• Korean Journal of Pharmacognosy
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• v.40 no.2
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• pp.143-149
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• 2009

Among aging diseases, the most basic problem is a decrease in bone mineral density. Patients with osteoporosis are steadily increasing in the world. This study was investigated to show the relationship between osteoporotic effects and oxidative damage. Water extracts of 15 medicinal plants and ethanol extracts of 14 medicinal plants with known anti-osteoporotic effects, were tested for their radical scavenging activity using DPPH, ABTS, SRSA and FRAP assay. Water extract of Cornus officinalis, Rubus coreanus and ethanol extract of Rubus coreanus, Viscium album var. coloratum, Cimicifuga heracleifolia showed about 15-20 mg/g of total phenolic contents. Water extract of Cornus officinalis, Rubus coreanus and Epimedium koreanum showed high radical scavenging activity. Ethanol extract of Drynaria fortunei, Cornus officinalis, Rubus coreanus, Gentiana scabra and Astragalus membranaceus showed high radical scavenging activity. Water extract of Drynaria fortunei, Cornus officinalis, Nelumbo nucifera, Epimedium koreanum, and Gentiana scabra showed very strong protective effect against oxidative damage to DNA. These results suggest the correlation between anti-osteoporotic effects and antioxidative effects.

• Journal of Microbiology
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• v.43 no.1
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• pp.54-61
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• 2005

In this study, we attempted to determine the effects of iron-availability and the activity of the bacterial iron-uptake system (IUS) on the growth of Staphylococcus aureus in human peritoneal dialysate (HPD) solution. A streptonigrin-resistant S. aureus (SRSA) strain, isolated from S. aureus ATCC 6538, exhibited defective siderophore production, thereby resulting in ineffective uptake of iron from low iron-saturated transferrin. The growth of both strains was stimulated in HPD solution supplemented with FeCl_3 and holotransferrin, but growth was inhibited in HPD solution which had been supplemented with apotransferrin and dipyridyl. The SRSA strain grew less robustly than did its parental strain in both iron-supplemented HPD solution and regular HPD solution. These results indicate that iron-availability and siderophore-mediated IUS activity in particular, the ability to produce siderophores and thus capture iron from low iron-saturated transferrin play critical roles in the growth of S. aureus in HPD solution. Our results also indicated that the possibility of using iron chelators as therapeutic or preventive agents warrants further evaluation.