Joongku Lee

Neuroprotective and free radical scavenging activities of phenolic compounds fromHovenia dulcis

The EtOAc-soluble fraction from a methanolic extract ofHovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1–8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds6 and8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound6 had a DPPH free radical scavenging effect with an IC50 value of 57.7 μM, and a superoxide anion radical scavenging effect with an 8.0 μM. Both compounds6 and8 had ABTS cation radical scavenging effects with IC50 values of 7.8 μM and 23.7 μM, respectively. These results suggest that compounds6 and8 could be neuroprotectants owing to their free radical scavenging activities.

Antiplasmodial activity of triterpenoid isolated from whole plants of Viola genus from South Korea

Species of the Viola genus, used in traditional medicines for the treatment of parasites, were collected and petroleum ether extract was obtained by sonication. The antiplasmodial activity of petroleum ether extracts was evaluated in vitro against the chloroquine-resistant FcB1 strain of Plasmodium falciparum. Bioactivity-guided fractionation of the petroleum ether extracts of the whole plants of Viola verecunda has led to the isolation of epi-oleanolic acid, a triterpenoid, displaying high antiplasmodial activity (IC50 0.18xa0μg/ml). This is the first report of the isolation and antiplasmodial activity of epi-oleanolic acid from this species.