Kang-Duk Choi

Sphingosinicella ginsenosidimutans sp. nov., with ginsenoside converting activity

The Gram-reaction-negative, strictly aerobic, non-motile, nonspore-forming, and rod-shaped bacterial strain designated BS11T was isolated from the compost and its taxonomic position was investigated by using a polyphasic approach. Strain BS11T grew optimally at 30–37°C and at pH 7.0 in the absence of NaCl on nutrient agar. Strain BS11T displayed β-glucosidase activity that was responsible for its ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to Rd. On the basis of 16S rRNA gene sequence similarity, strain BS11T was shown to belong to the family Sphingomonadaceae and was related to Sphingosinicella vermicomposti YC7378T (96.3% sequence similarity), S. xenopeptidilytica 3–2W4T (96.2%), S. microcystinivorans Y2T (96.1%), and S. soli KSL-125T (95.9%). The G+C content of the genomic DNA was 64.9%. The major menaquinone was Q-10 and the major fatty acids were summed feature 7 (comprising C18:1ω7c/ω9t/ω12t; 40.6%), C16:0 (22.5%), C17:1ω6c (13.7%) and C17:0 (9.1%). DNA and chemotaxonomic data supported the affiliation of strain BS11T to the genus Sphingosinicella. Strain BS11T could be differentiated genotypically and phenotypically from the recognized species of the genus Sphingosinicella. The novel isolate therefore represents a novel species, for which the name Sphingosinicella ginsenosidimutans sp. nov. is proposed, with the type strain BS11T (=KACC 16619T =JCM 18201T).

Dryopteris crassirhizoma has anti-cancer effects through both extrinsic and intrinsic apoptotic pathways and G0/G1 phase arrest in human prostate cancer cells

AIM OF THE STUDY The inhibitory effect of Dryopteris crassirhizoma on the proliferation of human metastatic prostate PC3-MM2 cells and the mechanism of action were examined to identify its anti-cancer properties. The effect of the extract on cell cycle progression and its combined cytotoxic effect with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on PC3-MM2 cells were also investigated. MATERIALS AND METHODS The anti-proliferative effects of Dryopteris crassirhizoma were examined by culturing PC3-MM2 cells in the presence or absence of various concentrations of Dryopteris crassirhizoma extract, and the inhibitory effects on cell proliferation were determined by Cell Counting Kit (CCK)-8 analysis. The quantities of apoptosis-inducing proteins were measured by western blotting analysis. Cell cycle progression was analyzed by PI staining using flow cytometry. RESULTS Dryopteris crassirhizoma (50 and 100 microg/ml) inhibited markedly the proliferation of PC-3 and PC3-MM2 cells without cytotoxicity to normal (spleen) cells from BALB/C mice. Dryopteris crassirhizoma (100 microg/ml) effectively induced apoptosis through the activation of caspase-3, -8, -9, bid, and PARP in PC3-MM2 cells. The cells exposed to Dryopteris crassirhizoma increased significantly the accumulation of the DNA contents in the G0/G1 phase and sub-G1 phase in contrast to the control. The combined cytotoxic effects of Dryopteris crassirhizoma and TRAIL induced the increased activity of 29% in contrast to the sum of the inhibitory effects of each agent alone. CONCLUSIONS Dryopteris crassirhizoma has anti-cancer properties by inducing cell cycle arrest and apoptosis through the extrinsic and intrinsic pathway in PC3-MM2 cells. The extract also showed a combined effect with TRAIL on the inhibition of proliferation in the cells. These findings suggest that possibly its extract could be used for treating androgen-independent prostate cancer with minimal side effects.

Capsaicin and tocopherol in red pepper seed oil enhances the thermal oxidative stability during frying

Thermal oxidative stability of red pepper (Capsicum annuum) seed oil added with different levels of capsaicin or tocopherol as antioxidant during heating up to 48 h at 140±5°C was studied. Lipid oxidation of soy and pepper oil with different levels of capsaicin (0.12, 0.24%) and tocopherol (0.3, 0.6%) were evaluated during storage at 1400C for 0, 12, 24 and 48 h by monitoring peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and chemiluminiscence (CL). Capsaicin content of crude pepper oil (0.16 mg/ml) was much higher than that of commercial brands (0.004–0.02 mg/ml). Oleate content was significantly (p<0.05) higher in soy oil (53.7%) than pepper oil (9.5%), however, linoleate and linolenate contents were significantly (p<0.05) higher in pepper oil (70.6, 5.8%) than in soy oil (25.9, 5.8%). TBARS, PV, and CL of pepper oil were significantly (p<0.05) lower than soy oil after frying. TBARS and CL values of pepper oil with different levels of capsaicin or tocopherol showed significantly (p<0.05) lower values than untreated pepper oil during frying and storage. TBARS and CL values of 0.6% tocopherol treated pepper oil showed significantly (p<0.05) lower values than those of soy oil. The study suggests that capsaicin and tocopherol may play a key role to prevent the thermal oxidation of pepper oil during frying.

Identification of Differentially Expressed Genes in Distinct Skeletal Muscles in Cattle using cDNA Microarray

The 788-gene microarray was manufactured using selected elements from three different cDNA libraries in order to identify molecular processes that determine phenotypic characteristics between loin (M. longissimus thoracis) and round (M. semimembranosus) muscles. Microarray analyses identified 24 differentially expressed genes between the two muscles investigated. Five of the genes were verified by quantitative RT-PCR and three of them were mapped on bovine chromosomes using 5,000 rad bovine radiation hybrid (RH) panel. The map locations indicated that they were mapped in the same chromosomal regions where IMF and growth QTLs were located, suggesting that they are most possible positional candidate genes for the traits.

