• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.562-570
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• 2021

Topoisomerase IIα has been a representative anti-cancer target for decades thanks to its functional necessity in highly proliferative cancer cells. As type of topoisomerase IIα targeting drugs, topoisomerase II poisons are frequently in clinical usage. However, topoisomerase II poisons result in crucial consequences resulted from mechanistically induced DNA toxicity. For this reason, it is needed to develop catalytic inhibitors of topoisomerase IIα through the alternative mechanism of enzymatic regulation. As a catalytic inhibitor of topoisomerase IIα, AK-I-191 was previously reported for its enzyme inhibitory activity. In this study, we clarified the mechanism of AK-I-191 and conducted various types of spectroscopic and biological evaluations for deeper understanding of its mechanism of action. Conclusively, AK-I-191 represented potent topoisomerase IIα inhibitory activity through binding to minor groove of DNA double helix and showed synergistic effects with tamoxifen in antiproliferative activity.

• Natural Product Sciences
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• v.29 no.1
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• pp.24-30
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• 2023

Adenanthera pavonina L. is an important medicinal plant for Indonesian traditional medicine ("Jamu"). The present study is to determine the phenolic content and evaluate the antioxidant activity of ethyl acetate and ethanolic extracts of leaves and bark of A. pavonina. The total phenolic content was determined using the Folin-Ciocalteu reagent methods, and the antioxidant activity was performed by phosphomolybdate assay, through EC₅₀ values. The highest phenolic content (81.379 mg GAE/g) was found in the hydro-ethanolic extract of the leaves and (80.630 mg GAE/g) in the bark. The antioxidant activity of the two samples was 42.270 ㎍/mL (leaves) and 45.261 ㎍/mL (bark). Plants have the potential as drugs with good antioxidant potential and phenolic compound content. Further scientific studies of this plant are supported to evaluate the antioxidant activity using other methods to validate these preliminary experiments properly.

• The Korea Journal of Herbology
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• v.31 no.6
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• pp.45-52
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• 2016

Objectives : This study was performed to investigate the antioxidant activity of water and ethanol extracts from Sasa borealis leaves, stems and roots. Methods : Sasa borealis leaves, stems and roots extract were prepared using water and ethanol. The total polyphenol and total flavonoid contents were analyzed. 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity, SOD like activity, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS), hydroxyl radical scavenging activity, and Nitrite scavenging activity assays were carried out to determine the antioxidant activities. Results : The antioxidant activities of the Sasa borealis appeared higher in ethanol extract than water extracts. Total polyphenol and total flavonoids contents in ethanol extracts of leaves were $24.6mg/m{\ell}$ and $14.3mg/m{\ell}$, respectively, which were much higher than those of any other parts. SOD like activity was 70% ethanol extract of the leaves was highest with 15.68%. Electron donating ability was 70% ethanol extract of the leaves had the highest 59.07%. It exhibited high electron donating ability than BHT(45.68%). Nitrite scavenging activity of 70% ethanol extract was higher than the water extract at pH 2.5 and pH 4.2. Nitrite scavenging activity was 70% ethanol extract of the leaves was the highest 75.2%. Hydroxyl radical scavenging activity was 70% ethanol extract of the leaves was highest with 16.16%, showed very low activity than BHT(61.56%). Conclusions : These results suggest that 70% ethanol extracts from Sasa borealis leaves, exhibited higher antioxidant activities than those of root and stem, and can be potentially used as proper natural antioxidants.

• Environmental Mutagens and Carcinogens
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• v.26 no.3
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• pp.89-92
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• 2006

To enhance our understanding of immunological stimulating effects through the pathway by which nitric oxide (NO) activity and alkaline phosphatase(ALP) enzyme activity from the marine algae, Ulva lactuca, we have investigated NO activity by using mouse RAW264.7 cell line. And ALP enzyme activity performed by spleen of ICR mouse. The results showed that NO activity of the $H_2O$ fraction is the most effective than activities of other solvent fractions.

