Hyun Ah Jung

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Reactive oxygen species (ROS) play an important role in the pathogenesis of many human degenerative diseases such as cancer, aging, arteriosclerosis, and rheumatism. Much attention has been focused on the development of safe and effective antioxidants. To discover sources of antioxidative activity in marine algae, extracts from 17 kinds of seaweed were(More)
Diabetic complications, including retinopathy, neuropathy, nephropathy and cataracts, are the leading causes of death in diabetics. Also, an increasing population of diabetic patients has triggered the increasing publicity for treatments and prevention of diabetic complications throughout the world. There are direct evidences indicating the relevance of(More)
As part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications, the rat lens aldose reductase (RLAR) inhibitory effect of Coptidis Rhizoma (the rhizome of Coptis chinensis Franch) was evaluated. Its extract and fractions exhibited broad and moderate RLAR inhibitory activities of 38.9 approximately 67.5(More)
As a component of our continuing investigations into herb-derived antioxidant agents, we have evaluated the antioxidant effects of Flos Lonicerae (Lonicera japonica flowers), via 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, total reactive oxygen species (ROS), hydroxyl radical (*OH), and peroxynitrite (ONOO-) assays. Among the methanolic extract and the(More)
In our consecutive research on an anti-AD remedy derived from maritime plants, the BACE1 inhibitory activities of Eisenia bicyclis and its isolated phlorotannins were evaluated. The E. bicyclis extract and its fractions exhibited predominant BACE1 inhibition. With the exception of phloroglucinol (1), all test phlorotannins isolated from the most active(More)
Peroxynitrite is a cytotoxic intermediate produced by the reaction between a superoxide anion radical and nitric oxide. The scavenging activities of flavonoids on peroxynitrite were investigated to illustrate the structure-activity relationship. Peroxynitrite was scavenged by the presence of various flavonoids, whose structures seem to be closely related to(More)
In our ongoing study to identity antioxidants from natural sources, the antioxidant activity of Nelumbo nucifera stamens was evaluated for their potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, inhibit total reactive oxygen species (ROS) generation, in kidney homogenatas using 2',7'-dichlorodihydrofluorescein diacetate(More)
The dramatic increase in obesity-related diseases emphasizes the need to elucidate the cellular and molecular mechanisms underlying fat metabolism. Inhibition of adipocyte differentiation has been suggested to be an important strategy for preventing or treating obesity. In our previous study, we characterized an Ecklonia stolonifera extract and non-polar(More)
Anti-inflammatory activity of Saccharina japonica and its active components was evaluated via in vitro inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) expression in RAW 264.7 murine macrophage cells. Since the methanolic extract of S. japonica(More)
The antioxidant activity of Eriobotrya japonica was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and lipid peroxidation produced when mouse liver homogenate was exposed to the air at 37 degrees C, using 2-thiobarbituric acid (TBA). The methanol extract and its fractions of Eriobotrya japonica leaves(More)