Hydroxytyrosol and olive leaf extract exert cardioprotective effects by inhibiting GRP78 and CHOP expression

Myocardial infarction triggers massive biochemical changes, even cardiac cell death. Endoplasmic reticulum stress is involved in the pathology of myocardial infarction-mediated apoptosis. In the present study, myocardial cell line H9c2 cells were treated with cobalt chloride（CoCl_2） to induce hypoxia. Isoproterenol was used for two successive days to induce myocardial infarction in SD rats. The cardioprotective effect of olive leaf extract（OLE） and its main constituent hydroxytyrosol and the underlying mechanisms were evaluated. The results showed that hydroxytyrosol markedly protected H9c2 cells against CoCl2-induced apoptosis. Hydroxytyrosol could reduce the mRNA and protein expression of GRP78 and CHOP induced by CoCl2 in vitro. In vivo, the decreased ejection fraction and fractional shortening, increased heart weight/body ratio, the formation of infarction, disordered cardiac muscle fibers and infiltration of inflammatory cells induced by isoproterenol could be significantly ameliorated by pretreatment with OLE for a month. Similarly, OLE could also reverse the increase of GRP78 and CHOP expression induced by isoproterenol. Therefore, OLE and hydroxytyrosol exert a cardioprotective effect through endoplasmic reticulum stress, which could be a new target for the prevention and treatment of cardiovascular diseases.

Studies of the Relationship between Structure and Antioxidant Activity in Interesting Systems, Including Tyrosol, Hydroxytyrosol Derivatives Indicated by Quantum Chemical Calculations

In nature, tyrosol (TY) and hydroxytyrosol (HT) are found in olive leaves which are for medical aims, with immune stimulant and antibiotic properties as well as the ability to be used for the treatment of neurodegenerative diseases such as Alzheimer. This ability of phytochemical TY and HT compounds are mainly believed to be of higher radical scavenging potential with effective antioxidant properties. In order to establish the possible structure-antioxidant activity relationship of tyrosol, hydroxytyrosol, hydroxytyrosol acetate and two designed hydroxytyrosol derivatives were studied by the help of quantum chemical calculations. The molecular electronic properties such as heat formation of the neutral, radical and orbitals energies were calculated as descriptors to predict the H atom donating abilities of compounds. Considering the results from the calculated descriptors, the derivatives having OH group substitutions in position number four of the aromatic ring can be classified highly active and better antioxidant compound. Therefore, the designed hydroxytyrosol derivatives showed most active feasible H atom donation. This work can be useful to design novel antioxidants.

Stability of Hydroxytyrosol in Aqueous Solutions at Different Concentration, Temperature and with Different Ionic Content: A Study Using UPLC-MS

The work describes a stability study of hydroxytyrosol (HTyr) in aqueous solutions carried out varying the following parameters: HTyr concentration, temperature and ionic content in the aqueous solution. First, an analytical method based on the use of ultra performance liquid chromatography (UPLC-MS) as analytical technique was developed and validated. The equation of the linear model was A/AISTD= –0.0013 + 0.0117. [HTyr], with a very good linearity, since the R-Squared was 99.9% and the P value of the lack of fit test was higher than 5%. Limits of quantification estimated, CCα(α= 0.05%) and CCβ(β= 0.05%), were 0.2 and 0.4 g/L respectively. As well, the relative standard deviation in the intra-day precision was lower than 3%. Therefore, the method is reproducible. We have applied this methodology to study the stability of HTyr and have observed that the most critical aspect turned to be the ionic content of the aqueous solutions. A tap water with high contents of calcium and magnesium (52 and 21 mg/L) degraded HTyr up to 64% in 48 hours whereas a low mineralization water with low contents of calcium and magnesium (4 and 2 mg/L) produced only 19% degradation.

