In vitro and in vivo anticancer effects of marmesin in U937 human leukemia cells are mediated via mitochondrial-mediated apoptosis, cell cycle arrest, and inhibition of cancer cell migration.

Leukemia is one of the highly lethal cancers among all pediatric cancers. With limited drug options and the severe side effects associated with the current chemotherapy, there is pressing need to look for new and novel anticancer agents. Against this backdrop, in the present study we evaluated the anticancer activity of a natural coumarin, marmesin against human leukemia cell line U937 and normal human monocytes It was observed that marmesin exhibited an IC50 value of 40 µM and exerted its cytotoxic effects in a dose-dependent manner. However, the cytotoxic effects of marmesin were comparatively lower for the normal human monocytes as evident from the IC50 of 125 µM. Our results indicated that marmesin inhibits colony formation and induces apoptosis dose-dependently. We also investigated the effect of marmesin on the expression of Bax and Bcl-2 proteins. It was observed that marmesin treatment triggered upregulation of Bax and downregulation of Bcl-2 causing significant increase in the Bax/Bcl-2 ratio, marmesin could also induce ROS mediated alterations in mitochondrial membrane potential. Additionally, marmesin induced G2/M cell cycle arrest and significantly inhibited cell migration potential of leukemia cells at the IC50. Remarkably, marmesin prevent tumor growth significantly in vivo at the dosage of 30 mg/kg in vivo. These results strongly indicate that marmesin may prove to be a novel anticancer lead for the management of leukemia.