Search Results (258)

Background: Sleep disorders, particularly insomnia, represent a major public health concern, while currently available hypnotic drugs are often limited by adverse effects and poor long-term tolerability. Methods: In this study, we investigated the sleep-promoting effects of a mixture of Hypericum perforatum L. and Melissa officinalis L. extract (HME) and its underlying mechanisms in male ICR and C57BL/6 mice. In a pentobarbital-induced sleep model in mice, sleep onset latency and total sleep time were measured. Pharmacological studies using various antagonists and agonists were conducted to elucidate receptor-mediated mechanisms. Immunohistochemical and immunofluorescence analyses were performed to assess neuronal activity, and cortical mRNA expression was evaluated by quantitative analysis. HPLC analysis was used to identify the major constituents of HME, and their pharmacological profiles were functionally evaluated. Results: HME significantly reduced sleep onset latency and prolonged total sleep time. These hypnotic effects were shown to be mediated through adenosine and melatonin receptor signaling pathways. Immunohistochemical and immunofluorescence analyses showed that HME suppressed neuronal activity in wake-promoting cholinergic and orexinergic neurons of the basal forebrain and lateral hypothalamus, while enhancing activation of sleep-promoting GABAergic neurons in the ventrolateral preoptic nucleus. At the molecular level, HME increased cortical mRNA expression levels of adenosine A₁ receptor, adenosine A_2A receptor, melatonin receptor ₁, and melatonin receptor ₂. From the HPLC analysis, rosmarinic acid and hyperoside were identified as the major constituents of HME. Functional evaluation of these compounds revealed complementary pharmacological profiles, with hyperoside primarily acting through adenosine receptors and rosmarinic acid engaging both adenosine and melatonin receptor pathways. Conclusion: These findings suggest that HME enhances both sleep initiation and maintenance through adenosine and melatonin receptor signaling pathways, thereby supporting its potential as a multitarget therapeutic agent for improving sleep quality. Full article

Caffeine is the most widely used psychoactive compound. In the brain, caffeine acts as a competitive, non-selective adenosine receptor antagonist of A₁ and A_2A, both known to modulate long-term potentiation (LTP), the cellular basis of learning and memory. But the effects of caffeine on synaptic function and plasticity cannot be reduced to a single inhibitory or facilitatory action. In the CA1 area of the hippocampus, low-micromolar caffeine has been reported to attenuate LTP, yet it remains unclear whether this action extends equally to other plasticity-related responses, including EPSP–spike coupling and paired-pulse responses. Here, we studied the effect of 30 μM caffeine on the field excitatory postsynaptic potentials (fEPSPs) and LTP evoked by Schaffer collateral stimulation in the CA1 region in mouse hippocampal slices. We compared theta-burst-induced long-term fEPSP potentiation, EPSP–spike (E-S) potentiation, input–output relationships, and paired-pulse responses after short (three burst-TBS3) and long (ten burst-TBS10) theta-burst stimulation. Caffeine attenuated long-term fEPSP potentiation induced by the longer theta-burst protocol and reduced the accompanying increase in population spike amplitude. In contrast, E-S potentiation induced by the shorter theta-burst protocol was preserved under caffeine exposure. Input–output analysis further showed that caffeine prevented the increase in population spike amplitude accompanying the development of long-term fEPSP potentiation, but did not prevent the population spike response changes associated with E-S potentiation. Caffeine also reduced paired-pulse deviations from 100%, most clearly for population spike amplitude, and this effect persisted after both the theta-burst protocols. Thus, 30 μM caffeine did not simply suppress CA1 plasticity-related responses, but distinguished TBS10-induced synaptic fEPSP potentiation from TBS3-induced EPSP–spike potentiation. These findings identify EPSP–spike coupling as a caffeine-preserved CA1 plasticity-related response and provide a basis for future receptor-selective and behavioral testing. Full article