Hydroxytyrosol But Not Resveratrol Ingestion Induced an Acute Increment of Post Exercise Blood Flow in Brachial Artery

The aim of this study was to test if previous ingestion of compounds containing resveratrol or hydroxytyrosol, followed by an exhausting hand grip exercise, could induce an acute post-exercise increase in brachial blood flow. Six healthy subjects (three males and three females, 35 ± 7 years), 60 minutes after ingestion of a capsule containing 200 mg of resveratrol or 30 ml of extra virgin olive oil enriched with tyrosol, oleuropein and hydroxytyrosol, performed a hand grip exercise equal to half of their maximum strength until they were no longer able to express the same force (2-day interval between tests). The nonparametric Wilcoxon signed rank test was used for statistical evaluations. Brachial artery blood flow (Fba) and both blood velocity (Vba) and artery diameter (Dba) were assessed immediately after exercise cessation by means of colour Doppler ultrasound. After ingestion of the oil mixture the post-exercise value of Fba median was 2.4 times higher than that after ingestion of the resveratrol compound (P = 0.03), and also the Vba median concerning the hydroxytyrosol was 1.9 times higher than that of the resveratrol (P = 0.03). Both functional foods did not lead to a significant difference in the Dba medians. These results indicate that hydroxytyrosol, but not resveratrol, may be an effective adjuvant of recreational or agonistic, long-lasting sports performances, thanks to the powerful blood flow increment which can be obtained as soon as one hour from its oral intake.

Predicting ADME/Tox properties of hydroxytyrosol in the leaves of Olea europaea L.

In order to study the possibility of hydroxytyrosol(HT)as a drug,we used SwissADME system to predict ADME of HT and pkCSM system to predict Tox of HT.The results show that hydroxytyrosol meets the Lipinski’s five principles of drug-like properties.With strong efficacy and pharmacological activity,HT has high drug-likeness degree.With good bioavailability,it can be easily absorbed by the gastrointestinal tract,though not absorbed by skin.Hydroxytyrosol has not only a strong potency and pharmacological activity,but also no liver toxicity and skin allergy.Tox data predicts that it has mutagenic potential,which may be the result of overreduction.

Ultrasonic assisted natural deep eutectic solvents as a green and efficient approach for extraction of hydroxytyrosol from olive leaves

In this study,an ultrasonic assisted natural deep eutectic solvent(DES)was used to extract hydroxytyrosol(HT)from olive leaves.The optimal extraction conditions of the MaPa-4 concentration,extraction time and solid-liquid ratio were obtained by single factor experiments.The formation mechanism of MaPa and its interaction with HT were analyzed by FTIR,^(1)H-NMR and density functional theory(DFT)calculation.Then,MaPa-4 and water extracts obtained under the optimal extraction conditions were selected for a series of efficacy tests.MaPa-4 extract demonstrated low cytotoxicity,good biocompatibility,and excellent antiinflammatory and bacteriostatic properties.Overall,MaPa-4,as an environmentally friendly and efficient solvent,was combined with ultrasound treatment to develop an efficient,green and feasible method to extract HT from olive leaves.

富含羟基酪醇和玉米黄质色素橄榄油对衰老小鼠影响的比较

【目的】研究富含羟基酪醇橄榄油(olive oil rich in hydroxyl tyrosol,OHT)和富含玉米黄质色素橄榄油(olive oil rich in zeaxanthin,OZT)对衰老小鼠的影响。【方法】利用0.5 mL/10g剂量颈部皮下注射5%的D-半乳糖(D-galactose)溶液42 d构建亚急性衰老模型,建模成功后,将小鼠随机分成5组,分别为模型组(Model group)、维生素E对照组(VE group)、普通橄榄油组(olive oil group,OL)、OHT组和OZT组,以生理盐水对照组CK(0)。连续灌胃28 d后,检测小鼠体质量、血清中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、丙氨酸氨基转移酶(alanine aminotransferase,ALT)、天门冬酸氨基转移酶(aspartate aminotransferase,AST)活性和丙二醛(malondialdehyde,MDA)、白细胞介素-2(IL-2)、和干扰素-γ(IFN-γ)生成水平等指标的影响,观察肝组织形态学变化。【结果】D-半乳糖诱导的衰老小鼠模型中,OHT和OZT均能控制衰老小鼠体质量(P<0.05),降低血清中的SOD、CAT、GSH-Px、ALT和AST的活性(P<0.05,P<0.01),能显著提高IL-2和IFN-γ生成(P<0.05,P<0.01),降低MDA含量(P<0.05,P<0.01),肝脏病理变化得到改善,OZT干预效果显著优于OHT。【结论】OHT和OZT对D-半乳糖致亚急性衰老动物模型均有很好的干预效果,能有效提高小鼠机体抗氧化能力,延缓衰老的作用。

