The ability of supercritical CO2 carrot and pumpkin extracts to counteract inflammation and oxidative stress in RAW 264.7 macrophages stimulated with LPS or MDA-MB-231 cell-conditioned media

Supercritical fluid extraction with CO2 (SFE) is an alternative technology to conventional solvent extraction(CSE), to obtain food-grade bioactives from plants. Here, SFE and CSE extracts from carrot and pumpkinmatrices, impregnated with hempseed or flaxseed oil as co-solvents, were characterized by HPLC andGC-MS, and their ability to counteract the inflammatory and oxidative phenomena underlying the onsetof several pathologies was assessed in vitro. All extracts showed dose-dependent anti-inflammatorypotential and demonstrated an ability to interfere with the pro-inflammatory effects of breast cancer cellconditioned media, and to inhibit reactive oxygen species (ROS) accumulation and nitrite production (NP)in lipopolysaccharide-stimulated macrophages. Nuclear factor-erythroid-2-related factor 2 (Nrf2) isinvolved in these response mechanisms, as highlighted by the increased mRNA levels of its target genesrevealed by quantitative real-time PCR analyses. NP and ROS concentrations negatively correlated with?-tocopherol and most carotenoids, but positively with the total tocopherol/total carotenoid ratio,suggesting an idiosyncratic effect ofof these bioactives on cell responses and emphasizing the need tofocus on extract constituents' interactions