Yacon ( Samallanthus sonchifolius ), a common edible plant grown throughout the world, is well known for its antidiabetic properties. It is also known to have several other pharmacological properties including anti-inflammatory, anti-oxidant, anti-allergic, and anti-cancer effects. To date, the effect of yacon on gliomas has not been studied. In this study, we investigated the effects of yacon on the migration and proliferation of C6 glioma cells stimulated by fetal bovine serum (FBS).

Cell growth and proliferation were determined by evaluating cell viability using an EZ-Cytox Cell Viability Assay Kit. FBS-induced migration of C6 glioma cells was evaluated by performing the scratch wound healing assay and the Boyden chamber assay. We also used western blot analysis to determine the expression levels of extracellular signal-regulated kinase 1/2 (ERK1/2), a major regulator of migration and proliferation of glioma cells. Matrix metallopeptidase (MMP) 9 and TIMP-1 levels were measured by performing reverse transcription PCR.

Yacon (300 µg/mL) reduced both the FBS-induced proliferation of C6 glioma cells and the dose-dependent migration of the FBS-stimulated C6 cells. FBS-stimulated C6 glioma cells treated with yacon (200 and 300 µg/mL) showed reduced phosphorylation of ERK1/2 and inhibition of MMP 9 expression compared to those shown by the untreated FBS-stimulated C6 cells. In contrast, yacon (200 and 300 µg/mL) induced TIMP-1 expression.

On the basis of these results, we suggest that yacon may exert an anti-cancer effect on FBS-stimulated C6 glioma cells by inhibiting their proliferation and migration. The most likely mechanism for this is down-regulation of ERK1/2 and MMP9 and up-regulation of TIMP-1 expression levels.