The anti-metastatic activity of a chinese herb Andrographis paniculata in esophageal cancer – a preclinical study

Esophageal cancer is usually diagnosed at advanced stage with high postoperative recurrence and systemic metastasis which leads to poor prognosis. In the present study, the in vitro anti-metastatic effects of the herb Andrographis paniculata (AP), a herbal medicine widely used in both Chinese and Indian traditional medicines, were evaluated in two esophageal cancer cell lines, EC-109 and KYSE-520. The cytotoxicities of AP aqueous and ethanolic extracts were determined by MTT assay. The effects of AP extracts at non-toxic concentrations were assessed using scratch wound and cell invasion assays. Our results showed that AP ethanolic extract (50µg/ml) and aqueous extract (800–1600µg/ml) significantly decreased the closed wound area in both cell lines, suggesting inhibitory effects on motility of cells. Unlike the ethanolic extract which has no inhibitory effect, AP aqueous extract (1600µg/ml) significantly inhibited the invasion of EC-109 and KYSE-520 cells through the Transwell. Besides, using real-time PCR, mRNA expression of metastasis-related gene TM4SF3 was significantly decreased in AP aqueous extract-treated EC-109 cells. To conclude, this is the first report of the inhibitory effects of AP aqueous extract on both migration and invasion of esophageal cancer cells EC-109 and KYSE-520, and also suppression of the metastasis-related gene TM4SF3 expression.