• Nutrition Research and Practice
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• v.18 no.2
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• pp.194-209
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• 2024

BACKGROUND/OBJECTIVES: High levels of plasma low-density lipoprotein (LDL) cholesterol are an important determinant of atherosclerotic lesion formation. The disruption of cholesterol efflux or reverse cholesterol transport (RCT) in peripheral tissues and macrophages may promote atherogenesis. The aim of the current study was to examine whether bioactive ellagic acid, a functional food component, improved RCT functionality and high-density lipoprotein (HDL) function in diet-induced atherogenesis of apolipoproteins E (apoE) knockout (KO) mice. MATERIALS/METHODS: Wild type mice and apoE KO mice were fed a high-cholesterol Paigen diet for 10 weeks to induce hypercholesterolemia and atherosclerosis, and concomitantly received 10 mg/kg ellagic acid via gavage. RESULTS: Supplying ellagic acid enhanced induction of apoE and ATP-binding cassette (ABC) transporter G1 in oxidized LDL-exposed macrophages, facilitating cholesterol efflux associated with RCT. Oral administration of ellagic acid to apoE KO mice fed on Paigen diet improved hypercholesterolemia with reduced atherogenic index. This compound enhanced the expression of ABC transporters in peritoneal macrophages isolated from apoE KO mice fed on Paigen diet, indicating increased cholesterol efflux. Plasma levels of cholesterol ester transport protein and phospholipid transport protein involved in RCT were elevated in mice lack of apoE gene, which was substantially reduced by supplementing ellagic acid to Paigen diet-fed mice. In addition, ellagic acid attenuated hepatic lipid accumulation in apoE KO mice, evidenced by staining of hematoxylin and eosin and oil red O. Furthermore, the supplementation of 10 mg/kg ellagic acid favorably influenced the transcriptional levels of hepatic LDL receptor and scavenger receptor-B1 in Paigen diet-fed apoE KO mice. CONCLUSION: Ellagic acid may be an athero-protective dietary compound encumbering diet-induced atherogenesis though improving the RCT functionality.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.271-280
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• 2020

This study compared soil CO₂ efflux rates after fertilization, in Pinus densiflora and Quercus variabilis stands. Compound fertilizers were applied to the forest floor in March 2016, following a one-year calibration period (from March 2015 to February 2016). In situ soil CO₂ efflux rates were measured every month during the two-year study periods, using an infrared gas analyzer with a closed chamber system. Mean annual soil CO₂ efflux rates were higher following fertilizer application in the P. densiflora and Q. variabilis stands (P. densiflora: 2.180 μmol m^-2 s^-1; Q. variabilis: 1.977 μmol m^-2 s^-1) as compared with the rates measured during the calibration period (P. densiflora: 1.620 μmol m^-2 s^-1; Q. variabilis: 1.557 μmol m^-2 s^-1). The mean annual soil CO₂ efflux rates in the unfertilized treatments of both stands were not significantly different between the two-year study periods. The Q₁₀ values of fertilized treatments in Q. variabilis stands were higher in the fertilization period (3.41) than in the calibration period (3.14), whereas the Q₁₀ values in P. densiflora stands did not change between the fertilization and calibration periods. The Q₁₀ values of unfertilized treatments in the Q. variabilis stands were lower during the 2016-2017 period (3.69), than in the 2015-2016 period (3.85), whereas the Q₁₀ values in P. densiflora stands were higher during the 2016-2017 period (3.65), than in the 2015-2016 period (3.15). These results indicate that the increase in soil CO₂ efflux rates in P. densiflora stands could be more sensitive to fertilization compared with the rates in Q. variabilis stands.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.17-24
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• 2016

