Showing papers by "You-Jin Jeon published in 2008"

Cytoprotective effect of fucoxanthin isolated from brown algae Sargassum siliquastrum against H2O2-induced cell damage

Abstract: In this study, the cytoprotective effect of fucoxanthin, which was isolated from Sargassum siliquastrum, against oxidative stress induced DNA damage was investigated Fucoxanthin, a kind of carotenoid, was pretreated to the medium and the protective effect was evaluated via 2′,7′-dichlorodihydrofluorescein diacetate, 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide, and comet assays Intracellular reactive oxygen species were over produced by addition of hydrogen peroxide (H2O2), but the production was significantly reduced by the treatment with fucoxanthin The fucoxanthin strongly enhanced cell viability against H2O2 induced oxidative damage and the inhibitory effect of cell damage was a dose-dependent manner Furthermore, a protective effect against oxidative stress-induced cell apoptosis was also demonstrated via nuclear staining with Hoechst dye These results clearly indicate that fucoxanthin isolated from S siliquastrum possesses prominent antioxidant activity against H2O2-mediated cell damage and which might be a potential therapeutic agent for treating or preventing several diseases implicated with oxidative stress

Identification of chemical structure and free radical scavenging activity of diphlorethohydroxycarmalol isolated from a brown alga, Ishige okamurae

Abstract: To obtain a natural antioxidant from a marine biomass, this study investigated the antioxidative activity of methanolic extracts from the marine brown alga, Ishige okamurae collected off Jeju Island. A potent free radical scavenging activity was detected in the ethyl acetate fraction containing polyphenolic compounds, and the potent antioxidant elucidated as a kind of phlorotannin, diphlorethohydroxycarmalol, by NMR and mass spectroscopic data. The free radical scavenging activities of the diphlorethohydroxycarmalol were investigated in relation to 1,1-diphenyl-2-picrylhydrazyl (DPPH), alkyl, and hydroxyl radicals using an electron spin resonance (ESR) system. The diphlorethohydroxycarmalol was found to scavenge DPPH (IC50=3.41 microM) and alkyl (IC50=4.92 microM) radicals more effectively than the commercial antioxidant, ascorbic acid. Therefore, these results present diphlorethohydroxycarmalol as a new phlorotannin with a potent antioxidative activity that could be useful in cosmetics, foods, and pharmaceuticals.

Immunomodulatory effects of an enzymatic extract from Ecklonia cava on murine splenocytes.

Abstract: We investigated whether the brown seaweed Alariaceae Ecklonia cava (E. cava) has immunological effects on splenocytes in vitro. For that purpose, we prepared an enzymatic extract from E. cava (ECK) by using the protease, Kojizyme. Here, ECK administered to ICR mice dramatically enhanced the proliferation of their splenocytes and increased the number of their lymphocytes, monocytes and granulocytes. In flow cytometry assays performed to identify in detail the specific phenotypes of these proliferating cells after ECK treatment, the numbers of CD4+ T cells, CD8+ T cells and CD45R/B220+ B cells increased significantly compared to those in untreated controls. In addition, the mRNA expression and production level of Th1-type cytokines, i.e., TNF-α and IFN-γ, were down-regulated, whereas those of Th2-type cytokines, i.e., IL-4 and IL-10, were up-regulated by ECK. Overall, this dramatic increase in numbers of splenocytes indicated that ECK could induce these cells to proliferate and could regulate the production of Th1- as well as Th2-type cytokines in immune cells. These results suggest that ECK has the immunomodulatory ability to activate the anti-inflammatory response and/or suppress the proinflammatory response, thereby endorsing its usefulness as therapy for diseases of the immune system.

Anticoagulant activity of sulfated polysaccharide isolated from fermented brown seaweed Sargassum fulvellum

Abstract: A sulfated polysaccharide with anticoagulant properties was isolated from the fermented brown seaweed Sargassum fulvellum. Freeze-dried S. fulvellum was fermented in an incubator for 10th week at 25°C to convert seaweed macromolecules into anticoagulant sulfated polysaccharides (ASP). Anticoagulant activity was determined by an activated partial thromboplastin time (APTT) test using citrated human blood plasma. The 8th week S. fulvellum crude seaweed extract (SWE) exhibited the highest blood anticoagulant activity. Therefore, 8th week crude SWE was used for purification of ASP by two steps; DEAE cellulose anion-exchange followed by Sepharose 4B chromatography. The isolated ASP showed a single spot on agarose gel electrophoresis, which confirmed the purification status of our ASP. Polyacrylamide gel electrophoresis (PAGE) analysis showed that the molecular mass of the purified ASP was between 8 and 20 kDa. Polysaccharide and sulfate concentrations of the purified ASP were 180 and 29.70 μg mL−1 respectively. ASP recovery was 1.32% (w/w) from the crude polysaccharide applied to the DEAE column. Purified ASP had a pH of 3.86 and was considered an acidic polysaccharide. Moreover, both ASP and heparin showed a relative clotting factor of 27.47 at the concentrations of 180 and 60 μg mL−1 respectively. Therefore, S. fulvellum ASP can be considered a weaker anticoagulant than heparin. Results of the APTT, PT, and TT clotting assays showed that ASP was able to inhibit both intrinsic and extrinsic blood coagulation pathways. Finally, this study established a feasible and simple experimental protocol to isolate anticoagulant from fermented seaweeds leading to potential further development of anticoagulant agent for the pharmaceutical industry.

