• Biomolecules & Therapeutics
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• 제17권4호
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• pp.379-387
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• 2009

We have previously reported that N-ethylmaleimide (NEM) induces apoptosis through activation of $K^+$, $Cl^-$-cotransport (KCC) in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of phospholipase $A_2$ ($PLA_2$)-arachidonic acid (AA) signals in the mechanism of the NEM-induced apoptosis. In these experiments we used arachidonyl trifluoromethylketone ($AACOCF_3$), bromoenol lactone (BEL) and p-bromophenacyl bromide (BPB) as inhibitors of the calcium-dependent cytosolic $PLA_2$ ($cPLA_2$), the calcium-independent $PLA_2$ ($iPLA_2$) and the secretory $PLA_2$ ($sPLA_2$), respectively. BEL significantly inhibited the NEM-induced apoptosis, whereas $AACOCF_3$ and BPB did not. NEM increased AA liberation in a dose-dependent manner, which was markedly prevented only by BEL. In addition AA by itself induced $K^+$ efflux, a hallmark of KCC activation, which was comparable to that of NEM. The NEM-induced apoptosis was not significantly altered by treatment with indomethacin (Indo) and nordihydroguaiaretic acid (NDGA), selective inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX), respectively. Treatment with AA or 5,8,11,14-eicosatetraynoic acid (ETYA), a non-metabolizable analogue of AA, significantly induced apoptosis. Collectively, these results suggest that AA liberated through activation of $iPLA_2$ may mediate the NEMinduced apoptosis in HepG2 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• 제33권3호
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• pp.566-570
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• 2004

Cultivation conditions for overproduction of lovastatins were investigated from the lovastatin producing strain N-03 which was obtained with NTG (N-methyl-N'-nitro-nitrosoguanidine) treatment from Aspergiliu ferrous ATCC 20542. Produced lactone and acid form of lovastatin were detected, and analyzed by HPLC method. In liquid culture, medium No. 2 containing soy protein produced higher amounts of the lovastatins than medium No. 1 (contained rapeseed oil). In solid culture, maximum production was obtained at 28$^{\circ}C$ for 15 days cultivation using cooked wheat bran. For the overproduction of lovastatin from this strain, solid culture method using plastic bag is more superior than liquid culture.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.322-328
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• 2005

Acylhomoserine lactones (AHLs) are known to be the triggering molecules in the quorum sensing mechanism of many gram-negative bacteria. In order to detect AHL inhibitors that are potential biofilm inhibitors, a convenient and sensitive bioassay was developed based on the $\beta$-galactosidase activity ($\beta$-GAL) of a recombinant Agrobacterium tumefaciens strain. A series of commercially available AHLs were tested for inducing $\beta$-GAL at varying concentrations in agar-plate and liquid cultures of the reporter strain. All AHLs tested exhibited a concentration­dependent induction, and octanoyl homoserine lactone (OHL) showed the highest sensitivity with a detection limit of 0.1 nM in the liquid culture assay. When fimbrolide, a known quorum sensing inhibitor, was added, induction of $\beta$-GAL by OHL was repressed. The repression at a constant OHL concentration was dependent on the fimbrolide concentration with the detection limit below 1 ppm, indicating that this assay is a sensitive method for screening AHL inhibitors.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.35-40
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• 2004

Ginkgolides (GK) and bilobalide are valuable compounds that belong to the lactone terpene. The contents of these metabolites were determined by HPLC from female and male tree of Ginkgo biloba L. The productivity of G. biloba cells was also compared with the corresponding individual trees. High variations in the ginkgolides and bilobalide were observed from different individuals, plant parts, and cultured cells. The ginkgolides and bilobalide contents were different depending on the plant parts. Callus was obtained from various plant tissues, and NAA was better at callogenesis than 2,4-D in both the female and male trees. The plants and their corresponding cells showed considerable variation in their ginkgolides and bilobalide concentrations. The ginkgolides and bilobalide contents were not correlated with the production between dominant trees and their corresponding cells. Light irradiation enhanced the production of GK-A and GK-B, however, the concentration of bilobalide decreased under dark conditions.

• Journal of Dairy Science and Biotechnology
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• 제36권3호
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• pp.171-177
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• 2018

In this study, we aimed to investigate the effects of low-temperature encapsulation on the viability of Weissella cibaria CMU under harsh conditions and in freeze-dried foods during storage. The capsules were prepared by gelation of sodium caseinate at different concentrations (5%, 6%, 7%, and 8%) with a combination of 0.5% gellan gum and 2% $glucono-{\delta}-lactone$. The size distribution of the capsules was determined using a Mastersizer 3000 laser diffraction particle size analyzer. Scanning and transmission electron microscopy revealed that the capsule with 6% sodium caseinate had a smooth and rounded external surface, with reproducibility. The acid, bile, and heat tolerances of the encapsulated cells were significantly higher than those of the control under prolonged acid (5 h), bile (12 and 24 h), and heat (2 h) exposure, respectively. During storage for up to 6 months at $4^{\circ}C$ or $25^{\circ}C$, the viability of encapsulated Weissella cibaria CMU in beef and vegetable rice porridge was effectively improved.

