Selective Anticancer Activity of Acacetin Against Chronic Lymphocytic Leukemia Using Both In Vivo and In Vitro Methods: Key Role of Oxidative Stress and Cancerous Mitochondria

ABSTRACT

The present study investigates the in vitro and in vivo effect of acacetin (4'-methoxy-5,7-dihydroxyflavone) on chronic lymphocytic leukemia (CLL) B-lymphocytes and mitochondria. CLL B-lymphocytes and healthy B-lymphocytes were obtained from CLL patients and healthy donors, respectively. Mitochondria were isolated from B-lymphocytes of both groups. Xenografts in severe combined immune deficient mice were used to examine the toxicity and anti CLL activity of acacetin. We evaluated and compared the mechanism of action of acacetin on CLL and healthy B-lymphocytes and their mitochondria. We have found that acacetin (10 μM) can selectively induce apoptosis on CLL B-lymphocyte (25% at 24 h) by directly targeting mitochondria, through increased reactive oxygen species (ROS) formation, MMP collapse, MPT, release of cytochrome c, caspase 3 activation, and finally apoptosis, while sparing normal healthy B-lymphocytes unaffected at similar concentrations. Besides, oral administration of acacetin showed a potent in vivo anticancer activity in CLL xenograft mouse models. Our in vivo findings indicate that acacetin accumulates and kills CLL B-lymphocyte in a rather selective way through targeting cancerous mitochondria and ROS formation, which ends in CLL therapy. Finally, we can recommend acacetin as a promising compound for further drug development assays for the CLL treatment.

Acknowledgments

The data provided in this article were extracted from the Ph.D. thesis of Dr. Ahmad Salimi. The thesis was conducted under the supervision of Prof. Jalal Pourahmad at the Department of Toxicology and Pharmacology, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. This study was supported by the Shahid Beheshti University of Medical Sciences, Deputy of Research, and grant number (1392-1-132-1183).