in vivo results demonstrated that both the compounds exhibited low acute toxicity. These results suggest that the mechanisms underlying the cytotoxicity of NQBio-06 and NQBio-21 are related to DNA damage induction and that the use of S9 enhanced these effects. In vivo analysis showed signs of toxicity after a single administration of the compounds in mice. These findings highlight the potential of ß-carboline compounds as sources for the development of new anticancer chemotherapeutic agents.

Insights on the comparative affinity of ribonucleic acids with plant-based beta carboline alkaloid, harmine: Spectroscopic, calorimetric and computational evaluation.

Small molecules as ligands target multifunctional ribonucleic acids (RNA) for therapeutic engagement. This study explores how the anticancer DNA intercalator harmine interacts various motifs of RNAs, including the single-stranded A-form poly (rA), the clover leaf tRNAphe, and the double-stranded A-form poly (rC)-poly (rG). Harmine showed the affinity to the polynucleotides in the order, poly (rA) > tRNAphe > poly (rC)·poly (rG). While no induced circular dichroism change was detected with poly (rC)poly (rG), significant structural alterations of poly (rA) followed by tRNAphe and occurrence of concurrent initiation of optical activity in the attached achiral molecule of alkaloid was reported. At 25 °C, the affinity further showed exothermic and entropy-driven binding. The interaction also highlighted heat capacity (ΔC o p ) and Gibbs energy contribution from the hydrophobic transfer (ΔG hyd) of binding with harmine. Molecular docking calculations indicated that harmine exhibits higher affinity for poly (rA) compared to tRNAphe and poly (rC)·poly (rG). Subsequent molecular dynamics simulations were conducted to investigate the binding mode and stability of harmine with poly(A), tRNAphe, and poly (rC)·poly (rG). The results revealed that harmine adopts a partial intercalative binding with poly (rA) and tRNAphe, characterized by pronounced stacking forces and stronger binding free energy observed with poly (rA), while a comparatively weaker binding free energy was observed with tRNAphe. In contrast, the stacking forces with poly (rC)·poly (rG) were comparatively less pronounced and adopts a groove binding mode. It was also supported by ferrocyanide quenching analysis. All these findings univocally provide detailed insight into the binding specificity of harmine, to single stranded poly (rA) over other RNA motifs, probably suggesting a self-structure formation in poly (rA) with harmine and its potential as a lead compound for RNA based drug targeting.

Kumujan B suppresses TNF-α-induced inflammatory response and alleviates experimental colitis in mice.

Treatments of inflammatory bowel disease (IBD) are diverse, but their efficacy is limited, and it is therefore urgent to find better therapies. Controlling mucosal inflammation is a must in IBD drug treatment. The occurrence of anti-tumor necrosis factor α (TNF-α) monoclonal antibodies has provided a safer and more efficacious therapy. However, this kind of treatment still faces failure in the form of loss of response. ß-Carboline alkaloids own an anti-inflammatory pharmacological activity. While Kumujan B contains ß-carboline, its biological activity remains unknown. In this study, we attempted to determine the anti-inflammatory effects of Kumujan B using both the TNF-α- induced in vitro inflammation and DSS-induced in vivo murine IBD models. Our data show that Kumujan B attenuated the expression of interleukin 1ß (IL-1ß) and interleukin 6 (IL-6) induced by TNF-α in mouse peritoneal macrophages. Kumujan B suppressed c-Jun N-terminal protein kinases (JNK) signaling, especially c-Jun, for anti-inflammatory response. Furthermore, Kumujan B promoted K11-linked ubiquitination and degradation of c-Jun through the proteasome pathway. In an in vivo study, Kumujan B inhibited the expression of IL-1ß, IL-6, and TNF-α and improved the colon barrier function in dextran sulfate sodium salt (DSS)-induced experimental mice colitis. Kumujan B exhibited in vivo and in vitro anti-inflammatory effects, making it a potential therapeutic candidate for treating IBD.

Biological and structural investigation of tetrahydro-ß-carboline-based selective HDAC6 inhibitors with improved stability.