Production of ginsenoside F1 using commercial enzyme Cellulase KN

Background Ginsenoside F1, a pharmaceutical component of ginseng, is known to have antiaging, antioxidant, anticancer, and keratinocyte protective effects. However, the usage of ginsenoside F1 is restricted owing to the small amount found in Korean ginseng. Methods To enhance the production of ginsenoside F1 as a 10 g unit with high specificity, yield, and purity, an enzymatic bioconversion method was developed to adopt the commercial enzyme Cellulase KN from Aspergillus niger with food grade, which has ginsenoside-transforming ability. The proposed optimum reaction conditions of Cellulase KN were pH 5.0 and 50°C. Results Cellulase KN could effectively transform the ginsenosides Re and Rg1 into F1. A scaled-up biotransformation reaction was performed in a 10 L jar fermenter at pH 5.0 and 50°C for 48 h with protopanaxatriol-type ginsenoside mixture (at a concentration of 10 mg/mL) from ginseng roots. Finally, 13.0 g of F1 was produced from 50 g of protopanaxatriol-type ginsenoside mixture with 91.5 ± 1.1% chromatographic purity. Conclusion The results suggest that this enzymatic method could be exploited usefully for the preparation of ginsenoside F1 to be used in cosmetic, functional food, and pharmaceutical industries.

Flavobacterium hankyongi sp. nov., isolated from activated sludge

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated strain KTCe-4T, was isolated from activated sludge. Based on 16S rRNA gene sequencing and phylogenetic analysis, the novel isolate was found to belong to the genus Flavobacterium and was most closely related to Flavobacteriumterrae DSM 18829T (97.8 %), Flavobacteriumvireti THG-SM1T (97.8 %), Flavobacteriumbrevivitae TTM-43T (97.4 %) and shared <96.4 % sequence similarity to the other members of the genus. Strain KTCe-4T contained MK-6 as the predominant isoprenoid quinone and iso-C15 : 0, iso-C15 : 0 G, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH and iso-C17 : 1ω9c, as the major fatty acids. The major polar lipids were phosphatidylethanolamine, two unidentified polar lipids and one unknown amino lipid. The DNA-DNA relatedness values of strain KTCe-4T with respect to type strains of recognized species of the genus Flavobacterium were less than 70 %. Based on 16S rRNA gene sequencing, low values of DNA-DNA hybridization and polyphasic taxonomic analysis, strain KTCe-4T represents a novel species within the genus Flavobacterium, for which the name Flavobacterium hankyongi sp. nov. is proposed. The type strain of Flavobacterium hankyongi is strain KTCe-4T (=KACC 16613T=JCM 18198T).

Production of the Rare Ginsenoside Rh2-MIX (20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3) by Enzymatic Conversion Combined with Acid Treatment and Evaluation of Its Anti-Cancer Activity

The ginsenoside Rh2 has strong anti-cancer, anti-inflammatory, and anti-diabetic effects. However, the application of ginsenoside Rh2 is restricted because of the small amounts found in Korean white and red ginsengs. To enhance the production of ginsenoside Rh2-MIX (comprising 20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3 as a 10-g unit) with high specificity, yield, and purity, a new combination of enzymatic conversion using the commercial enzyme Viscozyme L followed by acid treatment was developed. Viscozyme L treatment at pH 5.0 and 50°C was used initially to transform the major ginsenosides Rb1, Rb2, Rc, and Rd into ginsenoside F2, followed by acid-heat treatment using citric acid 2% (w/v) at pH 2.0 and 121°C for 15 min. Scale-up production in a 10-L jar fermenter, using 60 g of the protopanaxadiol-type ginsenoside mixture from ginseng roots, produced 24 g of ginsenoside Rh2-MIX. Using 2 g of Rh2-MIX, 131 mg of 20(S)-Rh2, 58 mg of 20(R)-Rh2, 47 mg of Rk2, and 26 mg of Rh3 were obtained at over 98% chromatographic purity. Then, the anti-cancer effect of the four purified ginsenosides was investigated on B16F10, MDA-MB-231, and HuH-7 cell lines. As a result, these four rare ginsenosides markedly inhibited the growth of the cancer cell lines. These results suggested that rare ginsenoside Rh2-MIX could be exploited to prepare an anti-cancer supplement in the functional food and pharmaceutical industries.

Herb mixture C5E aggravates doxorubicin-induced apoptosis of human breast cancer cell lines

A number of extracts from Asian traditional medicinal herbs have been successfully used as therapeutic agents against cancers. In this study we assessed the effect of C5E on the proliferation inhibition and apoptosis of breast cancer cell lines. C5E is an ethanol extract from traditional Asian medicinal plants which have anticancer activity. Nonetheless, little is known about the underlying mechanism. Thus, we studied the mechanism of C5E-induced cell death in the human breast cancer cell line MDA-MB-231 and MCF7 cells. The cell survival rate was reduced in a concentration- and time-dependent manner, as assessed by direct cell counting. After incubation for 48 h, typical apoptotic morphological changes were observed by microscope. To determine the synergetic effect with doxorubicin, we co-treated C5E with doxorubicin in breast cancer cells, and flow cytometry revealed that co-treatment obviously enhanced sub-G1 arrest and apoptosis in MDA-MB-231 and MCF7 cells. Furthermore, we showed that pro-apoptotic marker cleaved PARP was synergistically increased with the combined treatment of doxorubicin and C5E in MDAMB-231, but not in MCF-7. These results suggest that the effect of combined treatment of C5E with doxorubicin on sub-G1 arrest and apoptosis in breast cancer cells could be exerted by the different mechanism and its potential use as a therapeutic agent will be helpful in treatment for breast cancer.