β-diketone-cobalt complexes inhibit DNA synthesis and induce S-phase arrest in rat C6 glioma cells

β-diketone-cobalt complexes, a family of newly synthesized non-platinum metal compounds, exhibit potential antitumor activity; however, the antitumor mechanism is unclear. The current study investigated the mechanism by which β-diketone-cobalt complexes inhibit rat C6 glioma cell proliferation. It was found that β-diketone-cobalt complexes suppress rat C6 glioma cell viability in a dose-dependent manner (3.125–100 μg/ml). In rat C6 glioma cells, the IC(50) value of β-diketone-cobalt complexes was 24.7±3.395 μg/ml and the IC(10) value was 4.37±1.53 μg/ml, indicating a strong inhibitory effect. Further investigation suggested that β-diketone-cobalt complexes inhibit rat C6 glioma cell proliferation, which is associated with S-phase arrest and DNA synthesis inhibition. During this process, β-diketone-cobalt complexes decreased cyclin A expression and increased cyclin E and p21 expression. In addition, β-diketone-cobalt complexes exhibit a stronger antitumor capability than the antineoplastic agent, 5-fluorouracil.