H2O2 oxidative activity: modulatory effect of hydroxytyrosol

INCANI, ALESSANDRA;DEIANA, MONICA;Atzeri A;Loru D;Melis MP;ROSA, ANTONELLA;Cabboi B;Dessi MA

2012-01-01

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Abstract

Hydroxytyrosol (HT) is the major o-diphenol present in extra-virgin olive oil, either in free or esterified form, once absorbed, is present in high amount in the kidney, where it may exert a proctetive action. In this study we monitored the ability of HT to protect renal cells (LLC-PK1) against oxidative damage induced by H2O2. The peroxidation of lipid represents a primary consequences of cellular oxidative stress, leading to biophysical changes that disrupt membrane and organelle function; moreover oxidative stress is a process that may stimulate cellular signalling pathways, usually associated with the promotion of cellular death. HT exerted a significant antioxidant action, inhibiting the production of fatty acids hydroperoxides and 7-ketocholesterol induced by H2O2 treatment and thus preserving the membrane lipids. It has been shown that oxidative stress in LLC-PK1 cells is related also to the changes in the phosphorylation state of pro-death signalling pathways ERK1/2 and the pro-survival signalling Akt/PKB. Pretreatment with HT is able to modulate H2O2-induced changes in the phosphorylation state of ERK1/2 and Akt/PKB. We suggest that one potential protective mechanism of olive oil polyphenols in kidney cells may be attributed to interactions with intracellular signalling pathways activated in response to oxidative stress.