Curcumin combined with glycyrrhetinic acid inhibits the development of hepatocellular carcinoma cells by down-regulating the PTEN/PI3K/AKT signalling pathway.

Curcumin is an active component of turmeric, which is derived from the rhizomes of Curcuma longa. Glycyrrhetinic acid (GA) is a natural compound extracted from liquorice. Both curcumin and GA are widely used as anticancer agents for treating many human cancers. In this study, curcumin and GA were used separately and in combination to treat human hepatocellular carcinoma (HCC) HepG2 cells. MTT assays were used to evaluate cell proliferation. Flow cytometry was carried out to measure cell apoptosis and determine cell cycle progression. Western blot analyses were applied to determine the expression levels of B-cell lymphoma-2 (Bcl-2), B-cell associated X protein (Bax), phosphatase and tensin homolog (PTEN), phosphorylated phosphoinositide 3-kinase (PI3K) and AKT serine/threonine kinase 1 (Akt). The results showed that combined treatment with curcumin and GA resulted in a significant reduction in proliferation and an increase in apoptosis and G1 cell cycle arrest in HepG-2 cells. A xenograft tumour model showed that curcumin and GA suppressed HCC development in vivo. Moreover, by knocking down the expression of PTEN, we confirmed that curcumin and GA exert their anticancer effects by inhibiting the PTEN/PI3K/Akt signalling pathway. Collectively, these results indicate that the combination of curcumin and GA could effectively inhibit the development of HepG2 cells by inhibiting PTEN/PI3K/Akt signalling and could be a promising treatment strategy for patients with HCC.