Ung-Kyu Choi

Hypolipidemic and Antioxidant Effects of Dandelion (Taraxacum officinale) Root and Leaf on Cholesterol-Fed Rabbits

Dandelion (Taraxacum officinale), an oriental herbal medicine, has been shown to favorably affect choleretic, antirheumatic and diuretin properties. Recent reports have indicated that excessive oxidative stress contributes to the development of atherosclerosis-linked metabolic syndrome. The objective of this current study was to investigate the possible hypolipidemic and antioxidative effects of dandelion root and leaf in rabbits fed with a high-cholesterol diet. A group of twenty eight male rabbits was divided into four subgroups; a normal diet group, a high-cholesterol diet group, a high-cholesterol diet with 1% (w/w) dandelion leaf group, and a high-cholesterol diet with 1% (w/w) dandelion root group. After the treatment period, the plasma antioxidant enzymes and lipid profiles were determined. Our results show that treatment with dandelion root and leaf positively changed plasma antioxidant enzyme activities and lipid profiles in cholesterol-fed rabbits, and thus may have potential hypolipidemic and antioxidant effects. Dandelion root and leaf could protect against oxidative stress linked atherosclerosis and decrease the atherogenic index.

Hypolipidemic and Antioxidant Properties of Phenolic Compound-Rich Extracts from White Ginseng (Panax ginseng) in Cholesterol-Fed Rabbits

In this study, the effect of low-molecular weight white ginseng compounds on various biochemical indices, including blood lipid concentrations and antioxidant enzyme activities and morphological changes was investigated in rabbits with high cholesterol diet-induced hypercholesterolemia. The experimental animals were 16-week-old male New Zealand white rabbits divided into normal control diet, high cholesterol diet, and high cholesterol with 0.05% white ginseng low-molecule compound groups, treated for 4 weeks. Blood lipid concentrations were higher in the high cholesterol groups compared to the normal control group but were not improved by the white ginseng low-molecular weight compound. We note however that antioxidant enzyme activities and morphological changes of the aorta showed that white ginseng small compounds had a positive effect on hypercholesterolemia. Based on such results, low-molecular weight compounds rich in phenolic compounds in white ginseng can be said to be effective in part in improving hyperlipidemia and atherosclerosis induced by a high cholesterol diet among New Zealand white rabbits.

Optimization of Antibacterial Activity of Perilla frutescens var. acuta Leaf against Staphylococcus aureus Using Evolutionary Operation Factorial Design Technique

This study was undertaken to optimize extraction using evolutionary operation-factorial (EVOP) design technique to elicit the antibacterial activity of Perilla frutescens var. acuta leaf against Staphylococcus aureus ATCC6538. Higher antibacterial activity was achieved at higher extraction temperature and over a longer extraction time. Antibacterial activity was not affected by differentiation of the ethanol concentration in the extraction solvent. The maximum antibacterial activity of ethanolic extract of P. frutescens leaf against S. aureus was obtained at 75 °C (R = −0.7904**) extraction temperature, 24 h (R = −0.7273**) extraction time, and 45% (R = −0.0635) ethanol concentration. The population of S. aureus was decreased from 7.535 log CFU/mL in the initial set to 4.865 log CFU/mL in the third set by EVOP factorial design technique, as well as to 2.600 log CFU/mL by extraction with ethyl acetate. Further, the ethyl acetate extract revealed the highest phenolic contents (111.3 ± 8.6 mg% of dry sample) as compared to the other extracts. Also, the scanning electronic microscopic study of the ethanolic extract of P. frutescens revealed potential detrimental effect on the morphology of S. aureus.

Antinociceptive and anti-inflammatory effects of ethanolic extracts of Glycine max (L.) Merr and Rhynchosia nulubilis seeds.

