Antiproliferative Effect of Grammatophyllum speciosum Ethanolic Extract and Its Bioactive Compound on Human Breast Cancer Cells

Background / Aim . Grammatophyllum speciosum Blume exhibits various promising pharmacological activities. However, its effect on breast cancer has not been determined. Materials and Methods . The antiproliferation effects of the G. speciosum pseudobulb ethanolic extract (GSE) and isovitexin (bioactive constituent) were investigated on the MCF-7 human breast cancer cell line using MTT and colony formation assay. The expression levels of proliferation-regulatory proteins were determined by western blotting. Results . Noncytotoxic concentrations of GSE significantly suppressed the proliferation of MCF-7 cells. Tumor colony formation decreased in both number and size. The level of phosphorylated AKT and β -catenin was suppressed by GSE treatment. Antiproliferation was observed in isovitexin-treated MCF-7 cells in the form of inhibited colony formation and reduced expression of phosphorylated AKT and β -catenin protein. Conclusions . This study demonstrates the novel effect of G. speciosum as an antiproliferative via suppression of the AKT/ β -catenin-dependent pathway. This may prompt further investigation of this plant in breast cancer therapy.