Antioxidant and anti-inflammatory effects of PUFA-Rich marine oils: application to the ocular surface
Résumé
The cornea is susceptible to attack by reactive oxygen species (ROS), which may be generated through direct attack by UV light or indirectly through formation of toxic compounds or inflammation. The aim of this work was to study the modulation of oxidative stress and inflammation in cornea using polyunsaturated fatty acids (PUFA)-rich marine oils. First, rats were fed with different PUFA-rich oils by gavage during 28 days: microalgae DHA, fish EPAX 1050 (rich in EPA and DHA) and fish EPAX 6000 (rich in EPA). Fatty acids composition of corneal cell membranes was analysed by chromatography. Second, human corneal epithelial cells (HCE-T cell line) were exposed to different PUFA-rich marine oils (EPA and DHA) for 15 minutes, followed by a 24-hour recovery period. Oxidative stress and inflammation were chemically induced with tert-butylhydroperoxide (tBHP) and sodium dodecyl sulphate (SDS) for 1 hour and 20 minutes, respectively. Cell viability and reactive oxygen species were quantified with neutral red and DCFH-DA using cytofluorometry. IL-6 and IL-8 proteins levels from HCE supernatants were evaluated using enzyme-linked immunosorbent assay. Dietary oils changed the fatty acids composition of corneal cell membranes, indicating that per os administered fatty acids are able to reach the cornea. In vitro incubation of corneal cells with marine oils rich in EPA and DHA resulted in a decrease in tBHP-induced ROS overproduction and a decrease in SDS-induced IL-6 and IL-8 secretions. Conclusions: : Nutritional supplements rich in marine DHA and EPA could be prescribed as ocular treatment: they can target the cornea and prevent ocular surface pathologies implicating oxidative stress and/or inflammation, such as ocular dryness.