Our previously reported HDAC6 inhibitor (HDAC6i) Marbostat-100 (4) has provided many arguments for further clinical evaluation. By the substitution of the acidic hydrogen of 4 for different carbon residues, we were able to generate an all-carbon stereocenter, which significantly improves the hydrolytic stability of the inhibitor. Further asymmetric synthesis has shown that the (S)-configured inhibitors preferentially bind to HDAC6. This led to the highly selective and potent methyl-substituted derivative S-29b, which elicited a long-lasting tubulin hyperacetylation in MV4-11 cells. Finally, a crystal structure of the HDAC6/S-29b complex provided mechanistic explanation for the high potency and stereoselectivity of synthesized compound series.

Novel access to α-carbolines with biological applications.

In recent years, the 9H-pyrido[2,3-b]indole nuclei, also named α-carboline which is found in many organic compounds such as natural products, pharmaceuticals, and materials, have intensively stimulated the research of new synthetic pathways. After a brief report published in 2015 describing novel accesses and biological applications of α-carbolines, this update reports between 2015 and 2023 on the emergence of original syntheses to this heterocyclic nucleus. Examples representing these processes are described and the biological activities of α-carbolines are mentioned when they have been prepared for therapeutic purposes.

Design, synthesis and anticancer activity of ß-carboline based pseudo-natural products by inhibiting AKT/mTOR signaling pathway.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and remains the leading cause of cancer deaths. Much progress has been made to treat NSCLC, however, only limited patients can benefit from current treatments. Thus, more efforts are needed to pursue novel molecular modalities for NSCLC treatment. It was demonstrated that pseudo-natural products (PNP) are a critical source for antitumor drug discovery. Herein, we describe a CH activation protocol for the expedient construction of a focused library utilizing the PNP rational design strategy. This protocol features a rhodium-catalyzed CH activation/ [4+2] annulation reaction between N-OAc-indole-2-carboxamide and alkynyl quinols, enabling facile access to diverse quinol substituted ß-carboline derivatives (31 examples). The anticancer activities were assessed in vitro against NSCLC cell line A549, yielding a potent antiproliferative ß-carboline derivative (8r) with an IC50 value of 0.8 ± 0.1 µM. Further investigation revealed that this compound could decrease the expression of Caspase 3, and increase the expression of autophagic protein Cyclin B1, thus markedly inducing autophagy and apoptosis. Mechanistic study suggested that 8r could be a potent anti-NSCLC agent through the AKT/mTOR signaling pathway in A549 cells. Moreover, the anticancer activities were also assessed against three other cancer cell lines, and 8r exhibits a broader inhibitory effect on cell proliferation in all cancer cell lines tested. These results indicated that carboline-based PNPs show great potential to induce cell autophagy and apoptosis, which serve as good leads for further drug discovery.

Picrasma quassioides leaves: Insights from chemical profiling and bioactivity comparison with stems.

BACKGROUND: In Chinese Pharmacopeia, Picrasma quassioides (PQ) stems and leaves are recorded as Kumu with antimicrobial, anti-cancer, anti-parasitic effects, etc. However, thick stems are predominantly utilized as medicine in many Asian countries, with leaves rarely used. By now, the phytochemistry and bioactivity of PQ leaves are not well investigated. METHODS: An Orbitrap Elite mass spectrometer was employed to comprehensively investigate PQ stems and leaves sourced from 7 different locations. Additionally, their bioactivities were evaluated against 5 fungi, 6 Gram-positive bacteria and 9 Gram-negative bacteria, a tumor cell line (A549), a non-tumor cell line (WI-26 VA4) and N2 wild-type Caenorhabditis elegans. RESULTS: Bioassay results demonstrated the efficacy of both leaves and stems against tumor cells, several bacteria and fungi, while only leaves exhibited anthelmintic activity against C. elegans. A total of 181 compounds were identified from PQ stems and leaves, including 43 ß-carbolines, 20 bis ß-carbolines, 8 canthinone alkaloids, 56 quassinoids, 12 triterpenoids, 13 terpenoid derivatives, 11 flavonoids, 7 coumarins, and 11 phenolic derivatives, from which 10 compounds were identified as indicator components for quality evaluation. Most alkaloids and triterpenoids were concentrated in PQ stems, while leaves exhibited higher levels of quassinoids and other carbohydrate (CHO) components. CONCLUSION: PQ leaves exhibit distinct chemical profiles and bioactivity with the stems, suggesting their suitability for medicinal purposes. So far, the antibacterial, antifungal, and anthelmintic activities of PQ leaves were first reported here, and considering PQ sustainability, the abundant leaves are recommended for increased utilization, particularly for their rich content of PQ quassinoids.

