Effect of root extracts of medicinal herb Glycyrrhiza glabra on HSP90 gene expression and apoptosis in the HT-29 colon cancer cell line

Colorectal cancer is one of the most common lethal cancer types worldwide. In recent years, widespread and
large-scale studies have been done on medicinal plants for anti-cancer effects, including Glycyrrhiza glabra. The
aim of this study was to evaluate the effects of an ethanol extract Glycyrrhiza glabra on the expression of HSP90,
growth and apoptosis in the HT-29 colon cancer cell line. HT-29 cells were treated with different concentrations
of extract (50,100,150, and 200 μg/ml). For evaluation of cell proliferation and apoptosis, we used MTT assay and
flow cytometry technique, respectively. RT-PCR was also carried out to evaluate the expression levels of HSP90
genes. Results showed that Glycyrrhiza glabra inhibited proliferation of the HT-29 cell line at a concentration of
200 μg/ml and this was confirmed by the highest rate of cell death as measured by trypan blue and MTT assays.
RT-PCR results showed down-regulation of HSP90 gene expression which implied an ability of Glycyrrhiza
glabra to induce apoptosis in HT-29 cells and confirmed its anticancer property. Further studies are required
to evaluate effects of the extract on other genes and also it is necessary to make an extensive in vivo biological
evaluation and subsequently proceed with clinical evaluations.