This study was carried out to evaluate cytotoxicity of the extracts from Sophora flavescens Ait. against L1210 (lymphocytic leukemia) and $P388D_1$ (lymphoid neoplasms) cells in vitro. We have determined cytotoxicity by MTT {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazo-liumbromide} assay. The order of cytotoxicity of Sophora flavescens Ait. extracts against L1210 and $P388D_1$ cells in vitro is as follows: AM> EASF > CFSF > MTSF > WSF > HXSF and AM> EASF> CFSF> MTSF> HXSF> WSF. These results suggest that the ethyl acetate soluble extract of Sophora flavescens Ait may be a valuable choice for the development of antitumor agents.

New lectins have been isolated and purified from mung bean (Phaseolus radiatus) through physiological saline extraction, ammonium sulfate salt fractionation and column chromatographies. Ion exchanger were eluted by linear salt gradient and then further purified through gel filtration. Thus obtained lectin named as MBL. The gene expressions of 5 cytokines (IL-1, IL-2, IL-6, $TNF-{\aphpa}$ and $IFN-{\gamma}$) from human peripheral blood mononuclear cells (PBMC) stimulated with MBL were investigated by using reverse transcription polymerase chain reaction (RT-PCR). PBMC ($1{\times}106$ cells/ml) isolated from healthy volunteers were stimulated with lectins (4 mg/ml) for various time intervals (1 to 96 hrs). After each of the various stimulated times, total RNA was isolated and assessed for different cytokines mRNA by RT-PCR. The mRNA encoding IL-1, IL-2 were detected continuously from 1 to 20 hrs, and IL-6 was detected up to 24 hrs. But the mRNA encoding $IFN-{\gamma}$ and $TNF-{\alpha}$ were detected to 8 hours only and showed short time response compared with other cytokines. The significant expression of all cytokines mRNA were observed at 4 hrs. These results suggested that MBL, as inducer of cytokines could elicit detectable cytokine mRNA from PBMC.

Palmultang(PMT) consists of Ginseng Radix Alba, Atractylodis Rhizoma Alba, Hoelen, Glycyrrhizae Radix, Rehmanniae Radix Preparata, Paeoniae Radix, Cnidii Rhizoma and Angelicae Gigantis Radix. PMT enhanced the lucigenin chemiluminescence and the engulfment of fluorescein-conjugated E. coli particles and inhibited the production of nitric oxide in murine peritoneal macrophage. PMT enhanced the production of ${\gamma}-interferon$, interleukin-2 and the cell viability in murine thymocyte, but did not affect the production of interleukin-4. These results indicate that PMT enhances the phagocytosis of macrophage via the stimulation of ${\gamma}-interferon$ production in $T_H1$ cells and the reduction of nitric oxide production in peritoneal macrophage.

Twenty-four Oriental herbal medicines including Platycodi Radix and Scutellariae Radix, etc., which have been used for the cure of hyperlipidemia, coronary heart, disease were evaluated for the 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase inhibition and antioxidant effect on a free radical, 1,1-diphenyl-2-picrylhydrazyl(DPPH) in vitro, and antihyperlipidemic effect on hyperlipidemic rats induced by Triton WR-1339 in vivo. 80% MeOH extract of eight herbs including Scutellariae Radix, Coptidis Rhizoma, Paeoniae Radix Rubra, Moutan Cortex Radicis, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam, Cinnamomi Ramulus and Crataegi Fructus inhibited the HMG-CoA reductase activities and exhibited a radical-trapping action on a stable free radical, DPPH. On Triton WR-1339-induced hyperlipidemic rats, four herbs including Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus showed respectively the significant suppression of serum total cholesterol, triglyceride, phospholipid and LDL-cholesterol levels and serum transaminase(ALT and AST) activities. From these results, it is suggested that each 80% MeOH extract of Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus have effective antihyperlipidemic action against hyperlipidemia.

The anti-asthmatic activities of the extract of Lonicera japonica (BuOH fraction) and its mode of action were investigated using several in vitro and in vivo models. Lonicera japonica was extracted with 30% ethanol (v/v) and successively partitioned into BuOH. The BuOH fraction reduced antigen-induced contraction of isolated trachea from sensitized guinea pigs in a concentration-dependent manner. The BuOH fraction also inhibited histamine release from rat peritoneal mast cells induced by antigen or calcium ionophore A23187 ($IC_{50}=0.26$ and 0.32mg/ml, respectively). Eosinophil infiltration into bronchoalveolar lavage fluids induced by aeroallergen challenge in passively sensitized guinea pigs was inhibited by the BuOH fraction at a dose of 800mg/kg (51.7%). In addition, the BuOH fraction inhibited leukotriene $B_4$ prodution in rat basophilic leukemia cells ($IC_{50}=0.42\;mg/ml$) as well as phosphodiesterase 4 (PDE4) isolated from rat brain ($IC_{50}=0.015\;mg/ml$). All results from this study strongly suggest that the BuOH fraction of Lonicera japonica may be useful in the treatment of asthma and its mode of action may be related with inhibition of both 5-lipoxygenase and PDE4 enzyme.

