• 한국자원식물학회지
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• 제27권1호
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• pp.22-28
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• 2014

꽃치자나무 추출물의 HIV-1 reverse transcriptase, protease 및 alpha-glucosidase에 대한 억제활성실험을 실시하였다. ELOSA 방법으로 실험한 역전사효소 억제활성 실험에서는 꽃치자나무 잎 MeOH 추출물 $100{\mu}g/ml$ 농도에서 13.4%의 약한 억제활성이 관찰되었고, 줄기의 메탄올추출물에서는 32.5%의 높은 HIV-1 protease 억제활성과 줄기의 메탄올 추출물에서는 26.1%의 alpha-glucosidase 억제활성이 관찰되었다. 그리고 HIV-1 복제 억제활성은 MT-4 세포에 대한 HIV-1 유도 세포변성억제를 광학현미경으로 관찰하여 살펴본 결과 잎과 줄기의 모든 추출물에서 HIV-1 바이러스 증식억제에 억제활성이 관찰되지 않았다. In silico 실험결과 주요성분인 crocetin이 81.8%의 높은 역전사 효소활성이 예측되었으며, genipin이 55.39%, geniposidic acid aglycone이 64.5% 역전사효소 활성이 예측되었다. 주로 aglycone의 활성이 높게 예측되었으며 배당체의 경우 활성이 현저하게 저하되는 것으로 나타났다.

• 한국식품저장유통학회지
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• 제24권7호
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• pp.1007-1016
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• 2017

다슬기는 예로부터 간염, 간경화, 지방간 등의 치료 및 개선에 이용되어 왔으며, 특히 소변불통, 소갈증(당뇨) 등의 약용으로 이용되어 왔다. 본 연구에서는 이러한 다슬기를 대상으로 항당뇨에 대한 효능을 과학적으로 검증하고 그 기작을 규명하고자 하였다. 먼저 다슬기의 생물학적 기능성을 높이기 위해 효소 가수분해를 실시하였으며, protamex에 의한 가수분해도는 10시간 후 약 43% 수준을 나타내었다. PTP1B는 인슐린 신호전달기전에서 IRS-1의 인산화를 방해하여 인슐린 민감성을 저해시키는 효소이다. protamex를 이용한 다슬기 가수분해물(MPH)의 PTP1B에 대한 저해활성은 $15.42{\pm}1.1{\mu}g/mL$의 $IC_{50}$ 값을 나타내어 양성대조군 ursolic acid의 $16.7{\mu}g/mL$ 보다 높은 저해활성을 보이면서 강한 항당뇨 활성 소재로서의 가능성을 보였다. 이에 따라 유리지방산을 이용하여 C2C12 myoblast에서 인슐린 저항성을 유도하고, MPH에 의한 포도당 흡수 정도를 확인하였다. 그 결과, 1 mM PA 처리에 의해 약 32% 수준으로 떨어진 포도당 흡수율은 MPH 처리에 의해 약 199% 수준으로 증가하였다. 또한 장기간 고농도의 포도당(30 mM)에 의해 유도된 당독성 조건에서 MPH는 췌장의 베타세포 INS-1 세포의 생존율을 증가시키고, 대조군에 비해 약 160% 인슐린 mRNA 발현량을 증가시켰다. 이러한 결과에서 MPH는 PTP1B 활성을 저해함으로써 인슐린 신호전달 기작을 활성화하고, 인슐린저항성 환경에서 포도당 흡수를 증진시켜 인슐린저항성을 개선하며, 나아가 고농도 포도당에 의해 유도되는 당독성환경에서 췌장 베타세포를 보호하고 인슐린 mRNA발현량을 정상화할 수 있다는 것을 확인할 수 있었다.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.671-676
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• 1998

