Apples increase nitric oxide production by human saliva at the acidic pH of the stomach: A new biological function for polyphenols with a catechol group?
Apples increase nitric oxide production by human saliva at the acidic pH of the stomach: A new biological function for polyphenols with a catechol group?
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DOI：
10.1016/j.freeradbiomed.2005.04.021
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发表时间：
2005-09-01
影响因子：
7.4
通讯作者：
Minetti, M
中科院分区：
文献类型：
--
作者：
Peri, L;Pietraforte, D;Minetti, M
膳食中的无机硝酸盐在唾液中分泌，并被细菌菌群还原为亚硝酸盐。在胃的酸性pH值下，亚硝酸盐与一氧化氮（(NO)- n -中心点）以及其他具有硝化和亚硝化活性的氮氧化物以亚硝酸盐的形式存在。胃中的NO - n中心点具有多种有益作用，但亚硝化/硝化物种被认为是胃食管交界处上皮瘤变的可能原因。研究了pH值为2时苹果提取物对人唾液释放NO - n中心点的影响。从苹果匀浆中提取的水提取物增加了唾液酸化引起的(NO)- n中心点释放。数据表明，多酚类物质具有这种活性，其中绿原酸和(+)-儿茶素活性最强，浓度最高。而只有一个芳羟基的羟基肉桂酸阿魏酸并没有增加NO - n中心点的释放。苹果中最具代表性的糖果糖也不活跃。有趣的是，唾液中的抗坏血酸诱导了SCN增强(NO)- n中心点的爆发，但与苹果不同，释放是短暂的。同时添加抗坏血酸和苹果提取物引起(NO)- n -中心点的爆发，随后增加了含有苹果提取物的唾液的稳态水平特征。绿原酸和(+)-儿茶素形成邻半醌自由基和硝化多酚，而阿魏酸不形成，表明邻半自由基清除了(NO2)- n -中心点。我们的研究结果表明，一些苹果多酚不仅可以抑制亚硝化/硝化，还可以促进(NO)- n中心点在胃水平的生物利用度，这是一个以前未被认识到的功能。(c) 2005爱思唯尔公司版权所有。
Dietary inorganic nitrate is secreted in saliva and reduced to nitrite by bacterial flora. At the acidic pH of the stomach nitrite is present as nitrous acid in equilibrium with nitric oxide ((NO)-N-center dot), and other nitrogen oxides with nitrating and nitrosating activity. (NO)-N-center dot in the stomach exerts several beneficial effects, but nitrosating/nitrating species have been implicated as a possible cause of epithelial neoplasia at the gastroesophageal junction. We investigated the effects of apple extracts on (NO)-N-center dot release by human saliva at pH 2. A water extract obtained from apple homogenate increased (NO)-N-center dot release caused by acidification of saliva. Data show that polyphenols were responsible for this activity, with chlorogenic acid and (+)-catechin the most active and concentrated species. However, ferulic acid, a hydroxycinnamic acid with only one aromatic hydroxyl group, did not increase (NO)-N-center dot release. Fructose, the most representative sugar in apples, was also inactive. Interestingly, ascorbic acid in saliva induced a SCN--enhanced burst of (NO)-N-center dot but, unlike apple, the release was transient. The simultaneous addition of ascorbic acid and apple extract caused a burst of (NO)-N-center dot followed by the increased steady-state level characteristic of saliva containing apple extract. Chlorogenic acid and (+)-catechin, but not ferulic acid, formed o-semiquinone radicals and nitrated polyphenols, suggesting the scavenging of (NO2)-N-center dot by o-semiquitiones. Our results propose that some apple polyphenols not only inhibit nitrosation/nitration but also promote (NO)-N-center dot bioavailabilty at the gastric level, a previously unappreciated function. (c) 2005 Elsevier Inc. All rights reserved.