Anti-inflammatory activities of Olea europaea extracts from Jeju Island on LPS-induced RAW 264.7 cells

Lipopolysaccharide (LPS)-induced activation of murine RAW 264.7 cells results in the production of pro-inflammatory cytokines including PGE2, IL-6, TNF-α, and IL-1β. In this study, we investigated the anti-inflammatory effects of the Olea europaea extract from Jeju island using LPS which induces an inflammatory response. To examine the potential anti-inflammatory properties of the Olea europaea extract, we measured the amount of nitric oxide (NO), prostaglandin E2(PGE2), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β on RAW 264.7 cells after the Olea europaea extract treatment. The Olea europaea extracts showed higher anti-inflammatory activity by inhibiting the production of PGE2, NO, TNF-α, IL-6, and IL-1β induced by LPS stimulation in RAW 264.7 cells. Also, Olea europaea extracts decreased mRNA expression of iNOS, and COX-2. There was no cytotoxicity in the macrophage proliferation treated with the Olea europaea extract compared to the control in the LDH assay. These results suggest that the Olea europaea extract may exert significant effects on inflammatory factors and be a potential source as a new natural anti-inflammatory agent. Further investigations will focus on cell-based in vitro assays and in chemically identifying the major active components mediating the anti-aging and anti-inflammation responses.