Involvement of Hydrogen Peroxide Formation on Apoptosis Induction by Olive Oil Phenolic Compounds

Abstract

Abstract:In the present investigation the ability of different phenolic compounds, either present or not in olive oil, to induce both apoptosis on tumour cells and H 2 O 2 accumulation in cell culture medium was assesed. Among the phenols studied we found that tyrosol (p-HPEA), homovanillic alcohol and protocatechuic, o-coumaric, vanillic, homovanillic, ferulic and syringic acids did not induce either apoptosis on HL60 cells or H 2 O 2 accumulation, while hydroxytyrosol (3,4-DHPEA), 3,4-dihydroxyphenylacetic acid (3,4-DHPA), 3,4-dihydroxy-hydrocinnamic acid (3,4-DHHC) and gallic acid induced both apoptosis and accumulation of H 2 O 2 in the culture medium which were significantly reduced by catalase. In contrast, the dialdehydic form of elenoic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and to tyrosol (p-DHPEA-EDA) induced high level of apoptosis not reduced by catalase. Finally, oleuropein exerted a weak pro-apoptotic effect not mediated by H 2 O 2 release. From these results it is evident that: (i) the cathecol moiety of phenols is necessary but not sufficient to induce apoptosis and H 2 O 2 accumulation; (ii) the 3,4-DHPEA metabolism may partially reduce its pro-apoptotic potential; (iii) the pro-apoptotic activity of 3,4-DHPEA-EDA and p-DHPEA-EDA is not mediated by H 2 O 2 releasing activity.

Cancer Prevention and Health Benefices of Traditionally Consumed Borago officinalis Plants

“…The lack of cytotoxicity in HL-60 experiments that we have found for SY is in accordance with previous determination that indicated no cytotoxic effect of SY in extracts of Elaphomyces granulates at concentrations up to ~31 µg·mL −1 using this cell line [ 65 ]. Moreover, Fabiani et al [ 66 ] found that SY did not induce apoptosis in HL-60 cell when is applied to the cell medium at a concentration of 0.1 mM. It has been reported that SI biotransformation by plant peroxidases results in an anticarcinogenic effect from its derivates in HL-60 cells [ 67 ].…”

Potencial antitumoral dos compostos fenólicos de produtos da oliveira (Olea europaea L.): uma revisão integrativa da literatura

“…A partir dos dados obtidos, os autores sugeriram que a porção catecol dos fenóis é necessária, mas não suficiente para induzir a apoptose e a acumulação de H2O2. Além disso, o metabolismo do hidroxitirosol pode reduzir parcialmente seu potencial pró-apoptótico e a atividade pró-apoptótica da forma dialdeídica do ácido elenólico ligada ao hidroxitirosol e ao tirosol não é mediada pela atividade de liberação de H2O2 (Fabiani et al, 2009b). Somado a isso, os compostos fenólicos possuem potentes capacidades antioxidantes e anti-inflamatórias, além dos efeitos anticarcinogênicos utilizando a linhagem celular HL60, tratadas com diferentes componentes do azeite para avaliar as propriedades antitumorigênica dos fenóis na proliferação, apoptose e diferenciação.…”