Myung-Kon Kim

Rutin from Dendropanax morbifera Leveille Protects Human Dopaminergic Cells Against Rotenone Induced Cell Injury Through Inhibiting JNK and p38 MAPK Signaling

Dendropanax morbifera Leveille (Araliaceae) is well known in Korean traditional medicine for a variety of diseases. Rotenone is a commonly used neurotoxin to produce in vivo and in vitro Parkinson’s disease models. This study was designed to elucidate the processes underlying neuroprotection of rutin, a bioflavonoid isolated from D. morbifera Leveille in cellular models of rotenone-induced toxicity. We found that rutin significantly decreased rotenone-induced generation of reactive oxygen species levels in SH-SY5Y cells. Rutin protected the increased level of intracellular Ca2+ and depleted level of mitochondrial membrane potential (ΔΨm) induced by rotenone. Furthermore, it prevented the decreased ratio of Bax/Bcl-2 caused by rotenone treatment. Additionally, rutin protected SH-SY5Y cells from rotenone-induced caspase-9 and caspase-3 activation and apoptotic cell death. We also observed that rutin repressed rotenone-induced c-Jun N-terminal kinase and p38 mitogen-activated protein kinase phosphorylation. These results suggest that rutin may have therapeutic potential for the treatment of neurodegenerative diseases associated with oxidative stress.

Purification and characterization of fibrinolytic metalloprotease from Perenniporia fraxinea mycelia

In this study we purified and characterized a fibrinolytic protease from the mycelia of Perenniporia fraxinea. The apparent molecular mass of the purified enzyme was estimated to be 42kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), fibrin zymography and size exclusion using fast protein liquid chromatography (FPLC). The first 20 amino acid residues of the N-terminal sequence were ASYRVLPITKELLPPEFFVA, which shows a high degree of similarity with a fungalysin metallopeptidase from Coprinopsis cinerea. The optimal reaction pH value and temperature were pH 6.0 and 35-40 degrees C, respectively. Results for the fibrinolysis pattern showed that the protease rapidly hydrolyzed the fibrin alpha-chain followed by the beta-chain. The gamma-gamma chains were also hydrolyzed, but more slowly. The purified protease effectively hydrolyzed fibrinogen, preferentially digesting the Aalpha-chains of fibrinogen, followed by Bbeta- and gamma-chains. We found that protease activity was inhibited by Cu(2+), Fe(3+), and Zn(2+), but enhanced by the additions of Mn(2+), Mg(2+) and Ca(2+) metal ions. Furthermore, the protease activity was inhibited by EDTA, and it was found to exhibit a higher specificity for the chromogenic substrate S-2586 for chymotrypsin, indicating that the enzyme is a chymotrypsin-like metalloprotease. The mycelia of P. fraxinea may thus represent a source of new therapeutic agents to treat thrombosis.

Leaf extract of Rhus verniciflua Stokes protects dopaminergic neuronal cells in a rotenone model of Parkinson's disease

Objectives  The present study investigated the neuroprotective effects of Rhus verniciflua Stokes (RVS) leaf extract on rotenone‐induced apoptosis in human dopaminergic cells, SH‐SY5Y.

Anti-thrombotic effect of rutin isolated from Dendropanax morbifera Leveille

Dendropanax morbifera H. Lev. is well known in Korean traditional medicine for improvement of blood circulation. In this study, rutin, a bioflavonoid having anti-thrombotic and anticoagulant activities was isolated from a traditional medicinal plant, D. morbifera H. Lev. The chemical characteristics of rutin was studied to be quercetin 3-O-α-l-rhamnopyranosyl-(1-6)-β-d-glucopyranoside using high performance liquid chromatography mass spectrometry (HPLC-MS), proton nuclear magnetic resonance ((1)H NMR) and carbon-13 nuclear magnetic resonance ((13)C NMR). Turbidity and fibrin clotting studies revealed that rutin reduces fibrin clot in concentration dependent manner. Rutin was found to prolong activated partial thromboplastin time (aPTT), prothrombin time (PT) and closure time (CT). Furthermore, it decreased the activity of pro-coagulant protein, thrombin. In vivo study showed that rutin exerted a significant protective effect against collagen and epinephrine (or thrombin) induced acute thromboembolism in mice. These results suggest that rutin has a potent to be an anti-thrombotic agent for cardiovascular diseases.

A Detoxified Extract of Rhus verniciflua Stokes Upregulated the Expression of BDNF and GDNF in the Rat Brain and the Human Dopaminergic Cell Line SH-SY5Y

Rhus verniciflua Stokes (RVS) has traditionally been used as a food supplement and a traditional herbal medicine for centuries in Korea. This study attempted to evaluate the effects of RVS on the expression of Brain derived neurotrophic factor (BDNF) and Glial cell line-derived neurotrophic factor (GDNF) in SH-SY5Y cells and the rat brain. The results indicated that RVS is a potent inducer of Neurotrophic factor (NTF) production both in vitro and in vivo. Treatment with 10 μg/ml and 10 mg/kg RVS for 4 h of SH-SY5Y cells and rats yielded significant increases in BDNF and GDNF protein levels. We also detected BDNF and GDNF immunoreactive neurons in the rat brain. Both BDNF and GDNF-immunohistochemical staining was markedly enhanced in the animals treated with RVS. These results suggest that RVS serves as an ideal adjuvant in regard to regulating NTF expression, and can contribute to neuroprotection in neurodegenerative diseases.

