Guggulsterone inhibits human cholangiocarcinoma Sk-ChA-1 and Mz-ChA-1 cell growth by inducing caspase-dependent apoptosis and downregulation of survivin and Bcl-2 expression - Zhong, F; Yang, J; Tong, Z T; Chen, L L; Fan, L L; Wang, F; Zha, X L; Li, J (Oncol Lett, 2015)