Anticancer attributes of Illicium verum essential oils against colon cancer

Abstract

This study investigated the antioxidant and in vitro cytotoxic effects of essential oils (EOs) obtained from the fruits of Illicium verum. The solvent extraction method was used to extract oils from the fruits. Antioxidant properties were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays followed by estimation of the total phenolic and total flavonoid contents and gas chromatography–mass spectrometry (GC-MS) analysis. Anti-proliferative effects were studied by MTT assay. Fluorescent dyes were used to study the apoptotic effects of EOs. Furthermore, in vitro cell migration, matrigel invasion, and colony formation assays were employed to study the anti-metastatic properties of EOs. Three concentrations of EOs (25, 50, and 90 μg/mL), 0.5% dimethyl sulfoxide in media, and 5-Fluorouracil (5 μg/mL) were used as the test sample, negative control, and positive control, respectively. EOs showed promising antioxidant effects in the DPPH and FRAP models; GC-MS analysis identified trans-anethole as one of the major compounds. Among the cell lines tested, EOs showed the greatest cytotoxicity towards HCT 116, with an IC50 value of 50.34 ± 1.19 μg/mL. Distinct nuclear morphological changes and a reduction in mitochondrial membrane potential was observed in the treated cells in a dose-dependent manner. Similarly, dose-dependent inhibition of cell migration, invasion, and colony formation was observed in the treated cells. To conclude, the cytotoxic effect of Illicium verum EOs may be due to multiple mechanisms such as the induction of apoptosis and inhibition of key steps of metastasis.