Department of Pharmacology, Institute of Biomedical Sciences, Federal University of Uberlândia/UFU, Campus Umuarama, Uberlândia, Brazil.
Laboratório de Produtos Naturais e Espectrometria de Massas (LAPNEM), Federal University of Mato Grosso do Sul/UFMS, Campo Grande, Brazil.
Nat Prod Res. 2021 Nov;35(22):4798-4802. doi: 10.1080/14786419.2020.1727467. Epub 2020 Feb 21.
The ability of leaf extract (CXLE) to alter blood pressure and heart rate was evaluated in anesthetized rats. The CXLE-induced hypotension was evaluated before and after losartan, methylatropine, L-N(ω)-nitro-L-arginine methyl ester (L-NAME), hexamethonium, indomethacin, glibenclamide, or nifedipine administration. The constituents of CXLE were identified by LC-DAD-MS. CXLE decreased blood pressure in a dose-dependent manner; only the highest dose decreased heart rate. The hypotension induced by CXLE was sensitive only to losartan, nifedipine, and glibenclamide. L-NAME decreased the time to recover 50% of the hypotensive effect of CXLE without altering its magnitude. Flavan-3-ols, proanthocyanidins (dimers and trimers), and glycosylated flavonols were identified from CXLE. The chemical constituents of CXLE seem to induce not only angiotensin II type 1 receptor blockage, but also ATP-sensitive potassium channels activation and L-type voltage-dependent Ca channels inactivation. Nitric oxide is involved in the maintenance of the hypotensive effect of CXLE.
研究了叶提取物 (CXLE) 对麻醉大鼠血压和心率的影响。在给予氯沙坦、甲基阿托品、L-N(ω)-硝基-L-精氨酸甲酯 (L-NAME)、六烃季铵、吲哚美辛、格列本脲或硝苯地平之前和之后，评估了 CXLE 诱导的低血压。通过 LC-DAD-MS 鉴定了 CXLE 的成分。CXLE 呈剂量依赖性降低血压；只有最高剂量降低心率。CXLE 诱导的低血压仅对氯沙坦、硝苯地平和格列本脲敏感。L-NAME 降低了 CXLE 降压作用恢复 50%的时间，而不改变其幅度。从 CXLE 中鉴定出黄烷-3-醇、原花青素（二聚体和三聚体）和糖基化类黄酮。CXLE 的化学成分似乎不仅诱导血管紧张素 II 型 1 受体阻断，还诱导三磷酸腺苷敏感性钾通道激活和 L 型电压依赖性钙通道失活。一氧化氮参与了 CXLE 降压作用的维持。
