da Silva Rita de Cassia Vilhena, Bolda Mariano Luísa Nathália, Bidinha Eleine Renata, Bueno de Almeida Camila Leandra, Cechinel-Filho Valdir, Santos Zanuncio Vanessa Samudio, Silva Denise Brentan, Gasparotto Junior Arquimedes, de Souza Priscila
Postgraduate Program in Pharmaceutical Sciences, Nucleus of Chemical-Pharmaceutical Investigations, University of Vale do Itajaí, Itajaí, Brazil.
Laboratory of Natural Products and Mass Spectrometry, Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul, Campo Grande, MatoGrosso do Sul, Brazil.
Evid Based Complement Alternat Med. 2021 Nov 15;2021:7203934. doi: 10.1155/2021/7203934. eCollection 2021.
(A. Gray) Cong. is widely distributed in the south of Brazil and is commonly used for cardiovascular and kidney ailments. For this study, we used male Wistar normotensive rats (NTRs) and spontaneously hypertensive rats (SHRs) to verify the effects of the ethyl acetate fraction (EAF) obtained from leaves on isolated aorta relaxation and in the arterial blood pressure. The EAF was analyzed by LC-DAD-MS, and several components were annotated, including hydrolysable tannins, triterpenes, and - and -glycosylated dihydrochalcones, such as the most intense ion peak relative to -hexosyl phloretin (nothofagin; compound number ). The EAF caused a concentration and endothelium-dependent relaxation of the aorta in both NTRs and SHRs. This effect was abolished in the endothelium-denuded aorta. L-NAME, a nonselective nitric oxide synthase inhibitor, and ODQ, a soluble guanylate cyclase inhibitor, entirely blocked the EAF-induced relaxation. The presence of a muscarinic receptor antagonist or a cyclooxygenase inhibitor did not alter the EAF's effectiveness in relaxing the aorta. The preincubation with tetraethylammonium, a Ca-activated K channel blocker, and with 4-aminopyridine, a voltage-dependent K channel blocker, significantly interfered with the EAF's relaxation. However, the incubation with glibenclamide, an ATP-sensitive K channel blocker, and barium chloride, an inward-rectifier K channel blocker, did not interfere with the EAF-induced relaxation. The EAF treatment also caused a dose-dependent decrease in the mean arterial pressure, systolic arterial pressure, and diastolic arterial pressure of both NTRs and SHRs, without significantly interfering with heart rate values. In conclusion, this study demonstrated the EAF-induced vasorelaxant and hypotensive actions, primarily dependent on the endothelium function and mainly with the participation of the nitric oxide and Ca-activated and voltage-dependent K channels.
（A. 格雷）Cong. 在巴西南部广泛分布，常用于治疗心血管和肾脏疾病。在本研究中，我们使用雄性Wistar正常血压大鼠（NTRs）和自发性高血压大鼠（SHRs）来验证从叶片中获得的乙酸乙酯馏分（EAF）对离体主动脉舒张和动脉血压的影响。通过LC-DAD-MS对EAF进行分析，鉴定出了几种成分，包括可水解单宁、三萜以及α-和β-糖基化二氢查耳酮，例如相对于α-己糖基根皮苷（诺托法金；化合物编号）的最强离子峰。EAF在NTRs和SHRs中均引起主动脉的浓度和内皮依赖性舒张。在内皮剥脱的主动脉中，这种作用消失。L-NAME（一种非选择性一氧化氮合酶抑制剂）和ODQ（一种可溶性鸟苷酸环化酶抑制剂）完全阻断了EAF诱导的舒张。毒蕈碱受体拮抗剂或环氧化酶抑制剂的存在并未改变EAF舒张主动脉的有效性。用钙激活钾通道阻滞剂四乙铵和电压依赖性钾通道阻滞剂4-氨基吡啶预孵育，显著干扰了EAF的舒张作用。然而，用ATP敏感性钾通道阻滞剂格列本脲和内向整流钾通道阻滞剂氯化钡孵育，并未干扰EAF诱导的舒张。EAF处理还导致NTRs和SHRs的平均动脉压、收缩动脉压和舒张压呈剂量依赖性降低，而对心率值无明显干扰。总之，本研究证明了EAF诱导的血管舒张和降压作用，主要依赖于内皮功能，主要涉及一氧化氮以及钙激活和电压依赖性钾通道的参与。