ß-Carboline derivatives are potent against Acute Myeloid Leukemia in vitro and in vivo.

BACKGROUND: ß-carboline alkaloids exert a distinguished ability to impair cell growth and induce cell death in a variety of cancers and the evaluation of such new therapeutic candidates may denote new possibilities for leukemia treatment. In this present study, we screened 12 ß-carboline derivatives containing different substituents at 1- and 3-positions of ß-carboline nucleus for their antineoplastic activities in a panel of leukemia cell lines. METHODS: The cytotoxic effects of the ß-carboline derivatives were evaluated in different leukemia cell lines as well as reactive oxygen species (ROS) generation, autophagy, and important signaling pathways. RESULTS: Treatment with the ß-carboline derivatives resulted in a potent antineoplastic activity leading to a reduced cell viability that was associated with increased cell death in a concentration-dependent manner. Interestingly, the treatment of primary mononuclear cells isolated from the peripheral blood of healthy donors with the ß-carboline derivatives showed a minor change in cell survival. The antineoplastic activity occurs by blocking ROS production causing consequent interruption of the PI3K/AKT and MAPK/ERK signaling and modulating autophagy processes. Notably, in vivo, AML burden was diminished in peripheral blood and bone marrow of a xenograft mouse model. CONCLUSIONS: Our results indicated that ß-carboline derivatives have an on-target malignant cell-killing activity and may be promising candidates for treating leukemia cells by disrupting crucial events that promote leukemia expansion and chemotherapy resistance.

Synthesis and biological evaluation of novel 1,2,3,4-tetrahydro-ß-carboline derivatives as potential antibacterial agents.

The quest for novel antibacterial agents is imperative in the face of escalating antibiotic resistance. Naturally occurring tetrahydro-ß-carboline (THßC) alkaloids have been highlighted due to their significant biological derivatives. However, these structures have been little explored for antibacterial drugs development. In this study, a series of 1,2,3,4-THßC derivatives were synthesized and assessed for their antibacterial prowess against both gram-positive and gram-negative bacteria. The compounds exhibited moderate to good antibacterial activity, with some compounds showing superior efficacy against gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), to that of Gentamicin. Among these analogs, compound 3k emerged as a hit compound, demonstrating rapid bactericidal action and a significant post-antibacterial effect, with significant cytotoxicity towards human LO2 and HepG2 cells. In addition, compound 3k (10 mg/kg) showed comparable anti-MRSA efficacy to Ciprofloxacin (2 mg/kg) in a mouse model of abdominal infection. Overall, the present findings suggested that THßC derivatives based on the title compounds hold promising applications in the development of antibacterial drugs.

Next generation antimitotic ß-carboline derivatives modulate microtubule dynamics and downregulate NF-κB, ERK 1/2 and phospho HSP 27.

AIM: Exploring the efficacy of ß-carboline-based molecular inhibitors in targeting microtubules for the development of novel anticancer therapeutics. MATERIALS AND METHODS: We synthesized a series of 1-Aryl-N-substituted-ß-carboline-3-carboxamide compounds and evaluated their cytotoxicity against human lung carcinoma (A549) cells using the MTT assay. Normal lung fibroblast cells (WI-38) were used to assess compound selectivity. The mechanism of action of MJ-211 was elucidated through Western blot analysis of key pro-apoptotic and cell cycle regulatory proteins. Additionally, the inhibitory effect of MJ-211 on multicellular 3D spheroid growth of A549 cells was evaluated. KEY FINDINGS: Lead compound MJ-211 exhibited remarkable cytotoxicity against A549 cells with an IC50 of 4.075 µM at 24 h treatment and IC50 of 1.7 nM after 72 h of treatment, while demonstrating selectivity towards normal WI-38 cells. MJ-211 activated pro-apoptotic factors Bim and p53, and suppressed Cyclin B1, Phospho HSP 27, BubR1, Mad 2, ERK1/2, and NF-κB, indicating its potent antimitotic and pro-apoptotic effects. MJ-211 significantly suppressed the migration of cells and inhibited the growth of A549 cell-derived multicellular 3D spheroids, highlighting its efficacy in a more physiologically relevant model. SIGNIFICANCE: Cytotoxic effect of MJ-211 against cancer cells, selectivity towards normal cells, and ability to modulate key regulatory proteins involved in apoptosis and cell cycle progression underscore its potential as a promising template for further anticancer lead optimization. Moreover, the inhibitory effect of MJ-211 on multicellular spheroid growth suggests its efficacy in combating tumor heterogeneity and resistance mechanisms, thereby offering a promising avenue for future anticancer drug development.

