• The Korean Journal of Zoology
• /
• v.27 no.4
• /
• pp.221-230
• /
• 1984

The activities of aminopyrine demethylase which is marker enzyme of the microsomal drug-metabolizing system, NADPH-cytochrome a reductase and glutathione peroxidase were measured during the course of liver regeneration after about seventy percent hepatectomy in Wistar rats. In addition, the extent of lipid peroxidation and contents of cytochrome P-450 were also measured. Partial hepatectomy produced a significant depression in aminopyrine demethylase, to reach a minium about 24 hours after operation, but this activity was increased to normal value during regeneration. On the other hand, in sham-operated animals, this showed no change. All the activities of NADPH-chrome P-450 contents of liver microsomes were rapidly decreased at the early stage of regeneration. These values returned to normal after 7 days. By contrast, the activity of glutathione peroxidase was nearly unchanged. According to these results, at the early stage of regeneration, the decrease of cytochrome P-450 and NADPH-cytochrome c reductase activity lead to decrease of lipid peroxidation and drug metabolizing enzyme activity. But these phenomena were not detected after 7 days of regeneration.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.1
• /
• pp.43-49
• /
• 2003

Metabolism of a new fungicide ethaboxam by soil fungi was studied. Among the fungi tested, Cunninghamelia elegans produced metabolites from ethaboxam, which were not found in the control experiments. M5, a major metabolite from ethaboxam was firmly identified as N-deethylated ethaboxam by LC/MS/MS and NMR. N-Deethylated ethaboxam has been found as a single metabolite in in vitro metabolism with rat liver microsomes. Ml was proved to be 4-ethyl-2-(ethylamino)-1,3-thiazole-5-carboxamide (ETC) by comparing with the authentic compound. In addition, M2, M3, and M4, and M6 were tentatively Identified by LC/MS/MS as hydroxylated and methoxylated ethaboxams, respectively. Production of the major metabolite, N-deethylated ethaboxam, by the fungus suggested that C. elegans would be an efficient eukaryotic microbial candidate for evaluating xenobiotic-driven mammalian risk assessment.

• Korean Journal of Medicinal Crop Science
• /
• v.10 no.4
• /
• pp.269-272
• /
• 2002

Ethanol and butanol fractionation of E. senticosus showed strong anti-oxidant activity, and methanol and water extracts also had high anti-oxidant activity. The anti-oxidant activities in ethanol and butanol fractionation were higher than or similar to those of ${\alpha}-tocopherol$. The cytotoxic effect of root extract of E. senticosus was evaluated on seven different human cancer cell lines, The extracts of leaf and stem of E. senticosus also had strong antioxidant activity, but the antioxidant activity in root extract was higher than those in leaf and stem extracts. Methanol, hexane, and aqueous fraction layer had much higher inhibitory activities on lipid peroxidation in rat liver microsomes compared with ${\alpha}-tocopherol$. The effect of root extract of E. senticosus was evaluated on six human cancer cell lines. The values of 50% growth inhibition $(GI_{50})$ for the extracts were mostly below $30{\mu}g/ml$, and the extracts are considered as active inhibitory compounds on cancer cells.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.1
• /
• pp.183-187
• /
• 2005

Abstract The cancer chemopreventive potential of chitosanoligosaccharides was investigated by measuring the induction of quinone reductase and glutathione S-transferase activities and inhibition of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide I (1-${\kappa}$Da${\kappa}$Da) significantly induced glutathione S-transferase activity with a maximal 1.5-fold increase at 500 ${\mu}$g/ml, while chitosanoligosaccharide II (3-${\kappa}$Da${\kappa}$Da) (500 ${\mu}$g/ml) strongly induced quinone reductase (p<0.01) and glutathione S-transferase (p<0.005) activities. The in vitro incubation of rat liver microsomes with chitosanoligosaccharides I and II (2.5, 5, 50, and 500 ${\mu}$g/ml) showed a dose-dependent inhibiton of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide II was a more potent inhibitor of cytochrome P450 2B1 activity than chitosanoligosaccharide I. Accordingly, these findings suggest that chitosanoligosaccharides are potential chemopreventive agents.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.67-67
• /
• 1995

