近日，一项刊登在国际杂志Hypertension（《高血压》）上的研究报告中，来自罗马大学等机构的科学家们通过研究表示，从螺旋藻中提取出的一种肽类或能通过扩张血管来抵御高血压，相关研究结果有望帮助研究人员后期开发出治疗高血压的新型疗法。

如今，螺旋藻因具有多种有益效应而被越来越多的人认为是“超级食物”，但目前研究人员并不清楚螺旋藻在机体中的作用机制，螺旋藻的学名为钝顶节旋藻(Arthrospira platensis)，其是一种能进行光合作用的蓝细菌，有时候其被归类为“蓝藻”，而且被认为是阿兹特克人（Aztecs）的食物。

这项研究中，研究者发现，一种来自螺旋藻中的提取物或能通过扩张血管来有效中和动脉高血压。研究人员通过研究从螺旋藻中分离出了一种肽类（由氨基酸组成的特殊分子），当在实验室中对离体的动脉和动物模型进行研究后他们发现，这种肽类能够扩张动脉血管，从而产生抗高血压的效应。

研究者Albino Carrizzo表示，我们首先模拟螺旋藻提取物在机体中的消化过程，换句话说，我们能够再现摄入这种肽类物质后人类机体肠道所发生的改变，这样研究人员就能够分离出被机体所吸收的肽类分子。研究人员首先鉴别出了一种名为SP6的肽类分子，当在实验室中将SP6给予离体的血管后，该分子就能产生一种血管舒张的效应，而这就是一种潜在的抗高血压的效应，随后研究者将SP6给予高血压动物模型，结果发现，SP6能够产生一种降血压的反应。

研究者指出，高血压患者通常会在通过一氧化氮调节血管内壁反应的自然过程中存在缺陷，而我们从螺旋藻中分离出的肽类分子则能够发挥一种积极性的作用，后期研究人员还需要进行更为深入的研究来阐明SP6肽类分子的具体作用机制，研究者认为，SP6或许能作为常见药物的一种天然佐剂来帮助改善高血压患者的血管内皮功能，从而有效控制患者的高血压。（来源：生物谷Bioon.com）

Novel Potent Decameric Peptide of Spirulina platensis Reduces Blood Pressure Levels Through a PI3K/AKT/eNOS-Dependent Mechanism

Abstract  Considered as a superfood of the future, Spirulina platensis matrix has been extensively used because of its beneficial effect on the management of cardiovascular diseases. However, its nutraceutical properties, bioactive compounds, and molecular mechanisms are unknown. Here, we demonstrate that S platensis matrix processed in vitro by simulated gastrointestinal digestion induces direct endothelial nitric oxide (NO)-mediated vasorelaxation of resistance vessels in mice. To gain insight into the bioactive compounds responsible for this effect, we used a complex multistep peptidomic approach to fractionate the crude digest: of the 5 peptide fractions identified (A-E), only fraction E evoked vasorelaxation. High-resolution mass spectrometry-based screening revealed in E the presence of 4 main peptides (SP3-SP6 [spirulina peptides]), of which only SP6 (GIVAGDVTPI) exerted direct endothelium-dependent vasodilation of ex vivo vessels, an effect occurring via a PI3K (phosphoinositide-3-kinase)/AKT (serine/threonine kinase Akt) pathway converging on NO release. In vivo, administration of SP6 evoked a significant hemodynamic effect, reducing blood pressure, an action absent in eNOS (endothelial NO synthase)-de？cient mice. Of note, although lower doses of SP6 had no hemodynamic effects, it still enhanced endothelial NO vasorelaxation. Finally, in an experimental model of arterial hypertension, SP6 exerted an antihypertensive effect, improving endothelial vasorelaxation associated with enhanced serum nitrite levels. Based on our results, this novel decameric peptide may extend the possible fields of application for spirulina-derived peptides and could be developed into a promising nonpharmacological approach for the containment of pathologies associated with vascular NO misregulation.

原文链接：https://www.ahajournals.org/doi/10.1161/HYPERTENSIONAHA.118.11801