Aldose reductase (AR), the principal enzyme of the polyol pathway, has been shown to play an important role in the diabetic complications, including diabetic cataract. The inhibitors of AR, therefore, would be potential agents for prevention of diabetic complications. As part of our ongoing project directed toward the discovery of preventive and/or treatment for diabetic complications, 48 Korean herbal medicines have been investigated with an in vitro evaluation system using aldose reductase inhibitory activities. Of these, 12 herbal medicines exhibited a significant inhibitory activity against aldose reductase. Particularly, seven herbal medicines, i.e., Eurya japonica, Chrysanthemum indicum, Akebia quinata, Saururus chinensis, Catalpa bignonioides, Lonicera japonica, Vitex rotundifolia showed two times more potent inhibitory activity than the positive control 3.3-tetramethyleneglutaric acid (TMG). In addition, Catalpa bignonioides showed the retardation of cataract-opacification of the lens of the eye under diabetic condition by xylose. Therefore, this result may provide a potential therapeutic approach for preventing and treating diabetic cataracts.

Melanin is a polymer of phenol which produces hyperpigmentation in the skin. Melanin synthesis is catalyzed by the enzyme tyrosinase. To investigate the whitening activity of the fractions from the ethanol extract of Enteromorpha linza, we studied the inhibitory effect on the tyrosinase activity and melanogenesis in the B16/F1 melanoma cells. The inhibition ratio of tyrosinase activity of ethylacetate fraction from E. linza was as strong as that of kojic acid, a positive control. Also, the melanin production was significantly inhibited by the ethylacetate fraction in a dose dependent manner. The ethylacetate fraction showed the highest activity in the fractions and as strong activity as that of arbutin, a positive control. From these results, we suggest that the E. linza extract might be able to apply to cosmetic and medical fields.

Three species, such as Rheum palmatum L., R. tanguticum Maxim. and R. officinale Baillon are recognized as the source plants of Rhei Rhizoma in Korean Pharmacopeia. However, other herbal sources such as R. undulatum L. and Rumex crispus L. have been often misused as Rhei Rhizoma. A pattern analysis method to discriminate Rhei Rhizoma in Korean Pharmacopeia from other herbal plants using HPLC and TLC chromatograms was developed. The multivariate peak data of the chromatograms of methanol extracts of Rhei Rhizoma were used for hierarchical clustering analysis, principal components analysis and similarity calculation. Besides of the statistic analysis, TLC patterns of samples could be used as criteria of the discrimination. The developed pattern analysis method was specific and could be readily utilized for comprehensive evaluation of Rhei Rhizoma.

Astragali Radix, known as Huangqi, is the most important tonic in the traditional oriental medicine. It reinforces 'qi' (vital energy), strengthens the superficial resistance and promotes the discharge of pus and the growth of new tissue. It has long been used as an anti-perspirant, anti-diuretic or a tonic. Eleven compounds were isolated from the hexane and EtOAc fractions from the roots of Astragalus membranaceus (Leguminosae) and their structures were identified as four triterpenoids [lupenone (1), friedelin (2), lupeol (3), soyasapogenol E (9)] and seven sterols [${\beta}-sitosterol$ (4), stigmastane-3,6-dione (5), $7{\alpha}-hydroxysitosterol$ (6), $5{\alpha},6{\beta}-dihydroxysitosterol$ (7), $7-oxo-{\beta}-sitosterol$ (8), ${\beta}-sitosterol$ glucoside 6'-O-palmitate (10), ${\beta}-sitosterol$ glucoside (11)]. The chemical structures of these compounds were identified on the basis of spectroscopic methods and comparison with literature values. Among these compounds, lupenone (1), friedelin (2), lupeol (3), stigmastane-3,6-dione (5), $7{\alpha}-hydroxysitosterol$ (6), $5{\alpha},6{\beta}-dihydroxysitosterol$ (7), $7-oxo-{\beta}-sitosterol$ (8), soyasapogenol E (9), and ${\beta}-sitosterol$ glucoside 6'-O-palmitate (10) were isolated from this plant for the first time.

