Kalopanaxsaponin A is a Basic Saponin Structure for the Anti-Tumor Activity of Hederagenin Monodesmosides

다국어 초록 (Multilingual Abstract)

Hederagenin, δ-hederin {hederagenin α_-L-arabinoside}, kalopanax-saponin A (hederagenin 3-O-α_-L-rhamnosyl(1→2) -α_-L-arabinoside}, kalopanaxaponin I {hederagenin 3-O-β-_D-xylosyl(1→3)-α-_L-rhamnosyl(1→2)-α-L-arabinoside}, and sapindoside C {hederagenin 3-O-β-_D-glucosyl(1→4)-β-_D-xylosyl(1→3)-α-_L-rhamnosyl(1→2)-α-_L-arabinoside} were isolated from stem bark of Kalopanax pictus Nakai (Araliaceae). Among glycosides of hederagenin, disaccharide (kalopanaxaponin A, commonly also called α-hederin), trisaccharide (kalopanaxaponin l), and tetrasaccharide (sapindoside C) showed significant cytotoxicity on several types of tumor cells, while hederagenin itself exhibited only weak cytotoxicity and its monosaccharide (δ-hederin) was non-cytotoxic. From these results, it suggests that the arabinosyl moiety at C-3 blocks the activity of hederagenin and the position of the second sugar for glycoside linkage is also important for cytotoxicity. In the in vivo experiments, kalopanaxsaponin A (15 mg/kg, i.p.) apparently increased the life span of mice bearing Colon 26 and 3LL Lewis lang carcinoma, as well as cisplatin (3 mg/kg, i.p.). These results indicated that kalopanaxsaponin A has potential anti-tumor applications.