RESUMO
Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality, imposing an increasing global health burden. Cardiac ion channels (voltage-gated NaV, CaV, KVs, and others) synergistically shape the cardiac action potential (AP) and control the heartbeat. Dysfunction of these channels, due to genetic mutations, transcriptional or post-translational modifications, may disturb the AP and lead to arrhythmia, a major risk for CVD patients. Although there are five classes of anti-arrhythmic drugs available, they can have varying levels of efficacies and side effects on patients, possibly due to the complex pathogenesis of arrhythmias. As an alternative treatment option, Chinese herbal remedies have shown promise in regulating cardiac ion channels and providing anti-arrhythmic effects. In this review, we first discuss the role of cardiac ion channels in maintaining normal heart function and the pathogenesis of CVD, then summarize the classification of Chinese herbal compounds, and elaborate detailed mechanisms of their efficacy in regulating cardiac ion channels and in alleviating arrhythmia and CVD. We also address current limitations and opportunities for developing new anti-CVD drugs based on Chinese herbal medicines.
Assuntos
Doenças Cardiovasculares , Medicamentos de Ervas Chinesas , Humanos , Antiarrítmicos/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Canais Iônicos/fisiologia , Arritmias Cardíacas/tratamento farmacológicoRESUMO
Core-shell magnetic seeds with certain adsorption capacity that were prepared by sulfated roasting, served as the core of a magnetic separation technology for purification of starch wastewater. XRD and SEM results indicate that magnetite's surface transformed to be porous α-Fe2O3 structure. Compared with magnetite particles, the specific surface area was significantly improved to be 8.361 from 2.591â¯m2/g, with little decrease in specific susceptibility. Zeta potential, FT-IR and XPS experiments indicate that both phosphate and starch adsorbed on the surface of the core-shell magnetic seeds by chemical adsorption, which fits well with the Langmuir adsorption model. The porous surface structure of magnetic seeds significantly contributes to the adsorption of phosphate and starch species, which can be efficiently removed to be 1.51â¯mg/L (phosphate) and 9.51â¯mg/L (starch) using magnetic separation.
Assuntos
Fósforo/análise , Amido/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Óxido Ferroso-Férrico/química , Magnetismo , Sulfatos/químicaRESUMO
Large-conductance calcium-activated potassium (BK) channels regulate the electric properties and neurotransmitter release in excitable cells. Its auxiliary ß2 subunits not only enhance gating, but also confer inactivation via a short-lived preinactivated state. However, the mechanism of enhancement and preinactivation of BK channels by ß2 remains elusive. Using our newly developed methods, we demonstrated that electrostatic forces played a crucial role in forming multiple complementary pairs of binding sites between α and ß subunits including a "PI site" required for channel preinactivation, an "E site" enhancing calcium sensitivity and an "ECaB" coupling site transferring force to gate from the Ca(2+)-bowl via the ß2(K33, R34, K35), E site and S6-C linker, independent of another Ca(2+) binding site mSlo1(D362,D367). A comprehensive structural model of the BK(ß2) complex was reconstructed based on these functional studies, which paves the way for a clearer understanding of the structural mechanisms of activation and preinactivation of other BK(ß) complexes.