Hederagenin Glycoside Isolated from the Pericarps of Akebia quinata Fruits Induces Apoptotic Cell Death in Breast Cancer Cells.

Background/aim: Hederagenin (3β,4α-3,23-dihydroxyolean-12-en-28-oic acid) is a natural pentacyclic triterpene that is present in various medicinal plants and exhibits pharmacological activities against various diseases, including cancer. The aim of the study was to investigate the effect of Aq3639 (3β-[(O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid), a hederagenin glycoside comprising hederagenin and a disaccharide of L-rhamnose and L-arabinose, on breast cancer cells.

Materials and methods: Aq3639 was isolated from the pericarps of Akebia quinata fruits, and its effects on cells from the human breast cell line MCF-7 were examined.

Results: Aq3639 was found to markedly inhibit the proliferation of MCF-7 cells in a concentration-dependent manner (particularly at concentrations above 25 μmol/l). The inhibitory effect [half-maximal inhibitory concentration (IC₅₀)=13.10 μmol/l] was similar to that of tamoxifen, which is used as a therapeutic agent for estrogen receptor-positive breast cancer; the inhibitory effect was also approximately seven-times greater than that of hederagenin (IC₅₀=93.05 μmol/l). Interestingly, neither of the sugars present in Aq3639, L-rhamnose nor L-arabinose, affected cell inhibition. Additionally, Aq3639 increased the generation of reactive oxygen species and, consequently, induced apoptosis in the MCF-7 cells in a time-dependent manner.

Conclusion: Our results strongly suggest that Aq3639 may be useful in the prevention and treatment of breast cancer.