Inhibitory Effects of the Extracts of Juglans sigillata Green Husks on the Proliferation, Migration and Survival of KYSE150 and EC9706 Human Esophageal Cancer Cell Lines

This study evaluated the antitumor activity of the extracts of green husks of Juglans sigillata Dode on esophageal cancer. KYSE150 EC9706 cells were treated with different concentrations of six components of the extracts of J. sigillata green husks. Cell viability was measured by MTT. Cell migration and cell invasion were measured by wound-healing assays and transwell assays, respectively. Cell apoptosis and cycle were measured by flow cytometry. The expression of cell migration, cell cycle and cell apoptosis regulatory proteins was analyzed by Western blotting. Only the three constituents, including EtOH extractives, EtOAc soluble fraction and gallic acid (GA), exhibited inhibitory effects on the cell viability, migration and invasion by decreasing MMP2 and MMP9 expression (all P < 0.05). Flow cytometry revealed that these three constituents also induced cell apoptosis by increasing Bax and cleaved caspase-3 but decreasing Bcl-2 in KYSE150 and EC9706 cells. Furthermore, these constituents arrested the cell cycle at G0/G1 by downregulating the expression of Cyclin D1 but upregulating p53 and phospho-p53 expression in KYSE150 cells. In conclusion, the green husks of J. sigillata may act as a potential inhibitor on esophageal cancer growth. GA was the major single active constituent of the extracts.