Apoptosis Induced by (+)-Betulin Through NF-κB Inhibition in MDA-MB-231 Breast Cancer Cells

Background/Aim: This study aimed to uncover the effects of (+)-betulin on the NF-kappa B-apoptotic pathway in MDA-MB-231 cells, and determine its toxicity and protein expression in vivo. Materials and Methods: Cell cytotoxicity and toxicity were determined using the SRB assay and a zebrafish model, respectively. Western blot, mitochondrial transmembrane potential (MTP), and computational modeling analysis were performed. Results: (+)-betulin inhibited the growth of MDA-MB-231 cells, but did not induce toxicity in zebrafish. (+)-Betulin inhibited the activity of NF-kappa B p65 in silico and in vitro. In cells, (+)-betulin down-regulated NF-kappa B p50 and 65, IKK alpha and beta, ICAM-1 and bcl-2 expressions. Cell co-treatment with (+)-betulin and TNF alpha increased the (+)-betulin cytotoxic potential. Moreover, (+)-betulin induced the loss of MTP. Furthermore, (+)-betulin, in zebrafish, down-regulated the expression of NF-kappa B p65, IKK alpha, IKK beta and procaspase-3. Conclusion: The results contribute to the understanding of the mode of action on apoptosis induction by inhibiting NF-kappa B pathway in MDA-MB-231 cells.