Ginseng (the root of Panax ginseng C.A. MEYER, Araliaceae) is frequently taken orally, as a crude substance, as a traditional medicine in Asian countries. The major components of ginseng are ginsenosides, which contain an aglycone with a dammarane skeleton.1,2) These ginsenosides have been reported to exhibit various biological activities, including anti-inflammatory action and antitumor effects (inhibition of tumor-induced angiogenesis and the prevention of tumor invasion and metastasis). [3][4][5] The pharmacological actions of these ginsenosides have been explained by their biotransformation by human intestinal bacteria. [6][7][8] For example, protopanaxadiol ginsenosides are transformed to 20-O-b-D-glucopyranosyl-20(S)-protopanaxadiol (compound K) by human intestinal bacteria. The metabolite compound K induces an antimetastatic or anticarcinogenic effect by blocking tumor invasion or preventing chromosomal aberration and tumorigenesis.5) Ginsenosides Re and Rg1 are also transformed to ginsenoside Rh1 or 20(S)-protopanaxatriol, which have exhibited potent antiallergic and antiinflammatory effects. [9][10][11][12] However, the antiiflammatory effect of protopanaxadiol ginsenosides, such as ginsenoside Rb1, and compound K, has not been studied.Therefore, we isolated ginsenoside Rb1 from ginseng and its metabolite compound K and investigated the antiinflammatory effect of ginsenoside Rb1 and its metabolite compound K (Fig. 1), using RAW264.7 cell induced by lipopolysaccharide (LPS). The RAW 264.7 cells were purchased from the Korean Cell Line Bank (Seoul, Korea). MATERIALS AND METHODS Materials Isolation of Ginsenoside Rb1 and Its Metabolite Compound K by Human Intestinal Microflora GinsenosideRb1 and compound K were isolated from fermented Ginseng according to the previously published method.2,13) Ginsenoside Rb1 (2 g) from a BuOH extract of white ginseng (Kyung Dong Market, Seoul, Korea), was isolated by silica gel column chromatography using CHCl 3 -MeOH-H 2 O (10 : 3 : 1, lower layer), according to the previously reported methods.Fresh human feces (5 g) were suspended in TS broth, centrifuged at 500ϫg for 10 min, and the resulting supernatant * To whom correspondence should be addressed. Hoegi, Dongdaemun-ku, Seoul 130-701, Korea: and b Korea Food Research Institute; San 46-1, Baekhyun, Bundang-Ku, Seoungnam-Shi 463-420, Korea. Received August 25, 2004; accepted December 2, 2004 In this study, the antiinflammatory activities of ginsenoside Rb1, which is a main constituent of the root of Panax ginseng (Araliaceae), and of its metabolite compound K, as produced by human intestinal bacteria, on lipopolysaccharide (LPS)-induced RAW264.7 cells were investigated. Compound K potently inhibited the production of NO and prostaglandin E2 in LPS-induced RAW 264.7 cells, with IC 50 values of 0.012 and 0.004 mM, respectively. Compound K also reduced the expression levels of the inducible NO synthase (iNOS) and COX-2 proteins and inhibited the activation of NF-kB, a nuclear transcription factor. Compound K inhibite...

Ginseng (the root of Panax ginseng C. A. MEYER, family Araliaceae) has been used as a herbal medicine in China, Korea, Japan and other Asian countries. Its major components are ginsenosides, which are glycosides with a dammarane skeleton.1,2) When ginseng is steamed at 98-100 ЊC, it is called Red Ginseng (RG). Their main components are different: the former is a ginsenoside Rb1, and the latter is a ginsenoside Rg3.3) These results suggest that the ginsenosides could be easily transformed under steaming. These ginsenosides have been reported to show various biological activities including anti-inflammatory, 4) antiallergic, 5,6) antitumor, 7-11) vascular relaxation, 12) and hepatoprotective activities. 13,14) To express these pharmacological actions, it is thought that ginseng saponins must be metabolized by human intestinal microflora after being taken orally. 7,15,16) For example, ginsenosides Rb1, Rb2 and Rc are metabolized to compound K by human intestinal microflora, and the ginsenoside Rg3 is metabolized to ginsenoside Rh2 by human intestinal microflora.17) The transformed compound K and ginsenoside Rh2 induces an anti-metastatic or anti-carcinogenic effect.8,11) However, the relationship between hepatoprotective effects of RG and the metabolism of its main constituent ginsenoside Rg3 have not been thoroughly studied.Therefore, we transformed 20(S)-ginsenoside Rg3 by human intestinal bacteria, isolated its metabolite 20(S)-ginsenoside Rh2, and investigated their hepatoprotective effects on HepG2 cells and mice injured by tert-butyl hydroperoxide (t-BHP). MATERIALS AND METHODSMaterials Diagnostic kits for aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were purchased from Asan Pharmaceutical Co., Ltd. (Seoul, Korea). Silybin was purchased from Carl Roth (Karlsruhe, Germany). Minimum essential medium (MEM), fetal bovine serum (FBS) and antibiotics-antimycotics were obtained from Gibco BRL (Fig. 1) were isolated according to the previous method. 18)Culture of HepG2 Cells and Its Hepatoxicity Induction by t-BHP HepG2 cells (hepatocellular carcinoma cell line) donated from the Korean Cell Bank (Seoul, Korea) were cultured in MEM containing 10% FBS, 1% antibiotic-antimycotic solution, 1mM sodium pyruvate and 1.5 g/l sodium bicarbonate under 5% CO 2 at 37 ЊC. The protective effect of ginsenosides on HepG2 cells injured by t-BHP was measured using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. 19) Briefly, HepG2 cells were dispensed into 96 well plates at the concentration of 1ϫ10 4 cells per well. The test compounds were added into HepG2 cells, and preincubated for 2 h. Then the cultured media were replaced to the media containing t-BHP (100 mM), incubated for 3 h and then rinsed with phosphate-buffered saline. MTT reagent (0.25 mg/ml) was added into the cells, incubated for 1 h, and then added 100 ml of dimethylsulfoxide. Absorbance * To whom correspondence should be addressed. e-mail: dhkim@khu.ac.kr © 2005 Pharmaceutical Society of Japan Hepatoprotective Ef...

