Chloroform fraction of Foeniculum vulgare induced ROS mediated, mitochondria-caspase-dependent apoptotic pathway in MCF-7, human breast cancer cell line

Abstract

Ethnopharmacological relevance: Foeniculum vulgare Mill. (Fennel) is one of the most common herbs used in alternative medicines for its varied range of bioactivity. In Ecuador (South America), use of fennel in traditional cancer treatment is on record.

Aim of the study: The objective of the present study was to demonstrate the anti-proliferative and apoptotic effect of chloroform fraction of fennel (CFF) in MCF-7 cells.

Materials and methods: Anti-proliferative assay (MTT assay) and colony formation assay were performed to study the growth inhibitory effect of CFF. Various morphological changes of apoptosis were observed using Giemsa, Hoechst and Acridine orange/ ethidium bromide stains in MCF-7 cells. The extent of apoptosis and cell cycle arrest was measured by flow cytometer. Levels of ROS and mitochondrial membrane potential was measured by DCFH-DA and JC-1 respectively. Caspases activity was measured by luminescence and DNA fragmentation by comet assay.

Results: CFF appeared as a good inhibitor of growth against MCF-7 and MDA-MB-237 in time- and concentration-dependent manners. All the morphological changes of apoptosis were evident in treatment groups. Annexin V/PI-assay of apoptosis gave around 49% of apoptotic cells upon treatment of 0.5 mg/ml of CFF and PI-stained cells showed the G1 phase cell cycle arrest. Elevated levels of ROS, disrupted mitochondrial membrane, increased levels of caspase-9 & caspase-3 and DNA fragmentation were noted in treated MCF-7 cells.

Conclusion: Our findings revealed the proliferation inhibition, cell cycle arrest and apoptosis induction effect of CFF, which may help in exploring the novel anti-cancer drug for therapeutic implications.

Keywords: Apoptosis; Fennel; Foeniculum vulgare; Mitochondrial pathway; Reactive oxygen species.