Dendropanax morbifera Léveille (Araliaceae) is an endemic species growing in the south-western part of South Korea and has been used in folk medicine and health functional food. Several studies have indicated that extract of D. morbifera (DP) has cytotoxic activities on a number of human cancers, such as, breast cancer, lung cancer, hepatoma, and chorioepithelioma. Recently, polyacetylene and triterpene compounds have been isolated from the DP and showed to have anti-complement activity. β-Amyrin, α-amyrin, dendropanoxide, and β-sitosterol are isolated from DP. However, its biological activities in cancer have not yet been clearly elucidated. In this study, we evaluated the anti-cancer activity of isolated triterpenoids from the DP leaves by measuring the levels of cytotoxicity against MCF-7 human breast cancer and A549 human lung cancer cells. Six triterpenoids were isolated from the n-hexane fraction of DP leaves along with the known compounds. β-amyrin (1), α-amyrin (2), olean-12-en-3,24 β-diol (3), dendropanoxide (4), β-sitosterol (5), and stigmasterol (6). Compound 3 and 6 were isolated from DP for the first time. Cytotoxic activities of six compounds were evaluated against two human cancer cell lines by using the MTT in vitro assay. Among them, five compounds (1, 2, 4, 5, and 6) showed moderate cytotoxic activities toward the tested cell lines, and were safe to normal cells. Western blot analysis showed a decreased expression of anti-apoptotic protein Bcl-2 and increased levels of pro-apoptotic protein Bax in MCF-7 and A549 cells treated by β-amyrin and α-amyrin. Flow cytometry analysis confirmed that five compounds (1, 2, 4, 5, and 6) treatment increased populations of sub-G1 (apoptosis) phase. The results of the present study revealed that triterpenoids from DP have the potential for further development as anticancer agents.

The plant Rubus species (Rosaceae) mainly contains 19α-hydroxyurane-type triterpenoids (19α-HUT) as bioactive components. Available functional food includes blackberry (the fruit of thornless Rubus sp.), red raspberry (R. idaeus) and black raspberry (R. occidentalis). However, the fruit of R. coreanus, which is used in Korea as a functional food, substitutes black raspberry. Rubi Fructus, which has been traditionally used as an oriental medicinal drug, designates only unripe fruit of R. coreanus but not its ripe fruit which indicates that it needs high content of 19α-HUT as a crude drug. Throughout our experiment, we found that ripe fruits contain very little amount of 19α-HUT when compared to unripe fruits. In addition, various and rich 19α-HUT has been reported from Rubus species. The most common structure of 19α-HUT of Rubus species, euscaphic acid or tormentic acid with 3α-OH or 3β-OH, respectively, can be glycosylated or oxidized to produce a number of 19α-HUTs as euscaphic acid and tormentic acid derivatives and even esterified to form dimeric triterpenoids. In this review, the bioactivity and biosynthetic pathway and chemical characterization of 19α-HUTs found in Rubus species are discussed.