Chemical composition and antioxidant activity of Korean cactus (Opuntia humifusa) fruit

The chemical composition and antioxidant activities of the Korean cactus (Opuntia humifusa, OH) fruit were investigated in this study. Major minerals in the OH fruit were P, Ca, and Mg. Total dietary fiber content was 22.8% and the soluble dietary fiber/insoluble dietary fiber ratio was 1:1.3. An 80% ethanol extract was used to investigate antioxidant activities based on DPPH radical scavenging ability as well as total phenolic and flavonoid content. OH fruit extract from 80% ethanol was sequentially fractionated according to the polarity of solvents. Among various fractions, the ethyl acetate fraction showed the highest antioxidant activity as well as the highest total phenolic and total flavonoid contents compared to other fractions. The most abundant phenolic acid in the ethyl acetate fraction was ferulic acid, followed by protocatechuic acid. The most abundant flavonoid was taxifolin, followed by myricetin. The results suggested that OH fruit could be a good potential source of antioxidant.

Preparation and Characterization of Urushiol Free Fermented Rhus verniciflua Stem Bark (FRVSB) Extracts

The water extract of the fermented Rhus verniciflua stem bark (FRVSB) was prepared by hot water extracting at 100 o C for 8 h. The urushiol content of the FRVSB water extract was determined by HPLC. The urushiol was not contained in FRVSB water extract, whereas Rhus verniciflua stem bark (RVSB) water extract contained 3.4 mg%. At the lab scale size, suitable water extraction condition for a total solid, polyphenol and flavonoid from FRVSB was at over 100 o C for 6-8 h. The total solid contents was reduced in pilot scale processing system, with 5.7% of the extraction yield. The proximate composition (%) of FRVSB water extract obtained from industrial installation was moisture 4.34, crude fat 1.69, crude protein 10.21, and crude ash 15.80. Gallic acid (1,090.5 mg%) was the most abundant compound in phenolic acids, while fisetin (135.7 mg%) was the predominant flavonoid. The free sugar content was mannitol of 3.48%, glycerol of 0.19%, and glucose of 0.19%. Alanine (244 ppm), serine (231 ppm), and leucine (218 ppm) were predominant amino acids.

Enzymatic formation of compound-K from ginsenoside Rb1 by enzyme preparation from cultured mycelia of Armillaria mellea.

Background Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. Methods Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at 25°C for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30–80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. Results Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was Rb1 → Rd → F2 → compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72–96 h, pH 4.0–4.5, and temperature 45–55°C. Conclusion AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.

Isozyme evidence for the allotriploid origin of Lycoris flavescens (Amaryllidaceae)

Abstract. Variation in isozyme patterns from ten populations of the Korean endemic Lycoris species was used to test the hypothesis that L. flavescens originated from natural hybridization between diploid L. chinensis and L. sanguinea var. koreana. Lycoris sanguinea var. koreana shows fixed heterozygosity at four of nine loci assayed, suggesting that this species is an allotetraploid instead of a diploid. Electrophoretic data suggest that Lycoris flavescens is an allotriploid species derived from the hybridization between diploid L. chinensis and tetraploid L. sanguinea var. koreana. The patterns of allelic distribution in populations of L. flavescens suggest multiple origins of the allotriploid. Within the L. flavescens complex, our isozyme data support the recognition of two taxa, L. flavescens and a recently recognized species, L. uydoensis.

Physicochemical Properties and Physiological Activities of Rhus verniciflua Stem Bark Cultured with Fomitella fraxinea

The contents of proximate composition, free amino acids and phenolic acids in the Fomitella fraxinea cultivated-Rhus verniciflua stem bark(FRVSB), and its adipogenesis effect were investigated. The proximate composition(%) of FRVSB was as follows: moisture(7.64), ash(6.30), crude fat(3.86), crude protein(3.59) and sugar(not detected); while Rhus verniciflua stem bark(RVSB) contained 1.64, 8.09, 7.28, 6.48 and 5.39, respectively. The total free amino acids concentration was 97.41 mg% in FRVSB and 71.91 mg% in RVSB. Phosphoserine(55.06 mg%), ammonia(17.84mg%) and aspartic acid(6.05mg%) were predominant amino acids. The content of total phenolic acids was 422.89 ppm in ethanol extract and 283.86 ppm in water extract, with syringic and gallic acid as the main component. The FRVSB extracts showed a potent free radical scavenging activity for DPPH(2,2-diphenyl-1-picrylhydrazyl hydrate) with of (EtOH) and (water), respectively, whereas value of gallic acid was . The protective effect of both ethanol and water extract the extracts against UV-induced oxidative stress in NIH3T3 was observed. The water extracts of FRVSB may promote adipogenesis in 3T3-L1 cells.