响应面法优化羟化酶催化酪醇合成羟基酪醇工艺

以pET-22b为载体,将基因HpaB、HpaC在E.coli BL21(DE3)中表达,得到高纯度的羟化酶HpaB、HpaC,并采用单因素实验和响应面法对羟化酶催化酪醇合成羟基酪醇的反应条件进行优化。确定最佳反应条件如下:温度为32℃、缓冲液为20 mmol·L^(-1)磷酸钾缓冲液(pH值7)、酪醇浓度为17.67 mmol·L^(-1)、HpaC加量为0.78 mg·mL^(-1)、NADH浓度为9.88 mmol·L^(-1)、FAD浓度为2.88μmol·L^(-1),在此条件下,酪醇转化率为99.99%,底物酪醇几乎完全转化为羟基酪醇。该研究为酶法催化合成羟基酪醇的工业化生产提供了理论基础。

基于Nrf2/HO-1和NF-κB信号通路探讨羟基酪醇对环磷酰胺诱导的卵巢储备功能不足小鼠的影响

目的探讨羟基酪醇(HT)对环磷酰胺(CTX)诱导的卵巢储备功能不足(DOR)小鼠卵巢损伤的影响及其改善DOR小鼠卵巢功能的作用机制。方法将40只7~8周龄的雌性C57BL/6L小鼠随机分为对照组、模型组(CTX组)、HT低剂量实验组(CTX+L-HT组,50 mg·kg^(-1)·d^(-1))以及HT高剂量实验组(CTX+H-HT组,100 mg·kg^(-1)·d^(-1)),每组10只。腹腔注射CTX(50 mg·kg^(-1)·d^(-1))建立DOR小鼠模型,采用HE染色观察小鼠卵巢组织形态学变化及各级卵泡数量,酶联免疫吸附法(ELISA)测定小鼠血清中性激素、氧化应激因子指标和炎性因子指标,通过Western blot检测卵巢组织中Nrf2、HO-1、p-NF-κB以及NF-κB蛋白表达水平。结果与对照组相比,CTX组各级卵泡数量显著减少,而闭锁卵泡数量显著增加(P<0.05),颗粒细胞层减少,黄体减少,血清中FSH、LH的水平显著升高(P<0.05),雌二醇(E_(2))和抗苗勒管激素(AMH)的水平显著降低(P<0.05);CTX组卵巢组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及谷胱甘肽过氧化物酶(GSH-Px)活性均显著降低(P<0.05),而丙二醛(MDA)含量显著增加(P<0.05),卵巢组织中促炎因子水平(TNF-α、IL-6及IL-1β)显著增加(P<0.05),而抗炎因子(IL-10)水平显著减少(P<0.05),卵巢组织中Nrf2和HO-1蛋白表达量显著减少(P<0.05),而p-NF-κB/NF-κB蛋白表达水平比率显著增加(P<0.05)。与CTX组相比,CTX+L-HT组和CTX+H-HT组各级卵泡数目均显著增加(P<0.05),而闭锁卵泡数目均显著减少(P<0.05),小鼠血清中FSH、LH水平均显著减少(P<0.05),而E_(2)和AMH水平均显著增加(P<0.05);其次,CTX+L-HT组和CTX+H-HT组卵巢组织中SOD、CAT以及GSH-Px活性均显著增加(P<0.05),MDA含量显著减少(P<0.05),卵巢组织中促炎因子水平显著减少(P<0.05),而抗炎因子水平显著增加(P<0.05),小鼠卵巢组织中Nrf2和HO-1蛋白表达量均显著增加(P<0.05),而p-NF-κB/NF-κB蛋白表达水平比率均显著减少(P<0.05)。与CTX+L-HT组相比,CTX+H-HT组IL-10水平显著增加(P<0.05)。结论羟基酪醇对DOR小鼠卵巢损伤具有保护功能,其机制可能与激活Nrf2/HO-1信号通路、抑制NF-κB信号通路以及减少氧化应激和炎症反应有关。