Effects and mechanisms of using "clean" smoke particles in the smoking process on the formation of ß-carboline heterocyclic amines (ß-CHAs) in smoked meat patties.

ß-Carboline heterocyclic amines (ß-CHAs), known for their synergistic neurotoxic and carcinogenic effects, are predominantly produced by humans through cigarette smoke and food and are found particularly in meats cooked at high temperatures. Few studies have explored the differences in the mechanisms of accumulation of ß-CHAs in smoked meat and meat processed at high temperatures. In this research, the concentration of ß-CHAs in smoked meats prepared using a variety of wood materials was measured using LCMS/MS. Additionally, key volatile organic compound markers associated with ß-CHAs accumulation in smoke were identified through GCMS and multivariate statistical analysis and subsequently confirmed in a chemical simulation system. Three types of strainers, each with a distinct aperture size, were used to assess the efficacy of particle filtration in reducing ß-CHAs levels in smoked meat. The findings indicated that smoke exposure indeed increases the ß-CHAs content of meat. However, only the strainer capable of filtering PM2.5-sized particles reduced the amount of ß-CHAs present compared to the control group. In contrast, strainers with larger pore sizes facilitated excessive accumulation of ß-CHAs. The presence of aldehydes such as 1 H-pyrrole-2-carboxaldehyde, 5-methylfurfural, benzaldehyde, furfural, and nonanal exhibited a positive correlation with the accumulation of ß-CHAs. Conversely, phenolic compounds, including 2-methoxy-4-vinylphenol, 2-methoxy-5-methylphenol, p-cresol, phenol, 2-methoxy-4-(1-propenyl)-, (Z)-, phenol, 3-ethyl-, and phenol, 4-ethyl-2-methoxy-, showed a negative correlation. Thus, filters made from chelated carbonyl trap materials both chemically and physically disrupt the buildup of ß-CHAs in smoked meats. The use of this approach will not only improve the quality of these products but will also contribute to decreasing the amount of inhalation pollutants released into the environment.

Structurally diverse isoquinoline alkaloids from the barks of Alangium salviifolium (L. f.) Wangerin and their cytotoxicity.

Eleven undescribed isoquinoline alkaloids (1-8, 14, 15, and 24), along with 19 analogues (9-13, 16-23, and 25-30) were isolated from the barks of Alangium salviifolium. The structures of the undescribed compounds were elucidated through the analysis of their HR-ESI-MS, 1D and 2D NMR, IR, UV, and X-ray diffraction. The absolute configuration of 8 was established via the ECD calculation. Notably, compounds 1/2 and 3/4 were two pairs of C-14 epimers. The isolated alkaloids were evaluated for their cytotoxicity against various cancer cell lines, including SGC-7901, HeLa, K562, A549, BEL-7402, HepG2, and B16, ß-carboline-benzoquinolizidine (14-22) and cepheline-type (24-28) alkaloids exhibited remarkable cytotoxicity, with IC50 values ranging from 0.01 to 48.12 µM. Remarkably, compounds 17 and 21 demonstrated greater cytotoxicity than the positive control doxorubicin hydrochloride. Furthermore, a significant proportion of these bioactive alkaloids possess a C-1' epimer configuration. The exploration of their structure-activity relationship holds promise for directing future investigations into alkaloids derived from Alangium, potentially leading to novel insights and therapeutic advancements.

