Agonist Activity Research Articles

HYA ameliorated postprandial hyperglycemia in type 1 diabetes model rats with bolus insulin treatment.

The oral administration of linoleic acid immediately before glucose tolerance test (OGTT) ameliorated postprandial hyperglycemia via GPR120 pathway in normal and type 1 diabetes (T1DM) rats. Linoleic acid could promote inflammatory mediators, but 10-hydroxy-cis-12-octadecenoic acid (HYA) converted from linoleic acid by Lactobacillus plantarum has higher GPR120 agonistic activity without promoting inflammatory mediators. This study examined whether the oral-administration of HYA immediately before OGTT also ameliorated the postprandial hyperglycemia in normal rats and T1DM rats injected with bolus insulin. Normal and T1DM male Sprague-Dawley rats received HYA immediately before OGTT. Other T1DM rats were given HYA and Humulin R immediately before OGTT. We measured the concentration of glucose, insulin, glucagon-like peptide 1 (GLP-1) and cholecystokinin in blood before and after OGTT. We also measured the amount of glucose in the gastric tract after OGTT, and the amount of uptake of methyl-α-D-glucopyranoside in CACO-2 cells. Postprandial hyperglycemia was ameliorated by HYA in normal rats, and the postprandial blood glucose levels were slowly elevated by HYA in the T1DM model rats. HYA partially inhibited the uptake of methyl-α-D-glucopyranoside in CACO-2 cells. HYA slowed gastric motility and increased the plasma GLP-1 and cholecystokinin levels in normal rats. HYA also ameliorated the postprandial hyperglycemia in T1DM rats given bolus insulin. Oral administration of HYA immediately before OGTT ameliorated postprandial hyperglycemia through inhibition of glucose absorption and slowing of gastric motility in normal rats. Furthermore, this beneficial effect of HYA was also revealed in T1DM rats injected with bolus insulin.

Potential Serotonin 5-HT2A Receptor Agonist of Psychoactive Components of Silene undulata Aiton: LC-MS/MS, ADMET, and Molecular Docking Studies.

Silene undulata is historically used for inducing vivid and prophetic lucid dreams, but limited information exists on its phytochemical composition and potential pharmacological properties. This study aimed to investigate the phytochemical composition of S. undulata through LC-MS/MS analysis and explore its potential serotonergic activity, which could support and confirm the traditional use of S. undulata as a dream-inducing plant. LC-MS/MS analysis was conducted on S. undulata extract, identifying 51 phytochemicals, including norharman, harmalol, harmaline, harmine, and ibogaine alkaloids. ADMET and Molecular docking investigations were employed to assess the serotonergic potential of these compounds. The analysis revealed the presence of β-carboline alkaloids, such as norharman, harmalol, harmaline, harmine, and ibogaine, within S. undulata extract. ADMET analysis showed that these compounds have a favourable pharmacokinetic properties. In addition, molecular docking investigations showed that harmaline (-8.90 Kcal/mol), harmalol (-8.56 Kcal/mol), and ibogaine (-8.75 Kcal/mol) exhibited binding affinities comparable to the control molecule, LSD (-9.14 Kcal/mol), indicating potential agonistic activity at serotonin 5-HT2A receptor. These findings provide insights into the potential therapeutic benefits of S. undulata, supporting its traditional use as a psychoactive plant. This study investigated the chemical constituents and potential serotonergic agonist activity of S. undulata for the first time. While promising, further research is necessary to uncover additional medicinal properties associated with the identified phytochemical components.

Design, Synthesis, and Biological Evaluation of Aryl Pyrazolopyrimidines as Toll-Like Receptor 7 Agonists.

Compounds containing pyrazolopyrimidine scaffolds were designed and synthesized as toll-like receptor 7 (TLR7) agonists. Thirty-three compounds, including 22 novel compounds, were prepared, and their structures were identified using nuclear magnetic resonance spectroscopy and mass spectrometry. TLR7 agonist activity was determined in HEK-Blue hTLR7 reporter cells. Among the compounds tested, 2-((4-methoxyphenyl)amino)-7-(pyridin-2-yl)pyrazolo[1,5-a]pyrimidine-3-carbonitrile showed the highest activity, and further invitro biological experiments were performed using this compound. Treatment with the title compound activated the TLR7-mediated NF-κB pathway, triggering the IRAK4-IKKα/β-IκBα-p65 NF-κB signaling cascade, which led to an increase in the expression of NF-κB-regulated innate cytokines such as TNFα and IL-1β in RAW264.7 macrophages. These findings suggest that the title compound acts as a TLR7 agonist and enhances the innate immune response.