Five hundred and seventy clinical strains of Pseudomonas aeruginosa were isolated from August 1993 to August 1994 in Korea and screened for their resistance to ciprofloxacin, norfloxacin, and ofloxacin. Among these, two P. aeruginosa strains (PA150 and PA300) were selected based on their strong resistance (MICs > 50mcg/ml) to all three quinolones. The susceptible strain as well as two resistant strains had proton gradient-dependent efflux system. Efflux system in PA300 showed different specificities to ofloxacin and ciprofloxacin while PA150 had less permeability for ofloxacin. Ofloxacin had a less inhibitory action on DNA synthesis in permeabilized cells of PA150 and PA300 than 1771M. When quinolone resistance determining region (QRDR) in gyrA was sequenced, PA300 had one missense mutation, Asn 116Tyr, which was newly reported in this work. The results showed that PA150 became ofloxacin resistant by reduced ofloxacin accumulation due to the existence of efflux system and low permeability, while resistance of PA300 was due to the efflux system and a mutation in QRDR of gyrA -the target site of quinolone.

• BMB Reports
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• 제48권5호
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• pp.277-282
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• 2015

We demonstrated previously that a disintegrin and metalloproteinase 15 (ADAM15) is released into the extracellular space as an exosomal component, and that ADAM15-rich exosomes have tumor suppressive functions. However, the suppressive mechanism of ADAM15-rich exosomes remains unclear. In this study, we show that the ADAM15 ectodomain is cleaved from released exosomes. This shedding process of the ADAM15 ectodomain was dramatically enhanced in conditioned ovarian cancer cell medium. Proteolytic cleavage was completely blocked by phenylmethylsulfonyl fluoride, indicating that a serine protease is responsible for exosomal ADAM15 shedding. Experimental evidence indicates that the ADAM15 ectodomain itself has comparable functions with those of ADAM15-rich exosomes, which effectively inhibit vitronectininduced cancer cell migration and activation of the MEK/extracellular regulated kinase signaling pathway. We present a tumor suppressive mechanism for ADAM15 exosomes and provide insight into the functional significance of exosomes that generate tumor-inhibitory factors. [BMB Reports 2015; 48(5): 277-282]

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2129-2140
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• 2017

Silibinin is the major active component of silymarin, extracted from the medicinal plant Silybum marianum. Silibinin has potent antibacterial activity; however, the exact mechanism underlying its activity has not been elucidated. Here, we investigated the novel mechanism of silibinin against Escherichia coli. Time-kill kinetic assay showed that silibinin possess a bactericidal effect at minimal inhibitory concentration (MIC) and higher concentrations (2-and 4-fold MIC). At the membrane, depolarization and increased intracellular $Ca^{2+}$ levels were observed, considered as characteristics of bacterial apoptosis. Additionally, cells treated with MIC and higher concentrations showed apoptotic features like DNA fragmentation, phosphatidylserine exposure, and caspase-like protein expression. Generally, apoptotic death is closely related with ROS generation; however, silibinin did not induce ROS generation but acted as a scavenger of intracellular ROS. These results indicate that silibinin dose-dependently induces bacterial apoptosis-like death, which was affected by ROS depletion, suggesting that silibinin is a potential candidate for controlling bacteria.

• 한국약용작물학회지
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• 제16권1호
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• pp.27-32
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• 2008

This study aimed to investigate the anti-allergic activity and the mechanism of action of Crassirhizomae rhizoma (CR). The extract of CR exhibited potent inhibitory activity in mast cells; its $IC_{50}$ values were $31.2{\pm}1.5{\mu}g/m{\ell}$ for rat basophile leukemia (RBL)-2H3 mast cells and $51.5{\pm}2.1{\mu}g/m{\ell}$ for bone marrow-derived mast cells by antigen stimulation. It also suppressed the expression of TNF-${\alpha}$ and IL-4 mRNAs in RBL-2H3 cells. In an in-vivo animal allergy model, it inhibited a local allergic reaction, passive cutaneous anaphylaxis (PCA), in a dose-dependent manner. With regard to the mechanism of action, CR inhibited the activating phosphorylation of Syk kinase, a key signaling protein for the activation of mast cells. Taken together, these results strongly suggested that the anti-allergic activity of CR is mediated through the inhibition of histamine release and allergic cytokine production by the inhibition of Syk in mast cells.

• 한국환경과학회지
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• 제13권8호
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• pp.711-719
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• 2004

The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may playa role in nickel tolerance implicated in metal detoxification.

