Disease relevance of Hydroxytyrosol

• Hydroxytyrosol, a natural antioxidant from olive oil, prevents protein damage induced by long-wave ultraviolet radiation in melanoma cells [1].
• In this study, we selected three natural antioxidants, resveratrol, hydroxytyrosol and vitamin E, on the basis of their scavenging capabilities, and tested their protective effects against CsA toxicity [2].
• Keywords: Hydroxytyrosol; bioconversion; Pseudomonas aeruginosa; alginate beads; repeated batch [3].
• Metabolism of the olive oil phenols hydroxytyrosol, tyrosol, and hydroxytyrosyl acetate by human hepatoma HepG2 cells [4].
• Administration of a low-dose (2.5 mg/kg of body weight) of hydroxytyrosol and a high-dose (10 mg/kg of body weight) of OMW extract significantly lowered the serum levels of TC and LDL-C while increasing the serum levels of high-density lipoprotein cholesterol (HDL-C) [5].

High impact information on Hydroxytyrosol

• Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant [6].
• Here, we show that 2-(3,4-dihydroxyphenyl)ethanol (DPE), a phenol antioxidant derived from olive oil, induces growth arrest and apoptosis in human colon carcinoma HT-29 cells [7].
• Because some simple phenols and polyphenols with antioxidant activity have shown varying anti-inflammatory activities, we tested OVW and HT for their ability to inhibit the production of tumor necrosis factor-alpha (TNF-alpha), a pivotal cytokine in inflammation [8].
• Here, we investigated the mechanism of action of three antioxidants: resveratrol, which causes differentiation of HL-60 cells, and hydroxytyrosol and pyrrolidine dithiocarbamate which, in the same model system, activate apoptosis [9].
• Tyrosol and hydroxytyrosol concentrations were low (< 4 mol/100 mol of intake) in the ileostomy effluent, and no aglycones were detected [10].

Chemical compound and disease context of Hydroxytyrosol

• Production of High Hydroxytyrosol Yields via Tyrosol Conversion by Pseudomonas aeruginosa Immobilized Resting Cells [3].
• Synthesis of hydroxytyrosol, 2-hydroxyphenylacetic acid, and 3-hydroxyphenylacetic acid by differential conversion of tyrosol isomers using Serratia marcescens strain [11].

Biological context of Hydroxytyrosol

• Oral bioavailability estimates of hydroxytyrosol when administered in an olive oil solution and when dosed as an aqueous solution were 99% and 75%, respectively [12].
• The expression profile of hydroxytyrosol-treated cells showed the up-regulation of several genes, including c-jun and egr1 [9].
• Both HT and TYR transferred across human Caco-2 cell monolayers and rat segments of jejunum and ileum and were subject to classic phase I/II biotransformation [13].
• We hypothesized that aging-associated oxidative stress affects gene expression, and monitored the transcriptome in confluent fibroblasts from young and old individuals cultured without and with a lipophilic and hydrophilic anti-oxidant mixture (vitamin E, quercetin, hydroxytyrosol and kaempferol) [14].
• Conjugated forms underwent rapid hydrolysis under gastric conditions, resulting in significant increases in the amount of free HT and TYR entering the small intestine [15].

Anatomical context of Hydroxytyrosol

• In this study, the effects of hydroxytyrosol (DOPET), the major antioxidant compound present in olive oil, on UVA-induced cell damages, have been investigated, using a human melanoma cell line (M14) as a model system [1].
• Transport mechanism and metabolism of olive oil hydroxytyrosol in Caco-2 cells [16].
• Antioxidant effect of hydroxytyrosol, a polyphenol from olive oil: scavenging of hydrogen peroxide but not superoxide anion produced by human neutrophils [17].
• Both HT and TYR transferred across human Caco-2 cell monolayers and rat segments of jejunum and ileum and were subject to classic phase I/II biotransformation [15].
• It was possible for the first time, to detect free 3,4-dihydroxyphenylglycol, free 3,4-dihydroxyphenylethanol and 3,4-dihydroxymandelic acid in a small volume (25 microliter) of blood plasma of man, rat, dog and rabbit [18].

Associations of Hydroxytyrosol with other chemical compounds

• This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure [19].
• Moreover, vitamin E and resveratrol counteracted CsA-induced changes in the glutathione redox state via different mechanisms, whereas hydroxytyrosol was completely ineffective [2].
• Resveratrol and hydroxytyrosol, unexpectedly, amplified peroxynitrite-dependent upregulation of Band 3 tyrosine phosphorylation through the activation of lyn, a kinase of the src family [20].
• Hydroxytyrosol showed a higher activity than the natural antioxidant rosmarinic acid in scavenging the DPPH model radical [21].
• We investigated the effect of hydroxytyrosol (HT), a phenolic compound from virgin olive oil, on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in J774 murine macrophages stimulated with lipopolysaccharide (LPS) [22].

Gene context of Hydroxytyrosol

• However, hydroxytyrosol administration decreased apolipoprotein A-I and increased total cholesterol, atherosclerotic lesion areas and circulating monocytes expressing Mac-1 [23].
• When ileostomy subjects were given oleuropein-glycoside, 16 mol/100 mol was recovered in 24-h urine, mainly in the form of hydroxytyrosol [10].
• Hydroxytyrosol, a natural molecule occurring in olive oil, induces cytochrome c-dependent apoptosis [24].
• Synthesis of the antioxidant hydroxytyrosol using tyrosinase as biocatalyst [25].
• Cancer chemoprevention by hydroxytyrosol isolated from virgin olive oil through G1 cell cycle arrest and apoptosis [26].

Analytical, diagnostic and therapeutic context of Hydroxytyrosol

• The oral administration of hydroxytyrosol to rats and its subsequent detection in plasma showed that the method is suitable for pharmacokinetic studies [27].
• Determination of hydroxytyrosol in plasma by HPLC [27].
• At concentrations ranging from 50 to 100 micromol/l, hydroxytyrosol induced an appreciable apoptosis in HL60 cells after 24 h of incubation as evidenced by flow cytometry, fluorescence microscopy and internucleosomal DNA fragmentation [26].
• The amount of hydroxytyrosol, increased on decreasing the flow rate of bioreactor in recycle approach, following a non-linear trend and obtaining the highest value at a flow rate of 15 ml h-1 while in the single step approach the 3,4-dihydroxy-phenylethanol was at its maximum at higher flow rate (16 ml h-1) [28].
• The minimum inhibitory concentrations (MICs) calculated in our study are evidence of the broad antimicrobial activity of hydroxytyrosol against these bacterial strains (MIC values between 0.24 and 7.85 microg mL(-1) for ATCC strains and between 0.97 and 31.25 microg mL(-1) for clinically isolated strains) [29].

References