Artemisia capillaries is a major important food and medicinal resource in Korea. In order to confirm the biological activities of Artemisia capillaries, we investigated antioxidant and anticancer activities from in vitro assays. The Artemisia capillaries methanol (MeOH) extracts was used for the evaluation of DPPH scavenging, total phenolic content, total flavonoid content, hydroxyl radical (${\bullet}OH$) scavenging, reducing power assay as antioxidant activity, as well as anticancer activities as MTT assay. As a result, the Artemisia capillaries MeOH extracts showed potent antioxidative activity and anticancer activity in vitro. These results suggest that the Artemisia capillaries MeOH extracts have a potential alleviated oxidation process, cell motility activity, and tumorigenesis.

A high performance liquid chromatographic (HPLC) method for the simultaneous determination of hesperidin and glycyrrhizin was established for the quality control of traditional herbal medicinal preparation, Pyungwi-san (PWS). Separation and quantification were successfully achieved with a Waters XTerra RP18 column ($5{\mu}m$, 4.6 mm I.D. ${\times}$ 150 mm) by gradient elution of a mixture of acetonitrile and water containing 0.03% phosphoric acid (pH 2.03) at a flow rate of 1.0 ml/min. The diode-array UV/vis detector (DAD) was used for the detection and the wavelength for quantification was set at 230 nm. The presence of hesperidin and glycyrrhizin in this extract was ascertained by retention time, spiking with each authentic standard and UV spectrum. All four compounds showed good linearity $(r^2>0.995)$ in a relatively wide concentration ranges. The R.S.D. for intra-day and inter-day precision was less than 7.0% and the limits of detection (LOD) were less than 60 ng. The mean recovery of each compound was 99.0-105.6% with R.S.D. values less than 4.0%. This method was successfully applied to the determination of contents of hesperidin and glycyrrhizin in three commercial products of PWS. These results suggest that the developed HPLC method is simple, effective and could be readily utilized as a quality control method for commercial PWS products.

Man Kyung Dan(萬經丹) is a Chinese patent medicine which has been used for rheumatic neuralgia, apoplexy, extremitas neurolepsis in Korea. It consists of 16 kinds of powdered crude drugs. In powered crude drugs, it is hard to identify each component by chemical analysis or morphological examination. However, the method of identification of powdered crude drugs has not been clearly established. For the identification of individual crude drugs in such powdery mixtures, microscopic method may advantageously be used, as it requires only small amount of specimens. In this study, it is demonstrated that the microscopic method is very effective for the identification of 16 crude drug ingredients in Man kyung Dan.

Seung Ma(升摩) is a famous Chinese crude drug used for treatment of fever, piles and suppurative inflamation. With regard to the botanical origin of Seung Ma, it has been considered to be Cimicifuga spicies of Ranunculaceae, but there has no phrarmacognostical confirmation on it. To clarify the botanical origin of Seung Ma from Korea, the anatomical characteristics of Cimicfuga dahurica, Cimicifuga foetida, Cimicfuga heracleifolia and Cimicifuga simplex were studied. As a result, it was clarified that Seung Ma from Korea was the rhizomes of Cimicifuga dahurica, C, foetida and C, heracleifolia.

Oxidative stress is considered to play an important role in a variety of neurodegenerative disorders of central nervous system. The immortalized mouse hippocampal cell line, HT22, phenotypically resembles neuronal precursor cells but lacks functional ionotropic glutamate receptors, thus excluding excitotoxicity as a cause for glutamate triggered cell death. Therefore, HT22 cells are a useful model for studying oxidative glutamate toxicity. In this study, we examined whether the methanol extracts of some native plants at Mt. Baekdu could protect HT22-immortalized hippocampal cells against glutamate-induced oxidative stress. Seventy-eight plants sources were collected at Mt. Baekdu, and extracted with methanol. These extracts had been screened the protective effects against glutamate-induced oxidative damage in HT22 cells at the 100 and 300 ${\mu}g/ml$. Of these, thirteen methanolic extracts, Acer mono (leaf), Artemisia stolonifera (aerial part), Carduus crispus (aerial part), Carex mongolica (whole plant), Clematis hexapetala (whole plant), Galeopsis bifida (aerial part), Galium verum (whole plant), Ganoderma lucidum (whole plant), Ixeris chinensis (whole plant), Malva verticillata (aerial part), Polygonum senticosum (whole plant), Rebes mandshricum (branch), and Taraxacum mongolicum (aerial part), showed significant protective effects against glutamate-induced oxidative damage in HT22 cells.