AiGPro: a multi-tasks model for profiling of GPCRs for agonist and antagonist

G protein-coupled receptors (GPCRs) play vital roles in various physiological processes, making them attractive drug discovery targets. Meanwhile, deep learning techniques have revolutionized drug discovery by facilitating efficient tools for expediting the identification and optimization of ligands. However, existing models for the GPCRs often focus on single-target or a small subset of GPCRs or employ binary classification, constraining their applicability for high throughput virtual screening. To address these issues, we introduce AiGPro, a novel multitask model designed to predict small molecule agonists (EC50) and antagonists (IC50) across the 231 human GPCRs, making it a first-in-class solution for large-scale GPCR profiling.Leveraging multi-scale context aggregation and bidirectional multi-head cross-attention mechanisms, our approach demonstrates that ensemble models may not be necessary for predicting complex GPCR states and small molecule interactions. Through extensive validation using stratified tenfold cross-validation, AiGPro achieves robust performance with Pearson's correlation coefficient of 0.91, indicating broad generalizability. This breakthrough sets a new standard in the GPCR studies, outperforming previous studies. Moreover, our first-in-class multi-tasking model can predict agonist and antagonist activities across a wide range of GPCRs, offering a comprehensive perspective on ligand bioactivity within this diverse superfamily. To facilitate easy accessibility, we have deployed a web-based platform for model access at https://aicadd.ssu.ac.kr/AiGPro.Scientific Contribution We introduce a deep learning-based multi-task model to generalize the agonist and antagonist bioactivity prediction for GPCRs accurately. The model is implemented on a user-friendly web server to facilitate rapid screening of small-molecule libraries, expediting GPCR-targeted drug discovery. Covering a diverse set of 231 GPCR targets, the platform delivers a robust, scalable solution for advancing GPCR-focused therapeutic development.The proposed framework incorporates an innovative dual-label prediction strategy, enabling the simultaneous classification of molecules as agonists, antagonists, or both. Each prediction is further accompanied by a confidence score, offering a quantitative measure of activity likelihood. This advancement moves beyond conventional models focusing solely on binding affinity, providing a more comprehensive understanding of ligand-receptor interactions.At the core of our model lies the Bi-Directional Multi-Head Cross-Attention (BMCA) module, a novel architecture that captures forward and backward contextual embeddings of protein and ligand features. By leveraging BMCA, the model effectively integrates structural and sequence-level information, ensuring a precise representation of molecular interactions. Results show that this approach is highly accurate in binding affinity predictions and consistent across diverse GPCR families.By unifying agonist and antagonist bioactivity prediction into a single model architecture, we bridge a critical gap in GPCR modeling. This enhances prediction accuracy and accelerates virtual screening workflows, offering a valuable and innovative solution for advancing GPCR-targeted drug discovery.Graphical

Abstract B030: Novel strategy to improve response of high risk HPV+ HNSCC to radiation therapy

