Mitochondrial Pro-Apoptotic Properties of Sinularia compressa from Persian Gulf against Breast Cancer Cells and Its Chemical Composition

Locals in the Persian Gulf islands traditionally use Sinularia compressa to treat cancer. Therefore, this study deals with the cytotoxic activity of the soft coral Sinularia compressa chloroform extract (SCE), its pro-apoptotic activity, and the determination of its secondary metabolites. Cytotoxicity was done against MCF-7 and MDA-MB-231 and MCF‑10A cells. Apoptosis induction was checked by flow cytometry. The DCFDA and JC‐1 probes were used to assess the production of reactive oxygen species (ROS) and the mitochondrial transmembrane potential. Caspase-9, Bax, and Bcl-2 proteins were determined with ELISA Kit, and by western blot analysis. SCE exhibited cytotoxic activity with an IC50 value of 32.51 ± 0.70 μg/ml against MCF-7, and 8.53 ± 0.97 μg/ml against MDA-MB-231 cancer cells. The induction of the intrinsic apoptosis pathway was found by ROS generation, attenuation of Bcl-2 and induction of Bax proteins. It was supported by activation of caspase-9, increased apoptotic cells, as well as decrease of ΔΨm. In the acute toxicity, there was no detectable sign of hepatic or renal toxicity in the SCE 100 mg/kg. GC mass and NMR identified bioactive compounds as one monoterpene, one sesquiterpene, five fatty acids, one phthalate, and two steroidal compounds.