Involvement of Mitochondrial Damage and Oxidative Stress in Apoptosis Induced by Betulin Plus Arsenic Trioxide in Neuroblastoma Cells.

BACKGROUND/AIM: Arsenic trioxide (AsO), a potent toxin in traditional Chinese medicine, has been utilized as an anticancer agent in Chinese culture for over a millennium. Betulin, commonly extracted from the bark of birch trees, has been identified for its pharmacological properties, including antibacterial, anti-inflammatory, antitumor, and antiviral activities. The aim of this study was to determine the efficacy and underlying anticancer signaling cascade induced by AsO and betulin in neuroblastoma cells.

MATERIALS AND METHODS

SK-N-SH cells were treated with AsO with or without betulin. Cell viability and apoptotic signaling were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, measurement of mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS), and quantitative western blotting analysis. Student's t-test in addition to one- or two-way analysis of variance was used to examine significant differences between comparison groups.

RESULTS

The combined treatment of AsO plus betulin was more effective than single treatments in suppressing cell viability and induction of apoptosis, which correlated well with elevated ROS levels. The apoptotic signaling cascade of AsO plus betulin was revealed as ROS elevation and relative loss of MMP, leading to the cleavage of caspase-3 and -9. AsO plus betulin treatment also reduced the expression of BCL2 apoptosis regulator, BH3-interacting domain death agonist, and BCL2-like-1.

CONCLUSION

The novel combination of AsO plus betulin has the potential to serve as a practical anti-neuroblastoma drug.