• Journal of Dental Rehabilitation and Applied Science
• /
• v.28 no.4
• /
• pp.339-347
• /
• 2012

In previous studies, methods for enhancing cellular response on the Hydroxyapatite coated implant surface were described. In this study, the changes of surface characteristics such as surface roughness, contact angle, surface energy and surface morphology were observed when Hydroxyapatite coated Ti discs were immersed in NaCl solution for various time. Hydroxyapatite coated Ti discs were immersed in 0.9% NaCl solution for 7, 14 and 21 days at $37^{\circ}C$. The control group comprises dry identical discs not immersed in a solution. (n=3) All discs were dried in air completely and the surface roughness was measured using confocal laser scanning microscopy(CLSM). Static contact angle was recorded by video contact angle analyzer after dropping distilled water on the surface. The surface energy was calculated from contact angles of the three liquids. Surface was observed using a field emission-scanning electron microscope(FE-SEM). As a result, the surface roughness of immersed Hydroxyapatite coated Ti discs increased significantly and the contact angle decreased comparing with control group discs. The surface energy of immersed discs increased except for discs immersed for 14 days.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.206-213
• /
• 2005

Antibacterial, antifungal, anticancer and angiotensin-converting enzyme (ACE) inhibitory activities of water and 70% ethanol extracts of 32 medicinal herbs species were investigated. Terminalia chebula extracts showed strong antibacterial activities. Ethanol extract of Cinnamomum cassia showed good antifungal activity. ACE inhibitory activities or P. corylifolia water extract and Fraction I of P. corylifolia water extract were 65.2 and 81.8%, respectively. Cytotoxicity of ethanol precipitate fraction obtained from water extract of Eugenia caryophyllata was highest.

• Korean Journal of Food Science and Technology
• /
• v.32 no.1
• /
• pp.168-173
• /
• 2000

Anticariogenic activity of the unripe apple extract was studied by observing the inhibitory effects on GTase(glucosyltransferase) activity, cell adherence and acid production of Streptococcus mutans. Among the four S. mutans strains, S. mutans MT 8148 had the highest water-insoluble glucan forming activity. (+)-Catechin and tannic acid, the major components of the unripe apple polyphenols inhibited GTase activity by 60% at 1 mg/ml and 90% at 5 mg/ml. Tannic acid and unripe apple extract inhibited adherence ability of S. mutans by 50% and 30%, respectively. But the acid production of S. mutans was not influenced by the polyphenols. Disc diffusion test showed that the polyphenols have no antimicrobial activity against S. mutans, which indicates that the inhibition of GTase activity and cell adherence were not resulted from the cell growth inhibition. Our results convinced the possible application of the unripe apple extract as the anticariogenic food additives.

• Journal of Life Science
• /
• v.21 no.9
• /
• pp.1244-1250
• /
• 2011

The study was performed to evaluate the antibacterial and antiviral activities of ginseng fine root in order to search for antibacterial substances. Among 8 kinds of fermentation strains, Lactobacillus plantarum was selected based on viable cell count and antibacterial activities during incubation. Optimum conditions of ginseng fine root fermentation for L. plantarum were incubation at $35^{\circ}C$ for 48 hr in 5% ginseng fine root broth. That methanolic extract of fermented ginseng fine root broth was observed to be antibacterial and have antiviral activities. The results of paper disc method of non-fermented extract and fermented extract measured against E. coli was 11 mm and 20 mm, S. aureus was 15 mm and 22 mm, respectively. Shaking flask method was observed to inhibit the growth E. coli and S. aureus in fermented extract by 99.9%. However, antiviral activity of Feline calicivirus (FCV) was mostly activated. Fermented extract was used to investigate the compositional changes of ginsenosides on HPLC analysis. By fermentation, ginsenoside Rg1, Re and Rd were increased, with Rd showing a significant increase of 50 ${\mu}g/g$. These results suggest that ginseng fine root extract is a useful resource.

• Journal of Life Science
• /
• v.20 no.7
• /
• pp.1034-1040
• /
• 2010

Plants and their extracts can be utilized as inexpensive and rich resources of active constituents in the cosmetic field, as well as the food, pharmaceutical and medicinal fields. Until now, Aster glehni Fr. Schm. had no known active effect, except on anti-oxidation, that was found during investigations for application in the cosmetic field. In this study, we examined the inhibition of enzymatic reactions to protein levels in inclusive B16F10 melanoma cell lines. Significant inhibition of enzymatic reactions was observed in the EtOAc extract, which advanced to tyrosinase protein and TRP-1 in the B16F10 melanoma cell line. These results indicated that the effect of EtOAc extract inhibited expressions of tyrosinase protein and TRP-1 in the B16F10 melanoma cell line by 30.5% and 41.5% at 100ug/ml respectively. On the other hand, antimicrobial activity was evaluated to the four fractions in normal flora of the skin. Hexane extract was only exhibited in the higher clear zone in all strains. In conclusion, any cosmeceutical effects of Aster glehni Fr. Schm. may have a potential meaning, as well as possible value for further studies regarding the effects of chemical constituents of Aster glehni Fr. Schm.