This study was carried out to establish standard analytical methods for Ginkgo biloba leaf extract. Ginkgo flavonoids, terpene lactones, ginkgolic acids were employed as reference compounds for analytical method. Analytical method of US Pharmacopoeia was adopted for flavonoids and terpene lactones, and a new method was developed for ginkgolic acids. Analytical methods established in this study could be applied to a reasonable and unified quality control of G. biloba leaf extract.

Advanced glycation end products (AGEs) contribute to the progression of micro and macrovsacular complication of diabetes and therefore present a promising target for therapeutic agents. In this study, 40 Korean herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 21 herbal medicines $(IC_{50}<50{\mu}g/ml)$ exhibited an inhibitory activity against AGEs formation compared with anminoguanidine $(IC_{50}=72.12{\mu}g/ml)$. Particularly, 7 herbal medicines, Actinidia arguta (root and stem), Crataegus pinnatifida (twig), Camellia japonica (whole), Kalopanax pictus (bark), Lagerstroemia indica (leaf-stem), Reynoutria sachalinensis (root) showed more potent inhibitory activity (approximately 3-10 fold) than the positive control aminoguanidine.

Antidiabetic effects of an aqueous and solvent extract prepared from the root, stem and fruit parts of Acanthopanax senticosus, were investigated in experimental Streptozotocin (STZ)-induced diabetic rats model. The n-butanol and water extracts of A. senticosus were orally administrated once a day for 6 days. The n-butanol extracts of fruit (FB) showed highest efficiency than other groups (water extracts of stem, root and fruit; butanol extracts of stem, root) on serum glucose values in the STZ-induced diabetic rats. We have studied gene expression of glucose transporter genes in C2C12 skeletal muscle cell line during differentiation treated by the n-butanol and water extracts of A. senticosus, SW, RW, FW, SB, RB and FB. The GLUT4 gene was high expressed by FB treatment. These findings suggest that FB of A. senticosus have GLUT4 gene expression activity for glucose homeostasis and may have beneficial effects on blood glucose lowering in the diabetic patients.

In order to find the antioxidative components, fractionation of Cyperus amuricus (Cyperaceae) methanol extract was performed by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging effect. Three compounds, 3,4-dimethoxy benzoic acid (1), 4-hydroxybenzoic acid (2), and piceatannol (3) were isolated from the active ethylacetate soluble fraction of C. amuricus through repeated silica gel and Sephadex LH-20 column chromatography. Among them, compound 3 showed the significant antioxidative effect on DPPH free radical scavenging test. These compounds are reported for the first time from this plant.

C-22 is one of health food made in Han Kook Shin Yak. For studying its antitumor activity, the 50% ethanol extract from C-22 was tested on BDF1 mice bearing LLC tumor cell by Teruhiro’s method. The samples were intraperitoneally injected to mice once a day with a daily dose of 50, 100, and 200 mg/kg for 14 consecutive days. Taxol was used as positive control with a dose of 50 mg/kg. As a result, the C-22's extracts dose dependently inhibited the tumor volume with the IRTV values of 28.7, 46.7, 58.9% and the IRTW values of 28.1, 46.0, 57.8% in 50, 100, and 200 mg/kg, respectively, while the Taxol showed antitumor activity with IRTV and IRTW values of 68.5 and 67.3% in 50 mg/kg. No loss of body weight was observed at any samples. This data suggested that the C-22's antitumor activity was enough to use as a cancer chemopreventive agent, and it will be used for preventing cancer as health food.

Quantitative methods for the marker compounds of Cimicifugae Rhizoma, Achyranthis Radix, Artemisiae Capillaris Herba, Moutan Cortex Radicis and Arecae Semen, respectively, were developed using HPLC-DAD. Using the established methods, each extract of the natural medicines were evaluated. In addition, long term and accelerated stability test in the extracts were examined for six months. No significant change in content of the marker compounds of each extract observed during the time of investigation.

Six prenylated xanthones, cudraxanthone B (1), isocudraxanthone K (2), cudraxanthone H (3), cudratricusxanthone A (4), cudraxanthone L (5) and macluraxanthone B (6), have been isolated from the MeOH extract of Cudrania tricuspidata root barks. The evaluation for antibacterial effect of compounds 1-6 against the pathogenic microorganisms concerning with public health or zoonosis was conducted. Of these, compound 4 showed significant antibacterial effect in disk diffusion method.