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.

Anticancer mechanisms of ß-carbolines.

ß-Carboline nucleus is therapeutically valuable in medicinal chemistry for the treatment of varied number of diseases, most importantly cancer. The potent and wide-ranging activity of ß-carboline has established them as imperative pharmacological scaffolds especially in the cancer treatment. Numerous derivatives such as Tetrahydro ß-carbolines, metal complexed ß-carbolines, mono, di and tri substituted ß-carbolines have been reported to possess dynamic anticancer activity. These different substituted ß-carboline derivatives had shown different mechanism of action and plays important role in anticancer drug discovery and development. The review is an update of the chemistry of ß-carbolines, both synthetic and natural origin acting through various targets against cancerous cells. In addition to this, studies of multitarget molecules designed by coupling ß-carbolines along with other mechanisms for treatment of neoplasm are also summarized.

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.

1-Ethoxycarbonyl-beta-carboline inhibits the M2 polarization of tumor-associated macrophages: A study based on network pharmacology and molecular docking analyses.

AIM: Through network pharmacology, molecular docking, molecular dynamics in combination with experimentation, we explored the mechanism whereby 1-ethoxycarbonyl-beta-carboline (EBC) regulates the M2 polarization of tumor-associated macrophages. METHODS: Network pharmacology was adopted for analyzing the targets and signaling pathways related to the M2 polarization of EBC-macrophages, small molecular-protein docking was employed to analyze the possibility of EBC bonding to related protein, and molecular dynamics was introduced to analyze the binding energy between EBC and HDAC2. The M2 polarization of RAW264.7 macrophages was triggered in vitro by IL-4. After EBC intervention, the expressions of M1/M2 polarization-related cytokines were detected, and the mechanism of EBC action was explored in HDAC2-knockout RAW264.7 macrophages. A tumor-bearing mouse model was established in vitro to find the impact of EBC on tumor-associated M2 macrophages. RESULTS: As revealed by the network pharmacology, molecular docking and molecular dynamics analyses, EBC was associated with 51 proteins, including HDAC2, NF-κB and HDAC4. Molecular docking and dynamics analyses suggested that HDAC2 was the main target of EBC. In vitro experiments discovered that EBC could hinder the M2 polarization of RAW264.7 macrophages, which exerted insignificant effect on the M1-associated cytokines, but could lower the levels of M2-associated cytokines. After knocking out HDAC2, EBC could not further inhibit the M2 polarization of macrophages. At the mouse level, EBC could hinder the tumor growth and the tissue levels of M2 macrophages, whose effect was associated with HDAC2. CONCLUSION: Our study combining multiple methods finds that EBC inhibits the HDAC2-mediated M2 polarization of macrophages, thereby playing an anti-tumor role.

Synthesis and biological evaluation of 1-phenyl-tetrahydro-ß-carboline-based first dual PRMT5/EGFR inhibitors as potential anticancer agents.

Protein arginine methyltransferase 5 (PRMT5) and epidermal growth factor receptor (EGFR) are both involved in the regulation of various cancer-related processes, and their dysregulation or overexpression has been observed in many types of tumors. In this study, we designed and synthesized a series of 1-phenyl-tetrahydro-ß-carboline (THßC) derivatives as the first class of dual PRMT5/EGFR inhibitors. Among the synthesized compounds, 10p showed the most potent dual PRMT5/EGFR inhibitory activity, with IC50 values of 15.47 ± 1.31 and 19.31 ± 2.14 µM, respectively. Compound 10p also exhibited promising antiproliferative activity against A549, MCF7, HeLa, and MDA-MB-231 cell lines, with IC50 values below 10 µM. Molecular docking studies suggested that 10p could bind to PRMT5 and EGFR through hydrophobic, π-π, and cation-π interactions. Furthermore, 10p displayed favorable pharmacokinetic properties and oral bioavailability (F = 30.6%) in rats, and administrated orally 10p could significantly inhibit the growth of MCF7 orthotopic xenograft tumors. These results indicate that compound 10p is a promising hit compound for the development of novel and effective dual PRMT5/EGFR inhibitors as potential anticancer agents.