Chungsook Kim

Pharmacokinetic analysis of rhein in Rheum undulatum L.

This research aims to identify the main active compounds of Rhei undulati Rhizoma (roots of Rheum undulatum LINNE) and determine the types of anthraquinones absorbed into the body and their pharmacokinetic parameters. The boiling-water extract of the herb was administered to 12 healthy volunteers (9 men/3 women) at a dosage of 100 mg/kg the anthraquinone levels in plasma were determined with TLC, HPLC, and LC-MS. Rhein was the only anthraquinone compound absorbed by the body as determined for plasma analysis of the volunteers. The elimination rate constant of rhein in Rhei undulati Rhizoma was 0.23+/-0.02/h and the half life was 3.38+/-0.35 h. This experiment confirmed that rhein is the most important active compound absorbed by the body among anthraquinones contained in Rhei undulati Rhizoma, indicating that rhein is a promising marker substance to evaluate Rhei Rhizoma and Rhei undulati Rhizoma.

Effects of Eucommiae Cortex on osteoblast-like cell proliferation and osteoclast inhibition.

Methanol extract (MeOH),n-hexane (Hx), chloroform (CHCI3), ethyl acetate (EA), butanol (BuOH) and aqueous (H20) fractions of Eucommiae Cortex including geniposidic acid (GA), geniposide (GP) and aucubin (AU) were tested for their therapeutic efficacy on osteoporosis. The contents of GA, GP and AU in the cortex and leaf ofEucommia ulmoides Oliver were quantified by HPLC. The effect of Eucommiae Cortex on the induction of growth hormone (GH) release was studied by using rat pituitary cells. The proliferation of osteoblast-like cells increased by herbal extracts was assayed using a tetrazolium (MTT), alkaline phosphatase (ALP) activity, and [3H]-proline incorporation assays. The inhibition of osteoclast was studied by using the coculture of mouse bone marrow cells and ST-2 cells. As a result, the GA, GP and AU were present in the cortex more than in the leaf ofE. ulmoides Oliver. The MeOH (1 mg/mL), Hx, CHCI3 and EA fractions (each 20 μg/mL) had potent induction of GH release. The CHCI3 exhibited the potent proliferation of osteoblasts. The AU, GP and GA were increased proliferation of osteoblasts. In addition, GA (IC50: 4.43x10-7 M), AU and GP were significantly inhibited proliferation of osteoclast. In summary, it is thought that the components in a part of the fractions of Eucommiae Cortex participate in each step of mechanism for activating osteoblast to facilitate osteogenesis, and suppress osteoclast activity to inhibit osteolysis.

Herbal extract prevents bone loss in ovariectomized rats

This research aims to test a new drug candidate based on a traditional medicinal herb, F1, an herbal extract obtained fromAstragalus membranaceus and its main ingredient, 1-monoli-nolein that may have fewer side effects and less uterine hypertrophy.In vitro experiments, human osteoblast-like cell lines, MG-63 and Saos-2, were analyzed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and an alkaline phosphatase (ALP) assays. Mouse osteoclasts were induced through a calcium-deficient diet and inhibition effects were measured.In vivo experiments were done using ovariectomized (OVX) rats for 9 weeks. At necropsy, uterus weights were measured, trabecular bone area (TBA) of tibia and lumbar vertebra were measured bone histomorphology. In results, cell proliferation and ALP activity in Saos-2 by ether F1 or 1-monolinolein did not increased significantly compared to the control. The F1 inhibited osteoclast development (IC25= 3.37×10−5 mg/mL) less than 17²-estradiol. The OVX rats administered F1 (2 mg/kg/day and 10 mg/kg/day) showed an increase in TBA of the tibia significantly (136.3±4.2% and 138.5±10.3% of control). In conclusions, the herbal extract, F1 inhibited tibia and lumbar bone loss and did not cause uterine hypertrophy. However, 1-monolinolein, the main ingredient of the herbal extract, did not inhibit bone loss.

Induction of growth hormone by the roots ofAstragalus membranaceus in pituitary cell culture

The traditional Asian medicinal herb, roots ofAstragalus (A.) membranaceus (Leguminosae), is used for many purposes, some of which are purported to stimulate the release of growth hormonein vivo. Extracts ofA. membranaceus were tested to determine whether they stimulate the release of growth hormone in rat pituitary cell culture.A. membranaceus was extracted sequentially with 80% ethanol (fraction A),n-hexane (fraction B); the test compound from the herbal extraction was isolated using silica gel column chromatography and was identified with spectral data. Test compound was also extracted by traditional boiling water methods. Induction of growth hormone in pituitary cell culture was conducted with isolated compounds and extracted fractions ofA. Radix (dried roots ofA. membranaceus). The fraction A was not active in the rat pituitary cell culture, but the fraction B derived from the ethanol fraction stimulated the release of growth hormone in culture. Six compounds from fraction B (1–6) were isolated and identified previously. The compounds 1,2-benzendicarboxylic acid diisononylester (1), ν-sitosterol (2), and 3-O-β-D-galactopyranosyl-β-sitosterol (5) did not induce growth hormone release in the culture. Formononetin (3), 9Z,12Z-octadecadienoic acid (4), stiqmast-e-en-6β-ol-3-one (6) and 98-E, a mixture of 1′-9,12-octadecadienoic acid (Z,Z)-2′,3′-dihydroxy-propylester (7) and 1′-hexadecanoic acid-2′,3′-dihydroxy-propylester (8) stimulated the release of growth hormone in the rat pituitary cell culture significantly compared to the control. In conclusions, four compounds isolated from extracts ofA. Radix induced growth hormone release in the rat pituitary cell culture. The 98-E isolate was the most active inducer of growth hormone release.

