• Archives of Pharmacal Research
• /
• v.27 no.1
• /
• pp.106-110
• /
• 2004

The antioxidant activities of Acanthopanax senticosus stems were evaluated in $CCl_4$-intoxicated rats. The n-butanol fraction from the water extract of the stems, when pretreated orally at 200 mg/kg/day for 7 consecutive days in rats, was demonstrated to exhibit significant increases in antioxidant enzyme activities such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase by 30.31, 19.82 and 155%, respectively. The n-butanol fraction whereas showed a significant inhibition of serum GPT activity (65.79% inhibition) elevated with hepatic damage induced by $CCl_4$-intoxication. Eleutheroside B, a lignan component, isolated from the n-butanol fraction was found to cause a moderate free radical scavenging effection DPPH, its scavenging potency as indicated in $IC_{50}$ value, being 58.5$\mu$ M. These results suggested that the stems of A. senticosus possess not only antioxidant but also hepatoprotective activities.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.3
• /
• pp.378-386
• /
• 2023

The CYP707A family genes encoding ABA 8'-hydroxylase catabolize abscisic acid (ABA), a plant stress hormone that plays an important role in stress condition, such as drought, heat, cold and salinity. Phaseic acid (PA) is a catabolic product of ABA. Recent studies have shown that PA is important for the physiological functions in plants. It is also a neuroprotective molecule that protects against ischemic brain injury in mice. To obtain enzymes for the PA production, four CaCYP707A genes (CaCYP707A1, CaCYP707A2, CaCYP707A3 and CaCYP707A4) were isolated from hot pepper. They were heterologously expressed in Escherichia coli. Among them, CaCYP707A2 showed significantly higher expression levels in both the membrane fraction and the soluble fraction. Preferred redox partners were investigated to improve the efficiency of CaCYP707A2's catalytic reaction, and NADPH-cytochrome P450 reductase (CPR) from hot pepper (CaCPR) was preferred over other redox partners (i.e., rat CPR and ferredoxin reductase/ferredoxin). The production of 8'-hydroxy ABA and PA by ABA hydroxylation activity was confirmed in CaCYP707A2 from both membrane and soluble fractions. Therefore, CaCYP707A2 is the first identified plant CYP protein that is expressed a soluble form in cytosolic fraction having stable activity. Taken together, we propose a new CYP707A protein with industrial applications for PA production without additional modifications in E. coli heterologous expression.

• Animal cells and systems
• /
• v.8 no.3
• /
• pp.213-220
• /
• 2004

MicroRNA and siRNA (small interfering RNA), representative members of small RNA, exert their effects on target gene expression through association with protein complexes called miRNP (microRNA associated ribonucleoproteins) and RISC (RNA induced silencing complex), respectively. Although the protein complexes are yet to be fully characterized, human EIF2C2 protein has been identified as a component of both miRNP and RISC. In this report, we raised antiserum against EIF2C2 in order to begin understanding the protein complexes. An immunoblot result indicates that EIF2C2 protein is ubiquitously expressed in a variety of cell lines from human and mouse. EIF2C2 protein exists in both cellular compartments, as indicated by an immunoblot assay with a nuclear extract and a cytosolic fraction (S100 fraction) from HeLa S3 lysate. Depletion of EIF2C1 or EIF2C2 protein resulted in a decrease of microRNA, suggesting a possible role of these proteins in microRNA stability or biogenesis. We also prepared antiserum against dsRNA binding protein PACT, whose homologs in C. elegans and Drosophila are known to have a role in the RNAi (RNA interference) pathway. The expression of PACT protein was also observed in a wide range of cell lines.

