BACKGROUND Greek oregano is a culinary and medicinal herb native to the Mediterranean region; however nowadays it is cultivated in many regions all over the world. It is commonly used as a spice for flavoring food products and in various applications of traditional medicine. This study investigated the effect of nitrogen fertilization at range 0-150 kg N·ha-1 on the potential bioaccessibility and activity of Greek oregano compounds. For this purpose total phenolic content, rosmarinic acid content, and antioxidant activities of the raw material, as well as digested fractions, were determined. RESULTS Nitrogen fertilization had a negative influence on phenolic contents and antioxidant activity of raw material; however, its effect on the potential bioaccessibility varied depending on the dose. The highest potential bioaccessibility and activity was determined for plants fertilized with 30 kg N·ha-1 . For gastric and intestinal phase of a digestion, the potential bioaccessibility was 39.5% and 29.6% for total phenolics, 53.1% and 11.2% for rosmarinic acid content, 45.2% and 44.4% for antiradical activity against ABTS, 39.2% and 27.2% for antiradical activity against DPPH as well as 50.2% and 23.4% for reducing power, respectively. CONCLUSION Results showed that nitrogen fertilization is an important factor determining the in vitro bioaccessibility of Greek oregano compounds. Furthermore, the nutraceutical potential of herbs, in term of bioaccessibility of bioactive compounds, may be optimized during plant cultivation by applying the accurate nitrogen level. This article is protected by copyright. All rights reserved.

中文翻译：

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受氮肥影响的希腊牛至（Origanum vulgare L. ssp. hirtum (Link) Ietswaart）化合物的体外生物可及性和活性

背景希腊牛至是一种原产于地中海地区的烹饪和药用草本植物。然而，如今它在世界各地的许多地区都有种植。它通常用作调味食品和传统医学的各种应用的香料。本研究调查了在 0-150 kg N·ha-1 范围内施氮对希腊牛至化合物的潜在生物可及性和活性的影响。为此，测定了原料以及消化部分的总酚含量、迷迭香酸含量和抗氧化活性。结果施氮对原料酚类含量和抗氧化活性有负面影响；然而，它对潜在生物可及性的影响因剂量而异。用 30 kg N·ha-1 施肥的植物测定了最高的潜在生物可及性和活性。对于消化的胃和肠阶段，总酚类物质的潜在生物可及性分别为 39.5% 和 29.6%，迷迭香酸含量分别为 53.1% 和 11.2%，对 ABTS 的抗自由基活性分别为 45.2% 和 44.4%，抗自由基活性为 39.2% 和 27.2%。 DPPH 活性以及还原力分别为 50.2% 和 23.4%。结论 结果表明，施氮肥是决定希腊牛至化合物体外生物可及性的重要因素。此外，就生物活性化合物的生物可及性而言，可以通过应用准确的氮水平在植物栽培过程中优化草药的营养潜力。本文受版权保护。版权所有。