RAT GROWTH-HORMONE RELEASE STIMULATORS FROM FENUGREEK SEEDS

Bioassay‐guided fractionation of MeOH extract from fenugreek (Trigonella foenum‐graecum L.) seeds resulted in the isolation of two rat growth‐hormone release stimulators in vitro, fenugreek saponin I (1) and dioscin (9), along with two new, i.e., 2 and 3, and five known analogues, i.e., 4–8. The structures of the new steroidal saponins, fenugreek saponins I, II, and III (1–3, resp.), were determined as gitogenin 3‐O‐β‐D‐xylopyranosyl‐(1→6)‐β‐D‐glucopyranoside, sarsasapogenin 3‐O‐β‐D‐xylopyranosyl‐(1→6)‐β‐D‐glucopyranoside, and gitogenin 3‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐glucopyranoside, respectively. Fenugreek saponin I (1) and dioscin (9) caused ca. 12.5‐ and 17.7‐fold stimulation of release, respectively, of rat growth hormone from rat pituitary cells, whereas gitogenin (5) showed moderate activity. To our knowledge, this is the first study to demonstrate that steroidal saponins stimulate rat growth‐hormone release in rat pituitary cells.

study of substance changes in flowers ofpueraria thunbergiana benth. during storage

Puerariae Flos is a traditional herbal medicine that has long been used as a treatment for colds, diabetes, and hangovers. The herbal medicine contains a wide variety of isoflavones such as kakkalide, tectoridin, and tectorigenin. This study demonstrates that the substances undergo a certain degree of change depending on the storage period by the method of HPLC andp13C-NMR, and that the HPLC analysis can be used to determine the freshness of Puerar-iae Flos.

Formononetin Prevents Ovariectomy-Induced Bone Loss in Rats

The major risk factor of postmenopausal osteoporosis is estrogen deficiency. Hormone replacement therapy is efficacious against osteoporosis, but it induces several significant adverse effects. In this study, therefore, we compared therapeutic potencies of three phytoestrogens: genistein, daidzein, and formononetin. Our result showed that in Saos-2 cells, formononetin and genistein (5 × 10−7 M) treatment increased alkaline phosphatase activity by 33.0 ± 5.8% and 21.1 ± 4.0%. Genistein inhibited osteoclast formation in a dose-dependent manner. In OVX rats, formononetin-treated groups given 1 and 10 mg/kg/day displayed increased trabecular bone areas (TBAs) within the tibia. Genistein- and daidzein-treated groups also displayed increased tibial TBAs. TBAs of the lumbar vertebrae were higher in all treated groups than in the control group. In conclusion, formononetin as well as other isoflavones, such as daidzein and genistein, inhibited bone loss caused by estrogen-deficiency.

High performance liquid chromatographic analysis of isoflavones in medicinal herbs.

Phytoestrogens have been used as a food supplement to prevent osteoporosis. The isoflavones in the phytoestrogens are daidzein, genistein and formononetin which are present in various herbs. This study examined the quantity of isoflavones in medicinal herbs, which can be used as a phytoestrogen supplement; soybean. These isoflavones were quantified using high performance liquid chromatography (HPLC) with a UV/VIS detector. The concentration of daidzein in Puerariae Radix was 10,436.16±2, 143.83 mg/kg of the dried herb, which was much higher than that extracted from soybeans, 341.47±18.96 mg/kg. The amount of genistein in Sophorae flavescentis Radix (336.09±50.89 mg/kg) was approximately 11 times higher than that extracted from soybean (30.03±7.17 mg/kg). The level of formononetin in Dalbergiae odoriferae Lignum, 2,189.14±136.46 mg/kg, was the highest among the herbs tested. The total isoflavone content of Puerariae Radix was approximately 30 times higher than that extracted from soybean. Therefore, plants from the family Leguminosae, particularly Puerariae Radix can be a good source of phytoestrogens.

Norditerpenoid and dianthramide glucoside alkaloids from cultivated Aconitum species from korea.

A new norditerpene alkaloid named 8-O-methylhypaconine (1) was isolated along with twelve known alkaloids from the underground parts of an unknown species ofAconitum plant culti-vated in Korea. Among the known alkaloids, two dianthramide glucosides, N-(2′-β-glucopyra-nosyl-5′-hydroxysalicyl)-5-hydroxyanthranilic acid methyl ester (2) and N-(2′-β-glucopyranosyl-5′-hydroxysalicyl)-5-hydroxy-6-methoxyanthranilic acid methyl ester (3), were isolated fromAconitum plants for the first time. The structures were established on the basis of chemical and spectroscopic methods.