油橄榄叶中羟基酪醇含量及提取工艺研究

油橄榄含有橄榄苦苷、黄酮类和羟基酪醇等多酚抗氧化物。采用ODS(4.6 mm×200 mm,5μm)色谱柱,紫外检测波长为230 nm,甲醇-0.2%醋酸水溶液6∶94(体积比)为流动相,流速1 mL/min,建立羟基酪醇的HPLC分析方法,对不同品种的油橄榄叶进行含量分析。结果表明:10个品种油橄榄叶中羟基酪醇质量分数范围在0.3%～0.8%之间,小莱星含量最高,配多灵含量最低。通过单因素和正交试验研究了超声波提取油橄榄叶中羟基酪醇的工艺,1 g油橄榄叶粉末正交试验的优化结果为:功率120 W、90%甲醇提取、料液比1∶20(g∶mL)、时间20 min。采用90%甲醇提取油橄榄叶,提取液经AB-8大孔树脂、硅胶柱层析和HPLC制备色谱,分离质量分数95%以上的单体,通过MS、NMR鉴定该化合物为羟基酪醇。

油橄榄叶中羟基酪醇的含量变化规律研究

以90%甲醇-水溶液为提取剂,用超声波提取不同品种、月份和树龄油橄榄叶中羟基酪醇,采用HPLC方法分析5个品种油橄榄叶中羟基酪醇的含量变化规律,同时考察阿斯、莱星等10种油橄榄叶放置3年后其中橄榄苦苷转化为羟基酪醇的趋势。结果表明:油橄榄叶中羟基酪醇含量一年生长期内有1个高峰期和1个低谷期,5～6月份的含量最高;11～12月份最低;不同树龄和品种间含量差异较大,油橄榄叶中羟基酪醇树龄6年以下含量明显高于18年以上的;6年生鄂植8号幼叶中5月份达到0.768%,6年生九峰6号12月份最低,为0.058%;阿斯、莱星等10种18年以上树龄油橄榄叶放置3年后橄榄苦苷明显减少,羟基酪醇的含量增加1倍,因此大量橄榄苦苷在贮存期被降解为羟基酪醇。

羟基酪醇合成工艺研究

以邻苯二酚为起始原料,经过保护邻二酚羟基,溴化制得3,4-亚甲二氧基溴苯,制备其格氏试剂,再用格氏试剂与环氧乙烷反应,最后脱掉保护基团,以5步反应总收率24%得到高纯度羟基酪醇,并通过IR、MS等方法对终产物进行了表征。

羟基酪醇的研究进展

羟基酪醇是一种天然多酚类化合物,具有多种生物和药理活性,主要存在于橄榄油和加工橄榄油产生的废水中。本文主要综述了羟基酪醇的主要药理活性,包括抗癌、抗菌、抗炎作用,介绍了羟基酪醇的从生产橄榄油的废渣、废水中的提取、分离方法,化学合成方法以及生物合成方法。

油橄榄叶中羟基酪醇的提取及分离纯化

对油橄榄叶中的羟基酪醇进行提取及分离纯化。采用酶法对油橄榄叶中的羟基酪醇进行提取,大孔吸附树脂分离纯化。通过单因素实验和正交实验得到酶法提取羟基酪醇的最佳工艺为:酶解时间80 min,pH值为7,温度40℃,酶浓度为30μg/mL,在此条件下得到的羟基酪醇含量为3.72 mg/g。静态吸附实验筛选出DA-201大孔吸附树脂为分离纯化羟基酪醇的最佳树脂,动态吸附-脱附实验得到羟基酪醇分离纯化的最佳工艺为:上样液质量浓度为60μg/mL,上样流速为3 BV/h,脱附剂为体积分数80%的乙醇,脱附流速为3 BV/h,脱附剂用量为2 BV。按照以上最佳实验条件操作,1 g油橄榄叶可得到羟基酪醇总油状物为3.85 mg,纯度为87.01%。

羟基酪醇药理作用研究进展

羟基酪醇(Hydroxytyrosol,HT)化学名3,4-二羟基苯乙醇,具有很强的抗氧化活性,主要以酯类的形式存在于橄榄的果实和枝叶中。HT具有多方面的生物活性。本文就近年来国内外对羟基酪醇在抗癌、抗血栓、调血脂和抗动脉硬化、抗病原微生物、防治视网膜黄斑变性、保护软骨和抗骨质疏松及其他保健作用等方面的药理作用及其机制研究进行综述。