Background/Objectives: Promoting white adipose tissue (WAT) browning into thermogenic beige adipocytes is a promising anti-obesity strategy. Yanggyeoksanhwa-tang (YST) has been used traditionally to alleviate obesity-related conditions. Catalpol and rhoifolin are major bioactive components of Rehmannia glutinosa (Gaertn.) and Lonicera japonica (Thunb.) with known metabolic or anti-inflammatory effects. However, their direct roles in adipocyte browning and the mechanisms via β3-adrenergic receptor (β3-AR) signaling are not well defined, and this study addresses this gap. Methods: To evaluate browning potential, 3T3-L1 adipocytes were treated with catalpol and rhoifolin during differentiation. The expression of browning markers and lipid metabolism or catabolism transcription factors was analyzed using Western blotting and quantitative real-time polymerase chain reaction. The involvement of the β3-AR and adenosine monophosphate–activated protein kinase (AMPK) signaling pathways was further validated using specific agonists and antagonists. Results: Both compound treatments significantly upregulated beige-specific (Cd137, Cited, Tbx1, Cidea, Fgf21, Tmem26) and mitochondrial biogenesis markers (Cox4, Nrf1, Tfam), accompanied by a marked increase in thermogenic markers (UCP1, PGC-1α, Prdm16). Concurrently, lipolysis-related genes such as Atgl, Hsl, and Plin1 were elevated, while lipogenesis targets (Fasn, Lpl, Srebf1, Acaca) were downregulated through activation of the β3-AR signaling pathway. Conclusions: These findings suggest that catalpol and rhoifolin, key phytochemicals of YST, promote WAT browning and lipolysis. Our findings indicate that these compounds induce browning and modulate metabolism via the β3-AR pathway. These results serve as a cornerstone for natural anti-obesity therapy, pending further validation in vivo and clinical studies. Full article

Introduction: Caffeine is a widely consumed adenosine receptor antagonist with well-documented effects on arousal and performance, but its time-resolved neurophysiological signature across stages of information processing remains fragmented across event-related potential (ERP) paradigms. Objectives: This systematic and mechanistic review aimed to (i) identify and catalog human ERP studies testing caffeine effects, (ii) synthesize findings by task domain and ERP component family, and (iii) evaluate moderators including dose, timing, abstinence/withdrawal control, sleep status, and habitual use. Methods: Following PRISMA 2020 and PRISMA-S, we searched multiple databases (PubMed/MEDLINE, Embase, APA PsycINFO, Web of Science Core Collection, Scopus, IEEE Xplore, and Cochrane Central Register of Controlled Trials) from inception to 28 November 2025 and conducted a structured narrative synthesis using SWiM (Synthesis Without Meta-analysis, no prespecified quantitative pooling). Risk of bias was assessed using RoB-2 (Risk of Bias 2, including crossover extension) and ROBINS-I (Risk Of Bias In Nonrandomized Studies of Interventions). Of 761 records, 63 controlled human studies met the inclusion criteria. The evidence most consistently supported stage- and context-dependent modulation. Within the P3 family, target-related P3b/P300 latency was frequently shortened, or fatigue-related slowing was prevented, often without parallel increases in amplitude. P300 amplitude findings were mixed and context-dependent: amplitude was often unchanged in rested or low-demand paradigms, but increased or was restored when caffeine counteracted fatigue, sleep loss, sustained attention demands, or high workload. Preparatory activity (CNV/slow negativity) showed selective effects, while early sensory components were comparatively stable in many paradigms; higher doses (approximately 200–400 mg) were associated with weaker early auditory sensory gating in some studies. Conclusions: Across heterogeneous paradigms, caffeine was associated with context-dependent ERP changes rather than a uniform amplification of ERP amplitudes. The most consistent pattern was shorter or preserved latency of late positive ERP components, particularly in tasks requiring stimulus evaluation or target detection. In some fatigue, sleep deprivation, sustained attention, or high-demand paradigms, caffeine was also associated with larger or restored P300/P3b amplitudes. These findings are compatible with state-dependent changes in attentional engagement or stimulus evaluation, but mechanistic interpretation remains limited by heterogeneity in task paradigms, ERP definitions, dosing, abstinence procedures, and participant caffeine use profiles. Methodological heterogeneity, small samples, inconsistent control of habitual use and withdrawal, and the predominance of healthy young adult samples limit generalizability, particularly to children, older adults, clinical populations, and long-term high-dose caffeine users. Full article