The aim of this study was to assess the in vivo potential of ethanolic extracts of Glycine max (L.) Merr. (SoRiTae) and Rhynchosia nulubilis (Yak-Kong) seeds as natural anti-nociceptive and anti-inflammatory agents. To assess the anti-nociceptive and anti-inflammatory potential, the ethanolic extracts of SoRiTae and Yak-Kong seeds were tested in arachidonic acid-induced ear edema, carrageenan induced paw edema, formalin-induced licking time, acetic acid induced writhing and hot plate-induced thermal stimulation in mice. The administration of ethanolic extracts of SoRiTae and Yak-Kong seeds evoked a significant effect of anti-nociceptive and anti-inflammatory activities as compared to standards aminopyrine and indomethacin. The ear edema, paw edema, paw licking time, pain and writhes in mice were significantly reduced (p < 0.05) as compared to the control. The results obtained in this study indicate that both SoRiTae and Yak-Kong soybeans possesses potential anti-nociceptive and anti-inflammatory activities.

Optimization of Antibacterial Activity of Perilla frutescens var. acuta Leaf against Pseudomonas aeruginosa Using the Evolutionary Operation-Factorial Design Technique

This study was undertaken to optimize the conditions for the extraction of antibacterial activity of Perilla frutescens var. acuta leaf against Pseudomonas aeruginosa KCTC 2004 using the evolutionary operation-factorial (EVOP) design technique. Increased antibacterial activity was achieved at higher extraction temperatures and with a longer extraction time. Antibacterial activity was not affected by differing ethanol concentration in the extraction solvent. The maximum antibacterial activity of ethanolic extract of P. frutescens var. acuta leaf against P. aeruginosa, determined by the EVOP factorial technique, was obtained at an extraction temperature of 80 °C (R = −0.800**), 26 h (R = −0.731**) extraction time, and 50% (R = −0.075) ethanol concentration. The population of P. aeruginosa also decreased from 6.660 log CFU/mL in the initial set to 4.060 log CFU/mL in the third set. Also, scanning electron microscopy study of the ethanolic extract of P. frutescens var. acuta revealed potential detrimental effects on the morphology of P. aeruginosa.

Effect of Calcinated Oyster Shell Powder on Growth, Yield, Spawn Run, and Primordial Formation of King Oyster Mushroom (Pleurotus Eryngii)

This study was conducted to evaluate the calcium (Ca) absorption efficacy of king oyster mushroom (Pleurotus eryngii) grown on sawdust medium supplemented with Ca-sources, including oyster shell powder, and to determine the efficacy of oyster shell powder as a calcium supplement on growth, yield, spawn run and primordial formation of P. eryngii. Optimum calcination of oyster shell powder was achieved at the temperature of 620.56 °C. A 1% supplementation of oyster shell powder in sawdust medium did not suppress the mycelial growth of P. eryngii. Also the supplementation of 2% calcinated oyster shell powder to sawdust medium potentially increased the calcium content up to a level of 315.7 ± 15.7 mg/100 g in the fruiting body of P. eryngii, without extension of duration of spawn run and the retardation of the days to primordial formation. These results suggest that the shellfish by-products, including oyster shell powder, can be utilized to develop calcium enriched king oyster mushrooms.

Comparative Study of Quality Characteristics of Korean Soy Sauce Made with Soybeans Germinated Under Dark and Light Conditions

This study was conducted to evaluate the effects of germinating soybeans under dark and light conditions on the quality characteristics of Korean soy sauce made with germinated soybeans. The germination rate of soybeans germinated under dark conditions (GSD) was higher than that of soybeans germinated under light conditions (GSL), whereas the lengths of sprouts and relative weights of GSL did not differ from those of GSD. The L, a, b, and ΔT values of GSL were significantly lower than GSD. The color of GSD remained yellow, while GSL changed to a green color due to photosynthesis by chlorophyll. The total amino acid contents in soy sauce fermented with soybeans germinated under dark conditions (SSGD) and soy sauce fermented with soybeans germinated under light conditions (SSGL) were lower than in soy sauce fermented with non-germinated soybeans (SNGS). The levels of isoflavone content in SSGD and SSGL were significantly increased compared to the SNGS. In conclusion, the germination of soybeans under dark and light conditions is not only an increasing organoleptic preference, but also has implications for the health benefits of Korean soy sauce.