• Natural Product Sciences
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• v.26 no.2
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• pp.158-164
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• 2020

Helicobacter pylori is a well-known pathogen that is responsible for gastric disorders. Overcoming of the antibiotic-resistance is a main barrier to treat H. pylori infection. In our search for anti-H. pylori compounds from natural resources, bioactivity-guided isolation on the ethyl acetate fraction of Fraxinus mandshurica bark that had shown anti-H. pylori activity gave twelve compounds (1 - 12) of six coumarins, three phenylethanoids, two secoiridoids, and a lignan using silica gel column chromatography, Sephadex-LH 20, and recrystallization. The chemical structures were identified by spectroscopic data analysis, including 1D, 2D NMR, and mass spectrometry. Among them, compounds 2, 10, and 11 showed moderate growth inhibitory activity against three strains of H. pylori, compared with positive controls of quercetin and metronidazole. Compounds 5, 6, 8, and 12 exhibited the inhibitory activity against strains 26695 or 43504. This is the first report on the anti-H. pylori activity of this plant and the isolated compounds.

• YAKHAK HOEJI
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• v.38 no.5
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• pp.520-524
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• 1994

A number of 7-[(3-methylthio or methylthiomethyl)-3-pyrrolinyl] quinolone-3-carboxylic acids were synthesised by condensation of 7-fluoro substituted quinolone-3-carboxylic acid with 3-methylthio-3-pyrroline or 3-methylthiomethyl-3-pyrroline. The in vitro antimicrobial activity of them were tested against twenty species of Gram-positive or Gram-negative microorganisms. It showed remarkable antibacterial activity, particularly against Gram-positive microoganisms. Among those 1-cyclopropyl-6,8-difluoro-7-[(3-methylthiomethyl) -3-pyrrolinyl]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid(12a) and 1-cycl opropyl-6-fluoro-8-chlore-7-[(3-methylthiomethyl)-3-pyrrolinly]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid(12b) showed the most potent in vitro antibacterial activity.

• Korean Journal of Pharmacognosy
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• v.37 no.1 s.144
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• pp.48-52
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• 2006

Advanced glycation end products (AGEs) are largely involved in the pathogenesis of diabetic complications. As part of our ongoing project directed toward the discovery of preventive and/or delay agents for diabetic complications from natural sources, 92 Korean traditional herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 17 herbal medicines exhibited a significant inhibitory activity against AGEs formation. Particularly, 9 herbal medicines, i.e., Cinnamomi Cortex, Artemisiae Argyi Herba, Ammoni Tsao-ko Fructus, Menthae Herba, Amomi Semen, Polygoni Avicularis Herba, Lycopi Herba, Salviae Radix, and Nelumbinis Semen showed more potent inhibitory activity (2-4 fold) than the positive control aminoguanidine.

• Natural Product Sciences
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• v.2 no.2
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• pp.119-122
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• 1996

The antiinflammatory activity of the methanol extract of Leucas lavandulaefolia Rees was evaluated on different experimental models of inflammation in rats. The extract has been found to possess significant, inhibitory activity against carrageenin, histamine, serotonin, and dextran induced hind paw oedema in rats. The effect produced by extract was comparable to that of phenylbutazone and a prototype, nonsteroidal antiinflammatory agent.

• Natural Product Sciences
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• v.12 no.3
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• pp.153-156
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• 2006

The antisnake venom activity of Clerodendrum viscosum Vent. (Fam. Verbenaceae), a plant traditionally used in India for the treatment of snake bite was evaluated by in vitro and in vivo methods. While in vitro studies were performed using human blood, in vivo studies were carried out using mice administered three different i.p doses of the extract, 5 min before the administration of Naja naja snake venom. The results of the in vitro studies showed that the extract probably interacts with but does not stabilize membrane protein. In the in vivo studies the extract showed significant antisnake venom activity, which may be attributed to its possible interference with the acetylcholine receptor sites. Hence the present investigation justifies the traditional use of Clerodendrum viscosum (C. viscosum) as antisnake venom.

• Advances in Traditional Medicine
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• v.9 no.4
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• pp.303-306
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• 2009

The defatted methanol extract of Raphanus sativus Linn. (Cruciferae) seed (MERS) was evaluated for its antisteroidogenic potential in mature female Swiss albino mice. The methanol extract at the doses of 100 and 200 mg/kg body weight significantly elevated the levels of cholesterol and ascorbic acid contents which serve as a precursor for the synthesis of steroid hormones in ovaries. The extract also significantly inhibited glucose-6-phosphate dehydrogenase and ${\Delta}^5-3{\beta}$-hydroxy steroid dehydrogenase, the two key enzymes involved in ovarian steroidogenesis. Hence the extract (MERS) exhibited significant antisteroidogenic activity.