Cardiovascular disease remains a leading cause of morbidity and mortality worldwide, frequently arising from platelet hyperactivation and subsequent thrombus formation. Although conventional antiplatelet therapies are available, challenges, such as drug resistance and bleeding complications, require the development of novel agents. In this study, dihydrogeodin (DHG) was isolated from Fennellia flavipes and evaluated using platelets derived from Sprague–Dawley rats. Platelet aggregation induced by collagen, adenosine diphosphate, or thrombin was assessed by light transmission aggregometry; DHG significantly reduced aggregation in a dose-dependent manner. Further assays demonstrated that DHG suppressed intracellular calcium mobilization, adenosine triphosphate release, and integrin αIIbβ3-dependent fibrinogen binding, thereby impairing clot retraction. Western blot analysis revealed that DHG reduced the phosphorylation of mitogen-activated protein kinases (ERK, JNK, p38) and PI3K/Akt, indicating inhibition across multiple platelet-signaling pathways. Additionally, SwissADME-assisted pharmacokinetics predicted favorable properties without violations of the Lipinski (Pfizer) filter, Muegge (Bayer) filter, Ghose filter, Veber filter, and Egan filter, and network pharmacology revealed inhibition of calcium and MAPK pathways. These results highlight the potential of DHG as a novel antiplatelet agent with broad-spectrum activity and promising drug-like characteristics. Further studies are warranted to assess its therapeutic window, safety profile, and potential for synergistic use with existing antiplatelet drugs.
20 December 2024 in Journal of Applied Biological Chemistry
Cardiovascular disease remains a leading cause of morbidity and mortality worldwide, frequently arising from platelet hyperactivation and subsequent thrombus formation. Although conventional antiplatelet therapies are available, challenges such as drug resistance and bleeding complications require the development of novel agents. In this study, dihydrogeodin (DHG) was isolated from Fennellia flavipes and evaluated using platelets derived from Sprague-Dawley rats. Platelet aggregation induced by collagen, adenosine diphosphate, or thrombin was assessed by light transmission aggregometry; DHG significantly reduced aggregation in a dose-dependent manner. Further assays demonstrated that DHG suppressed intracellular calcium mobilization, adenosine triphosphate release, and integrin αIIbβ3-dependent fibrinogen binding, thereby impairing clot retraction. Western blot analysis revealed that DHG reduced the phosphorylation of mitogen-activated protein kinases (ERK, JNK, p38) and PI3K/Akt, indicating inhibition across multiple platelet signaling pathways. Additionally, SwissADME-assisted pharmacokinetics predicted favorable properties without violations of the Lipinski (Pfizer) filter, Muegge (Bayer) filter, Ghose filter, Veber filter, and Egan filter, and network pharmacology revealed inhibition of calcium and MAPK pathways. These results highlight the potential of DHG as a novel antiplatelet agent with broad-spectrum activity and promising drug-like characteristics. Further studies are warranted to assess its therapeutic window, safety profile, and potential for synergistic use with existing antiplatelet drugs.
Background/Objectives: Pestalotic acid A (PAA), a polyketide derived from Pestalotiopsis vismiae, an endophyte of the Japanese holly (Ilex crenata), is known to exhibit known antimicrobial activity, but its anti-inflammatory properties remain uncharacterized. This study aimed to investigate the anti-inflammatory effects of PAA in lipopolysaccharide (LPS)-stimulated murine macrophages, RAW264.7 cells. Methods: PAA was isolated from P. vismiae endophytes of Ilex crenata, and its structure was confirmed. RAW264.7 macrophages were treated with 0–50 μM of PAA in the presence of 100 ng/mL LPS. Cell viability was assessed by MTS assay; nitric oxide (NO) production was measured via Griess reagent; interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF) were quantified by enzyme-linked immunosorbent assay. Protein expression of inducible NO synthase (iNOS), nuclear factor (NF)-κB p65 phosphorylation, and related signaling proteins was evaluated by Western blot analysis and immunofluorescence staining. Results: PAA significantly increased macrophage viability and dose-dependently inhibited the release of NO by alleviating the protein expression of iNOS in LPS-treated RAW264.7 cells. Furthermore, PAA suppressed the release of IL-6, IL-1β, and TNF induced by LPS. Western blot and immunofluorescence results also indicated that PAA blocked the p65 subunit phosphorylation of NF-κB, which is one of the underlying mechanisms of the anti-inflammatory action of pestalotic acid A. Conclusions: PAA exerts potent anti-inflammatory effects in LPS-stimulated macrophages via inhibition of the NF-κB pathway, highlighting its potential as a natural therapeutic agent for inflammatory diseases.
Powdery mildew caused by Sphaerotheca fusca poses a significant threat to cucumber (Cucumis sativus L.) production worldwide, underscoring the need for sustainable disease management strategies. This study investigates the potential of L-lysine, abundantly produced by Bacillus subtilis M 320 (BSM320), to prime systemic acquired resistance (SAR) pathways in cucumber plants. Liquid chromatography–mass spectrometry analysis identified L-lysine as the primary bioactive metabolite in the BSM320 culture filtrate. Foliar application of purified L-lysine significantly reduced powdery mildew symptoms, lowering disease severity by up to 92% at concentrations ≥ 2500 mg/L. However, in vitro spore germination assays indicated that L-lysine did not exhibit direct antifungal activity, indicating that its protective effect is likely mediated through the activation of plant immune responses. Quantitative reverse transcription PCR revealed marked upregulation of key defense-related genes encoding pathogenesis-related proteins 1 and 3, lipoxygenase 1 and 23, WRKY transcription factor 20, and L-type lectin receptor kinase 6.1 within 24 h of treatment. Concurrently, salicylic acid (SA) levels increased threefold in lysine-treated plants, confirming the induction of an SA-dependent SAR pathway. These findings highlight L-lysine as a sustainable, residue-free priming agent capable of enhancing broad-spectrum plant immunity, offering a promising approach for amino acid-based crop protection.