An 80% EtOH extract and the solvent fractions of the seeds of Cornus officinalis were evaluated for their inhibitory activities against advanced glycation end products (AGEs) formation and AGEs-induced protein cross-linking in vitro. In vitro assay for AGEs-bovine serum albumin (BSA) formation showed that the 80% EtOH extract, n-hexane, EtOAc, n-BuOH and water fractions significantly inhibited AGEs formation with observed $IC_{50}$ values of 1.13, 17.64, 1.52, 1.24 and $3.27{\mu}g/ml$, respectively. In indirect AGEs-ELISA assay, the 800% EtOH extract, EtOAc and n-BuOH fractions exhibited more potent inhibitory activity on AGEs-BSA formation than aminoguanidine, a well know AGEs inhibitor. Furthermore, the 80% EtOH extract and all the solvent fractions inhibited concentration-dependently AGE-BSA cross-linking to collagen. The 80% EtOH extract, EtOAc, n-BuOH and water fractions also had a breaking activity against preformed AGE-BSA cross-linking concentration dependently. Thus these results suggest that the 80% EtOH extract and fractions of the seeds of C. officinalis could be an inhibitor as well as breaker of AGE-BSA cross-linking.

This study was investigated antioxidant and anticancer activity of water, methanol extract from upper and root part of Taraxacum mongolicum H. Total phenolic compound contents of methanol and water extracts from upper part were $51.95{\pm}0.18$ mg/g and $48.16{\pm}0.89$ mg/g respectively, and total flavonoid compound contents were estimated as $20.57{\pm}1.12$ mg/g in methanol extract and $6.55{\pm}1.20$ mg/g in water extract. $EC_{50}$ values for DPPH radical scavenging activity of methanol and water extract from upper part were $138.47{\pm}3.78{\mu}g/mL$ and $204.38{\pm}5.32{\mu}g/mL$, and methanol and water extracts from root part were as $512{\pm}8.11{\mu}g/mL$ in methanol extract and $1315.05{\pm}11.98{\mu}g/mL$ in water extract. Reducing power and hydroxyl radical $({\bullet}OH)$ scavenging activity estimated that methanol extract of each part were higher than water extracts. The cell viability showed that the methanol extract from upper part had a cytotoxicity in the growth of colon carcinoma cell (44.58%). Both water extract $(51.97{\pm}11.43%)$ from upper part and methanol $(53.46{\pm}19.77%)$, water $(52.79{\pm}13.53%)$ extracts from root part had quite higher cytotoxicity than that of methanol extract $(88.25{\pm}2.02%)$ from upper part. Based on the results, It was suggested that the methanol extract of Taraxacum mongolicum H. were potential materials for use as functional food and medicine.

Eight compounds were isolated from the EtOAc soluble fraction of Euphorbia supina MeOH extract as the radical scavengers for antioxidant activity. Their structures were identified as kaempferol (1), quercetin (2), juglanin (3), avicularin (4), astragalin (5), isoquercitrin (6), hyperin (7), and nicotiflorin (8) by spectroscopic analysis. The antioxidant activity was evaluated by the ORAC (oxygen radical absorbance capacity) assay, which measures scavenging activity against peroxy radicals induced by 2,2'-azobis (2-methylpropionamidine) dihydrochloride, and the ORAC value is expressed as relative trolox equivalent. Compounds 4, 6, and 7 exhibited potent antioxidant activity, whereas the other compounds showed weaker activity than trolox.

This study was carried out to observe the antioxidative activity, fibrinolytic activity, nitrite savenging ability and adenosine content of three medicinal mushrooms. Among water and ethanol extract of each mushroom, water extract of Inonotus obliquus (Czech) showed the highest antioxidative activity $(57.1{\mu}g/ml)$, nitrite scavenging ability (52.04%), fibrinolytic activity (86.8%) and adenosin content $(94.3{\mu}g/g)$, whereas nitrite scavenging ability of ethanol extract of Phellinus linteus showed higher than that of water extract. Apart from the above statements, water was effective than ethanol as extracting solvent in general. These results suggest that Inonotus obliquus (Czech) showed higher activities such as antioxidative activity, nitrite scavenging ability, fibrinolytic activity and adenosin content and water was effective as solvent except for nitrite scavenging ability.