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Five compounds previously known structures, scopoletin (1), northalifoline (2), stigmast-4-en-3-one (3), tiliroside (4), and oplopanone (5) were obtained from the flower buds of Magnolia fargesii using chromatographic separation methods. The structures of 1-5 were identified by the interpretation of their spectroscopic data including 1D- and 2D-NMR as well as by comparison with reported values. Three compounds 1-3 were found from M. fargesii for the first time in this study. All the isolates (1-5) were subjected to in vitro bioassays to evaluate the inhibitory activity on advanced glycation end products formation and rat lens aldose reductase (RLAR). Compound 1 showed a remarkable inhibitory activity on advanced glycation end products formation with IC(50) value of 2.93 μM (aminoguanidine: 961 μM), and showed a significant RLAR inhibitory activity with IC(50) value of 22.5 μM (3.3-tetramethyleneglutaric acid: 28.7 μM). Compound 4 exhibited potent inhibitory activity against RLAR (IC(50) = 14.9 μM). In the further experiment ex vivo, cataractogenesis of rat lenses induced with xylose was significantly inhibited by compound 1 treatment.

Seven phenolic compounds, caffeic acid (1), 4-hydroxybenzoic acid (2), 4-methoxybenzoic acid (3), protocatechuic acid (4), eugenol O-beta-D: -glucopyranoside (5), 3,6-di-O-feruloylsucrose (6), and 3,5-di-O-caffeoylquinic acid methyl ester (7), were isolated from an EtOAc-soluble partition of the flowers of Erigeron annuus. The structures of 1-7 were determined by spectroscopic data interpretation, particularly 1D and 2D NMR studies, and by comparison of their data with those published in the literature. All the isolates were subjected to in vitro bioassays to evaluate their inhibitory activities against the formation of advanced glycation end products (AGEs) and rat lens aldose reductase (RLAR). Of the compounds, 1, 6, and 7 exhibited potent inhibitory activities against the formation of AGEs. In the RLAR assay, compound 7 showed the most potent inhibitory activity.

In the particulate fraction obtained from PKC-down regulated K562 cells by treatment for 24 h with 200 nM TPA, phosphorylation of two proteins with molecular weight, 100 kDa and 23 kDa (designated p100 and p23, respectively) was depleted and addition of exogenous purified PKC to this fraction failed to restore their phosphorylation. However, in the soluble fraction, all of phosphoproteins abolished by long-term treatment with TPA were restored by exogenously added PKC. Phosphorylation of two proteins was increased by short-term treatment (20 min), and diminished with the persistant exposure to TPA as well as at a concentration as low as 1 nM. When K562 cells were treated with 1 nM and 200 nM TPA for 24 h, phosphorylation of p100 was restored with or without exogenous PKC on 2–3 day and 6 day after removal of treated TPA, respectively. Two-dimensional electrophoresis of phosphoproteins revealed that phosphorylated p100 (pl=5.9) and a p66 species were completely absent from the particulate fraction of K562 cells treated with 200 nM TPA for 24 h. These results suggest that the interaction of sensitive endogenous substrates, p100 and p23 with the plasma membrane might be regulated by PKC-down regulation without their displacement to the cytosol and the interaction of p100 with the membrane might be reversible.

A new coumaroyl triterpene, 3-O-trans-p-coumaroyl actinidic acid (1), as well as five known triterpenes, ursolic acid (2), 23-hydroxyursolic acid (3), corosolic acid (4), asiatic acid (5) and betulinic acid (6) were isolated from an EtOAc-soluble extract of the roots of Actinidia arguta. The structure of compound 1 was elucidated from interpretation of the spectroscopic data, particularly by extensive 1D and 2D NMR studies. All the isolates (1-6) were evaluated in vitro for their inhibitory activities on pancreatic lipase (PL). Of the isolates, the new compound 1 possessed the highest inhibitory activity on PL, with an IC(50) of 14.95 microM, followed by ursolic acid (2, IC(50) = 15.83 microM). The other four triterpenes (3-6) also showed significant PL inhibitory activity, with IC(50) values ranging from 20.42 to 76.45 microM.

The crude polysaccharide fromPanax ginseng prepared by hot water extraction and precipitation with ethanol was further fractionated into neutral and acidic fractions by DEAE-cellulose ion exchange chromatography. The chemical compositions were 85.0% carbohydrate and 15.0% protein for the neutral fraction, and 28.4% carbohydrate, 10.0% protein and 29.0% uronic acid for the acidic fraction. The acidic fraction was more effective in increasing of the ratio of spleen to body weight, the number of antibody secreting cells to SRBC and phagocytic activity of reticuloendothelial system, as well as antitumor activity against the solid form of sarcoma 180 in ICR mice than the neutral fraction. All polysaccharide fractions were mitogenic to cultured spleen cells of C57BL/6 mice. However, FA was different from FN in the co-mitogenicities with lectin mitogens. Both crude and acidic fractions potentiated remarkably the mitogenic activity of PHA-P or LPS in dose-dependent manner but neutral fraction enhanced only that of LPS. Three polysaccharide fractoins had no effect on that of Con A. These results suggest that the acidic fraction may stimulate B and T cells as well as macrophages while the neutral fraction may stimulate only B cells and macropages.