• Weed & Turfgrass Science
• /
• v.4 no.2
• /
• pp.118-123
• /
• 2015

Metagenomics is a powerful tool to isolate novel biocatalyst and biomolecules directly from the environmental DNA libraries. Since the metagenomics approach bypasses cultivation of microorganisms, un-cultured microorganisms that are majority of exists can be the richest reservoir for natural products discovery. To discover novel herbicidal substances from soil metagenome, we established three easy, simple and effective high throughput screening methods such as cucumber cotyledon leaf disc assay, microalgae assay and seed germination assay. Employing the methods, we isolated two active single clones (9-G1 and 9-G12) expressing herbicidal activity which whitened leaf discs, inhibited growth of microalgae and inhibited root growth of germinated Arabidopsis seeds. Spraying butanol fraction of the isolated active clones' culture broth led to growth retardation or desiccation of Digitalia sanguinalis (L) Scop. in vivo. These results represent that the screening methods established in this study are useful to screen herbicidal substances from metagenome libraries. Further identifying molecular structure of the herbicidal active substances and analyzing gene clusters encoding synthesis systems for the active substances are in progress.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.6
• /
• pp.797-804
• /
• 2005

Physiological activity of citrus essential oil (CEO) was determined to examine possible use of the food processing by-product as a functional material for food and cosmetic composition. The effect of gamma irradiation on the change of physiological activity also investigated at 0, 10 and 20 kGy. Limonene contents of CEO was $88.3\pm1.30\%$. Electron donating ability of CEO was $69\%$. Lipid oxidation was retarded by CEO. CEO showed antimicrobial activity against 1 yeast,4 molds and 4 bacteria species tested. More than $80\%$ of inhibition of cancer cell growth was presented by CEO using A549, HT29, HepG2, B16F10 and G361 cells at a 500 ppm level. Irradiation of CEO did not affect any physiological functions. A Salmonella mutagenicity assay indicated that the 20 kGy irradiated CEO did not show any mutagenicity Therefore, CEO, which is a major by-product in citrus processing, could be used as a functional material in various application.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.6
• /
• pp.765-770
• /
• 2005

In this study, we investigated antimicrobial and cytotoxicity effects of Undaria pinnatifida Sporophyll, which using methanol, dichloromethane and ethanol were extracted and fractionated into four different types: methanol (UPMM), hexane (UPMH), butanol (UPMB) and aqueous (UPMA). The antimicrobial activity was increased in proportion to its concentration by the paper disc method. Among the solvent fractions, UPMM and UPMB showed relatively strong antimicrobial activities in the order. Among various partition layers, the methanol partition layer (UPMM) was showed the strongest cytotoxic effects on all cancer cell lines. We also observed quinone reductase (QR) induced effects in all fraction layers of UP on HepG2 cells. The QR induced effects of UPMH on HepG2 cells at $320\mu g/mL$ concentration indicated 2.36 with a control value of 1.0.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.10
• /
• pp.1433-1438
• /
• 2010

This study was carried out to investigate the antioxidative and antimicrobial activities of internal organs of Aplysia kurodai (AK). The internal organs of AK were extracted with methanol (AKM), which was then further fractionated into four subfractions by using solvent partition method, affording hexane (AKMH), methanol (AKMM), butanol (AKMB), and aqueous (AKMA) soluble fractions. The antioxidative activity of fractions from AK was investigated by measuring the scavenging activities of AK against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen species (ROS). Among the various solvent fractions, AKMB showed a marked scavenging effect against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen species (ROS). The antimicrobial activity was increased in proportion to its concentration by the paper disk method. Among the various solvent fractions, AKMM fractions of AK showed the strongest antimicrobial activities. The methanol extracts exhibited antimicrobial activity against all organisms tested, while the hexane extracts showed antimicrobial activity only against Proteus vulgaris. The results suggest that the AK may be suitable for development as a food preservative and alternative antioxidant.

• Journal of the Korean Ceramic Society
• /
• v.39 no.9
• /
• pp.851-856
• /
• 2002

Tribological behavior of plasma-sprayed $Cr_2O_3$-based coatings containing $MoO_3$ at 450$^{\circ}C$ was investigated to understand the influence of $MoO_3$. A reciprocal disc-on-plate type tribo-tester was employed to examine fricition and wear behavior of the specimens. The microstructure and phase composition of the coating was characterized with Transmission Electron Microscopy(TEM). The TEM analysis indicated that $MoO_3$ was dispersed into the grain boundary, resulting in the increase of the hardness and density of the coating. Worn surfaces were investigated by scanning electron microscopy and chemistry of the worn surfaces was analyzed using a X-ray Photoelectron Spectrometer(XPS). The results showed that the friction coefficient of the $MoO_3$-added coatings was lower than that without $MoO_3$ addition. The larger protecting layers were observed at the worn surface of plasma spray coated specimens with $MoO_3$ composition in the protecting layer appears to be more favorable in reducing the friction.