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.

Acacetin‐induced cell apoptosis in head and neck squamous cell carcinoma cells: Evidence for the role of muscarinic M3 receptor

“…Acacetin has also been reported an inhibitory effect against suspension cells, such as chronic lymphocytic leukemia (CLL) cells. Acacetin treated for 48 hr differentially decreased the viability of CLL B‐lymphocytes, and 10 μM acacetin inhibited about 50% viability (Salimi et al, ). Although without providing exact IC 50 value, acacetin has also been reported to inhibit cell growth in other cancer cell lines.…”

“…Cells treated with 25 μM of acacetin for a period of 24 hr showed typical morphological changes of apoptosis. In terms of inducing early apoptosis, 60 μM acacetin treated for 24 hr in human gastric carcinoma cells (Pan et al, ),10–20 mg/mL (37–70 μM) acacetin treated for 24 hr in HepG2 cells (Hsu, Kuo, & Lin, ), 5–10 μM acacetin treated for 12 and 24 hr in A549 cells (Hsu, Kuo, Liu, & Lin, ),and 10 μM acacetin treated for 12–24 hr in CLL B‐lymphocytes (Salimi et al, ) have been reported. Together, for most cancer cells, 10–60 μM acacetin treatment lead to varying degree of cell growth inhibition and cell apoptosis.…”

“…In terms of inducing early apoptosis, 60 μM acacetin treated for 24 hr in human gastric carcinoma cells (Pan et al, 2005),10-20 mg/ mL (37-70 μM) acacetin treated for 24 hr in HepG2 cells , 5-10 μM acacetin treated for 12 and 24 hr in A549 cells (Hsu, Kuo, Liu, & Lin, 2004),and 10 μM acacetin treated for 12-24 hr in CLL B-lymphocytes (Salimi et al, 2016) have been reported.…”

Calcitriol Reduces Adverse Effects of Diclofenac on Mitochondrial Function in Isolated Rat Heart Mitochondria

“…After 1 h 0.4 % MTT was added to the medium and incubated at 37 °C for 30 min. The purple formazan crystals were dissolved in DMSO and the absorbance was measured at 570 nm with an ELISA reader (BioTek, USA) [20].…”

“…The mitochondrial H 2 O 2 production was measured by flowcytometry (Cyflow Space-Partec, Germany) after 1 h. Mitochondria were read on the FL1 channel of flowcytometry and mean of fluorescence intensities were compared between groups. Hydrogen peroxide (H 2 O 2 ) was used as a positive control (100 µM) [20].…”