Antiproliferative Effect and Induction of Apoptosis by Inula viscosa L. and Retama monosperma L. Extracts in Human Cervical Cancer Cells

Abstract

The antiproliferative effect of different extracts obtained from Retama monosperma L. was investigated on human SiHa and HeLa cervical cancer cell lines using a MTT colorimetric assay. The Retama monosperma L. dichloromethane fraction (Rm-DF) was the most active extract, exhibiting a significant cytotoxic activity on both cell lines in a dose-dependent manner, after 72 h of treatment. IC50 values obtained were 14.57 ± 4.15 μg/ml and 21.33 ± 7.88 μg/ml, for SiHa and HeLa cell lines respectively. The morphological features assessment of apoptosis in Rm-DF-treated cells showed a condensation of chromatin and apoptotic bodies, accompanied by a decrease in mitochondrial membrane potential (ΔΨm) and an increase in reactive oxygen species in both cell lines. The induction of apoptosis was further confirmed by Western blotting pro-caspase 3, Bcl2 and PARP; caspase 3 activity assay; and Annexin V labelling. Analysis of Rm-DF by CG/MS revealed the presence of five known quinolizidine alkaloids as well as, sparteine (10,97%), L-methyl cytisine (9.11%), 17-oxosparteine (3.49%), lupanine (0.93%) and anagyrine (39.63%). This study shows that Retama monosperma L. extract exhibits a potential anticancer activity against cervical cancer cell lines in vitro through the inhibition of proliferation and induction of apoptosis, which may involve a mitochondria-mediated signaling pathway.