We showed recently that the adenosine system and nitric oxide (NO) can interact differently in the control of renal function in normoglycaemia (NG) versus streptozotocin-induced diabetes (DM). Herein, we investigated if this relationship is modulated by dietary betaine (Bet, food compound possessing antioxidant and anti-inflammatory properties), to examine if adenosine receptor signalling in NG and DM females is altered by chronic Bet supplementation. The effects of intravenous infusion of theophylline, non-selective adenosine receptor antagonist, were examined in anaesthetised Sprague–Dawley female rats, pretreated for 2 weeks with Bet alone or combined with 4-day NO synthesis blockade with L-NAME (Bet + L-NAME). Renal blood flow (RBF, ultrasound artery probe), perfusion of the cortex, outer (OM-BF) and inner medulla (IM-BF; laser-Doppler technique), and tissue NO signal (selective electrode) were determined along with renal excretion. Bet and Bet + L-NAME decreased baseline RBF irrespective of glycaemia, whereas Bet lowered (NG) or elevated (DM) basal OM-BF; Bet + L-NAME treatment abolished these effects. Baseline sodium excretion decreased after Bet and Bet + L-NAME in NG only. Bet modified theophylline effects: IM-BF was lowered in DM rats, while tissue NO changes shown in the control were modified: NO increased in NG and decreased in DM. In NG, these effects were abolished by Bet + L-NAME. Bet pretreatment did not alter diuresis, natriuresis and kaliuresis, but after Bet + L-NAME these parameters increased (NG) or decreased (DM). Dietary Bet has the potential to affect renal medullary blood circulation; however, the eventual effect depends on glycaemia. Bet can modify renal functional changes induced by the interplay of the adenosine and NO systems, both in rats with normoglycaemia and streptozotocin diabetes. Full article

Background/Objectives: Leprosy is a chronic infection caused by Mycobacterium leprae that, in addition to Schwann cells, macrophages, and adipocytes, also infects human peripheral blood monocytes and subverts their metabolism in its favor. Infection is marked by cholesterol and fatty acid accumulation in lipid droplets (LDs), and a reduction in mitochondrial membrane potential (Δψm). Previous studies showed that M. leprae downregulates adenosine receptor A_2A (A_2AR) expression in Schwann cells, while activation reduces LD accumulation and bacterial viability. Since A_2AR controls immunometabolic response, we investigated whether A_2AR signaling restrains M. leprae-driven reprogramming in monocytes. Methods: Peripheral blood mononuclear cells from healthy donors were enriched for monocytes and infected with M. leprae in the presence or absence of adenosinergic modulators (5′AMP, adenosine (ADO), A_2AR agonist CGS21680, the antagonist ZM241385, or A_2BR antagonist, MRS1754). We used flow cytometry, fluorescence microscopy, and RT-qPCR to evaluate purinergic components expression and bacillary viability. LDs and Δψm were measured by fluorescence microscopy, and extracellular levels of inosine (INO) and hypoxanthine (HPX) by LC-MS/MS. Results: The results show that infection increased CD39, ADA, A_2AR and A₃R expression, decreased ENT1, A₁R and A_2BR, and raised extracellular INO and HPX. In addition, 5′AMP, ADO and CGS21680 reversed infection-induced LD accumulation. CGS21680 also restored Δψm and decreased intracellular M. leprae viability. Conclusions: Our data suggest that M. leprae suppresses A_2AR signaling to favor its survival in monocytes, indicating that the extracellular ADO–A_2AR pathway may be a potential target to limit early M. leprae infection. Full article

