Anti-Irritant and Anti-Inflammatory Effects of DHA Encapsulated in Resveratrol-Based Solid Lipid Nanoparticles in Human Keratinocytes

We recently found that the dietary long chain omega-3 polyunsaturated fatty acid (LC-omega-3 PUFA), docosahexaenoic acid (DHA), showed enhanced antineoplastic activity against colon cancer cells if encapsulated in resveratrol-based solid lipid nanoparticles (RV-SLNs). In the present study, we investigated whether the DHA enclosed in RV-SLNs (DHA-RV-SLNs) could have the potential of attenuating irritation and inflammation caused by environmental factors at the skin level. To this aim, we used two keratinocyte lines (HaCaT and NCTC 2544 cells) and exposed them to the cytotoxic action of the surfactant, sodium dodecyl sulfate (SDS), as an in vitro model of irritation, or to the pro-inflammatory activity of the cytokine TNF-alpha. We found that DHA enclosed in RV-SLNs significantly enhanced its ability to contrast the cytotoxic effect of SDS and to inhibit the SDS- and TNF-alpha-induced production of the inflammatory cytokines IL-1 beta, IL-6, and 1 MCP-1, in the two keratinocyte cell lines, as well as the NLRP3 inflammasome activation. Moreover, it more efficiently reduced the upsurge of reactive oxygen species (ROS) levels obtained in the presence of a pro-oxidant (H2O2). Overall, our findings suggest the possibility that a sustained dietary supplementation with DHA-RV-SLNs could efficiently protect skin from the pro-irritant and pro-inflammatory activity of environmental attacks.