Chemopreventive effect of 18β-glycyrrhetinic acid via modulation of inflammatory markers and induction of apoptosis in human hepatoma cell line (HepG2)

Hepatocellular carcinoma is one of the most common lethal diseases worldwide and there is no effective treatment till date. Natural products derived from the plants play an important role in chemoprevention and act as therapeutic antitumor agents. Licorice is a plant that has been used in food and medicine for the treatment of various diseases. 18β-Glycyrrhetinic acid (18β-GA), a pentacyclic triterpenoid obtained from the roots of licorice plant, is reported to possess various pharmacological properties such as antitumor and antiinflammatory activities. The present study was designed to elucidate the chemopreventive effect of 18β-GA through antiinflammation, antiproliferation, and induction of apoptosis in human hepatoma cell line HepG2. 18β-GA significantly inhibits the proliferation of HepG2 cell without affecting the normal liver cell line (Chang’s). In the present study, 18β-GA increased the formation of reactive oxygen species, nitric oxide production, and loss of mitochondrial membrane potential, suggesting the involvement of 18β-GA in apoptosis which was also confirmed by assessing the markers involved in apoptosis like caspase-3, caspase-9, Bax:Bcl-2 ratio, and cleaved PARP. 18β-GA also downregulated the expression of inflammatory proteins such as NF-κB, iNOS, and COX-2. Keeping these data into consideration, our results suggest that 18β-GA may be used as a chemopreventive agent in liver cancer.