• Applied Chemistry for Engineering
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• 제5권5호
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• pp.801-807
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• 1994

Lactose substituted styrene monomer, N-(p-vinylbenzyl)-D-lactonamide(VLA) was prepared by coupling the lactose lactone with p-vinylbenzylamine. The carboxyl group of biotin was activated with N-hydroxysuccinimide in the presence of N, N'-dicyclohexylcarbodiimide. Subsquently, biotin substituted styrene monomer, N-(p-vinylbenzyl)-biotinamide(VBA) was prepared by amidation of the activated biotin with p-vinylbenzylamine. Poly(vinylbenzylactonamide-co-vinylbenzylbiotinamide), p(VLA-co-VBA) were synthesized through radical polymerization from the synthetic monomers(VLA-VBA) by using various mole ratio. The percentages of yield were 67~71%. The copolymers were found amphlphilic which had hydrophilic lactose, hydrophobic vinylbenzyl and biotin site within the structure. IR and $^{13}C-NMR$ analysis on the monomers and copolymer were carried out.

• Food Science of Animal Resources
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• 제29권5호
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• pp.590-598
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• 2009

The aim of this study was to model and optimize the calcium alginate (CA) and microbial transglutaminase (TG) systems to form a cold-set myofibrillar protein (MP) gel containing 0.1 M or 0.3 M NaCl using a response surface methodology. The gel strengths of cold-set and heat-induced MP gels, and cooking yields were measured. All measured parameters showed determination coefficients ($R^2$) above 0.7 without a lack-of-fit. The CA system had the best results with component ratios of 1.0:0.3:1.0 corresponding to sodium alginate, calcium carbonate and glucono-$\delta$-lactone, respectively, and was favourable at 0.1 M NaCl. In contrast, the TG system only had an effect on cold-set MP gelation at 0.3 M salt, and the optimal ratio of TG to sodium caseinate was 0.6:0.5. By combining the two systems at 0.3 M NaCl, an acceptable cold-set MP gel with an improved texture and high cooking yield could be formed. Therefore, these results indicated that the functionality of the cold-set MP gel could be enhanced by combining these two optimized gelling system.

• Biomedical Science Letters
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• 제16권1호
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• pp.39-45
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• 2010

Toll-like receptors (TLRs), which are pattern recognition receptors (PRRs), recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Parthenolide, a sesquiterpene lactone isolated from the herb feverfew (Tanacetum parthenium), has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that parthenolide inhibits the NF-${\kappa}B$ activation induced by TLR agonists and the overexpression of downstream signaling components of TLRs, MyD88, $IKK{\beta}$, and p65. Parthenolide also inhibits TLR agonists-induced COX-2 and iNOS expression. These results suggest that parthenolide can modulate the immune responses regulated by TLR signaling pathways.

• ALGAE
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• 제26권2호
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• pp.201-208
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• 2011

A monoterpene lactone, loliolide was successively isolated from brown seaweed, Sargassum ringgoldianum subsp. coreanum using column chromatography and high-performance liquid chromatography. The structure of the isolated compound was determined by comparison of EIMS and NMR spectral data with the previously published data. The antioxidant activities of loliolide were also evaluated by DPPH and $H_2O_2$ radical and intracellular reactive oxygen species scavenging assays, and it showed moderate activities in all antioxidant assays. Furthermore, loliolide was found to exert positive dose-dependent effects in the protective effects against $H_2O_2$-induced cell damage which were determined via MTT, Hoechst staining assays and cell cycle analysis. This is the first study on chemical constituent of this seaweed according to our best knowledge. These results clearly indicated that loliolide isolated from Sargassum ringgoldianum subsp. coreanum can protect the cells against $H_2O_2$-induced cell damage or apoptosis.

• Journal of Ginseng Research
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• 제35권3호
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• pp.294-300
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• 2011

Zearalenone (ZEA) is a phenolic resorcylic acid lactone compound produced by several species of Fusarium. ZEA has toxic effects in the testes of domestic and laboratory animals. Korean red ginseng (KRG), the steamed root of Panax ginseng Meyer, has multiple pharmacological effects such as vasorelaxation, anti-thrombosis, anti-hypertension, etc. In this study, we investigated the effects of KRG extract on testicular toxicity induced by ZEA. Rats were treated with 300 mg/kg oral doses of KRG for 4 weeks every other day. The rats were then treated with a single dose of 5 mg/kg ZEA delivered intraperitoneally, whereas control rats received only doses of the vehicle. As a result, germ cell apoptosis induced by ZEA was decreased by KRG pre-treatment. In addition, Fas and Fas-L expression was reduced in rats that received KRG pre-treatment compared to ones treated with ZEA alone. In conclusion, impaired spermatogenesis resulting from ZEA treatment was prevented by KRG through Fas-Fas L modulating.