• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.80-80
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• 2002

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.80-80
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• 2002

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of cytokines. The presence of oncogenic ras has been associated with sustained induction of COX-2, which confers resistance to apoptosis. Contrary to the above notion, we found that MCF10A-ras cells treated with an anti-tumor agent, ET-18-O-$CH_3$, underwent apoptosis as revealed by proteolytic cleavage of poly(ADP-ribose)polymerase, pro-caspase 3 activity, and TUNEL staining, while the same treatment caused an increased expression of COX-2 as well as the elevated production of prostaglandin E$_2$(PGE$_2$).(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.100-101
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• 2003

It has been known that elevated levels of COX-2 is associated with resistance to apoptosis in cancerous or transformed cells. However, recent studies have shown that up-regulation of COX-2 may be implicated in induction of apoptosis. Previous studies from this laboratory have shown that a novel alkylphospholipid type antitumor agent ET-18-O-$CH_3$ (l-O-octadecyl-2-0-methyl-glycero-3-phosphocholine) induces COX-2 expression in H-ras transformed human breast epithelial cells (MCF10A-ras) while it causes apoptosis in the same concentration range.(omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.313.3-314
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• 2002

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of cytokines and other proinflammatory stimuli. It has been known that aberrant up-regulation of COX-2 is associated with resistance to apoptosis. Contrary to the above notion. treatment of MCF10A-ras cells with the anti-tumor agent ET -18-O-$CH_3$ caused increased expression of COX-2 and its mRNA transcript. while inducing apoptosis as revealed by proteolytic cleavage of poly(ADP-ribose)polymerase. caspase-3 activation, and positive TUNEL staining. (omitted)

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.154-155
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• 2001

• Applied Biological Chemistry
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• v.50 no.4
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• pp.348-351
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• 2007

The stem barks of Fraxinus rhynchophylla was extracted with 95% EtOH, and the concentrated extract was successively partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$ in order to investigate the major phytochemicals. From the $CH_2Cl_2$ soluble fraction, a sterol (1) was isolated through the repeated silica gel column chromatographies. Three additional compounds (2-4) were isolated from the n-BuOH soluble fraction through silica gel, RP-18, and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as daucosterol $(1;{\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside)$, caffeic acid (2), 6,8-dihydroxy-7-methoxycoumarin (3), and coniferaldehyde glucoside (4) by comparing their spectral data with those in the literatures. All isolates (1-4) were the first to be isolated from F. rhynchophylla.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.135-135
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• 2002

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.05a
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• pp.100-101
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• 2003

• Natural Product Sciences
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• v.25 no.4
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• pp.326-333
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• 2019

The purpose of our study was to evaluate anti-AD potential of Cirsium maackii flowers. MeOH extract, CH₂Cl₂, EtOAc, and n-BuOH fraction of this flower notably inhibited BACE1 (IC₅₀ = 76.47 ± 1.66, 22.98 ± 1.45, 8.65 ± 0.63, and 72.47 ± 3.04 ㎍/mL, respectively). β-amyrenone (49.70 mg) (1), lupeol acetate (1.43 g) (2), lupeol (1.22 g) (3), lupenone (23.70 mg) (4), β-sitosterol (1.01 g) (6), and β-sitosterol glucoside (13.00 mg) (7) from CH₂Cl₂, apigenin (100.20 mg) (8), luteolin (19.00 mg) (9), apigenin 7-O-glucuronide methyl ester (21.30 mg) (14), and tracheloside (53.70 mg) (5) from EtOAc, apigenin 5-O-glucoside (11.00 mg) (10), luteolin 5-O-glucoside (11.00 mg) (11) and apigenin 7-O-glucuronide (91.00 mg) (12) from n-BuOH, and luteolin 7-O-glucuronide (22.00 mg) (13) from H₂O fraction were isolated. HPLC showed high levels of 8, 9 and 12 in MeOH extract (33.07 ± 0.07, 31. 44 ± 0.17 and 16.89 ± 0.33 mg/g, respectively), EtOAc (161.01 ± 1.78, 96.93 ± 0.34 and 73.38 ± 0.06 mg/g, respectively), and n-BuOH fraction (32.18 ± 0.33, 44.31 ± 0.32 and 105.94 ± 0.36 mg/g, respectively). Since, 3 and 9 are well-known BACE1 inhibitors, the anti-AD activity of C. maackii flower might be attributable to their presence.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2001.10a
• /
• pp.154-155
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• 2001

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of proinflammatory agents and cytokines. COX-2 expression has been shown to be elevated in several different types of human cancer. The presence of oncogenic ras has been associated with constitutive induction of COX-2 in certain H-ras transformed cells, and COX-2 overexpression confers resistance to apoptosis.(omitted)