Amyloid-β peptides (Aβ) are considered a main culprit of Alzheimer’s disease (AD), leading to synaptic dysfunction and memory deficits. Although studies in animal models of AD converge to show alterations of synaptic plasticity, namely of long-term potentiation (LTP), the mechanisms through which Aβ affects synaptic function remain to be unveiled. In this study, we established experimental conditions showing that the acute exposure of mouse hippocampal slices to optimized concentrations of Aβ impaired short-term (PPF-paired-pulse facilitation) and long-term (LTP-long-term potentiation) plasticity without altering basal synaptic transmission. We observed that the elimination of extracellular adenosine with adenosine deaminase abrogated the impact of Aβ on synaptic plasticity, showing a mandatory involvement of extracellular adenosine in the neurophysiological effects of Aβ. Additionally, inhibiting adenosine receptor function with caffeine, as well as selectively blocking adenosine A₁ receptors (A₁R) with DPCPX, or adenosine A_2A receptor (A_2AR) with either an antagonist SCH58261 or through knocking out A_2AR, demonstrated that acute Aβ modified mouse hippocampal PPF via A₁R and LTP through A_2AR. Furthermore, the use of slices from mice bearing forebrain-neuron A_2AR deletion, along with the application of α,β-methylene ADP, a CD73 inhibitor, confirmed that the neurophysiological actions of Aβ on hippocampal LTP occur selectively through the overfunction of neuronal A_2AR via CD73-mediated formation of extracellular adenosine. Overall, the exploitation of a neurophysiological model of early AD, based on the acute administration of Aβ to hippocampal slices, confirmed the critical involvement of adenosine signaling in the impact of Aβ on synaptic plasticity. Full article

Background/Objectives: Poly(ADP-ribose) polymerase inhibitors (PARPis) have significantly transformed the treatment landscape for ovarian cancer; however, their clinical efficacy is often limited by poor response rates and the emergence of resistance. Recent studies have revealed that in ovarian cancer cells resistant to PARPi, the expression levels of adenosine receptors are upregulated. Accumulation of adenosine activates adenosine A2A receptor (A2AR) on immune cells, leading to immune suppression and immune escape. We hypothesize that this is a key factor limiting the efficacy of PARPi and driving the development of resistance. Therefore, the rational combination of PARPi with A2AR antagonists (A2ARas) may represent a highly promising anticancer strategy. Methods: To assess the effects of the PARPi AG14361 and the A2ARa AZD4635 on ovarian cancer growth and the immune microenvironment, we conducted in vitro and in vivo experiments and utilized single-cell RNA sequencing (scRNA-seq) to construct a high-resolution immune landscape. Results: AG14361 significantly inhibited ovarian cancer growth both in vitro and in vivo, accompanied by the accumulation of cyclic adenosine monophosphate (cAMP) and activation of the cAMP/cAMP response element-binding protein (CREB) pathway in mouse cells and tumor tissues. However, compared to monotherapy, the combination of AG14361 and AZD4635 significantly enhanced antitumor activity by inhibiting cAMP accumulation and the cAMP/CREB pathway. More importantly, the combination therapy of PARPi and A2ARa reduced the infiltration of immunosuppressive cells (such as regulatory T cells and M2 macrophages) while increasing the infiltration of cytotoxic T cells and granzyme B-positive cells, thereby creating a more favorable immune microenvironment for tumor clearance. Single-cell analysis revealed distinct functional subpopulations of macrophages and T cells, highlighting the complexity of immune heterogeneity and the potential for targeting specific immune cell subpopulations to enhance therapeutic efficacy. Conclusions: These findings suggest that the combination therapy of PARPi and A2ARa is a highly promising strategy that overcomes PARPi-induced immune escape by targeting the cAMP/CREB axis, thereby synergistically enhancing antitumor effects and holding promise as an effective treatment for solid tumors. Full article