• Biomedical Science Letters
• /
• v.23 no.4
• /
• pp.310-320
• /
• 2017

Ginseng has been widely used for traditional medicine in eastern Asia and is known to have inhibitory effects on cardiovascular disease (CVD) such as thrombosis, atherosclerosis, and myocardial infarction. Because, platelet is a crucial mediator of CVD, many studies are focusing on inhibitory mechanism of platelet functions. Among platelet activating molecules, thromboxane $A_2$ ($TXA_2$) and P-selectin play a central role in CVD. $TXA_2$ leads to intracellular signaling cascades and P-selectin plays an important role in platelet-neutrophil and platelet-monocyte interactions leading to the inflammatory response. In this study, we investigated the inhibitory mechanisms of total saponin fraction from Korean red ginseng (KRG-TS) on $TXA_2$ production and P-selectin expression. Thrombin-elevated $TXA_2$ production and arachidonic acid release were decreased by KRG-TS dose (25 to $150{\mu}g/mL$)-dependently via down regulation of microsomal cyclooxygenase-1 (COX-1), $TXA_2$ synthase (TXAS) activity and dephosphorylation of cytosolic phospholipase $A_2$ ($cPLA_2$). In addition, KRG-TS suppressed thrombin-activated P-selectin expression, an indicator of granule release via dephosphorylation of mitogen-activated protein kinases (MAPK). Taken together, we revealed that KRG-TS is a beneficial novel compound inhibiting $TXA_2$ production and P-selectin expression, which may prevent platelet aggregation-mediated thrombotic disease.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.197-197
• /
• 1998

Chronic electroconvulsive shock(ECS) was shown to Increase phosphatidylinositol-4,5-bisphosphate(PIP$_2$) breakdown and the activity of PLC with the accumulation of inositol-1,4,5-triphosphate(IP3). The purpose of the present study was to determine the effect of ECS on the expression of phospholipase C(PLC) isotypes in rat brain. Two groups of animals were prepared: sham and ECS treated groups. Rats in ECS treated groups received maximal ECS(70mA, 0.5second, 60㎐) by constant current stimulator through ear-clip to induce tonic extension seizures for 12 consecutive days. The expression of PLC isotypes in rat brain was determined by immunohistochemical procedure using sagital section of rat brain. The immunoreactivity of PLC${\beta}$1 was observed in corpus striatum, hippocampus, thalamus and that of PLC${\gamma}$1 in corpus striatum, hippocampus, thalamus, frontal cortex, parietooccipital cortex, limbic forebrain, pons, medulla, superior colliculus, inferior colliculus, rest of midbrain. The amount of PLC was analyzed by Western blot using antibodies against PLC${\beta}$1 and PLC${\gamma}$1. Chronic ECS reduced the immunoreactivity of PLC${\beta}$1 in corpus striatum, hippocampus, thalamus but had little effect on PLC${\gamma}$1. To quantify this change, quantitative Western blot using antibodies against PLC${\beta}$1 and PLC${\gamma}$1 was conducted. The immunoreactivity of PLC${\beta}$1 in ECS treated rat whole brain was decreased by 40 % in cytosolic fraction and 26 % in membrane fraction. This different effect of ECS on PLC isotypes may results from the difference of their activation mechanisms and the different effects of ECS on them. The results from the present study suggest that chronic ECS primalily affects neurotransmitter receptors related IP$_3$ signaling in rat brain.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.4
• /
• pp.581-586
• /
• 1994

The study was initiated elucidate the mechanism by examining the effect of GE-132 on hepatic glutathione S-transferase (GST) activity. Activity of GST increased with dose-dependent manner in hepatic cytosolic fraction of GE-132 treatment rats. Double reciprocal plotting gave Vmax value 1.4 fold increase by the treatment of GE-132(100mg/kg, p.o.for 6 weeks) compared with control group, but did not change Km value. Ethacryinc acid (85mg/kg, once a day, i.p) was injected to control rat, the GST activity decreased remarkably . However, GE-132 pretreated group, the effect caused by ethacrynic acid was markedly reduced. And activity of ${\gamma}$-glutamylcys- teine synthetase was not changed either by GE-132 treatment , but the activity of glutathione reudctase increased significantly. Decreasing properties of ethacrynic acid decreased level of hepatic glutathione , which was restored to same degree by GE -132 pretreatment . GE-132 protective effect on ethacrynic acid-induced mortality. It is concluded that the efect of GE-132 is partly mediated by increase in hepatic GST activity.

• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.217-224
• /
• 1998

The heavy metal concentrations of seawater collected from the Onsan coastal zone in February and July 1996 and mussels(Mytilus edulis) in February 1997 were analysed. The concentrations of cadmium in seawater were in the range of 0.008-2.988 ${\mu}g/L$, while the ranges of copper and zinc concentrations were 0.08-2.55, and 0.21-35.12 ${\mu}g/L$, respectively. The metal concentrations decreased gradually with increasing distances from Daejeong stream, indicating that this stream was the major source of heavy metal input into the Onsan coastal zone. The concentrations of cadmium, copper and zinc in mussels were in the ranges of 1.40-25.09, 8.5-64.5, and 46.8-291.2 ${\mu}g/g$, respectively. The metal concentrations decreased gradually with increasing distances from Daejeong stream. Among organs of mussels, gill showed the highest concentrations of cadmium and the digestive gland showed the highest concentrations of copper and for zine the kidney showed the highest concentrations. The digestive gland and kidney revealed high proportion of cadmium in cytosolic fraction and the percentage of copper was high in the kidney and that of zine was high in the digestive gland. Metal-binding protein of mussels collected from the mouth of Daejeong stream was separated, using gel-filtration chromatography. In the kidney and gill of mussels, most of cadmium was associated with metal-binding protein. In contrast, most of the metal in the digestive gland and remaining tissues is bound to high molecular weight protein rather than metal-binding protein.

• Biomolecules & Therapeutics
• /
• v.2 no.1
• /
• pp.47-53
• /
• 1994

The methylation response as well as the level of methyl donor substance, 5-adenosyl-L-methionine (SAM) has been suggested to be related to hepatotoxicity including hepatocarcinogenesis. But direct correlation between protein methylation and hepatotoxicity has not been established to the present. To observe relationship between protein methylation and short-term hepatotoxicity induced by chemical substances, the activities of protein methylase I and II (PM I, PM II) were examined in cytosolic fraction of SD rat treated orally with acetaminophen(AA), $\alpha$-naphtyl-isothiocyanate (ANIT) and tetracycline (TC) that was known to produce necrosis, cholestasis and steatosis respectively. To evaluate the degree of hepatotoxicity induced by each chemicals, we observed the serum levels of indicative parameters and histopathological alteration. In AA treated group, the activities of PM I were increased at 6, 12 hours after administration, prior to the appearance of the hepatotoxicity by clinical parameters. It was suggested that the levels of PM I were related with the initial stage of hepatotoxic mechanism induced by AA. In ANIT treated group, though most of clinical parameters were significantly increased at 24, 48 hours after administration, the activity of PM I was not changed, indicating that ANIT induced hepatotoxicity was not coupled to protein methylation.

• BMB Reports
• /
• v.31 no.1
• /
• pp.31-36
• /
• 1998

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), the first enzyme in the phenylpropanoid biosynthesis, catalyzes the elimination reaction of ammonium ion from L-phenylalanine. PAL was purified from the cytosolic fraction of Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography. It consists of four identical subunits, the molecular mass of which was estimated to be about 38,000 daltons on SDS-PAGE. The optimal pH and temperature of the purified enzyme are 8~9 and $45^{\circ}C$, respectively. Its activity is greatly inhibited by $Zn^{2+}$ ion, and strongly activated by caffeic acid. The purified PAL has some different characteristics compared to those obtained with other PALs.

• Journal of Microbiology
• /
• v.34 no.2
• /
• pp.206-213
• /
• 1996

NADH-quinone reductase was purified 22-fold from the cytosolic fraction of Streptomyces sp. Imsnu-1 to apparent hemogenity, with an overall yield of 9%, by the purification procedure consisting of ammonium, sulfate precipitation and DEAE Sephacryl S-200 and DEAE 5 PW chromatographies. Thes molecular mass of the enzyme determined by gel filtration chromatography was found to be 110 kDa. SDS-PAGE revealed that the enzyme consists of two sugunits with a molecular mass of 54 kDa. The enzyme contained 1 mol of FMN per subunit as a cofactor. The $A_{272}$ A$_{457}$ ratio was 6.14 and the molar extinction coefficients were calculated to be 20, 800 and 25, 400M$^{-1}$ $cm^{-1}$ / AT 349 AND 457 nm, respectively. The N-terminal sequence of the enzyme contained the highly conserved fingerprint of ADP-binding domain. The enzyme used NADH as an electron donor and various quinones as electron acceptors. Cytochrome c was practically inactive. Air-stable flavin semiquinone was produced by the addition of NADH to the enzyme. Also, naphthosemiquinone was detected in the reaction mixture containing the enzyme.