包载丁香苦苷和羟基酪醇的mPEG-PLGA纳米粒处方与制备工艺的优化

目的优化包载丁香苦苷和羟基酪醇的聚乙二醇单甲醚-聚乳酸-乙醇酸(mPEG-PLGA)纳米粒处方与制备工艺。方法沉淀法制备纳米粒后,以水相与有机相比例、药物用量、表面活性剂(Pluronic F-68)浓度为影响因素,总包封率和总载药量为评价指标,星点设计-效应面法优化处方与制备工艺。结果所得纳米粒溶液呈淡蓝色乳光,最佳条件为水相与有机相比例2.1∶1,药物用量14.1 mg,Pluronic F-68浓度0.1%,平均总包封率(32.38±1.21)%,总载药量(12.01±0.32)%,平均粒径(69.03±1.89)nm,Zeta电位(-25.2±0.99)m V。结论该方法稳定可靠,可用于优化包载丁香苦苷和羟基酪醇的mPEG-PLGA纳米粒处方与制备工艺。

盐酸法和β-葡萄糖苷酶法水解橄榄叶提取物制备羟基酪醇的比较

采用盐酸和β-葡萄糖苷酶分别水解橄榄叶提取物制备羟基酪醇。通过单因素实验和正交实验得出了酸水解的较优参数为:时间6h、温度80℃、盐酸浓度为0.2mol/L、液料比为50∶1(mL/g)。酶水解的最佳工艺参数为:温度50℃、时间5h、pH7.0、加酶量25U/mg。通过酶解的方法羟基酪醇最高含量为3.91%,而酸解的羟基酪醇最高含量为7.83%。从生产成本和提高羟基酪醇含量考虑,盐酸法优于酶法。

油橄榄羟基酪醇的生物合成及其衍生物研究进展

介绍了传统化学合成羟基酪醇的方法,针对化学合成反应步骤多、催化剂昂贵、产率低、污染大等问题,重点总结了以橄榄苦苷和酪醇为原料生物法合成羟基酪醇的途径,同时还综述了羟基酪醇烷基醚、脂肪酸酯、糖基化等衍生物的制备方法、生物活性及其构效关系,为羟基酪醇及其衍生物批量制备及其抗肿瘤、抗癌、心脑血管疾病新药的筛选提供参考和指导作用。

羟基酪醇的热稳定性和分解动力学研究

研究不同升温速率（β=5、10、20、40 K/min）下羟基酪醇的热稳定性、分解动力学和贮存期。利用热重分析得到羟基酪醇在氮气氛围中不同升温速率（β）下的热分解曲线,运用3种多升温速率法Kissinger法、Friedman法和Flynn-Wall-Ozawa法以及2种单升温速率方法 Coats-Redfern法和Achar法进行动力学分析,计算热分解的表观活化能（Ea）和指前因子（A）,且根据Ea和A推算羟基酪醇的贮存期。结果显示：羟基酪醇的热分解过程一步完成,在升温速率为10 K/min时,从260-409℃为羟基酪醇的主要失重阶段;TG曲线随着温度的升高而迅速出现陡峭明显的失重台阶,DTG曲线亦出现负值,且随着温度的升高而急剧下降,在305.2℃达到了DTG的峰值,此时达到最大热失重速率为-12.91%/min;升温速率的变化对羟基酪醇的分解有影响,随着速率的升高,羟基酪醇的热分解温度逐渐升高,热分解曲线略微向高温移动,呈现了分解滞后现象。羟基酪醇的热分解机制符合一维扩散（D1）模型。测得平均Ea为122.40 k J/mol,A为3.37×1010min-1。根据Ea和A可推断,在室温25℃下,羟基酪醇在氮气氛围下的理论贮存期为4-5年。

HPLC测定紫丁香叶中羟基酪醇含量

目的：建立一种测定紫丁香叶中羟基酪醇含量的方法。方法：采用HPLC，色谱柱为DikmaTech-nologies C18柱（250mm ＆#215;4．6mm，5μm），流动相为甲醇-水溶液（70∶30），检测波长为221nm。结果：羟基酪醇在3．03～48．40μg/mL内呈良好的线性关系，平均加样回收率为98．3％（ RSD＝1．6％）。结论：本方法简便易行、准确可靠，可为紫丁香叶药材及制剂的质量评价提供依据。