This study aims to investigate the protective effect of the natural phthalide compound Levistolide A (LA) against myocardial ischemia–reperfusion injury (MIRI) and to elucidate its underlying mechanisms. Utilizing network pharmacology, potential targets of LA in the treatment of MIRI were predicted. Subsequently, a hypoxia/reoxygenation (H/R) model was established using rat H9C2 cardiomyocytes to simulate MIRI, and the mechanisms of action were validated through cellular experiments. Network pharmacology analysis indicated that the potential targets of LA in treating MIRI were significantly enriched in calcium signaling pathways, with the adenosine A2B receptor (ADORA2B), a G protein-coupled receptor (GPCR), identified as a key protein. Cellular experiments demonstrated that 24 μM LA significantly alleviated H/R-induced damage in H9C2 cells, enhanced cell viability, and reduced the release of lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI). Pre-treatment with LA significantly activated the ADORA2B/Cyclic adenosine monophosphate (cAMP)/Protein kinase A (PKA) signaling axis, promoting the phosphorylation of phospholamban (PLB), enhancing the activity and protein expression of sarco/endoplasmic reticulum Ca²⁺-ATPase 2 alpha (SERCA2α), and effectively mitigating intracellular calcium overload induced by H/R. However, the ADORA2B antagonist MRS 1754 partially reverses the aforementioned protective effects of LA. The findings of this study reveal a novel mechanism by which LA exerts cardioprotective effects through the ADORA2B/cAMP/PKA/PLB/SERCA2α signaling axis, preventing calcium overload and improving calcium homeostasis, and identify potential candidate compounds and precise targets for the treatment of MIRI. Full article

Aging reduces the tissue regenerative capacity, promotes chronic inflammation, and contributes to neurodegenerative diseases, including age-related macular degeneration (AMD). AMD is a leading cause of vision loss in older adults and manifests as dry (atrophic) or wet (neovascular) disease. Although dry AMD is more prevalent, neovascular AMD (nAMD) causes the most severe vision impairment and remains a major public health burden. Oxidative stress-mediated inflammation and dysfunction of retinal pigment epithelium (RPE) cells and choriocapillaris drive early AMD. Neovascular AMD is marked by pathologic choroidal neovascularization (CNV), driven largely by dysregulated VEGF signaling. Anti-VEGF therapies are the current standard of care for nAMD but require frequent intravitreal injections, carry procedure-related risks, and are ineffective in a substantial subset of patients, underscoring the need for new therapeutic approaches. Caffeine, a widely consumed and well-tolerated adenosine receptor antagonist, has emerging relevance in vascular regulation and inflammatory signaling. Extracellular ATP and its metabolites, including adenosine, accumulate under stress and act through purinergic receptors to influence angioinflammatory processes. We recently showed that systemic caffeine administration suppressed CNV in vivo, an effect partly reproduced by the adenosine receptor A_2A antagonist Istradefylline. Here, we investigated the cell-autonomous effects of caffeine on mouse choroidal endothelial cells, focusing on its role as an adenosine receptor antagonist and its potential to inhibit pathological neovascularization. Full article

