• Journal of Life Science
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• v.25 no.7
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• pp.801-809
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• 2015

Homotypic cell adhesion (homotypic aggregation) in activated monocytes plays a central role in physiological and pathological processes including inflammatory responses, differentiation and migration. The extract of the Prunus mume Sieb. et Zucc. fruit (Maesil) has potential benefits to human health; such as anti-viral, anti-microbial, and anti-cancer activities. Indeed, Maesil extract may modulate inflammatory responses via interference with homotypic aggregation in monocytes. In the present study, the molecular mechanisms underpinning the therapeutic efficacy of Maesil extract in inflammatory diseases were investigated. It was found that Maesil extract inhibited homotypic aggregation in lipopolysaccharide (LPS)-activated monocytes. This was mediated by reduction of nitric oxide (NO) production, partly via inhibition of inducible nitric oxide synthase (iNOS) expression in LPS-activated THP-1 cells. It was confirmed that NO inhibition is a key mechanism in Maesil induced blockade of monocyte aggregation through identification of reversal of this inhibitory effect by the NO-producing agent S-nitroso-N-acetyl penicillamine (SNAP). In addition, Maesil extract significantly attenuated LPS-induced IκB-α phosphorylation and NF-κB translocation into the nucleus. In conclusion, Maesil extract exerts anti-inflammatory effects via inhibition of homotypic aggregation of LPS-activated monocytes through mechanisms involving the suppression of NO production and NF-κB activity, suggesting Maesil extract as a potential therapeutic candidate for the prevention and treatment of chronic inflammatory diseases.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.382.3-382.3
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• 2002

Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous elements in the arteries. Monocytes/macrophages are involved in many aspects of the development of atheroscleotic plaques. It is known that the intercellular adhesion molecule-1 (ICAM-1) expressed preferentially on endothelial cells of atheroscleotic plaque. promotes local adhesion and transendothelial migration of monocytes, neutrophils. and lymphocytes. Using the human promyelocytic leukemia HL-60 cell line, we investigated the inhibitory effects of methoanol extracts of 175 plants on ICAM-1/LFA-1 mediated cell adhesion. Eight kinds of methanol extracts of tested plants inhibited PMA-induced homotypic aggregated cell adhesion. Eight kinds of methanol extracts of tested plants inhibited PMA-induced homotypic aggregation of HL-60 cells without cytotoxicity at the concentration of 6.25 ${\mu}$g/ml. $CHCl_3$ extracts (1.0 ${\mu}$g/ml) of Saururus chinensis and Chloranthus japonicus significantly inhibited agregation of HL-60 cells without cytoxicity.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.199.1-199.1
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• 2003

In the course of our search for intercellular adhesion molecule-1 (ICAM-1)/leukocyte function-associated antigen-1 (LFA-1) mediated cell adhesion inhibitors from natural sources, new type of cell adhesion inhibitors were isolated from the MeOH extract of Saururus chinensis roots. On the basis of spectral evidence, the structures of the active compounds were identified as manassantin A and B. Manassantin A and B inhibited phorbol 12-myristate 13-acetate (PMA)-induced homotypic aggregation of the human promyelocytic leukemia HL-60 cells without cytotoxicity with MIC value of 1.0 and 5.5 nM, respectively. (omitted)

• Journal of Life Science
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• v.19 no.7
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• pp.976-982
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• 2009

Little is known about the cardiovascular roles of alliin, a functional component in garlic that has been used as food material. Thus, we examined a broad range of cardiovascular activities of alliin in this study. From our in vitro experiments, alliin was determined to act as a stimulant to induce endothelial cell proliferation and endothelial cell migration. Since endothelial cell proliferation and migration are highly associated with angiogenesis and wound healing, alliin is suggested as a regulator to control angiogenesis and wound healing. In addition, alliin was elucidated to prevent lipopolysaccharide (LPS)-induced adhesion of THP-1 leukocytes to endothelial cells and LPS-induced homotypic THP-1 cell aggregation. These inhibitory effects indicate that alliin is likely to act as an anti-atherosclerotic and anti-thrombotic factor, because leukocytic adhesion to endothelial cells and homotypic leukocyte aggregation are highly associated with atherosclerosis and thrombosis, respectively. Our additional findings show that alliin has no effect on the production of nitric oxide (NO), an important vasoregulator. In conclusion, alliin is suggested as a regulator for controlling various cardiovascular functions.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.11-17
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• 2002

$\beta$-Immunan, a proteoglycan, was isolated from the mycelium of Canoderma lucidum which belongs to a medicinal mushroom. The effects of $\beta$-Immunan on cell-cell and cell-matrix interactions mediated by carbohydrate-recognition and the mechanism responsible for the inhibition of experimental metastasis of Bl6-F10 and B16/BL6 murine melanoma were studied. The results showed that $\beta$-Immunan inhibited Bl6-Fl melanoma cell's adhesion to laminin and asialofetuin-induced homotypic aggregation and reduced invasion against Bl6-F10 murine melanoma cells through matrigel in vivo assay. When $\beta$-Immunan was intraperitoneally administrated to C57B/6 mice bearing B16/BL6 murine melanoma cells, it was decreased the number of pulmonary metastatic colony by the dose dependent manner ranging from 20 to 100 mg/kg/day. The results indirectly indicate that clinical treatment with $\beta$-Immunan might be expected to exhibit anti-metastatic effect. In the pulmonary metastasis, the number of pulmonary metastatic colony of melanoma when $\beta$-Immunan was intraperitoneally administrated to C57BL/6 mice bearing B16/BL6 murine melanoma cells by intravenous injection were decreased by the dose dependent manner ranging from 20 to 100 mg/kg/day.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.343-351
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• 2002

Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous elements in the arteries. Monocyter/macrophages are involved in many aspects of the development of atherosclerotic plaques. It is known that the intercellular adhesion molecule-1(ICAM-1) expressed preferentially on endothelial cells of atherosclerotic plaque, promotes local adhesion and transendothelial migration of monocytes, neutrophils, and lymphocytes. Using the human promyelocytic leukemia HL-60 cell line, we investigated the inhibitory effects of methanol extracts of 175 natural plants on ICAM-1/LFA-1 mediated cell adhesion. Eight kinds of methanol extracts of tested plants inhibited PMA-induces homotypic aggregationof HL-60 cells without cytotoxicity at the concentration of $6.25\;{\mu}g/ml$. They were divided two fractions of $CHCI_3$ and $H_2O$ to use solvent partition. Among them, $CHCI_3$ extract $(1.0\;{\mu}g/ml)$ of Saururus chinensis and Chloranthus japonicus singificantly inhibited aggregation of HL-60 cells without cytotoxicity, respectively.

• Journal of Life Science
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• v.20 no.6
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• pp.914-921
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• 2010

In this study, we carried out a series of experiments to know whether melatonin, an anti-oxidative and immunosuppressive agent, played an important role in endothelial cells. It was revealed that melatonin had little or no effect on endothelial proliferation, cell death or migration. Additionally, melatonin had no effect on adhesion of THP-1 leukocytes to bovine aortic endothelial cells (BAECs) and THP-1 homotypic cell aggregation. In contrast, it was shown that melatonin diminished the basal level of nitric oxide by PP2A-mediated dephosphorylation of endothelial nitric oxide synthase (eNOS), leading to enhanced detachment of BAEC from the extracellular matrix. Collectively, melatonin in high doses decreases the NO production via regulations of PP2A and eNOS activities, inducing detachment of endothelial cells, a possible initial step for thrombosis.