Chan-Ho Oh

Characterization and quantification of anthocyanins in grape juices obtained from the grapes cultivated in Korea by HPLC/DAD, HPLC/MS, and HPLC/MS/MS.

The characterization and quantification of anthocyanins in grape cultivars of Oll-Meoru (Vitis coignetiaexVitis labrusca), Neut-Meoru (Vitis coignetiaexVitis labrusca), Muscal Bailey A. (Vitis labruscana), and Campbell Early (Vitis labruscaxV. vinifera) cultivated in Korea were carried out by partial purification through XAD-7 column chromatography followed by C-18 HPLC/diode array detector (DAD), HPLC/MS, and HPLC/MS/MS analyses. The column oven temperature during the reverse phase C-18 HPLC greatly affected the separation of individual anthocyanins. The result showed that the optimum column oven temperature was 35 degrees C. Sixteen different anthocyanins (11 nonacylated and 5 acylated anthocyanins) were identified in the grape juices. Oll-Meoru, Neut-Meoru, and Muscat Bailey A (MBA) grape juices contained only nonacylated anthocyanins. Oll-Meoru and Neut-Meoru grape juices had same anthocyanins, but their proportions were considerably different. Peonidin 3,5-diglucoside and malvidin 3,5-diglucoside were the major anthocyanins in Oll-Meoru grape juice. Delphinidin 3-glucoside was, however, the major anthocyanin in Neut-Meoru grape juice. Peonidin 3-glucoside and malvidin 3-glucoside were the most abundant anthocyanins in Muscal Bailey A grape juice. Campbell Early grape juice contained both nonacylated and acylated anthocyanins. Cyanidin 3-(p-coumaroyl)glucoside-5-glucoside and peonidin 3-(p-coumaroyl)glucoside-5-glucoside were the most abundant anthocyanins in Campbell Early grape juice. Total anthocyanin contents were greatly different in different grape jucies, with the highest in Neut-Meoru juice (1043.5 microg/mL), followed by Oll-Meoru (997.7 microg/mL), MBA (390.2 microg/mL), and Campbell Early (183.9 microg/mL) juices. The total anthocyanin content in Neut-Meoru grape juice was 5.67 times higher than that in Campbell Early grape juice. This represents the 1st report on the systematic characterization and quantification of anthocyanins in the juices of these grapes cultivated in Korea.

Apoptosis-inducing effect of Akebia saponin D from the roots of Dipsacus asper Wall in U937 cells

Methanol extracts of the root of Dipsacus asper Wall (Dipsacaceae) were found to exhibit apoptosis-inducing activities in U937 (human monocyte-like histiocytic) cells. Investigation of the active n-BuOH fraction led to the isolation of akebia saponin D (ASD). Structure was established by spectroscopic methods. Treatment of U937 cells with ASD induced apoptosis in a dose dependent manner. ASD exerted strong cytotoxicity against human and murine leukemia cells. It is significantly increased the subG1 cell population and expression of p53 and Bax gene. And also ASD enhanced NO production from RAW264.7 macrophage cells. Taken together, these results strongly indicate that ASD may exert apoptosis-inducing activity via induction of apoptosis through activation chiefly via the nitric oxide and apoptosis-related p53 and Bax gene expression. These data provide scientific evidence that Dipsacus asper Wall can be useful as a chemopreventive agent.

Gallic Acid Inhibits Cell Viability and Induces Apoptosis in Human Monocytic Cell Line U937

In the present study, we investigated the effects of gallic acid (GA) (3,4,5-trihydroxybenzoic acid), a polyhydroxyphenolic compound, isolated from Rhus chinensis, on the human monocytic lymphoma cell line U937. In vitro experiments showed that treating U937 cells with various amounts of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA induces apoptosis, we examined the gene expression of p53, nuclear factor κB (NF-κB), and inhibitor of NF-κB (I-κB) after treating the cells with GA and found that expression levels of the genes for p53 and NF-κB increased and that for I-κB decreased. The results obtained from western blotting with U937 cells showed up-regulation of NF-κB protein and down-regulation of proliferating cell nuclear antigen and I-κB protein. These results demonstrate that GA efficiently induces apoptosis in U937 cells and that GA is a potential chemotherapeutic agent against lymphoma.

A new cytotoxic prenylated chalcone fromsophora flavescens

We have isolated a new prenylated chalcone from the roots of Sophora flavescens (Leguminosae). We determined that structure of this compound is 7,9,2’,4’-tetrahydroxy-8-isopentenyl-5-methoxychalcone (1) on the basis of spectroscopic analysis (1D and 2D NMR data). Compound 1 exhibited potent cytotoxicity against human acute promyelocytic (HL60), mouse lymphocytic (L1210) and human histiocytic (U937) leukemia cells.

Effects of isolated compounds from Catalpa ovata on the T cell-mediated immune responses and proliferation of leukemic cells

Three compounds were isolated from the ethyl acetate soluble fraction of the methanolic extract of the leaves of Catalpa ovata (Bignoniaceae) through repeated column chromatography. We investigated the effects of these compounds on T cell-mediated responses for tumor surveillance and proliferation in U937, HL60, and Molt-4 leukemia cells. Compounds 1–3 inhibited proliferation of those cells in a dose-dependent manner. Compound 3 showed mild effect in Molt-4 cell cytotoxicity. Compound 3 enhanced gene expressions of p53 and IL-4, but decreased IL-2 and IFN-Γ genes in Molt-4 cell. Our findings indicate that compound 3 may enhance T cell-mediated immune responses and anticancer properties.

INDUCTION OF T LYMPHOCYTE APOPTOSIS BY TREATMENT WITH GLYCYRRHIZIN

The effect of glycyrrhizin (GL), a Chinese herbal drug extracted from licolice roots, on murine lymphocytes for inducing apoptotic cell death was studied. Addition of GL (25-400 micrograms/ml) to cultured splenocytes and thymocytes from BALB/c mice definitely promoted DNA fragmentation. A single injection of GL (100 micrograms/mouse) into BALB/c mice did not cause any detectable DNA fragmentation or cell death of splenocytes and thymocytes. Cytofluorometric analysis of these cells, however, demonstrated a reduction in mitochondrial transmembrane potentials (delta psi m). Repeated injections of GL (100 micrograms/mouse/day) into mice for 7 days actually resulted in induction of low grade DNA fragmentation selectively in splenocytes. Cell population analysis of viable lymphocytes suggested that both CD4+ Th lymphocytes and CD8+ Tc lymphocytes may have been relatively more sensitive than B220+ B lymphocytes for the apoptotic cell death. We concluded from these results that GL acts as a rather selective inducer of mature T lymphocyte apoptosis with a reduction in delta psi m potentially preceding lymphocyte death.