Fibrosis manifests as an excessive accumulation of fibrillar collagen in tissues where secreted collagen exceeds degradation. Myofibroblasts are important contributors to the excessive collagen seen in fibrotic lesions. Accordingly, targeting signaling pathways that enhance collagen degradation and subdue myofibroblast differentiation has the potential to optimize collagen remodeling and improve organ fibrosis. One of the most promising molecular targets for therapeutic development is the G protein-coupled receptor (GPCR) family, which is diverse, cell-type-specific, multi-pass transmembrane receptors that participate in the regulation of extracellular matrix remodeling. GPCRs are categorized into multiple subclasses, some of which activate signaling cascades that can augment or reduce pro-fibrotic processes, depending on which Gα class is activated. Specifically, activation of Gαs GPCR stimulates production of the second messenger, cyclic adenosine monophosphate (cAMP), which generally inhibits pro-fibrotic mediators. A related, second approach for control of fibrosis is the blockade of a specific mechanosensitive, Ca²⁺-permeable channel that is implicated in fibrosis and contributes to myofibroblast differentiation, the transient receptor potential vanilloid type 4 (TRPV4). In health, TRPV4 activation regulates collagen remodeling, but when dysregulated, it promotes pro-fibrotic gene expression through mechanosensitive transcription factors. In this review, we focus on the functions of the Gαs GPCR pathway and TRPV4 activation through the interplay of the second messengers cAMP and Ca²⁺ ions. Ca²⁺ influx modulates cAMP levels by regulating phosphodiesterases and adenylyl cyclases. We consider evidence that Gαs GPCR and TRPV4 signaling pathways interact antagonistically to either promote collagen degradation or to increase the formation of myofibroblasts through signaling that involves cAMP and Ca²⁺ conductance. Coordinated activation of the Gαs GPCR pathway and inhibition of TRPV4 could provide a novel, bimodal approach to control tissue fibrosis. Full article

Glucagon is an endogenous peptide that is produced in the pancreas. Via glucagon receptors, glucagon increases the beating rate in cultured rat neonatal cardiomyocytes and also in isolated right atrial preparations from adult rats. Moreover, in living adult mice, injections of glucagon can elevate the heart rate. It is unknown whether these effects of glucagon in living adult mice are mediated via central glucagon receptors or via a direct effect on cardiac glucagon receptors. Thus, we tested the hypothesis that glucagon can exert a direct positive chronotropic effect in the adult mouse heart. We measured the contractile effects of cumulatively increasing concentrations of glucagon (0.1–100 nM) in isolated paced (1 Hz) left atrial preparations, in isolated spontaneously beating right atrial preparations and in isolated spontaneously beating retrogradely perfused whole hearts. We detected in isolated right atrial preparations time- and concentration-dependent positive chronotropic effects of glucagon that were reversed by the glucagon receptor antagonists SC203972 and desglucagon. The positive chronotropic effects of glucagon were also attenuated by 1 µM of ivabradine, an inhibitor of the hyperpolarization-activated cation channels (HCN), but not by 100 nM rolipram, a phosphodiesterase 4 inhibitor, nor by 10 µM of propranolol, a β-adrenoceptor antagonist. Moreover, the positive chronotropic effects of glucagon were also attenuated by stimulation of the A₁-adenosine receptor or muscarinic receptors. Glucagon decreased the force of contraction in right atrial preparations. In left atrial preparations, glucagon failed to alter the force of contraction. In isolated adult mouse hearts perfused in the Langendorff mode, 10 nM of glucagon increased the beating rate and reduced left ventricular force of contraction. The gene expression of the glucagon receptors was lowest in the left atrium, higher in the ventricle and highest in the right atrium of adult mice. In summary, glucagon exerted a positive chronotropic effect in the mouse heart via glucagon receptors, mediated, at least in part, via HCN channels in the sinus node. Full article

