Numerous studies have been carried out on the bioactive properties of hydroxytyrosol (HT) in olive oils (OOs), although there are few reports comparing anti-inflammatory activity among different olive varieties or regions of production. The purpose of this study was to investigate the in vitro inflammatory action of HT in extracts of four OO varieties in the Languedoc region of the French Mediterranean. Factors other than cultivar were eliminated, which enabled unambiguous varietal differences to be identified. Purified extracts of OO were obtained using an optimized solid-phase extraction procedure by which only polar compounds were recovered. High performance liquid chromatography-photodiode array detection-tandem mass spectrometry was used to identify and quantify HT and oleacein in the extracts. The total polyphenol concentration ranged from 93.00 mg gallic acid equivalent/kg OO for Picholine to 27 mg gallic acid equivalent for Verdale OOs. The concentrations of HT in Picholine, Olivère, and Lucques varieties were 25.3, 18.8 and 12.1 mg/kg, respectively, whereas the concentration of HT in Verdale OOs was less, 1 mg/kg. The in vitro anti-inflammatory response of purified OO extracts, evaluated by the inhibition of nitric oxide release in lipopolysaccharide-induced interferon-γ activated J774.A1 macrophages, strongly correlated with total polyphenol content (R² > 0.995). The effect increased asymptotically between the equivalent of 2 and 37 mg of OO, reaching, at the maximum tested concentration, 90%, 75%, 62%, and 30% activity for Picholine, Olivière, Lucques, and Verdale, respectively. The results presented here clearly show that, by comparison with authentic standards, the activity of HT in OO extracts was enhanced in a concentration-dependent manner, varying from 3-fold at the highest extract concentration to over 6.5-fold at the lowest extract concentration. Therefore, the anti-inflammatory activity of OOs should be rationalized on the basis of whole extracts rather than solely on the concentration of HT or other bioactive compounds in OO.

中文翻译：

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对法国橄榄油中羟基酪醇浓度和抗炎活性的各种影响。

关于羟基酪醇（HT）在橄榄油（OOs）中的生物活性特性已经进行了许多研究，尽管很少有报道比较不同橄榄品种或产区之间的抗炎活性。这项研究的目的是研究体外HT在法国地中海朗格多克地区四个OO品种的提取物中的发炎作用。消除了除栽培品种以外的其他因素，从而能够确定明确的品种差异。使用优化的固相萃取程序获得的OO纯化提取物，仅能回收极性化合物。高效液相色谱-光电二极管阵列检测-串联质谱用于鉴定和定量提取物中的HT和油精。总多酚浓度范围从Picholine的93.00 mg没食子酸当量/ kg OO到Verdale OOs的27 mg没食子酸当量。Picholine，Olivère和Lucques品种中的HT浓度分别为25.3、18.8和12.1 mg / kg，而Verdale OOs中的HT浓度较低，为1 mg / kg。的纯化的OO提取物的体外抗炎反应，通过抑制脂多糖诱导的γ-干扰素激活的J774.A1巨噬细胞中一氧化氮的释放来评估，与总多酚含量（R ² > 0.995）。该作用在2至37 mg OO的当量之间渐近增加，在最大测试浓度下分别达到Picholine，Olivière，Lucques和Verdale的90％，75％，62％和30％活性。此处显示的结果清楚地表明，与真实标准品相比，OO提取物中的HT活性以浓度依赖性方式增强，从最高提取物浓度的3倍变化到最低提取物浓度的6.5倍以上。 。因此，OOs的抗炎活性应基于整个提取物而不是仅基于OO中HT或其他生物活性化合物的浓度进行合理化。