engleski

Pre-exposure to olive oil polyphenols extract stimulates liver regeneration in mice via stress sensitive genes

Several studies addressing the role of polyphenols in tissue repair attributed wound healing potential of these compounds to their antioxidant capacity based on the observation that reactive oxygen species (ROS), produced in response to tissue injury, impede or exacerbate the healing process. We investigated the effect of pre-exposure with the olive oil polyphenols extract (PFE) on the course of liver regeneration induced by one-thirds hepatectomy (pH) – a process during which ROS account for the early signals involved in the initiation of tissue mass restoration. Prior to pH mice were administered PFE (50 mg/kg bwt ; i.p.) or saline during seven consecutive days, while controls received vehicle alone. Stress sensitive gene expression profile along with the oxidant and electrophilic load, involving hepatic glutathione, lipid peroxidation (LP) and serum α-glutathione S-transferase (GSTα) level was determined at different time intervals after pH. A calculated relative liver weight was used to assess the liver mass restoration. Although regenerating liver itself exhibited intrinsic metabolic load, pre-treatment with PFE increased LP and GSTα level and promoted glutathione depletion within the first three hours after pH, pointing to the increase in oxidant and electrophilic load during the early phase of the liver regeneration. These changes were accompanied by the adaptive stress response induction, as indicated by the Nrf2, heme oxygenase-1 and γ-glutamylcystein synthetase gene upregulation, leading to the normalization of parameters of oxidative stress, reduced detoxification demands and recovery of glutathione status, with the final outcome in increased liver mass recovery. Pre-exposure to polyphenols extract increases oxidant and electrophilic load and induces endogenous defense mechanism under the control of stress response gene-profiles, thereby stimulating the development of liver regeneration in a model of a minor tissue loss.

olive oil polyphenols; stress-response genes; oxidant/electrophilic load; partial hepatectomy

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