European journal of pharmacology最新文献

Fucoidan, a sulfated polysaccharide with a complex structure, has gradually become the focus of biomedical research due to its remarkable biological activity and low toxicity. In this research, it was noted that low molecular weight fucoidan (LMWF) exhibited significant antimicrobial effects on Methicillin-resistant Staphylococcus aureus (MRSA) and promoted polarization towards M2 macrophages, leading to a substantial reduction in inflammatory responses within the lipopolysaccharide (LPS)-activated macrophages. We further explored the mechanism underlying the anti-inflammation activity. Our findings indicated that LMWF significantly enhanced the phosphorylation level of AMP-activated protein kinase (AMPK), inhibited the phosphorylation of the mammalian target of rapamycin (mTOR), and enhanced the expression of LC3II. Meanwhile, Compound C (CC) substantially reversed the anti-inflammation effect of LMWF, indicating that the AMPK pathway plays a pivotal role in this effect. In in vivo research, LMWF revealed impressive anti-inflammatory potential. LMWF treatment significantly eliminated MRSA and ameliorated inflammatory symptoms in mice's MRSA-infected skin wound model. Further analysis using Western Blot (WB) indicated significant AMPK/mTOR signaling pathway activation in mice treated with LMWF, which led to accelerated polarization of macrophages from the M1 to the M2 phenotype. In summary, we systematically explored the mechanism by which LMWF exerts anti-inflammatory effects through in vitro and in vivo experiments. It was confirmed that LMWF effectively induced the conversion of macrophages to an anti-inflammatory M2 phenotype by activating the AMPK/mTOR pathway. Simultaneously, LMWF effectively eradicated MRSA and accelerated wound healing in mice. This finding provides an important theoretical basis for further research on fucoidan.

Non-small cell lung cancer (NSCLC), although considered non-immunogenic, is often resistant to chemotherapy agents during the course of treatment in clinical patients. Melittin (C₁₃₁H₂₂₉N₃₉O₃₁, CAS: 20449-79-0), the major component of honey bee venom, is a promising anticancer drug. However, the mechanism employed by melittin to reverse chemotherapy resistance of NSCLC cells remains unknown. In this study, the Cell Counting Kit 8, ethynyl deoxyuridine assay, and other assays were utilized to elucidate the melittin effects upon cell proliferation. Proteomics, lung cancer (LC) tissue chip, and Western blot analysis were used to identify potential targets of melittin. A549/DDP cells were employed to investigate the melittin effects against cisplatin resistance. Also, an in vivo animal experiment was conducted to further clarify the regulatory function of melittin towards cisplatin resistance of A549/DDP cells. Results showed that melittin inhibited malignant progression of A549/DDP cells by down-regulation of pyruvate dehydrogenase kinase 3 (PDK3)-mediated aerobic glycolysis and inhibition of heat shock factor 1 (HSF1) expression. The therapeutic effect of melittin was increased by combination with KNK437 and impaired chemotherapy resistance regarding A549/DDP cells via reversing aerobic glycolysis. The in vivo experiments confirmed that melittin incremented A549/DDP cell cisplatin sensitivities. Collectively, the data suggested that melittin suppressed aerobic glycolysis by regulating HSF1/PDK3, which incremented cisplatin sensitivity of A549/DDP cells. It may provide a new treatment method for chemotherapy resistance in clinical NSCLC patients.

Background: Ellagic acid (EA) serves as a pivotal coenzyme for various dehydrogenases, influencing diverse biological processes. Recognized for its potential in impeding disease progression, EA's effectiveness and mechanism in treating 5xFAD remain elusive.

Aim of the study: This study aims to investigate EA's potential roles and underlying mechanisms in mitigating symptoms associated with 5xFAD.

Materials and methods: 5 × FAD mice underwent a 12-week EA treatment regimen. The efficacy of EA against 5 × FAD was assessed through in vivo experiments, including Morris water maze and contextual fear conditioning tests for learning and memory abilities. Immunofluorescence (IF) and thioflavin staining examined changes in Aβ/neurons in brain tissue. RT‒qPCR evaluated inflammatory cytokine expression, while Bcl2/Bax protein levels were analyzed via Western blot (WB).

Results: EA demonstrates promise in alleviating symptoms associated with 5xFAD. It significantly reduced the mice's escape latency in the Morris water maze, increased the frequency of crossings in the target quadrant, and prolonged freezing time in the contextual fear memory test. EA also improved neuronal pathology in the hippocampus and cortex, decreased neuronal loss, and reduced Aβ levels. Moreover, EA significantly increased MDA and SOD levels, effectively modulated the Bcl2/Bax ratio, and decreased the production of proinflammatory factors in brain tissue of 5xFAD model mice.

In conclusion: Our findings highlight the potential therapeutic efficacy of EA in addressing 5xFAD-related nervous system disorders by targeting Aβ levels, oxidative stress, and inflammation.