At present, summer cloudburst and local torrential rainfalls have increased in this country, because of climatic change. Therefore, studies on prevention of soil loss have been actively proceeded, and Korea Forest Service has offered landslide hazard map. Landslide hazard map divides risks into 5 classes, by giving weight with 9 kinds of elements. In August 25 2014, soil loss occurred in the whole Oryun Tunnel, Geumjeong-gu, Busan, because of local torrential heavy rain. As a result of comparing with landslide hazard map, the area where soil loss occurred in reality is a safety zone on hazard map. Rainfall, soil map, geological map, forest type map, gradient, drainage network, watershed, basin shape, and efflux of the whole Oryun Tunnel where soil loss occurred were analyzed. As a result of an analysis, it is judged that soil, forest type, much efflux and peak discharge, degree of water network and basin shape of a place where landslide occurred are causes of soil loss. It is judged that efflux, peak discharge, and basin shape by the localized rainfall that is not considered in landslide hazard map of them are the biggest causes of soil loss. It is judged that efflux, peak discharge, degree of water network and basin shape by the rainfall are important through a study on a causual analysis on soil loss in the whole Oryun Tunnel where is one of occurrence area where a lot of propertywere lost by the record local torrential rainfalls. A localized torrential downpour should be prepared by considering these elements on judgement of a landslide hazard area.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.89-102
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• 1982

The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

• The Korean Journal of Pharmacology
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• v.19 no.2
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• pp.25-34
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• 1983

In this isolated study, it was aimed to elucidate the pharmacological properties of non-cholinergic, non-adrenergic inhibitory responses in the longitudinal strips of rabbit portal vein. 1) The portal vein responded inhibitory to electrical field stimulation in a frequency - and calcium-dependent manner after pretreatment with atropine, guanethidine and ergotamine, simultaneously. 2) When exogenous ATP, ADP, adenosine and cyclic AMP were added, respectively, they only showed the relaxations in the higher concentration without mimicing or affecting the inhibitory response induced by the electrical stimulation. The antagonist of purine substances, neither quinine nor isobutyl-methyl xanthine did influence on the relaxation. 3) The inhibitory response was significantly increased in the presence of $1{\mu}g/ml 4-amino-pyrineine (4-AP) which is $K^+-conduction$ blockade, but higher concentration of 4-AP directly decreased the vascular tone. 4) Though repeated application of ATP revealed the inhibitory effect on the relaxation, however, that of adenosine resulted rather increase of the amplitude. 5) After pretreatment with $^3H-adenosine$, $^3H-efflux$ induced by ATP or adenosine was markedly enhanced, but the electrical stimulation caused less $^3H-efflux$. 6) ^3H-efflux by electrical stimulation was not affected by the administration 4-AP, tetrodotoxin and adenosine.

• Development and Reproduction
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• v.5 no.1
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• pp.53-57
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• 2001

Sperm capacitation and acrosome reaction (AR) have been known to be Ca$^{2+}$-dependent events. Sperm capacitation accompanies with cholesterol efflux fiom plasma membrane, that eventually stimulates AR. However, whether the AR mediated by cholesterol efflux is Ca$^{2+}$ dependent has not been verified yet. Recently, methyl beta cyclodextrin (MBCD) was found to evoke AR by stimulating the cholesterol efflux fiom sperm membrane. In the present study, we examined the requirement of Ca$^{2+}$ in the MBCD-induced AR. During incubation of sperm in the bicarbonate buffered media MBCD increased AR in a dose-dependent manner regardless of the Ca$^{2+}$ presence. In the presence of low molar concentration of Ca$^{2+}$ (100 ${\mu}$M), MBCD-induced AR was slightly increased compared to Ca$^{2+}$-free condition. In the absence of Ca$^{2+}$ supplement, spontaneous AR was slightly increased during the incubation but inhibited by 100 ${\mu}$M EGTA. MBCD potentiated AR even the presence of EGTA. However, EGTA attenuated MBCD-induced AR, suagesting the functional involvement of intracellular Ca$^{2+}$ in the MBCD-induced AR. Taken together, it was suggested that cholesterol efflux from the sperm plasma membrane was sufficient for induction of AR even in the absence of extracellular Ca$^{2+}$and that a condition permissive for mobilization of intracellular Ca$^{2+}$ is important for MBCD-induced AR.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.8-14
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• 2006

