title: Cucurbitacin IIa induces caspase-3-dependent apoptosis and enhances autophagy in lipopolysaccharide-stimulated RAW 264.7 macrophages.
abstract: Cucurbitacin IIa (CuIIa), a member of cucurbitacin family, is isolated from the root of Hemsleya amabilis which has been used as an ancient remedy for bacillary dysentery and gastroenteritis. The anti-inflammatory properties of CuIIa have long been recognized but the underlying mechanism is largely unknown. In this study, we investigated the anti-inflammatory effect of CuIIa on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The results showed that CuIIa inhibited the proliferation and migration of RAW 264.7 cells in a dose-dependent manner. Whereas CuIIa did not cause apoptosis in unstimulated RAW 264.7 cells, it did induce a significant apoptosis in LPS-stimulated cells, which was caspase-3-dependent and associated with downregulation of survivin. Furthermore, LPS induced autophagy in RAW 264.7 cells and this effect was further enhanced by CuIIa as evidenced by increased levels of LC3-II conjugates and formation of LC3 puncta. In addition, CuIIa disrupted actin cytoskeleton via inducing actin aggregation. However, neither the synthesis of tumor necrosis factor-α, nor the activation of the mitogen-activated protein kinases and NF-κB pathways in LPS-stimulated cells was suppressed by CuIIa treatment. Collectively, these results suggested that induction of apoptosis and enhancement of autophagy contributed to the anti-inflammatory activity of CuIIa against inflammation-related diseases.
authors.affiliation: Department of Immunobiology, Institute of Tissue Transplantation and Immunology, College of Life Science and Technology, Jinan University, Guangzhou 510630, China.
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.forename: Li-hui
authors.initials: LH
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Qiao
authors.forename: Dong-yun
authors.initials: DY
authors.lastname: Ouyang
authors.forename: Xian-hui
authors.initials: XH
authors.lastname: He
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D053148:Caspase 3; D002460:Cell Line; D054728:Cucurbitacins / Q000494:pharmacology*; D008070:Lipopolysaccharides; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; C557526:cucurbitacin IIa; D054728:Cucurbitacins; D020928:Mitogen-Activated Protein Kinases; D053148:Caspase 3