Production of aralin, a selective cytotoxic lectin against human transformed cells, in callus culture of Aralia elata.

Recently we found that aralin, a novel lectin, from Aralia elata selectively induces apoptosis in human virus-transformed and cancer cells compared with normal cells. To overcome the reduction of aralin biosynthesis according to the development of leaves, we established callus tissues from the young shoots. The N-terminal amino acid sequence and immunochemical analyses revealed that ca-aralin, an aralin synthesized in the callus, was structurally identical with aralin except for the glycosylation of the B chain. The selective cytotoxic index (ratio of IC50 value against human lung normal cells versus virus-transformed cells) of ca-aralin was 2-fold higher than that of aralin. Thus, these results suggest that ca-aralin is more useful than aralin as an anticancer agent.