Department of Legal Medicine, Nara Medical University, 840 Shijocho, Kashihara 634-8521, Nara, Japan.
Nutrients. 2021 Dec 26;14(1):89. doi: 10.3390/nu14010089.
The vasorelaxant effect of polyphenols is well known, and the mortality rate due to coronary artery disease is low in people who consume polyphenol-containing foods. We aimed to elucidate the mechanism by which polyphenols derived from persimmon juice (PJ) and persimmon leaves (PLs) induce vasorelaxation and suppress vasocontraction in the superior mesenteric arteries isolated from male Sprague Dawley rats. Vasocontraction was induced with 1 µM phenylephrine, and polyphenol-induced vasorelaxation was expressed as a percentage of the previous tone induced by phenylephrine. PJ powder (100 mg/L) induced higher levels of vasorelaxation (mean ± standard error of the mean, 88.6% ± 4.4%) than PLs powder (1 g/L; 72.0% ± 10.8%). Nitric oxide pathway inhibitors (NG-nitro-L-arginine methyl ester + carboxy-PTIO) did not affect persimmon-derived polyphenol-induced vasorelaxation, whereas potassium chloride, tetraethylammonium, and potassium-channel inhibitors did. Vasorelaxation was endothelium independent with both extracts. Phenylephrine-induced vasocontraction was suppressed by pretreatment with PJ and PLs powder, even when inositol triphosphate-mediated Ca release and extracellular Ca influx were inhibited. These results suggest that persimmon-derived polyphenol phytocomplex cause vasorelaxation and inhibit vasocontraction through hyperpolarization of smooth muscle cells. Persimmon-derived polyphenols may be able to prevent cardiovascular diseases caused by abnormal contraction of blood vessels.
多酚具有血管舒张作用，而摄入富含多酚的食物可降低冠心病的死亡率。本研究旨在阐明柿子汁（PJ）和柿子叶（PLs）中提取的多酚诱导雄性 Sprague Dawley 大鼠肠系膜上动脉舒张和抑制血管收缩的机制。采用 1µM 苯肾上腺素诱导血管收缩，并用苯肾上腺素诱导的收缩幅度来表示多酚诱导的舒张幅度。PJ 粉（100mg/L）诱导的舒张幅度（88.6%±4.4%）显著高于 PLs 粉（1g/L；72.0%±10.8%）。一氧化氮通路抑制剂（NG-硝基-L-精氨酸甲酯+羧基-PTIO）不影响柿子多酚诱导的血管舒张，但氯化钾、四乙铵和钾通道抑制剂则有影响。两种提取物均显示出非内皮依赖性的血管舒张作用。PJ 和 PLs 粉预处理可抑制苯肾上腺素诱导的血管收缩，即使抑制三磷酸肌醇介导的 Ca2+释放和细胞外 Ca2+内流也有此作用。这些结果表明，柿子来源的多酚植物复合物通过平滑肌细胞的超极化引起血管舒张和抑制血管收缩。柿子来源的多酚可能能够预防由血管异常收缩引起的心血管疾病。