Abstract Background: Improving understanding of head and neck squamous cell carcinoma (HNSCC) has led to the discovery of novel molecular markers to stratify risk and guide treatment decisions. Recently, we have identified two subtypes of HPV+ OPSCC – one with good prognosis and one with poor prognosis. The subtypes are distinct in many ways – somatic genes mutated, HPV viral oncogenes expression, the physical state of the viral genome (integrated vs episomal), as well as global mutation and methylation profiles. Intriguingly, all differences converge on intrinsic tumor NF-κB activity with constitutively active NF-κB (usually arising from genetic defects in NF-κB regulators, including TRAF3 and CYLD) driving significantly elevated radiation sensitivity and improved patient survival. NF-κB-based groups define an important clinically actionable prognostic biomarker in HPV+ HNSCC: one important goal is to de-escalate therapy for patients with molecularly low-risk tumors to improve quality of life amongst survivors, while another goal is to improve the cure for of patients with a high risk of treatment failure. Material and methods: We utilized HPV+ head and neck cancer cells, HPV+ HNSCC xenografted mouse model, patient-derived xenografts (PDX), as well as our novel fully immunocompetent mouse model of high risk HPV+ HNSCC; we applied targeted fractionated radiation. To activate NF-κB, we used two clinically applicable drugs with different mechanisms of action: Toll-like receptor 5 (TLR5) agonist and mitochondria-derived activator of caspases (SMAC) mimetic. Custom NF-κB NanoString panel contains our recently developed NF-κB gene signature along with HPV genes and housekeeping genes that are used to normalize the gene expression data. Results: Both drugs activated NF-κB in HPV+ HNSCC and significantly improved response of HPV+ head and neck cancer cells and tumors to radiation. Interestingly, TLR5 agonist alone had a strong tumor suppressing effect in low NF-κB HPV+ HNSCC; this effect was significantly better than 32 Gy focused radiation given in fractions of 4 Gy. Custom NF-κB NanoString panel is robustly prognostic with NF-κB active tumors having improved outcomes after chemoradiation. Conclusions: Because of the average relatively favorable prognosis of HPV+ HNSCC, urgent need for improved therapy for patients with aggressive high risk tumors is greatly undervalued. Here, we present a clinical assay to risk stratify patients with HPV+ HNSCC and begin to explore pharmacological activation of NF-κB as a strategy to sensitize high risk HPV+ HNSCC to radiation therapy. TLR5 agonist is well known for the remarkable normal tissue protective effects against radiation and other damaging conditions; the dual effect of entolimod – sensitization of HPV+ HNSCC to radiation, while simultaneously protecting normal tissues from severe side effects - may be useful for patients with high-risk HPV+ head and neck cancer in combination with radiotherapy. Citation Format: Sri Vemulamanda, Natalia Issaeva1, Aditi Kothari, Travis Schrank, Wendell G. Yarbrough. Novel strategy to improve response of high risk HPV+ HNSCC to radiation therapy. [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Targeted Therapies in Combination with Radiotherapy; 2025 Jan 26-29; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(2_Suppl):Abstract nr B030.

Convergent Agonist and Heat Activation of Nociceptor TRPM3.

Detecting noxious heat is vital for survival, triggering pain responses that protect against harm 1,2 . The TRPM3 channel is a key nociceptor for sensing noxious heat and a promising therapeutic target for pain treatment and neurological disorders such as epilepsy 3-11 . Here, we functionally and structurally characterized TRPM3 in response to diverse stimuli: the synthetic superagonist CIM0216 Ref12 , the anticonvulsant antagonist primidone 13,14 , and heat 1,10,15 . Our findings reveal that TRPM3 is intrinsically dynamic, with its intracellular domain (ICD) sampling both resting and activated states, though strongly favoring the resting state without stimulation. CIM0216 binds to the S1-S4 domain, inducing conformational changes in the ICD and shifting the equilibrium toward activation. Remarkably, heat induces similar ICD rearrangements, revealing a converged activation mechanism driven by chemical compounds and temperature. This mechanism is supported by functional data showing that mutations facilitating the ICD movement markedly increase the sensitivity of TRPM3 to both chemical and thermal signals. These findings establish a critical role of the ICD in temperature sensing in TRPM3, a mechanism likely conserved across the TRPM family. Finally, we show that primidone binds to the same site as CIM0216 but acts as an antagonist. This study provides a framework for understanding the thermal sensing mechanisms of temperature-sensitive ion channels and offers a structural foundation for developing TRPM3-target therapeutics for pain and neurological disorders.

Low-molecular-weight Ligand of the Thyroid-stimulating Hormone Receptor with the Activity of a Partial Agonist and a Negative Allosteric Modulator.

Graves' disease is caused by overactivation of the thyroid-stimulating hormone receptor (TSHR). One approach for its treatment may be the use of negative allosteric modulators (NAM) of TSHR, which normalize TSHR activity and do not cause thyroid hormone (TH) deficiency. The aim of the work was to study the effect of a new compound 5-amino-4-(4-bromophenyl)-2-(methylthio)thieno[2,3-d]pyrimidine-6-carboxylic acid N-tert-butylamide (TPY4) on the basal and TSH-stimulated TH production in cultured FRTL-5 thyrocytes and on basal and thyrotropin-releasing hormone (TRH)-stimulated TH levels in the blood of rats. TPY4 stimulated TH production by thyrocytes and increased TH levels when administered intraperitoneally and orally in rats. It also decreased the TSH-stimulated TH production in thyrocytes and the TRH-stimulated TH levels in rats. Thus, TPY4 is the first known allosteric regulator of TSHR, combining the properties of NAM and a partial agonist, and can be considered as a prototype of drugs for the treatment of Graves' disease.

The safety, tolerability, pharmacokinetics and pharmacodynamics of an optimized dual GLP-1/GIP receptor agonist (BGM0504) in healthy volunteers: A dose-escalation Phase I study.