• IMMUNE NETWORK
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• 제12권6호
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• pp.240-246
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• 2012

Natural killer (NK) cells play a pivotal role in early surveillance against virus infection and cellular transformation, and are also implicated in the control of inflammatory response through their effector functions of direct lysis of target cells and cytokine secretion. NK cell activation toward target cell is determined by the net balance of signals transmitted from diverse activating and inhibitory receptors. A distinct feature of NK cell activation is that stimulation of resting NK cells with single activating receptor on its own cannot mount natural cytotoxicity. Instead, specific pairs of co-activation receptors are required to unleash NK cell activation via synergy- dependent mechanism. Because each co-activation receptor uses distinct signaling modules, NK cell synergy relies on the integration of such disparate signals. This explains why the study of the mechanism underlying NK cell synergy is important and necessary. Recent studies revealed that NK cell synergy depends on the integration of complementary signals converged at a critical checkpoint element but not on simple amplification of the individual signaling to overcome intrinsic activation threshold. This review focuses on the signaling events during NK cells activation and recent advances in the study of NK cell synergy.

• 약학회지
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• 제37권3호
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• pp.270-277
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• 1993

It is well known that lipidperoxide, formed in vivo, induced the denaturation of enzyme and destruction of cell membrane to acute injury of tissue. Aralia elata have physiological activates, the improvement of lipid metabolism, antidiabetic activity etc., which was thought to have the relationship to lipid peroxidation. The anti-lipidperoxidative effect of Aralia elata have not yet established. In this study, we examined the anti-lipidperoxidative effects of Aralia elata (Butanol fraction) on CCI$_{4}$ induced lipidperoxidation in rats, and elucidated the anti-lipidperoxidative mechanism. In rat liver homogenate intoxicated with CCI$_{4}$ (0.5 ml/100g), BuOH fraction of Aralia elata (80 mg/Kg/day) exhibited 85.41% anti-lipidperoxidative effect but in serum 69.63% inhibitory effects, respectively. In mitochondrial and microsomal fraction showed inhibition of 55.85% and 69.30%, respectively. In order to elucidate the mechanism of anti-lipidperoxidation effects of Aralia elata, enzymatic (NADPH dependent) and non-enzymatic (Ascorbic acid catalyzed) reaction, in vitro, were performed. In enzymatic reation, Aralia elata exhibited 59.43% anti-lipidperoxidation effects, but in non-enzymatic reaction exhibited 43.27% inhibition. Therefore, it is noteworthy that antioxidative power of them may mainly results from the inhibition by enzymatic reaction.

• 대한한방부인과학회지
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• 제21권2호
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• pp.152-165
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• 2008

Purpose: It is the purpose of this study to investigate the anti-inflammatory effects and mechanism of cheukbaekjurpihwan(CBJPH) extract on LPS (lipopolysaccharide)-induced inflammatory mediators in murine peritoneal macrophages. Methods: To evaluate anti-inflammatory effects of CBJPH extract, the production of cytokines(TNF-${\alpha}$(tumor necrosis factor-alpha), IL(interleukin)-6, IL-12) and NO(nitric oxide) was measured in vitro and in vivo. And western blot analysis has been done to look into the mechanism. Results: CBJPH extract reduced LPS-induced NO, TNF-${\alpha}$ and IL-6, IL-12 productions in peritoneal macrophages. CBJPH extract inhibited the activation of JNK(c-Jun N-terminal kinase), but didn't inhibit the activation of MAPKs (mitogen-activated protein kinases) such as p38, ERK1/2(extracelluar signal-regulated kinase1/2) and the degradation of $I_{\kappa}B-{\alpha}$(inhibitory kappa B-alpha) in the LPS-stimulated peritoneal macrophages. CBJPH extract suppressed LPS-induced endotoxin shock and the productions of TNF-${\alpha}$, but not of IL-6, after an oral administration of CBJPH extract Conclusion: CBJPH extract suppressed the productions of LPS-induced NO and cytokines by preventing JNK from phosphorylation, which may provide a clinical basis for anti-inflammatory properties of CBJPH.