Huu Tung Nguyen

Oleanane-type triterpenoids from Panax stipuleanatus and their anticancer activities

One newly (1) and 10 known oleanane-type triterpenoids (2-11) were isolated from the methanol extract of Panax stipuleanatus rhizomes. Based on their spectroscopic data, these compounds were identified as spinasaponin A methyl ester (1), pesudoginsenoside RP(1) methyl ester (2), spinasaponin A 28-O-glucoside (3), pseudoginsenoside RT(1) methyl ester (4), pseudoginsenoside RT(1) (5), stipuleanoside R(2) methyl ester (6), stipuleanoside R(2) (7), araloside A methyl ester (8), 3-O-β-D-glucopyranosyl (1→3)-β-D-glucuronopyranoside-28-O-β-D-glucopyranosyl oleanolic acid methyl ester (9), 3-O-β-D-xylopyranosyl (1→2)-β-D-glucopyranosyl-28-O-β-D-glucopyranosyl oleanolic acid (10), and chikusetsusaponin IVa (11). When the cytotoxic activities of the isolated compounds were evaluated, compound 1 exhibited significant cytotoxic activity with IC(50) values of 4.44 and 0.63 μM against HL-60 (leukemia) and HCT-116 (colon cancer) cell lines, respectively. Compound 2 showed potent cytotoxicity with an IC(50) of 6.50 μM against HCT-116, whereas it was less cytotoxic against HL-60 (IC(50)=41.45 μM). After HL-60 and HCT-116 were treated with compounds 1 and 2, increased production of apoptotic bodies was observed. Furthermore, compounds 1 and 2 in HCT-116 cells activated intrinsic and extrinsic apoptosis pathways by upregulating DR-5 and Bax, downregulating Bcl-2, activating caspase-9, and cleaving poly-ADP-ribose polymerase (PARP). We also observed the activation of ERK1/2 MAPK by both compounds in the HCT-116 cells. Together, compounds 1 and 2 might induce intrinsic and extrinsic apoptosis pathways through the activation of the ERK1/2 MAPK pathway in HCT-116 colon cancer cells. Structure-activity relationship analysis indicated that a carboxyl group at position-28 is potentially responsible for the cytotoxic effects.

Rhusonoside A, a New Megastigmane Glycoside from Rhus sylvestris, Increases the Function of Osteoblastic MC3T3-E1 Cells

Chemical investigation of the stems and leaves of Rhus Sylvestris afforded a new megastigmane glycoside named rhusonoside A ( 1), along with four other known compounds: dihydroquercetin ( 2), astragalin ( 3), hyperin ( 4), and kaempferol-3- O-rutinoside ( 5). Their structures were determined by a combination of spectroscopic analysis and application of the modified Moshers method. The effect of compounds 1 - 5 on the function of osteoblastic MC3T3-E1 cells was examined by determining cell viability, alkaline phosphatase (ALP) activity, collagen synthesis, and mineralization. Rhusonoside A ( 1) significantly increased the function of osteoblastic MC3T3-E1 cells. Cell viability, ALP activity, and collagen synthesis were increased dose dependently, up to 155.39 %, 171.27 %, and 134.25 %, respectively, of the basal value at 10 muM ( P < 0.05). In addition, 0.1 muM of compound 1 significantly increased mineralization of MC3T3-E1 cells to 142.78 % ( P < 0.05) of the basal value.