Previous experiments have demonstrated that BGM0504, a GLP-1R/GIPR dual agonist drug by molecular dynamics-guided optimization, had enhanced agonistic activity compared to tirzepatide. This study aims to investigate its safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) in Chinese healthy volunteers. A randomized, double-blind, placebo-controlled and dose-escalation Phase I study was conducted as follows: a single dose (2.5 mg) and once-weekly administration for 2 weeks to reach target doses (5, 10 and 15 mg) by titration. A total of 40 volunteers received at least one dose of BGM0504 or placebo. The PK profile of BGM0504 was investigated over a wide dose range and supported once-weekly administration. It was observed that Cmax and AUC of BGM0504 were linearly proportional to the dose from 2.5-15 mg. The change in body weight (%) from baseline in BGM0504 groups was greater than that in the placebo group, with -3.24%, -6.26%, -7.09% and - 8.30% in 2.5, 5, 10 and 15 mg groups, respectively, indicating a certain dose correlation. Meanwhile, the potential roles of BGM0504 in glycaemic control were also observed. The most frequent adverse events reported were gastrointestinal (vomiting, nausea, decreased appetite, diarrhoea and abdominal distension). BGM0504 was generally safe and well tolerated with favourable PK profile and potential role in weight loss was also confirmed. These findings support subsequent development of BGM0504 for type 2 diabetes mellitus (T2DM) and obesity.

DOP033 Pre-Clinical Development of SL-325, a High Affinity DR3 Blocking Antibody, for Durable Blockade of the DR3/TL1A Axis in Inflammatory Bowel Disease

Abstract Background TL1A blocking antibodies have demonstrated promising clinical remission rates in patients with inflammatory bowel disease (Sands B et al, NEJM 2024). TL1A promotes inflammation through binding to a single receptor, DR3. There are no known signaling ligands for DR3 aside from TL1A. Whereas TL1A is transiently expressed by antigen presenting and endothelial cells at sites of active inflammation in the small and large intestine, DR3 is constitutively expressed by lymphoid cells in the peripheral blood, and throughout the GI tract at both inflamed and adjacent non-inflamed tissue. Methods A human DR3 blocking antibody, SL-325, was produced from stably transfected CHO cells and purified using an affinity chromatography capture step, followed by two polishing steps. Sequence equivalents of tulisokibart and RO7790121 were produced by transient transfection and affinity purification. The safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of SL-325 were evaluated in a GLP toxicology study in cynomolgus macaques over a 6-week in-life period followed by a 4-week recovery at Charles River Laboratories. Results SL-325 binding affinity to human DR3 was measured at 1.3 pM. SL-325 bound to both monomeric and trimeric human DR3 prevented recombinant human TL1A binding with an approximately ~10X improvement in potency in comparison to sequence equivalents of tulisokibart or RO7790121. The DR3 epitope bound by SL-325 did not trigger receptor-mediated endocytosis, and no evidence of SL-325 mediated DR3 agonism was observed in the absence or presence of T cell receptor activation of primary human lymphocytes from healthy donors, or donors with Crohn’s Disease or Ulcerative Colitis. Naïve cynomolgus macaques received 3 doses of intravenous SL-325 (vehicle, 1 mg/kg, 10 mg/kg or 100 mg/kg dose groups), each given two weeks apart, and no evidence of toxicity, organ dysfunction or changes to complete blood counts or metabolic panels were observed. Full and durable DR3 receptor occupancy (RO) was observed in peripheral blood lymphocytes at doses of 1 mg/kg and higher within two hours of infusion and throughout the 14 day inter-dose interval. Serum exposure of free SL-325 increased in a dose proportional manner. No evidence of residual DR3 agonist activity was observed. Conclusion These results indicate SL-325 is a high-affinity DR3 blocking antibody with no evidence of toxicity or residual agonism in cynomolgus macaques, and with an RO/PK profile suggestive of extended dosing intervals that will be studied in an upcoming Phase 1 clinical trial. References Sands BE, Feagan BG, Peyrin-Biroulet L, Danese S, Rubin DT, Laurent O, Luo A, Nguyen DD, Lu J, Yen M, Leszczyszyn J, Kempinski R, McGovern DPB, Ma C, Ritter TE, Targan S. Phase 2 Trial of Anti-TL1A Monoclonal Antobidy Tulisokibart for Ulcerative Colitis. NEJM 2024;391(12):1119-1129

DOP035 Anti-inflammatory potential of novel tethered agonists of the adhesion G protein-coupled receptor F5

