Induction of Apoptosis and Cell Cycle Arrest by Dorema Glabrum Root Extracts in a Gastric Adenocarcinoma (AGS) Cell Line

Objective: Dorema glabrum Fisch. & C.A. Mey is a perennial plant that has several curative properties. Anti-proliferative activity of seeds of this plant has been demonstrated in a mouse fibrosarcoma cell line. The aim of the present study was to evaluate cytotoxicity of D. glabrum root extracts in a human gastric adenocarcinoma (AGS) cell line and explore mechanisms of apoptosis induction, cell cycle arrest and altered gene expression in cancer cells. Materials and Methods: The MTT assay was used to evaluate IC50 values, EB/AO staining to analyze the mode of cell death, and flow cytometry to assess the cell cycle. Quantitative real-time polymerase chain reaction (qRT-PCR) amplification was performed with apoptosis and cell cycle-related gene primers, for cyclin D1, c-myc, survivin, VEGF, Bcl-2, Bax, and caspase-3 to determine alteration of gene expression. Results: Our results showed that n-hexane and chloroform extracts had greatest toxic effects on gastric cancer cells with IC50 values of 6.4 μg/ml and 4.6 μg/ml, respectively, after 72 h. Cell cycle analysis revealed that the population of treated cells in the G1 phase was increased in comparison to controls. Cellular morphological changes indicated induction of apoptosis. In addition, mRNA expression levels of Bax and caspase-3 were increased, and of bcl-2 survivin, VEGF, c-myc and cyclin D1 were decreased. Conclusion: Our study results suggest that D. glabrum has cytotoxic effects on AGS cells, characterized by enhanced apoptosis, reduced cell viability and arrest of cell cycling.