Anti-inflammatory effects of maslinic acid, a natural triterpene, in cultured cortical astrocytes via suppression of nuclear factor-kappa B

Maslinic acid (2-α, 3-β-dihydroxyolean-12-en-28-oic acid) is a natural triterpenoid compound from Olea europaea. This compound prevents oxidative stress and pro-inflammatory cytokine generation in vitro. This study was planned to investigate the anti-inflammatory effects of maslinic acid in central nervous system by using rat astrocyte cultures stimulated with lipopolysaccharide (LPS). We evaluated different proteins implicated in the nuclear factor kappa B (NF-κB) signal transducer pathway employing Western blot and quantitative real time PCR techniques. Results demonstrated that maslinic acid treatment exerted potent anti-inflammatory action by inhibiting the production of Nitric Oxide and tumor necrosis factor alpha (TNF-α). Western blot analysis showed that maslinic acid treatment attenuated LPS-induced translocation of NF-κB p65 subunit to the nucleus and prevented LPS-induced IκBα phosphorylation in a concentration-dependent manner, Moreover, maslinic acid significantly suppressed the expression of cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) at protein and mRNA levels. These results suggest that maslinic acid can potentially reduce neuroinflammation by inhibiting NF-κB signal transducer pathway in cultured cortical astrocytes.