Abstract Background An accumulating data suggest that the adhesion G protein-coupled receptor F5 (ADGRF5) is fundamental for human health and diseases1-3. It was noted that ADGRF5 mediates immune response in cancers but its impact on colitis development is still unknown. Moreover, recent findings identified mature tethered agonist of ADGRF5 which corresponds to Stachel sequence of this receptor4. The purpose of this work was to design peptides corresponding to Stachel sequence able to activate ADGRF5 with higher activity than the mature ADGRF5 tethered agonist and evaluate them in colitis model. Methods Single amino acid substitutions in the mature ADGRF5 tethered agonist sequence combined with calcium accumulation and inositol phosphate conversion assays as well as ADGRF5 overexpressing cells were used to identify novel ADGRF5 tethered agonists. The downstream signalling pathway induced by ADGRF5 tethered agonists was estimated using Western blot technique. In vivo studies employing murine model of colitis induced by dextran sulphate sodium salt (DSS) administration were performed. Anti-inflammatory potential of novel ADGRF5 tethered agonists was assessed using macroscopic and microscopic damage score as well as total length of inflamed colon. Results The comparison of mature and modified ADGRF5 tethered agonist activity documented that substitution of the amino acids in position 11 and 13 improves their activity in ADGRF5 overexpressing cells when compared to wild-type cells. In vitro approach using calcium accumulation and inositol phosphate conversion assays revealed that novel ADGRF5 tethered agonists are characterized by 6-fold lower EC50 value than parent ADGRF5 tethered agonist. Moreover, our novel ADGRF5 tethered agonists are able to induce phosphorylation of protein kinase A and B as well as extracellular signal-regulated kinase signalling pathways in time and dose-dependent manner. Finally, administration of novel ADGRF5 tethered agonists in the murine model of colitis led to a significant improvement of macroscopic and microscopic damage score compared to animals treated with mature ADGRF5 tethered agonist. Additionally, the colons of mice treated with novel ADGRF5 tethered agonists but not with mature ADGRF5 tethered agonist were characterized by reduction of total length of inflammation and improvement of colon architecture. Conclusion We found critical positions in the Stachel sequence of ADGRF5 agonists which are required for their activity. New ADGRF5 tethered agonists displayed anti-inflammatory action highlighting that modulation of ADGRF5 activity may serve as an attractive target in colitis treatment.

Thyromimetics and MASLD: Unveiling the Novel Molecules Beyond Resmetirom.

Resmetirom, the first FDA-approved drug for nonalcoholic steatohepatitis (NASH) with fibrosis in obese patients, when combined with lifestyle modifications, improves NASH resolution and reduces fibrosis by at least one stage. Low thyroid hormone (T3) levels are linked to a higher risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD). Epidemiological studies have confirmed the positive correlation between hypothyroidism and MASLD. Unraveling the molecular mechanisms of T3 signaling pathways in MASLD will enhance the prospects of identifying effective and specific targets. Therefore, this review discusses the significant role of thyroid hormones in the homeostasis of fat metabolism and describes the possible molecular mechanisms of thyromimetics in the treatment of MASLD. A comprehensive search in PubMed and EMBASE was conducted using the keywords "thyromimetics and liver diseases," "thyroid hormone and liver diseases," "hypothyroidism and liver diseases," "T3, T4 and liver disease," and "resmetirom and liver disease." Relevant papers published before October 2024 were included. T3 treatment enhances mitochondrial respiration, biogenesis, β-oxidation, and mitophagy, reducing liver lipid accumulation. However, T3 treatment causes cardiotoxicity through thyroid hormone receptor (THR)α agonistic activity. To address this, molecules with high THRβ agonistic but lower THRα activity have been developed. Besides resmetirom, other THRβ agonists like TG68, CS27109, MB07811, and KB-141 show promising results in experimental studies. These molecules upregulate THRβ target genes, activate genes for fatty acid β-oxidation in mitochondria and fatty acid breakdown in peroxisomes, downregulate the genes involved in de novo lipogenesis, reduce inflammation by downregulating NF-κB/JNK/STAT3 signaling pathways, and accelerate fibrosis resolution by downregulating the expressions of fibrosis marker genes in NASH liver tissue. Future clinical studies should thoroughly investigate THRβ agonists, including TG68, CS27109, MB07811, and KB-141.

Effect of a Low-Molecular-Weight Allosteric Agonist of the Thyroid-Stimulating Hormone Receptor on Basal and Thyroliberin-Stimulated Activity of Thyroid System in Diabetic Rats.