Acyl-CoA: Cholesterol Acyltransferase (ACAT) is a key enzyme responsible for cholesteryl ester formation in atherogenesis and in cholesterol absorption from the intestines. In addition under pathological conditions, formation and accumulation of cholesteryl ester as lipid droplets by ACAT within macrophages constitute a characteristic feature of early lesions of atherosclerotic plaques. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. ACAT inhibitors of natural origin have been rarely reported. In our screening program for ACAT inhibitors, 303 plants were extracted with methanol or ethanol, and screened for the inhibitory activity against ACAT from the rat liver microsome. Extracts of 13 plants including Quercus aliena, Diospyros kaki, Platycarya strobilacea and Hibiscus syriacus inhibited more than 90% of ACAT activity and 43 samples in alcohol extracts such as Magnolia obovata and Panax ginseng also inhibited more than 70% of ACAT activity at a concentration of $100\;{\mu}g/ml$.

Tyrosinase plays an important role in the process of melanin polymer biosynthesis. Therefore, the enzyme inhibitors have been of great concern as cosmetics to have skin-whitening effects on the local hyperpigmentation. During the search for new inhibitory compounds on melanin polymer biosynthesis from natural sources, MeOH extracts of 589 higher plants were tested for the inhibitory effect on tyrosinase activity by the muschroom tyrosinase assay in vitro. Among plants tested, the leaves of Cercis chinensis exhibited potent inhibitory effect on mushroom tyrosinase activity. Subsequently seven active compounds were isolated from the ethyl acetate soluble part of acetone extract of the leaves of C. chinensis by the activity guided fractionation monitoring the inhibitory effect on tyrosinase activity. Their chemical structures were identified as $kaempferol-3-0-{\alpha}-L-rhamnoside$, quercitrin, $myricetin-3-0-{\alpha}-L-rhamnoside$, myricetin-3-0-(2'-O-galloyl)- ${\alpha}$ -L-rhamopyranoside (desmanthin), (-)-epicatechin-3-0-gallate, (-)-epigallocatechin-3-0-gallate, and methyl gallate on the basis of the speculation of spectral data and chemical reaction. Among the flavonol rhamnosides, myricetin-3-0-(2'-O-galloyl)- -L-rhamnoside(desmanthin) showed most potent inhibitory effect on tyrosinase activity and the structure of B-ring in flavonol moiety was related to the activity. (-)-Epigallocatechin-3-O-gallate having pyrogallol group in flavan-3-ol moiety exhibited more potent inhibitory effect than (-)-epicatechin-3-0-gallate having catechol group in flavan-3-ol moiety on mushroom tyrosinase activity.

SH2 domains and their associated catalytic or noncatalytic proteins constitute critical signal transduction targets for drug discovery. Grb2 associates with phosphotyrosine sites of the activated receptors or Shc via their SH2 domain to link receptor tyrosine kinases to ras signalling. Blocking of the Grb2-Shc complex may be to intervene the oncogenic signal transduction pathways and to develop a new antitumor drug. In the search for blockers of Grb2 SH2-Shc interaction, Lutein, a family of carotenoids, was isolated from the extract of the leaf of Agastache rugosa O. Kuntze as SH2 domain antagonists. The $IC_{50}$ of Lutein against Grb2-Shc binding was $6.8\;{\mu}M$.

The in vitro anticoagulant and fibrinolytic activities of crude extract from insects which have been used as traditional medicines. The extracts of Formica, Huechys and Eupolyph-aga/Steleophaga prolonged activated partial thromboplastin time and thrombin time compared to the value of the control. The fibrinolytic activity of insect extracts was also tested by fibrin plate method. We found that the extracts of Cicadae Periostracum, Eupolyphaga/Steleophdga, Mantidis $O{\ddot{o}}otheca$ and Huechys directly could hydrolyze the fibrin clot without the activation of plasminogen by plasminogen activators.

During the screening for inhibitors on nitric oxide (NO) production in LPS-activated murine macrophage, RAW 264.7 cells, two coumarins were isolated from chloroform extract of Ponciri Fructus. They were identified as imperatorin (10), phellopterin (11) on the basis of spectroscopic methods. The $IC_{50}$ values for NO formatiom were about $5.4\;{\um}M$ and $35.0\;{\um}M$, respectively, and then eleven coumarins were tested for the inhibitory effects on NO production in activated macrophages. All the test coumarins inhibited NO production in concentration-dependent manner and furanocoumarins (6-11) showed much more potent inhibitory effect than simple coumarins. Among the compounds examined xanthotoxin (8) was the most potent inhibitors of NO production $(IC_{50}=1.4\;{\mu}M)$. Analysis of the structure-activity relationship among these coumarins led to the conclusion that the substitution of C-5 position in furanocoumarins reduces greatly their inhibitory potency although the substitution of C-8 does not almost affect it.

$Three\;compounds-ethyl-{\beta}-D-glucopyranoside$, 1,2,3,7-tetramethoxyxanthone, 1,7-dimethoxyxanthone-were isolated from roots of Polygala tenuifolia. The structures of these compounds were establised on the basis of spectral evidence including 2D NMR and HMBC studies. $Ethyl-{\beta}-D-glucopyranoside$ was isolated for the first time from Polygala genus and HMBC data of these compounds were first reported.

From the EtOAc fraction of Dipsacus asper, four compounds have been isolated. On the basis of spectral data, these compounds were identified as protocatechuic acid, caffeic acid, 3,4-di-O-caffeoyl quinic acid and methyl 3,4-di-O-caffeoyl quinate.