Abstract:
3-demethyl-2-geranyl-4-prenylbellidifoline (DGP), a natural xanthone isolated from Garcinia achachairu, has previously demonstrated remarkable diuretic and renal protective actions. The present study expands its actions on the cardiovascular system by evaluating its vasorelaxant and blood pressure-lowering effects in spontaneously hypertensive rats (SHRs). Aortic endothelium-intact (E+) preparations of SHRs pre-contracted by phenylephrine and exposed to cumulative concentrations of G. achachairu extract, fractions, and DGP exhibited a significant relaxation compared to vehicle-only exposed rings. The non-selective muscarinic receptor antagonist (atropine), the non-selective inhibitor of nitric oxide synthase (L-NAME), as well as the inhibitor of soluble guanylate cyclase (ODQ) altogether avoided DGP-induced relaxation. Tetraethylammonium (small conductance Ca2+-activated K+ channel blocker), 4-aminopyridine (a voltage-dependent K+ channel blocker), and barium chloride (an influx-rectifying K+ channel blocker) significantly reduced DGP capacity to induce relaxation without the interference of glibenclamide (an ATP-sensitive inward rectifier 6.1 and 6.2 K+ channel blocker). Additionally, administration of DGP, 1 mg/kg i.v., decreased the mean, systolic, and diastolic arterial pressures, and the heart rate of SHRs. The natural xanthone DGP showed promising potential as an endothelium-dependent vasorelaxant, operating through the nitric oxide pathway and potassium channels, ultimately significantly reducing blood pressure in hypertensive rats.
摘要:
3-去甲基-2-香叶基-4-异戊烯基bellidifoline(DGP),从藤黄中分离出的一种天然黄原酮,先前已证明了显着的利尿和肾脏保护作用。本研究通过评估其在自发性高血压大鼠(SHR)中的血管舒张和降血压作用来扩展其对心血管系统的作用。SHR的主动脉内皮完整(E+)制剂被去氧肾上腺素预收缩,并暴露于累积浓度的白毛甘草提取物,分数,与仅暴露于载体的环相比,DGP表现出明显的松弛。非选择性毒蕈碱受体拮抗剂(阿托品),一氧化氮合酶(L-NAME)的非选择性抑制剂,以及可溶性鸟苷酸环化酶(ODQ)的抑制剂完全避免了DGP诱导的松弛。四乙铵(小电导Ca2+激活的K+通道阻滞剂),4-氨基吡啶(电压依赖性K通道阻滞剂),和氯化钡(一种内流整流K通道阻滞剂)显着降低了DGP诱导松弛的能力,而不受格列本脲(一种ATP敏感的内向整流器6.1和6.2K通道阻滞剂)的干扰。此外,DGP的管理,1mg/kg静脉注射,降低了平均值,收缩压,和舒张压,和SHR的心率。天然黄吨酮DGP显示出作为内皮依赖性血管舒张剂的潜力,通过一氧化氮途径和钾通道运作,最终显著降低高血压大鼠的血压。