Acyl-CoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) plays an important role in the control of intracellular free cholesterol content via its cholesterol esterifying activity. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. In the course of a screening program for ACAT inhibitors from microbial sources, GERI-BP001 M, A, and B were isolated from the fermentation broth of a fungal strain. GERI-BP001 compounds were isolated from a culture broth of Aspergillus fumigatus F37 by acetone extraction, EtOAc extraction, SiO$_2$ column chromatography, and reverse phase HPLC. The structure of GERI-BP001 coumpounds were determined by $^1$H-NMR, $\^$l3/C-NMR, 2D-NMR, NOESY, and long range C-H COSY experiments. GERI-BP001 M, A, and B inhibit ACAT activity in an enzyme assay system using rat liver microsomes by 50% at concentrations of 75, 147, and 71 ${\mu}$M, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.11
• /
• pp.1785-1788
• /
• 2008

Phenylpyropenes A, B, and C, isolated from Penicillium griseofulvum F1959, inhibited DGAT in rat liver microsomes with $IC_{50}$ values of $78.7{\pm}1.6$, $21.7{\pm}0.2$, and $11.04{\pm}0.2{\mu}M$, respectively. In addition, a kinetic analysis using a Lineweaver-Burk plot revealed that phenylpyropene C was a noncompetitive inhibitor of DGAT. The apparent Michaelis constant ($K_m$) value and inhibition constant ($K_i$) value were calculated to be $8{\mu}M$ and $10.48{\mu}M$, respectively. Moreover, phenylpyropene C inhibited triglyceride formation in HepG2 cells.

• Journal of Environmental Health Sciences
• /
• v.19 no.3
• /
• pp.58-63
• /
• 1993

In order to elucidate the alteration of drug-metabolizing enzymes and mechanism in the animal with hepatic injury and ketosis, the regulation of P450IIE was studied in the rats with heaptic injury caused by CCl$_4$ and with ketosis caused by streptozotocin and high-fat diet. P450IIE expression in liver was examined by the combination of enzyme activities, Western immunoblot, and mRNA Northern blot analyses using specific polyclonal antibody and cDNA probe for P450IIE. Enzyme activity and amounts of immunoreactive P450IIE were rapidly decreased in a time-dependent manner after a single dose of CCl$_4$ . However, the decreases in P450IIE enzyme activity and immunoreactive protein by CCl$_4$ were not accompanied by a decline in its mRNA level. The data thus suggested a post-translational reduction of P450IIE by CCl$_4$. The enzyme activities (aniline hydroxylase) in hepatic microsomes were elevated about 2-3-fold by streptozotocin and feeding with a high fat diet. This increases in enzyme activities were also accompanied by 3-fold increases in immunoreactive P450IIE protein and its mRNA. Our data thus indicated that P450IIE induction during the ketosis appears to be due to pretranslational activation.

• Applied Biological Chemistry
• /
• v.46 no.3
• /
• pp.165-170
• /
• 2003

The antioxidative activity of antioxidative substances produced from several bacterial strains isolated from fermented foods were tested by $DPPH\;({\alpha},{\alpha}'-diphenyl-{\beta}-picrylhydrazyl)$ free radical scavenging activity. One of the strains showing the highest antioxidative activity was identified as Bacillus sp. based on the morphological, biochemical, physiological characteristics, and 16S rRNA sequence, and named FF-7. The most optimal medium condition for the production of antioxidative substance from Bacillus sp. FF-7 was 2% galactose as carbon source and l% tryptone as nitrogen source. The antioxidative substance produced from FF-7 in these cultural medium was also tested by in vitro experimental models, the peruxidation of linoleic acid and the peroxidation of rat tissues microsomes by using thiobarbituric acid (TBA) for assay of free malondialdehyde production. The antioxidative activity against lipid peroxidation of rat tissues microsomes was shown in the following order; brain 97.50% > heart 79.95% > kidney 77.84% > spleen 77.47% > testis 69.96% > liver 62.45%. The antioxidative substance produced from FF-7 on linoleic acid peroxidation by IBA method was effectively inhibited during four days, and 0.05% BHT (butylated hydroxytoluene) used comparative control was also effectively inhibited. Results showed that the highest antioxidative activity by DPPH method of antioxidative substance produced from Bacillus sp. FF-7 was obtained by supplementing 2% galactose as carton source and l% tryptone as nitrogen source in cultured medium, this substance effectively inhibited the formation of TBARS in brain microsome in vit개 system and in linoleic acid peroxidation.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.22-39
• /
• 2003

