In Vitro Antioxidant Mechanism of Action of Hibiscus Sabdariffa in the Induction of Apoptosis against Breast Cancer

ABSTRACT The antioxidant mechanism of action in the process of cytotoxicity, and pro-apoptotic activity of Hibiscus sabdariffa water extract (HSWE) was assessed against non-cancerous (MCF12A) and breast cancer (MCF7) cells grown in DMEM-F12 and DMEM, respectively. The treated cells revealed a polyphenolic and anthocyanin content of 17.7 ± 0.4 mg g−1 and 24.8 ± 0.5 mg g,−1 respectively. The oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assay values were 1506 ± 30.1 µmoleTE g−1 and 428.9 ± 3.8 µmoleAAE g−1 at 1.0 mg mL−1, respectively, indicating a high antioxidant capacity. The HSWE induced greater apoptosis than doxorubicin (62.5 ± 2.6%), as more cytotoxic effect was noted against MCF7 with 70.4 ± 2.4% than MCF12A (15.3 ± 1.4%) cells at 0.4 mg mL−1. The HSWE depolarized mitochondrial MCF7 by 42.5 ± 0.5% compared to 4.6 ± 0.3% against MCF12A at 0.3 mg mL−1. It altered the intracellular redox status of MCF7 cells by depleting antioxidant enzymes with high levels of lipid peroxidation and reactive oxygen species [ROS] in MCF7 than in MCF12A. HSWE selectively induced apoptosis on MCF7 cells via ROS generation, lipid peroxidation, and mitochondrial dysfunction pathway.