Annona cherimola Seed Extract Activates Extrinsic and Intrinsic Apoptotic Pathways in Leukemic Cells By Peter Nasr A thesis

Abstract

Annona cherimola Mill is a large green fruit with black seeds widely known to possess toxic properties due to the presence of Annonaceous acetogenins. The present study investigates the anti-cancer properties of an A. cherimola Mill ethanolic seed extract on Acute Myeloid Leukemia (AML) cell lines in vitro and elucidates the underlying cellular mechanism. The antiproliferative effects of the extract on various AML cell lines and normal mesenchymal cells (MSCs) were assessed using WST-1 viability reagent. The pro-apoptotic effect of the extract was evaluated using Annexin V/PI staining and Cell Death ELISA. The underlying mechanism was deciphered by analyzing the expression of various proteins using western blots. Treatment with an A. cherimola seed ethanolic extract promotes a dose- and time-dependent inhibition of the proliferation of various AML cell lines, but not MSCs. Positive Annexin V staining, as well as DNA fragmentation, confirm an increase in apoptotic cell death by upregulating the expression of pro-apoptotic proteins which control both intrinsic and extrinsic pathways of apoptosis. GC/MS analysis revealed the presence of phytosterols, in addition to other bioactive compounds. In conclusion, A. cherimola seed extract, previously known to possess a potent toxic activity, induces apoptosis in AML cell lines by the activation of both the extrinsic and the intrinsic pathways.