Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hydroxytyrosol [3,4-dihydroxyphenylethanol (3,4-DHPEA)], a phenolic compound found exclusively in olive oil, exerts growth-suppressive and pro-apoptotic effects on different cancer cells. Although some molecular mechanisms involved in the pro-apoptotic activity of 3,4-DHPEA have been proposed, the initial stress signals responsible of this phenomenon are not known. Our aim was to assess the involvement of reactive oxygen species as mediators of apoptosis induced by 3,4-DHPEA on HL60 cells. Apoptosis was determined by analyzing the nuclear fragmentation by both fluorescence microscopy and flow cytometry. The externalization of phosphatidylserine was evidenced using an Annexin V-FITC kit. The concentration of H(2)O(2) in the culture medium was measured by the ferrous ion oxidation-xylenol orange method. The pro-apoptotic effect of 3,4-DHPEA (100 muM) was prevented by N-acetyl-cysteine, ascorbate, and alpha-tocopherol. Catalase suppressed the 3,4-DHPEA-induced apoptosis, while the Fe(II)-chelating reagent o-phenantroline showed no effect, suggesting the involvement of H(2)O(2 )but not of OH(*). Indeed, 3,4-DHPEA caused accumulation of H(2)O(2) in the culture medium. Tyrosol (p-hydroxyphenylethanol) and caffeic acid, compounds structurally similar to 3,4-DHPEA but not able to generate H(2)O(2), did not induce an appreciable apoptotic effect. This is the first study demonstrating that apoptosis induction by 3,4-DHPEA is mediated by the extracellular production of H(2)O(2).
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PMID:Production of hydrogen peroxide is responsible for the induction of apoptosis by hydroxytyrosol on HL60 cells. 1953 71

Reactive oxygen species are critically involved in the endothelial dysfunction that contributes to atherosclerosis development. Hydroxytyrosol (HT), a main phenolic compound in olive oil and leaves from Olea europaea L., has antiatherogenic properties with powerful antioxidant activity. The present study verifies the antioxidant activity of HT on H2O2-induced intracellular reactive oxygen species in porcine pulmonary artery endothelial cells (VECs) and the involved molecular mechanisms. Incubation of VECs with HT prevented the increase in intracellular reactive oxygen species levels in the presence of H2O2. HT increased catalase mRNA, protein and activity. Catalase siRNA suppressed HT-dependent reduction of intracellular reactive oxygen species. HT increased both cytosolic and nuclear protein levels of forkhead transcription factor 3a (FOXO3a), as well as the phosphorylation of AMP-activated protein kinase (AMPK) that translocates FOXO3a to the nucleus. AMPK siRNA and a specific inhibitor suppressed HT-induced FOXO3a upregulation and catalase expression. Moreover, FOXO3a siRNA blocked HT-dependent increase in catalase expression. Taken together, our findings strongly demonstrate that HT positively regulates the antioxidant defense system in VECs by inducing the phosphorylation of AMPK with subsequent activation of FOXO3a and catalase expression, and provides a molecular basis for the prevention of cardiovascular diseases by HT.
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PMID:Hydroxytyrosol reduces intracellular reactive oxygen species levels in vascular endothelial cells by upregulating catalase expression through the AMPK-FOXO3a pathway. 2149 91