Cytotoxicity of alkaloids isolated from Peganum harmala seeds on HCT116 human colon cancer cells

The present study aimed to elucidate the potential anticancer activity and mechanism of P. harmala’s alkaloid extract, harmine (HAR), and harmaline (HAL) in HCT-116 colorectal cancer cells.

P. harmala’s alkaloid was extracted from harmala seeds. HCT-116 cells were treated with P. harmala’s alkaloid extract, HAR and HAL. Cytotoxicity was determined by MTT assay, apoptotic activity detected via flow cytometry and acridine orange (AO)/ethidium bromide (EB) dual staining, and cell cycle distribution analyzed with flow cytometry. The mRNA expression of Bcl-2-associated X protein (Bax) and glycogen synthase kinase-3 beta (GSK3β) was measured by real-time PCR. Furthermore, the expression of Bax, Bcl-2, GSK3β and p53 proteins, were determined by western blotting. The findings indicated that, P. harmala’s alkaloids extract, HAR and HAL were significantly cytotoxic toward HCT116 cells after 24 and 48 h of treatment. We showed that P. harmala’s alkaloid extract induce apoptosis and cell cycle arrest at G2 phase in the HCT116 cell line. Downregulation of GSK3β and Bcl-2 and upregulation of Bax and p53 were observed.

The findings of this study indicate that the P. harmala’s alkaloid extract has anticancer activity and may be further investigated to develop future anticancer chemotherapeutic agents.