In human neuroblastoma SK-N-BE(2) cells undergoing apoptotic death induced by ginsenoside Rh2, a dammarane glycoside that was isolated from Panax ginseng C. A. Meyer, caspase-1 and caspase-3 were activated. The expression of Bax was increased in the cells treated with ginsenoside Rh2, whereas Bcl-2 expression was not altered. Treatment with caspase-1 inhibitor, Ac-YVAD-CMK, or caspase-3 inhibitor, Z-DEVD-FMK, partially inhibited ginsenoside Rh2-induced cell death but almost suppressed the cleavage of the 116 kDa PARP into a 85 kDa fragment. When the levels of p53 were examined in this process, p53 accumulated rapidly in the cells treated early with ginsenoside Rh2. These results suggest that activation of caspase-1 and -3 and the up-regulation of Bax are required in order for apoptotic death of SK-N-BE(2) cells to be induced by ginsenoside Rh2, and p53 plays an important role in the pathways to promote apoptosis.

We examined the modulation of protein kinase C (PKC) subtypes during apoptosis induced by ginsenoside Rh2 (G-Rh2) in human neuroblastoma SK-N-BE(2) and rat glioma C6Bu-1 cells. Apoptosis induced by G-Rh2 in both cell lines was confirmed, as indicated by DNA fragmentation and in situ strand breaks, and characteristic morphological changes. During apoptosis induced by G-Rh2 in SK-N-BE(2) cells, PKC subtypes alpha, beta and gamma were progressively increased with prolonged treatment, whereas PKC delta increased transiently at 3 and 6 h and PKC epsilon was gradually down-regulated after 6 h following the treatment. On the other hand, PKC subtype zeta markedly increased at 24 h when maximal apoptosis was achieved. In C6Bu-1 cells, no significant changes in PKC subtypes alpha, gamma, delta, epsilon and zeta were observed during apoptosis induced by G-Rh2. These results suggest the evidence for a possible role of PKC subtype in apoptosis induced by G-Rh2 in SK-N-BE(2) cells but not in C6Bu-1 cells, and raise the possibility that G-Rh2 may induce apoptosis via different pathways interacting with or without PKC in different cell types.

In ginsenoside Rh2-treated rat glioma C6Bu-1 cells, apoptotic morphological changes, such as cell shrinkage, chromatin condensation and pyknosis were confirmed by means of electron microscopy. To evaluate whether induction of apoptosis by ginsenoside Rh2 is mediated by the members of Bcl-2 family, we first established C6Bu-1 cells overexpressing Bcl-2. It was demonstrated that the expression of Bcl-2, Bcl-xL and Bax was not altered in ginsenoside Rh2-treated C6Bu-1 cells. Bcl-2 overexpressing C6Bu-1 cells failed to prevent from ginsenoside Rh2-induced cell death. These results suggest the existence of other apoptotic pathway that requires induction of apoptosis by ginsenoside Rh2 rather than the pathway through Bcl-2, Bcl-xL or Bax in C6Bu-1 cells.

This study was performed to investigate the mechanism ofin vitro cytotoxic actions of polyacetylenes which are panaxydol, panaxynol and panaxytriol isolated fromPanax ginseng C.A. Meyer. DNA synthesis of L1210 cells was significantly inhibited with dose-dependent pattern when L1210 cells were treated for 1 hour with over 5 μg/ml of polyacetylenes. Panaxydol which had the most potent cytotoxicity among three polyacetylenes showed also the strongest inhibitory effect on DNA synthesis. Intracellular cyclic AMP levels of L1210 cells treated with 2.5 μg/ml of panaxydol or panaxytriol were significantly elevated on the incubation duration. The elevation of cyclic AMP levels by panaxytriol was higher than that by panaxydol, but no significant increase in cyclic AMP by panaxynol was observed. All three polyacetylenes had no effect on glycolysis of L1210 cells. Electron microscopic observations revealed that polyacetylenes caused damage to plasma membranes of L1210 cells in proportion to their cytotoxicities at each ED50 value (panaxydol>panaxynol>panaxytriol). These results suggest that cytotoxicities of polyacetylenes against L1210 cells might be mediated by elevated cyclic AMP level, even though the relationship among their cytotoxicities, inhibitory effect on DNA synthesis and ability to elevation of cyclic AMP level are not fully agreed, and might be also related to membrane damage.