Antiproliferative activity of Origanum compactum extract on lung cancer and hepatoma cells

Abstract

Natural products have been shown to present interesting biological and pharmacological activities and are used as cancer preventive and therapeutic agents. Plants have historically been used in treating cancer and are recognized for their ability to produce secondary metabolites. Origanum compactum Benth. (Lamiaceae) is a well-known Moroccan plant with cancer-related ethnobotanical use. Previously, we demonstrated that ethyl acetate extract of O. compactum had antiproliferative potential on human breast tumor MCF-7 cells. The purpose of this study was to investigate if the antiproliferative effect of this extract was similar for diverse human cancer cell lines such as A549 lung cancer and SMMC-7721 hepatoma cells. Furthermore, this study essentially focused on the intrinsic apoptotic signaling pathway. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide on A549 and SMMC-7721 cells. The characterization of the mechanisms involved in this effect was determined by lactate dehydrogenase test, apoptosis assays and protein expression analyses. Our present work has shown that this extract remarkably inhibited proliferation of A549 (IC50: 198 ± 12 μg/ml) and SMMC-7721 (IC50: 266 ± 14 μg/ml) cells. The characterization of antiproliferative activity demonstrated that this extract was an apoptosis inducer in both cell lines tested. The results of protein expression analyses have shown in A549 cells that this extract activated caspase signaling triggered by the modulation of Bcl-2 family proteins. These results suggest that these natural extract-induced effects may have novel therapeutic applications for the treatment of various cancer types.