The aim of this study is to investigate the A_2BAR-dependence of okhotoside A₁-1 cytotoxic and antiproliferative action on triple-negative MDA-MB-231 breast cancer cells using monolayer and 3D culture approaches. Earlier triterpene glycoside okhotoside A₁-1 (Okh) was isolated from the sea cucumbers Cucumaria djakonovi and C. conicospermium and its selective cytotoxicity against MDA-MB-231 vs. non-tumorigenic MCF-10A cells was reported. Now it has been found that the A_2B adenosine receptor (A_2BAR) is one of the molecular targets for Okh and its antiproliferative effect is A_2BAR-dependent. Molecular docking studies suggested a unique behavior for Okh demonstrating two highly probable binding modes with comparable affinity, when the aglycone is immersed in the binding pocket, or alternatively, the carbohydrate moiety occupies the site. The glycoside modulated cAMP and intracellular Ca²⁺ levels in an A_2BAR-dependent manner, which accompanied by the suppression of p38 MAPK and ERK1/2 phosphorylation, and blocked cell cycle progression. Okh induced mitochondrial dysfunction, characterized by increased ROS production and loss of the mitochondrial membrane potential (ΔΨm), which led to the upregulation of APAF-1 and cytochrome C, activation of caspases-9 and -3, and initiation of apoptosis. The antitumor potential of Okh was confirmed in a 3D culture of MDA-MB-231 cells and was more significant than those of another A_2BAR-targeted triterpene glycoside cucumarioside A₀-1 and cisplatin. Full article

Breast cancer is the most prevalent cancer in women worldwide and presents a major therapeutic challenge, particularly triple-negative breast cancer (TNBC), a subtype characterized by an aggressive clinical course but heightened sensitivity to chemotherapy. Natural products, such as triterpene glycosides derived from sea cucumbers, have emerged as promising candidates with high anticancer potential against TNBC. This study investigated the pathways of anticancer action of cucumarioside A₀-1 (Cuc A₀-1) and djakonovioside A (Dj A), isolated from the sea cucumber Cucumaria djakonovi, triggered and regulated in MDA-MB-231 cells (triple-negative breast cancer cell line). We employed functional assays (cAMP level, Ca²⁺ influx, control of cell proliferation and colony formation), Western blotting for mitogen-activated protein kinase MAPK) signaling, and in silico molecular docking. A_2B adenosine receptor (A_2BAR) was identified as a novel target for both glycosides. As antagonists, they reduced cAMP production and inhibited NECA (5-(N-ethylcarboxamido)adenosine)-induced Ca²⁺ influx. This A_2BAR blockade suppressed the MAPK pathway, profoundly inhibiting phospho-ERK1/2, p38, and JNK1/2, which led to the activation of the intrinsic apoptotic pathway and strong inhibition of cell proliferation and colony formation. Surprisingly, co-treatment with the NECA agonist enhanced the antiproliferative effects of the glycosides. It was supposed that the interaction of glycosides with the NECA-preactivated receptor may bias signaling toward the Gi and Gq/PLC/ERK1/2 pathways, underscoring the central role of the MAPK pathway in controlling cell growth. Molecular docking confirmed binding to the A_2BAR orthosteric site, revealing that Cuc A₀-1 and Dj A employ distinct interaction modes. To our knowledge, this is the first report to define A_2BAR as a target for sea cucumber glycosides. Their potent antitumor effects, mediated through the antagonism of A_2BAR and subsequent MAPK pathway inhibition, position them as promising lead compounds for cancer types with high expression A_2BAR. Full article

Adenosine receptor (AR) antagonists have attracted considerable interest due to their therapeutic potential in a wide range of pathological conditions, including neurological, cardiovascular, and inflammatory disorders. Although a large number of AR antagonists have been developed worldwide, the interest in new derivatives remains high, and achieving subtype selectivity continue to be a major challenge. This review summarizes our research on adenosine receptor antagonists, highlighting the discovery of potent and selective compounds for the diverse AR subtypes across various chemical classes. Specifically, the paper focuses on the study of the triazolo[4,3-a]quinoxalin-1-one (TQX) and pyrazolo[3,4-c]quinoline (PQ) series, along with their simplified analogues, which have yielded highly potent and selective AR antagonists. An overview of the structure–activity relationship (SAR) studies and molecular docking investigations is provided, emphasizing the structural requirements for A_2A and A₃ receptor–ligand interaction. In addition, we present pharmacological studies of selected AR antagonists, in various in vitro and in vivo models of pain, depression, neuroinflammation-related diseases, and cancer. Full article