The approaches to correct thyroid deficiency include replacement therapy with thyroid hormones (THs), but such therapy causes a number of side effects. A possible alternative is thyroid-stimulating hormone (TSH) receptor activators, including allosteric agonists. The aim of this work was to study the effect of ethyl-2-(4-(4-(5-amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[2,3-d]pyrimidin-4-yl)phenyl)-1H-1,2,3-triazol-1-yl) acetate (TPY3m), a TSH receptor allosteric agonist developed by us, on basal and thyroliberin (TRH)-stimulated TH levels and the hypothalamic-pituitary-thyroid (HPT) axis in male rats with high-fat diet/low-dose streptozotocin-induced type 2 diabetes mellitus (T2DM). Single and three-day administration of TPY3m (i.p., 20 mg/kg) was studied, and the effect of TPY3m on the HPT axis was compared with that of levothyroxine. TPY3m increased TH levels when administered to both healthy and diabetic rats, normalizing thyroxine and triiodothyronine levels in T2DM and, unlike levothyroxine, without negatively affecting TSH levels or the expression of hypothalamic and pituitary genes responsible for TSH production. TPY3m pretreatment preserved the stimulatory effects of TRH on TH levels and thyroid gene expression. This indicates the absence of competition between TPY3m and endogenous TSH for TSH receptor activation and is supported by our in vitro results on TPY3m- and TSH-stimulated adenylate cyclase activity in rat thyroid membranes. Morphological analysis of thyroid glands in diabetic rats after three-day TPY3m administration shows an increase in its functional activity without destructive changes. To summarize, TPY3m, with the activity of a partial allosteric agonist of the TSH receptor, was created as a prototype of drugs to correct thyroid insufficiency in T2DM.

Design, Synthesis, and Biological Assessment of Novel Aminobenzidazole Agonists Targeting the Stimulator of Interferon Genes (STING) Receptor Signaling Pathway for Oncology Immunotherapy.

The activation of the STING-mediated signaling pathway leads to the secretion of type I interferon (IFN) and the activation of tumor-specific T cells. STING, a pattern recognition receptor located on the endoplasmic reticulum membrane of immune cells, binds with endogenous cyclic dinucleotides. STING undergoes phosphorylation, triggering the STING-TBK1-IRF3 pathway and NF-κB pathway, resulting in the release of IFN-β and other pro-inflammatory cytokines, ultimately enhancing the activation of tumor-specific T cells. This mechanism serves to complement the limitations of immune checkpoint inhibitors and enhances the efficiency of the immune response. This study selected benzimidazole compounds GSK and SR-717, which exhibit promising potential as patented medicines, as our lead compounds. Aiming to address the challenges associated with the short half-life of benzimidazole compounds and the limited molecular activity of SR-717, we designed and synthesized a series of STING agonists (compounds 6~29). The compound 17 showed excellent agonistic activity on hSTING protein in vitro. The cytotoxicity tests of all the synthesized compounds were performed in vitro. Performed in vivo pharmacokinetic studies on the most promising compounds and conducted molecular docking analyses.

The psychoplastogens ibogaminalog and ibogainalog induce antidepressant-like activity in naïve and depressed mice by mechanisms involving 5-HT2A receptor activation and serotonergic transmission.

The antidepressant-like activity of two psychoplastogens, ibogainalog (IBG) and ibogaminalog (DM506), was studied in naïve mice using the forced swim test (FST) and tail suspension test (TST). The behavioral results showed that a single administration of 25mg/kg DM506 or 10mg/kg IBG induced antidepressant-like activity in naïve mice in a volinanserin-sensitive manner that persisted for 72h. Similar results were observed using the chronic immobilization stress (CIS) test, in which depression symptoms were reduced for 48h. To assess the contribution of serotonergic and/or norepinephrinergic neurotransmission, serotonin (5-HT) and norepinephrine (NE) levels were depleted. The reduction in 5-HT levels, but not NE levels, inhibited the antidepressant-like activity of ibogalogs, suggesting that serotonergic transmission may play a more significant role than norepinephrinergic transmission. Concurrently, DM506, IBG, and TBG (derived from tabernanthine) inhibited monoamine transporters with the following order of selectivity: SERT > NE transporter > dopamine transporter. The IBG exhibited the highest selectivity for SERT. Only TBG inhibited monoamine oxidase A activity, indicating its relatively minor role. Radioligand and functional assays showed that all ibogalogs bind to the 5-HT2 receptor subfamily (DM506>IBG>TBG) and fully activate 5-HT2A/2C receptors with similar potency in the nM range. However, they act as competitive antagonists of the 5-HT2B receptor, with DM506 as an exception, exhibiting partial but potent agonist activity. In conclusion, ibogalogs induce acute and sustained antidepressant-like activity in naïve and depressed mice through mechanisms involving 5-HT2A receptor activation and serotonergic transmission.

