Dual effects of extra virgin olive oil in acute wounds.

Extra virgin olive oil (EVOO) has proved beneficial effects in skin wound healing of chronic lesions; however, the effects of EVOO in acute wounds are not completely understood. This study investigated the effects of short-term and long-term administration of a diet rich in EVOO on acute wound healing. To check this, mice were fed with a diet rich in EVOO for 1 week (short term), 1 month, or 3 months (long term). The control group received a standard diet. Mouse macrophages were treated in vitro with EVOO or hydroxytyrosol (HT), which is the main EVOO polyphenol. Short-term administration of an EVOO rich diet in vivo increased lipid peroxidation and mRNA levels of pro-inflammatory cytokine levels and impaired acute wound closure. In contrast, long-term administration of an EVOO rich diet resulted in increased mRNA levels of anti-inflammatory cytokines and enhanced acute wound closure. In both in vivo and in vitro assays, the administration of EVOO or HT resulted in a predominantly anti-inflammatory macrophage phenotype. In conclusion, a diet rich in EVOO has a positive effect on acute wound healing that is dependent on the duration of EVOO administration. Short-term EVOO diet supplementation increases oxidative damage and pro-inflammatory responses, which impaired acute wound closure. On the other hand, long-term EVOO supplementation reduces oxidative damage and enhances anti-inflammatory responses, which improved acute wound closure. The effects of EVOO on oxidation and inflammation in acute wounds are linked to the EVOO polyphenol HT.

Olive oil promotes the survival and migration of dermal fibroblasts through Nrf2 pathway activation.

Olive oil has beneficial effects on skin wound healing due to its anti-inflammatory and antioxidant properties; however, the mechanism by which olive oil promotes wound healing is unclear. We evaluated the mechanisms involved in Nrf2 pathway activation by olive oil and its role in cell survival and migration in mouse dermal fibroblasts in a short-term exposition. Our data demonstrated that olive oil and oleic acid promoted reactive oxygen species (ROS) production, while olive oil and hydroxytyrosol stimulated nuclear factor erythroid 2-related factor 2 (Nrf2) activation. Olive oil-mediated ROS production increased nuclear factor kappa B p65 expression, while olive oil-stimulated reactive nitrogen species production augmented the levels of Nrf2. Olive oil augmented cell proliferation, cell migration, and AKT phosphorylation, but decreased apoptotic cell number and cleaved caspase-3 levels. The effect of olive oil on cell migration and protein levels of AKT, BCL-2, and Nrf2 were reversed by an Nrf2 inhibitor. In conclusion, the activation of the Nrf2 pathway by olive oil promotes the survival and migration of dermal fibroblasts that are essential for the resolution of skin wound healing.