Hak-Seob Lim

Effect of Ethanol Extract from Peel of Citrus junos and Poncirus trifoliata on Antioxidant and Immune Activity

In this study, we compared with 80% ethanol extracts from peel of Poncirus trifoliata (PTP) and peel of Citrus junos (CJP) against antioxidant and immune activities. Total phenolics and flavonoids contents in PTP extracts were 60.75±1.15 and 33.75±0.15 ㎎/100 g, respectively, and those were lower than CJP extracts. Antioxidant activities of PTP were increased with the more concentration, and were similar to CJP. Antioxidant activities of PTP were increased with increasing of concentration, and were similar to those of CJP. The NO production in macrophage cell lines were increased in a dose-dependent manner, until 5 ㎎/ml of CJP and 1 ㎎/ml of PTP compared with control cells, but decreased at higher concentrations. The proliferation of mouse spleen cells were increased in a dose-dependent manner, until 1 ㎎/ml of CJP and PTP compared with control cells but decreased at higher concentrations. The NO production in macrophage cell lines treated with PTP and CJP were increased in a dose-dependent manner, compared with untreated control cells until the concentrations of 1~5 ㎎/ml (CJP) and 1 ㎎/ml (PTP) but decreased at higher concentrations than that. The proliferation of mouse spleen cells treated with PTP and CJP were increased in a dose-dependent manner, compared with untreated control cells until the concentration of 1 mg/ml but decreased at higher concentrations than that.

Anticancer Activity of Ethanol Extract from Peel of Citrus junos and Poncirus trifoliata on MCF-7 Breast Cancer Cells

In this study, anti-cancer activities of peel of Citrus junos (CJP) and Poncirus trifoliata (PTP) on MCF-7 breast cancer cells, and anti-proliferative effects of cancer cells induced by environmental hormones were investigated. The ethanol extracts of CJP and PTP inhibited cancer cell growth and induced apoptosis at the concentration over 300 mg/ml treatment for 72 hr. Morphological change of MCF-7 breast cancer cells were observed treated with the CJP and PTP of 500 mg/ml concentration for 72 hr, and apoptosis was induced by activation of caspase-3. The proliferation of MCF-7 breast cancer cells was decreased in a dose-dependent manner treated with various concentration of CJP and PTP, when compared with the control at 300 mg/ml, the proliferation of the MCF-7 breast cancer cells of both extracts was decreased over 70% and 80%, respectively.

Genistein-induced Growth Inhibition was Associated with Inhibition of Cyclooxygenase-2 and Telomerase Activity in Human Cancer Cells.

Genistein, an isoflavone in soybean products, is a potential chemopreventive agent against various types of cancer. There are several studies documenting molecular alterations leading to cell cycle arrest at G2/M phase and induction of apoptosis; however, its mechanism of action and its molecular targets on the prostaglandin () production and telomere length regulation in human cancer remain unclear. In this study, we investigated the effect of genistein on the levels of cyclooxygenases (COXs) and telomere regulatory components of several human cancer cell lines (T24, human bladder carcinoma cells; U937, human leukemic cells; AGS, human stomach adenocarcinoma cells and SK-MEL-2, human skin melanoma cells). Genistein treatment resulted in the inhibition of cancer cell proliferation in a concentration-dependent manner. It was found that genistein treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in synthesis. Genistein treatment also partly inhibited the levels of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR) and telomerase-associated protein (TEP)-1, and the activity of telomerase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of genistein.

Purification and Characterization of β-Lactamase Secreted from Bacillus sp. J105 Strain having β-Lectam Antibiotics Resistance.

, secreted from Bacillus sp. J105 strain was purified to a single band on SDS-PAGE by ammonium sulfate precipitation, ion exchange column chromatography and gel-filtration. The molecular weight of the purified enzyme was 31 kDa on SDS-PAGE and its isoelectric point was 7.35. Optimal pH and temperature for enzymatic reaction were 5 and , respectively. As a result of total amino acid composition analysis of the purified enzyme, Gly and Ala were occupied 14.1 and 13.3 mole %, respectively. Km and Vmax value of purified enzyme were 1.33 mM and 0.36 mM/ml using ampicillin as a substrate, respectively.