Biological activity of phenolic compounds in seeds and leaves of safflower (Carthamu tinctorius L.) were evaluated using several in vitro and in vivo assays. Six phenolic constituents were isolated from the seeds and identified as N-feruloylserotonia, N- (p-coumaroyl)serotonin, matairesinol, 8′-hydroxyarctigenin, acacetin 7-O-$\beta$-D-glucoside (tilianine) and acacetin. Six phenolic compounds exhibited considerable antioxidative activity, and especially two serotonins showed potent DPPH radical scavenging activity and antiperoxidative activity against rat liver microsomal lipid peroxidation induced by the hydroxyl radical generated via a Fenton-type reaction. Additionally, six phenolic compounds possessed comparable cytotoxicity against three cancer cells, Hela cell, MCF-7 and HepG2 cell, and particularly acacetin and its glycosides had the most potent cytotoxicity. Moreover, we found that feeding safflower seeds attenuated bone loss, and lowered levels of plasma and liver lipids in ovariectomized rats. Serotonins, lignans and flavones stimulated proliferation of the osteoblast-like cells in a dose-dependent manner (10$^{-15}$ ~10$^{-6}$ M), as potently as E$_2$ (17$\beta$-estradiol). Particularly, serotonins were mainly responsible for bone-protecting and lipid lowering effects in ovariectomized rats. Meanwhile, eight flavonoids, including a novel quercetin-7-O-(6"-O-acetyl)-$\beta$-D-glucopyranoside and seven kown flavonoids, luteolin quercetin, luteolin 7-O-$\beta$-D-glucopyranoside, luteolin-7-O-(6"-O-acetyl)-$\beta$-D-gluco-pyranoside, quercetin 7-O- -glucopyranoside, acacetin 7-O-$\beta$-D-glucuronide and apigenin-6-C-$\beta$-D-glucopyranosyl-8-C-$\beta$-D-glucopyranoside were first isolated and identified from safflower leaf. Among these flavonoids, luteolin-acetyl-glucoside and $\beta$quercetin- acetyl-glucoside showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin, quercetin and their corresponding glycosides also exhibited strong antioxidative activity, while acacetin glucuronide and apigenin-6, 8-di-C-glucoside were relatively less active. Finally, changes in phenolic compositions were also determined by HPLC in the safflower seed and leaf during growth stages and roasting process to produce standardized supplement powerds. These results suggest that phenolic compounds in the roasted safflower seed and leaf may be useful as potential sources of therapeutic agents against several pathological disorders such as carcinogenesis, atherosclerosis and osteoporosis.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.1
• /
• pp.124-130
• /
• 2003

Effect of Korean red ginseng (KRG) on the level of serum and liver lipids and lipid peroxidation was investigated in the rats fed high fat diet. Content of serum total cholesterol was significantly decreased (P<0.05) in KRG I group and KRG II group. Content of HDL-cholesterol was significantly increased by 69.75% and 39.15% in KRG I and KRG II group compared to control group, respectively. Atherogenic index (hi) was also significantly decreased by 74.76% and 37.38% in KRG I and KRG II groups compared to control group, respectively. Serum triglyceride content was significantly decreased (p<0.05) in only KRG II group. Antioxidative activity of KRG on the lipid peroxidation of serum and tissues in rats was also studied in vivo by measuring the formation of thiobarbituric acid reactive substances (TBARS). Contents of TBARS in the serum of both KRG groups were significantly decreased (p<0.05) and that of nonheme iron in serum was significantly increased (p<0.05) in a dose-dependent manner, which suggested that lipid peroxidation contents are inversely correlated with serum nonheme iron content. Content of TBARS in liver was significantly decreased (p<0.05) in KRG I and KRG II groups, without any influence in other tissues. Content of TBIARS in liver microsomal fractions stimulated by Fe$^{2+}$/ascorbate was significantly decreased (p<0.05) in KRG I and KRG II groups, whereas this observation did not occur in liver mitochondrial fractions. When the effect of KRG on TBARS content in the liver fractions of homogenates, microsomes, and mitochodria stimulated by Fe$^{2+}$/ascorbate was tested in vitro experimental model, TBARS of liver three fractions was significantly decreased at 6 mg/mL KRG compared with those of control. These results suggested that KRG powder have hypocholesterolemic effect as well as antioxidative effect in the serum and liver of the rats fed high fat diet.