1. Department of General Surgery, Xinhua Hospital, affiliated to School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China;
2. Institute of Biliary Tract Disease, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China;
3. Department of Otorhinolaryngology - Head and Neck Surgery, The Sixth Hospital of Sun Yat-sen University, Guangzhou 510655, China.
4. Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
* Jiasheng Mu and Tianrun Liu contributed equally to this work.
Baicalein, a traditional Chinese medicine, is a member of the flavone subclass of flavonoids. It has been reported to have anticancer activities in several human cancer cell lines in vitro. However, the therapeutic effects of baicalein on human gastric cancer and the mechanisms of action of baicalein have not been extensively studied. In the present study, we utilized a cell viability assay and an in vivo tumor growth assay to test the inhibitory effects of baicalein on gastric cancer. Analyses of the cell cycle, apoptosis and alterations in protein levels were performed to elucidate how baicalein functions in gastric cancer. We found that baicalein could potently inhibit gastric cancer cell growth and colony formation. Baicalein robustly induced arrest at the S phase in the gastric cancer cell line SGC-7901. It induced SGC-7901 cell apoptosis and disrupted the mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Analysis of protein expression levels in SGC-7901 cells showed downregulation of Bcl-2 and upregulation of Bax in response to baicalein treatment. These results indicate that baicalein induces apoptosis of gastric cancer cells through the mitochondrial pathway. In an in vivo subcutaneous xenograft model, baicalein exhibited excellent tumor inhibitory effects. These results indicate that baicalein may be a potential drug for gastric cancer therapy.
Keywords: baicalein, traditional Chinese medicine, gastric cancer, S phase arrest, apoptosis, mitochondria.