Kwang Keun Cho

Antimicrobial activities of stearidonic and gamma-linolenic acids from the green seaweed Enteromorpha linza against several oral pathogenic bacteria

BackgroundWe found that the edible green seaweed Enteromorpha linza displayed potent antimicrobial activity against Prevotella intermedia and Porphyromonas gingivalis. To elucidate the active component of E. linza, isolation procedures were performed.ResultsThe main active compound was isolated by polarity fractionation, Sephadex LH-20 gel chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). The active compounds were eluted at isocratic 95% acetonitrile by RP-HPLC and identified as unsaturated fatty acids, stearidonic acid (SA, C18:4 n-3) and gamma-linolenic acid (GLA, C18:3 n-6) by gas chromatography–mass spectrometry, 1H nuclear magnetic resonance (NMR) spectroscopy, and 13C NMR spectroscopy. The yields of SA and GLA from dried seaweed tissue were 6.33 × 10-3% and 6.47 × 10-3%, respectively. The minimal inhibitory concentration values of SA and GLA were 39.06 μg/mL against P. intermedia and 9.76 μg/mL against P. gingivalis, respectively. SA and GLA were also active against several other oral pathogens, including Aggregatibacter actinomycetemcomitans, Candida albicans, Fusobacterium nucleatum subsp. vincenti, and Streptococcus mutans, at micromolar concentrations.ConclusionsThese data suggest that the E. linza extracts SA and GLA are useful antimicrobial agents for the prevention and/or treatment of periodontitis.

In vitro Activities of Polycalcium, a Mixture of Polycan and Calcium Lactate-Gluconate, on Osteoclasts and Osteoblasts

The present study evaluated the beneficial effects of polycalcium (a mixture of Polycan and calcium lactate-gluconate 1:9 [g/g]) on osteoporosis using in vitro assays. Cell proliferation and alkaline phosphatase activities of osteoblasts (human primary osteoblasts) and osteoclast differentiation of RAW264.7 cells (murine osteoclast progenitor cells) treated with different concentrations of polycalcium for various periods were assessed. Osteoblast proliferation was stimulated and prevented RANKL-induced osteoclast differentiation of RAW264.7 cells. These results support the development of ideal anti-osteoporotic agents, such as polycalcium, that exhibit properties that accelerate bone formation and inhibit bone resorption.

Simple freezing and thawing protocol for long-term storage of harvested fresh Undaria pinnatifida

The development of a simple and effective long-term storage protocol for harvested fresh Undaria pinnatifida is required to increase the market for U. pinnatifida products. We investigated the quality of U. pinnatifida after the application of various freezing and thawing methods to establish an optimum storage protocol. Four freezing temperatures (−40, −30, −20, and −10xa0°C), four freezing conditions (in air without seawater and with 50, 75, and 100xa0% seawater), and four thawing times (6, 12, 18, and 24xa0h) were employed. Changes in color value, tensile strength, total bacterial count, and most probable number of coliforms were measured. The best method for preserving the overall quality of U. pinnatifida is freezing at −30xa0°C with 50xa0% seawater and thawing in running tap water for 6xa0h. During retail display, changes in color, odor, tensile strength, and bacterial count of U. pinnatifida that had been freeze-thawed under optimum conditions were also measured, and a sensory evaluation was performed. There was no significant difference compared with the control within twoxa0days at 10xa0°C. In conclusion, we developed a simple and effective long-term storage protocol that led to no significant loss of quality of fresh U. pinnatifida.

Safety, functionality and stability tests of Ecklonia cava extract for dermal application

Ecklonia cava demonstrated anti-Propionibacterium acnes and anti-inflammatory activity, without any serious toxic effect, at moderate doses in an in vitro study. However, there has been no in vivo study on dermal application of E. cava extract. We evaluated the safety, functionality, and stability of a cosmetic containing E. cava extract for dermal administration. A cytotoxicity assay revealed no inhibitory effects on cell viability in a mouse leukemic monocyte macrophage cell line (RAW 264.7) after incubation with 100 μg/mL of the E. cava acetone fraction (ECAF) for 24 h. The anti-P. acnes activity of ECAF was not affected by any significant variation in temperature, pH, or exposure to artificial UV light or natural sunlight. ECAF also showed negative reactions in a patch test. No change in appearance, color, or odor was observed in a stability test on an emulsion product with ECAF. On the basis of these results, it is expected that ECAF will be a very useful or applicable raw material for skin goods such as cosmetics for treating or improving acne.