Abstract. To clarify the hepatoprotective effects of tectoridin and tectorigenin from Puerariae Flos, their effects on tert-butyl hyperoxide (t-BHP)-injured HepG2 cells and mice were investigated. When tectorigenin at a dose of 50 mg / kg was intraperitoneally administered to mice injured by t-BHP, it significantly inhibited the increase the activities of plasma ALT and AST by 39% and 41%, respectively, in the t-BHP-treated group. The inhibitory effect of tectorigenin is much more potent than that of a commercially available dimethyl diphenyl bicarboxylate. Orally administered tectoridin showed hepatoprotective activity. However, when tectoridin was intraperitoneally administrated to mice, no hepatoprotective activity was observed. Tectorigenin also protected against the cytotoxicity of HepG2 cells induced by t-BHP. This protection may have originated from the inhibition of apoptosis. Tectorigenin may be hepatoprotective and tectoridin should be a prodrug that is transformed to tectorigenin.Keywords: tectorigenin, HepG2, hepatic injury t-Butyl hydroperoxide (t-BHP) can be metabolized to free radical intermediates by cytochrome P450 (hepatocytes) or hemoglobin (erythrocytes), which can subsequently initiate lipid peroxidation (1), affect cell integrity, and form covalent bonds with cellular molecules, resulting in cell injury (2). t-BHP is known to cause lactate dehydrogenase and alanine transferase (ALT) leakage in hepatocyte cells (3, 4). Therefore, t-BHP has been used as a chemical inducer for the preparation of a liver injured animal model (5, 6).In traditional Chinese medicine, Puerariae Flos has been used in therapy to counteract the problems associated with alcohol drinking and liver injury (7). Niiho et al. (8,9) reported that the isoflavonoid fraction of Puerariae Flos suppressed the increase in the concentration of blood ethanol, acetaldehyde, and ketones induced by ethanol administration and that its isoflavonoid and triterpenoid saponin fractions improved both the abnormal metabolism induced by ethanol and hepatic injuries induced by carbon tetrachloride or highfat food. Jang et al. (10) reported that Puerariae Flos protected against ethanol-induced apoptosis in the human neuroblastoma cell line SK-N-MC. Lee et al. (11) reported that tectorigenin isolated from Puerariae Flos as an inhibitor of b-glucuronidase showed hepatoprotective activity on the CCl 4 -induced hepatotoxicity in mice.To clarify the hepatoprotective effects of isoflavones tectorigenin and tectoridin (Fig. 1) from Puerariae Flos, tectoridin was isolated from Puerariae Flos and its metabolite tectorigenin from human fecal microflora, and then we investigated their effects in t-BHP-injured HepG2 cells and mice.*Corresponding author. FAX: +82-2-957-5030 E-mail: dhkim@khu.ac.kr

To clarify the hepatoprotective effects of kakkalide and its metabolite irisolidone by human fecal microflora, their effects on tert-butyl hydroperoxide (t-BHP)-injured HepG2 cells and mice were investigated. Irisolidone protected HepG2 cells against cytotoxicity induced by t-BHP. However, kakkalide did not protect cytotoxicity. When kakkalide 100 mg/kg was orally administered to mice injured by t-BHP, it significantly inhibited the increase in plasma alanine aminotransferase and aspartate aminotransferase activities by 84% and 85% of t-BHP-treated control group, respectively. The inhibitory effect of kakkalide is much more potent than that of silybin, a hepatoprotective agent. However, intraperitoneally administered kakkalide did not exhibit hepatoprotective activity. When irisolidone was intraperitoneally administered to mice, it exhibited potent hepatoprotective activity. Based on these findings, irisolidone can be hepatoprotective and kakkalide may be a prodrug transformed to irisolidone.

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