We aimed to assess the antitumor activity of Orobanche crenata methanolic extract and evaluate its cytotoxic effect on different cancer cell lines to develop an effective natural anticancer drug. Components of O. crenata methanolic extract were analyzed using gas chromatography-mass spectrometry. The extract's antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power procedures and cytotoxicity of the extract was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase assays. Caspase-3 activity was also estimated. O. crenata methanolic extract shows powerful antioxidant activity. The extract inhibited the propagation of human hepatocellular carcinoma (HepG2), human prostate cancer (PC3), human breast adenocarcinoma (MCF-7), and human colon carcinoma (HCT-116) in a dose-dependent manner. O. crenata-treated cells displayed obvious morphological structures distinctive of apoptosis. MTT assay exposed that the extract presented prevention of cell persistence in a dose-dependent means and revealed extremely cytotoxic activity against HepG2, PC3, MCF-7, and HCT-116 with 50% inhibitory concentration values 30.3, 111, 89.6, and 28.6 µg/mL, respectively, after 24 h of incubation. In addition, treatment of HCT-116 with various concentrations of the extract caused the release of lactate dehydrogenase and induction of caspase-3 activity in a dose-dependent way. In conclusion, our findings suggested that the O. crenata extract possesses potent antioxidant, cytotoxic activity, and anticancer properties which are possibly due to the principal bioactive phytochemical composites existing in this plant. These results can be used to develop new drugs for cancer treatment.
Keywords: HCT-116; HepG2; MCF-7; Orobanche crenata; PC3; cytotoxicity; gas chromatography–mass spectrometry.