Molecular Mechanisms Responsible for In Vitro Cytotoxic Attributes of Conyza bonariensis Extract against Lymphoblastic Leukaemia Jurkat Cells

Abstract

Background: Conyza bonariensis is known to have anti-cancer properties.

Objective: The current study investigated the in vitro pro-apoptotic properties of Conyza bonariensis (C. bonariensis) towards human lymphoblastic leukemia Jurkat cells.

Methods: Ariel parts of C. bonariensis were macerated in a non-polar (n-Hexane) solvent. MTS cell viability assay was employed to determine the cytotoxic activity of the extract towards human leukemia Jurket cells and normal Peripheral Blood Mononuclear Cells (PBMCs). The phytochemical composition of the extract was screened using HPLC method. Flow cytometric studies (FACS) were conducted to explore the pro-apoptotic potential of the extract. Western blot studies were employed to identify the molecular targets involved in the induction of apoptosis.

Results: The n-hexane extract showed selective cytotoxic activity towards Jurkat cells. FACS analysis indicated that the extract induced early and late apoptosis in Jurkat cells. Western blot studies revealed that the extract downregulated the expression of DNMT1, SIRT1, and UHRF1 with a simultaneous up-regulation of p73 and caspases-3 proteins expression. HPLC characterization of the extract revealed the presence of phenolic compounds.

Conclusion: Overall, these findings demonstrate that the anti-cancer effects of a Conyza bonariensis extract towards human lymphoblastic leukemia Jurkat cells are due to the modulation of the activity of multiple oncogenic and tumor suppressor proteins. Phenolic contents of the extract are proposed to be responsible for these activities.

Keywords: Conyza bonariensis; Jurkat cells; flow-cytometry; peripheral blood mononuclear cells; phenolic contents; pro-apoptotic.