This study was carried out to investigate the protective effect of crude saponin from red ginseng efflux (RGE-CS) on biochemical parameters in male rats acutely exposed to 2,3,7,8-tetrachlorodibenzo-$\rho$-dioxin (TCDD). Forty male rats ($200{\pm}20g$) were divided into 4 groups. Normal control group (NC) received vehicle and saline; only TCDD-treated group (TT) received TCDD ($5{\mu}g/kg$, single dose) intrperitoneally; RGE-CS 20 received 20 mg/kg of crude saponin i.p. for 4 weeks from 1 week before TCDD-exposure; RGE-CS 40 also received 40 mg/kg of crude saponin i.p. for 4 weeks from 1 week before TCDD-exposure. Body weight of TT group was significantly decreased after TCDD-exposure. However, body weight of crude saponin groups increased throughout the experimental period, although the increasing rate was slower than that of NC group. Decrease in body weight was not observed during the experimental period in RGE-CS 40. Increases in triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), AST, ALT and $Fe^{2+}$ levels by TCDD intoxication were significantly attenuated by the RGE-CS treatment. Decrease in glucose, amylase, lactate dehydrogenase (LDH) and creatinine kinase (CK) by TCDD also were inhibited by the RGE-CS. These results suggest that saponin from red-ginseng efflux might be a useful protective agent against TCDD, an endocrine disrupter.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.59-59
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• 2018

Panax ginseng Meyer (Korean ginseng) is in the spotlight of Oriental medicine and is proclaimed as the king of medicinal plants owing to its adaptogenic characteristics. Ginseng root rot is a devastating disease caused by the fungus, Ilyonectria mors-panacis that generally attacks younger roots (~2 years), leading to defects in root quality, ginsenoside accumulation and also life cycle of the plant. Hence, there is an indispensable need to develop strategies resulting in tolerance against ginseng root rot. In the present study, we evaluated the effect of silica nanoparticles(N-SiO2) in Panax ginseng during I. mors-panacis infection. Long term analysis (30 dpi) revealed a striking 50% reduction in disease severity index upon 1mM and 2mM treatment of N-SiO2. However, N-SiO2 did not have any direct antifungal activity against I. mors-panacis. Membrane bound sugar efflux transporter, SWEET (Sugars Will Eventually be Exported Transporters) was identified in ginseng and as expected, its expression was suppressed upon N-SiO2 treatment in the root rot pathosystem. Furthermore, the total and reducing sugars in the apoplastic fluid clearly revealed that N-SiO2 regulates sugar efflux into apoplast. In a nut shell, N-SiO2 administration induces transcriptional reprogramming in ginseng roots, leading to regulated sugar efflux into apoplast resulting in enhanced tolerance against I. mors-panacis.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.135-140
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• 2017

The aim of this study was to investigate the distribution of genes that encode multi-drug efflux pumps and virulence factors in Enterococcus faecalis isolated from retail meat and antibiotic resistance patterns of these strains. Of the 277 retail meat samples, 93 Enterococcus faecalis were isolated. The strains exhibited resistance to ampicillin (35.5%), chloramphenicol (6.4%), ciprofloxacin (4.3%), erythromycin (18.3%), levofloxacin (0%), quinupristin-dalfopristin (76.3%), tetracycline (45.2%), teicoplanin (0%) and vancomycin (0%). The strains were positive for MFS type eme(A) (100%), ABC type efr(A) (100%), ABC type efr(B) (98.9%) and ABC type lsa (91.4%) efflux pump gene. The strains were positive for gelE (68.8%), ace (90.3%), asa1 (47.3%), efaA (91.4%) and esp (12.9%) virulence gene. This research will help to assess the hazards associated with the occurrence of drug resistance among enterococci from retail meat. Therefore, it is necessary to monitor enterococcus spp. isolated from retail meat continuously.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.11a
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• pp.141.2-141.2
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• 2004