Targeting B and T Lymphocyte Attenuator Regulates Lupus Disease Development in NZB/W Mice.

The co-inhibitory receptor B and T Lymphocyte Attenuator (BTLA) negatively regulates B and T cell activation. We have previously shown an altered BTLA expression by regulatory T cells and an impaired capacity of BTLA to inhibit CD4+ T cell activation in lupus patients. In this study, we analyzed BTLA expression and function in the NZB/W lupus-mouse model and examined the therapeutic potential of BTLA targeting. BTLA expression and function were analyzed in young (10-12-week-old) and old-diseased NZB/W mice (>35-week-old with proteinuria) in comparison to age-related BALB/W control mice. 20-22weeks old NZB/W mice (n=10) were injected i.p with 3 mg/kg, twice a week for ten weeks, with the anti-BTLA antibody 6F7 or its isotype control. In old-diseased NZB/W mice, BTLA expression is slightly modified in B cell subsets whereas CD4+ T cells display impaired BTLA functionality. Administration of the 6F7 anti-BTLA antibody into 20-22week-old NZB/W mice resulted in a delayed onset of proteinuria (p<0.01), limited kidney damages (p<0.05) and an increased survival rate (p<0.01) compared to isotype-treated mice. This beneficial effect was associated with a decrease in circulating B cell and spleen follicular B cell numbers. Regarding its mode of action, we demonstrated that the 6F7 antibody is not a depleting antibody and does not block HVEM binding to BTLA, but instead induces BTLA down modulation and exhibits in vivo agonist activity. Overall, our data confirm the involvement of BTLA in lupus pathogenesis and provide the first evidence that BTLA is a potential therapeutic target for the treatment of lupus.

Novel tertiary diarylethylamines as functionally selective agonists of the kappa opioid receptor.

Novel kappa opioid receptor (KOR) agonists that preferentially activate G-protein signaling versus β-arrestin-2 recruitment are described. Starting from a literature-reported phenol-containing diphenethylamine KOR agonist, structure-activity relationship (SAR) studies revealed replacement of the phenol with various non-hydroxylated bicyclic heteroaromatics led to tertiary diarylethylamines which retained KOR agonist activity and improved metabolic stability in human liver microsomes. Further optimizations produced compound 39, a potent activator of G-protein signaling (GTPγS EC50 = 14 nM, 83 % Emax) that did not elicit a β-arrestin-2 recruitment functional response (Emax < 10 %). Compound 39 demonstrated moderate to high intrinsic clearance in human hepatocytes and low potential for Pgp-mediated efflux when evaluated in the MDR1-MDCK permeability assay. Compound 39 exhibited 60- and 810-fold selectivities versus the related mu (MOR) and delta (DOR) opioid receptors in recombinant radioligand binding (Ki) assays. These findings highlight compound 39 and related structures as potential leads toward safe and tolerable therapeutics that target central nervous system (CNS) disorders for which KOR agonism could provide benefit.

Angelica gigas Nakai (Korean Dang-gui) Root Alcoholic Extracts in Health Promotion and Disease Therapy – active Phytochemicals and In Vivo Molecular Targets

