Chrysophanol exhibits anti-cancer activities in lung cancer cell through regulating ROS/HIF-1a/VEGF signaling pathway

In the present study, we explored the anti-tumor and anti-angiogenesis effects of chrysophanol, and to investigate the underlying mechanism of the chrysophanol on anti-tumor and anti-angiogenesis in human lung cancer. The viability of cells was measured by CCK-8 assay, cell apoptosis was measured by Annexin-FITC/PI staining assay, and the cell migration and invasion were analyzed by wound-healing assay and transwell assay. ROS generation and mitochondrial membrane potential were analyzed by DCFH-DA probe and mitochondrial staining kit. Angiogenesis was analyzed by tube formation assay. The expression of CD31 was analyzed by immunofluorescence. The levels of proteins were measured by western blot assay. The anti-tumor effects of chrysophanol in vivo were detected by established xenograft mice model. In this study, we found that the cell proliferation, migration, invasion, tube formation, the mitochondrial membrane potential, and the expression of CD31 were inhibited by chrysophanol in a dose-dependent manner, but cell apoptotic ratios and ROS levels were increased by chrysophanol in a dose-dependent manner. Furthermore, the effects of chrysophanol on A549, H738, and HUVEC cell apoptotic rates were reversed by the ROS inhibitor NAC. Besides, the effects of chrysophanol on HUVEC cell tube formation were reversed by the HIF-1α inhibitor KC7F2 and the VEGF inhibitor axitinib in vitro. Moreover, tumor growth was reduced by chrysophanol, and the expression of CD31, CD34, and angiogenin was suppressed by chrysophanol in vivo. Our finding demonstrated that chrysophanol is a highly effective and low-toxic drug for inhibition of tumor growth especially in high vascularized lung cancer.