Uvangoletin induces mitochondria-mediated apoptosis in HL-60 cells in vitro and in vivo without adverse reactions of myelosuppression, leucopenia and gastrointestinal tract disturbances

This study investigated the cytotoxic effect of uvangoletin on HL-60 cells, and the effects of uvangoletin on myelosuppression, leucopenia, gastrointestinal tract disturbances and the possible cytotoxic mechanisms by using CCK-8, flow cytometry, western blot, xenograft, cyclophosphamide-induced leucopenia, copper sulfate-induced emesis and ethanol-induced gastric mucosal lesions assays. The results of CCK-8, flow cytometry and western blot assays indicated that uvangoletin showed the cytotoxic effect on HL-60 cells and induced the apoptosis of HL-60 cells by downregulating the expression levels of anti-apoptotic proteins (Survivin, Bcl-xl and Bcl-2), upregulating the expression levels of pro-apoptotic proteins (Smac, Bax, Bad, c-caspase-3 and c-caspase-9), and promoting the release of cytochrome c from mitochondria to cytoplasm. Further, the results of xenograft assay suggested that uvangoletin inhibited the HL-60-induced tumor growth without adverse effect on body weight of nude mice in vivo by regulating the expression levels of above apoptotic proteins. The results indicated that the reductions of WBCs count and thighbone marrow granulocytes percentage in cyclophosphamide-induced leucopenia assay, the incubation period and number of emesis in copper sulfate-induced emesis assay and the gastric mucosal lesions in ethanol-induced gastric mucosal lesions assay were not exacerbated or reversed by uvangoletin. In conclusion, the research preliminarily indicated that uvangoletin induced apoptosis of HL-60 cells in vitro and in vivo without adverse reactions of myelosuppression, leucopenia and gastrointestinal tract disturbances, and the pro-apoptotic mechanisms may be related to mitochondria-mediated apoptotic pathway.