Magnolol affects expression of IGF-1 and associated binding proteins in human prostate cancer cells in vitro

This study investigated the effects of magnolol, a compound from Magnolia officinalis, on the behavior of LNCaP and PC3 human prostate cancer cells in vitro. Materials and Methods: In vitro cell culture approach with biochemical tests and Western blot analyses was used. Results: Magnolol, (80 μM, 6 hour exposure) was found to affect the expression of insulin-like growth factor-1 (IGF-1) and associated proteins. In both cell lines, protein expression of IGF-1 and insulin-like growth factor binding protein-5 (IGFBP-5) were significantly decreased, while protein expression of IGFBP-3 was significantly increased. Additionally, protein expression of insulin-like growth factor-1 receptor (IGF-1R) was significantly increased and the phosphorylated form of IGF-1 (p-IGF-1R) was significantly decreased in PC3 cells, while IGFBP-4 protein expression was significantly increased in LNCaP cells. Conclusion: This study has demonstrated for the first time that magnolol can alter the expression of IGF-1 and associated proteins in human prostate cancer cells in vitro and suggests that magnolol may have a potential role as a novel anti-prostate cancer agent.