Angelica gigas Nakai (AGN) root is a medicinal herbal widely used in traditional medicine in Korea. AGN root ethanolic extracts have been marketed as dietary supplements in the United States for memory health and pain management. We have recently reviewed the pharmacokinetics (PK) and first-pass hepatic metabolism of ingested AGN supplements in humans for the signature pyranocoumarins decursin (D, Cmax 1x), decursinol angelate (DA, Cmax ~ 10x) and their common botanical precursor and hepatic metabolite decursinol (DOH, Cmax ~ 1000x). Here we update in vivo medicinal activities of AGN and/or its pyranocoumarins and furanocoumarin nodakenin in cancer, pain, memory loss, cerebral ischemia reperfusion stroke, metabolic syndrome and vascular endothelial dysfunctions, anxiety, sleep disorder, epilepsy, inflammatory bowel disease, osteoporosis and osteoarthritis. Given their polypharmacology nature, the pertinent mechanisms of action are likely misrepresented by many cell culture studies that did not consider the drug metabolism knowledge. We report here Rho-associated protein kinases (ROCK1/2) as novel targets for DA and DOH. Combining with published inhibitory activity of DOH on acetylcholinesterase, agonist activity of DOH and antagonist/degrader activity of DA/D on androgen and estrogen receptors, D/DA promoting activity for glutamic acid decarboxylase (GAD)- gamma-aminobutyric acid (GABA) inhibitory axis and inhibition of glutamate dehydrogenase (GDH), monoamine oxidase-A (MAO-A) and transient receptor potential vanilloid 1 (TRPV1), we postulate their contributions to neuro-cognitive, metabolic, oncologic, vascular and other beneficial bioactivities of AGN extracts. A clinical trial is being planned for an AGN extract to manage side effects of androgen deprivation therapy in prostate cancer patients.

High-Throughput Zebrafish Screening Reveals Cardiotoxic Effects of Organophosphate Flame Retardants.

The toxicity of organophosphorus flame retardants (OPFRs) remains poorly understood, despite their widespread environmental presence and potential risks to human and ecological health. This study aimed to characterize the cardiovascular developmental toxicity of OPFRs using a high-throughput zebrafish screening model. Over thirty representative OPFRs, classified into three major groups-alkyl, aryl, and halogenated-were evaluated. Our results demonstrated that aryl-substituted OPFRs, such as triphenyl phosphate (TPHP) and tris(3,5-dimethylphenyl) phosphate (TXP), exhibit significantly more potent cardiotoxic effects compared to alkyl- and halogenated-substituted OPFRs. Specifically, heart rate of zebrafish increased by 8.3% and 11.9%, and cardiac output increased by 30.8% and 39.9% for TPHP and TXP, respectively, at a concentration of 160 μg/L. Additionally, exposure to aryl-substituted compounds like TPHP resulted in notable developmental abnormalities, including pericardial edema and skeletal bending. Molecular descriptor analysis further identified a series of essential structural features, including estrogen receptor agonist activity and bioconversion rates, which are closely linked to the observed cardiotoxicity, thus providing a mechanistic explanation for these effects. These findings offer valuable insights into the molecular mechanisms underlying OPFRs toxicity, which could inform the development of safer flame retardant alternatives. Moreover, addressing the research gaps in translating zebrafish findings to other species and real-world ecological scenarios should be further concerned.

Prediction of Potential Risk for Ten Azole and Benzimidazole Fungicides with the Aryl Hydrocarbon Receptor Agonistic Activity to Aquatic Ecosystems.

Azole and benzimidazole fungicides are widely used agrochemicals to prevent and treat fungal growth and are frequently detected in aquatic environments. Here, we aimed to assess the aquatic ecological risks of ten currently used azole and benzimidazole fungicides, which with the aryl hydrocarbon receptor (AhR) agonistic activity, and their transformation products (TPs). We obtained over 400 types of aerobic TPs for ten fungicides. Some fungicides and their TPs (approximately 26.7%) exhibited the potential AhR agonistic activity and toxicity to different aquatic species. Meanwhile, some compounds with the chlorine element and benzene ring structure exhibited environmental persistence and mobile ability. Several of them were frequently detected in aquatic environments, posing potential risks to aquatic ecosystems. These harmful fungicides and their TPs should be given attention. This study provides important insight into the aquatic ecological risks caused by azole and benzimidazole fungicides, which can provide theoretical guidance for their pollution control.

Synthesis and Biological Evaluation of 5'-Deoxy-adenosine Derivatives as A3 Adenosine Receptor Ligands.

The A3 Adenosine Receptor (A3AR) is an important therapeutic target due to its role in inflammation and immune response regulation. Herein, we synthesized and evaluated 5'-deoxy-adenosine derivatives with oxygen at the 4'-position, comparing them to previously studied 4'-thionucleosides. Compound 1h exhibited the highest binding affinity (K i = 5.9 ± 1.1 nM), consistent with the trend observed in the 4'-thionucleosides. Notably, the 5'-deoxy-adenosine derivatives demonstrated enhanced agonistic activity. Docking studies with compound 1h revealed a shift in binding mode when oxygen replaced sulfur at the 4'-position. The compounds retained strong interactions with critical residues, such as Thr94, even without a hydrogen bond donor at the 5'-position. These results explain the increased agonistic effect observed when the ring heteroatom was changed from sulfur to oxygen.