ABSTRACT
Objective To investigate the anti-inflammatory effect of Cucurbitacin B on the inflammatory reaction of murine alveolar macrophages induced by lipopolysaccharide and its molecular mechanism. Methods The alveolar macrophages were randomly divided into five groups: blank group, LPS group, different concentrations of Cucurbitacin B (1μM, 2.5μM, 5μM)+) +LPS groups. All group cells were pretreated with different concentrations for 2 h, and followed by 1μg/mL LPS. The protein level of TNF-α, IL-1β, IL-6 and PGE2 were detected by ELISA assay, and the NO was detected by Griess methods, and its upstream protein i-NOS,COX-2, Nrf2 and HO-1 were detected by Western-blot. Results The secretion of TNF-α, IL-1β, IL-6 and PGE2 in LPS group were increased significantly than blank groups, while Cucurbitacin B suppressed its protein level inadose-dependent manner. The nuclear erythroid related factor 2 and antioxidant gene were activated while Cucurbitacin B was added into alveolar macrophages in adose-dependent manner. Conclusion Cucurbitacin B can inhibit the extracellar secretion of inflammatory cytokines production, and its molecular mechanism could be due to the promoting Nrf2 translocation to the nucleus, activating the expression of HO-1 gene, reducing the expression of iNOS and COX-2, and thereby alleviating the inflammatory reaction.
