Improved anticancer effect of ginseng extract by microwave-assisted processing through the generation of ginsenosides Rg3, Rg5 and Rk1

In this study, we demonstrated the efficient structural conversion of ginsenosides, which enhances the anticancer activity of ginseng by microwave irradiation. The microwave-irradiated product of ginseng (MG) had a higher content of ginsenosides, Rg3+Rg5+Rk1, particularly Rg5 and Rk1, and, thus, has an increased medicinal effect. To confirm the anticancer effect of MG, it was tested in 5 human cancer cell lines (cervical cancer HeLa, gastric cancer AGS, colon cancer HCT-116, lung cancer A549, and liver cancer HepG2 cells). Anti-proliferation results for 5 human cancer cell lines treated with ginseng extracts indicate that HeLa cells treated with MG showed the highest activity with an IC50 value of 130.1 µg/mL. MG also suppressed the growth of human cervical cancer cell xenografts in athymic nude mice as an in vivo model. This growth suppression by MG is associated with the induction of cell death and autophagy. Moreover, there were no toxic sign or decrease in renal and hepatic function in mice administered with MG. Therefore, heat processing by microwave irradiation is a useful method to enhance the anticancer effect of ginseng as it increases the content of ginsenosides, Rg3, Rg5, and Rk1.