Moreno-Loaiza Oscar, Paz-Aliaga Azael
Facultad de Medicina, Universidad Nacional San Agustín, Arequipa, Perú.
Rev Peru Med Exp Salud Publica. 2010 Oct-Dec;27(4):527-31. doi: 10.1590/s1726-46342010000400006.
To evaluate the vasodilator response of the hydroalcoholic extract of Zea mays L. (Andean purple corn) and to determine if this response is mediated by nitric oxide (NO).
We obtained an extract by maceration for eight days of Andean purple corn cobs in 70% ethanol and subsequent concentration of the product. Thoracic aortic rings were evaluated in an isolated organ chamber, bathed with Krebs-Hensleit solution (KH), and vasomotor activity was recorded with an isometric tension transducer. Basal contraction was produced with 120 mM KCl and then, we proceeded to determinate the vasodilator effect of 3 doses of the extract: 0.1, 0.5, and 1.0 mg/mL. We used L-NG-Nitroarginin methyl ester (L-NAME) to verify that the vasodilation depends on nitric oxide sinteasa (NOs). Then we compared the inhibition of vascular contraction after incubation for 30 minutes, with purple corn extract and captopril 10-5 M.
We observed a reduction in maximum contraction (100%) to 85.25 ± 2.60%, 77.76 ± 3.23%, and 73.3 ± 4.87% for doses of 0.1, 0.5 and 1,0 mg/mL respectively. The vasodilation was inhibited by prior incubation with L-NAME. Andean purple corn extract did not inhibit vascular contraction as captopril did (reduction to 75.27 ± 8.61%).
The hydroalcoholic extract of Zea mays L produces NO dependent vasodilation.
评估玉米（安第斯紫玉米）水醇提取物的血管舒张反应，并确定该反应是否由一氧化氮（NO）介导。
我们通过将安第斯紫玉米棒在70%乙醇中浸渍八天，随后浓缩产物来获得提取物。在离体器官浴槽中评估胸主动脉环，用Krebs-Hensleit溶液（KH）灌注，并使用等长张力换能器记录血管舒缩活动。用120 mM KCl引发基础收缩，然后测定3种剂量提取物（0.1、0.5和1.0 mg/mL）的血管舒张作用。我们使用L-NG-硝基精氨酸甲酯（L-NAME）来验证血管舒张是否依赖于一氧化氮合酶（NOs）。然后比较在与紫玉米提取物和10-5 M卡托普利孵育30分钟后血管收缩的抑制情况。
我们观察到，对于0.1、0.5和1.0 mg/mL的剂量，最大收缩率分别从100%降至85.25±2.60%、77.76±3.23%和73.3±4.87%。预先用L-NAME孵育可抑制血管舒张。安第斯紫玉米提取物不像卡托普利那样抑制血管收缩（降至75.27±8.61%）。
玉米水醇提取物产生依赖于NO的血管舒张作用。