Optimisation of hydrophilic antioxidant extraction from Hizikiafusiformis by integrating treatments of enzymes, heat and pH control

Abstract: Summary Effective extraction of algal bioactive compounds can be achieved by treatments such as pH control, heat and enzymatic hydrolysis. Hizikia fusiformis antioxidants were extracted with those treatments individually and extraction efficacies were compared by measuring yield, total phenolic content and antioxidant activities. Increased pH could successfully improve the extraction, and incubation at pH 12.0 for 12 h was the most effective pH treatment. Incubation at 100 °C for 45 min was significantly (P < 0.05) more effective than the other heat treatments. Optimum condition for enzymatic treatment was combination of 2% Alcalase (alkaline endopeptidase/protease) and 3% Ultraflo (β-glucanase/carbohydrase) at pH 8.0 and 54–58 °C for 24 h. Integration of those optimised treatments in the extraction sequence of heat (H), enzymatic hydrolysis (E) and pH control (P) was the most effective sequence. Compared with other extraction sequences, HEP sequence indicated significantly higher phenolic content and antioxidative activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays.

Synergistic Effect between Dieckol from Ecklonia stolonifera and β-Lactams against Methicillin-resistant Staphylococcus aureus

Abstract: We have been attempting for some time to discover a compound evidencing antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The dieckol isolated from Ecklonia stolonifera has been shown to exhibit antibacterial activity against methicillin-susceptible S. aureus (MSSA) and MRSA. The minimum inhibitory concentrations (MICs) of dieckol were determined in a range of 32 to 64 μg/mL against standard MSSA and MRSA strains. Furthermore, dieckol clearly reversed the high-level ampicillin and penicillin resistance of MRSA. The MICs of ampicillin against two standard strains of MRSA were dramatically reduced from 512 to 0.5 μg/mL in combination with 1/4 MIC of dieckol (16 μg/mL). The fractional inhibitory concentration (FIC) indices of ampicillin and penicillin were measured from 0.066 to 0.266 in combination with 8 or 16 μg/mL of dieckol against all tested MRSA strains, thereby suggesting that dieckol-ampicillin or dieckol-penicillin combinations exert a synergistic effect against MRSA. The results of this study indicate that dieckol, administered in combination with β-lactams, may prove effective in the treatment of MRSA infections. Our finding may also contribute to the development of an alternative phytotherapeutic anti-MRSA agent.

Radical scavenging capacity and cytoprotective effect of enzymatic digests of Ishige okamurae

Abstract: In order to obtain natural antioxidants of good quality from a marine bioresource, we selected the brown marine alga, Ishige okamurae, which is an abundant and unutilized source of biomass and grows near Jeju Island, South Korea. An enzymatic extraction technique was used in order to determine the antioxidant effects of I. okamurae using commercially available food-grade digestive enzymes. In the evaluation of the radical scavenging capacity of the enzymatic extracts from I. okamurae using an electron spin resonance (ESR) spectrophotometer, all of the enzymatic extracts showed profound dose-dependent radical scavenging abilities. The majority of enzymatic extracts generated by proteases (except for Neutrase) had stronger hydrogen peroxide scavenging effects than the carbohydrase extract. In particular, the cytoprotective effects of the Kojizyme extract against H2O2 - induced DNA damage increased significantly with increasing extract concentrations in our comet assay tests. These results showed that I. okamurae may prove to be a valuable natural source of antioxidants.

Antioxidative and Neuroprotective Effects of Enzymatic Extracts from Leaves of Perilla frutescens var. japonica

Abstract: The antioxidative activity of various enzymatic extracts from leaves of Perilla frutescens var. japonica was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. For this study, the leaves were enzymatically hydrolyzed by 8 carbohydrases (Dextrozyme, AMG, Promozyme, Maltogenase, Termamyl, Viscozyme, Celluclast, and BAN) and 9 proteases [Flavourzyme, Neutrase, Protamex, Alcalase, PP-trypsin (trypsin from porcine pancreas), papain, pepsin, α-chymotrypsin, and BP-trypsin (trypsin from bovine pancreas)]. The DPPH radical scavenging activities of Promozyme and Alcalase extracts were the highest, and the IC 50 values were 77.25 and 109.66 μg/mL, respectively. All enzymatic extracts of the leaves scavenged hydroxyl radical, and the IC 50 values of Celluclast and pepsin extracts which were the highest activity were 243.34 and 241.86 μg/mL, respectively. The BAN and α-chymotrypsin extracts showed the highest scavenging activities, and the IC 50 values were 21.13 and 33.23 μg/mL, respectively. The pepsin extracts from the leaves showed protective effect on H 2 O 2 -induced DNA damage. In addition, the pepsin extracts decreased cell death in PC-12 cells against H 2 O 2 -induced oxidative damage. The findings of the present study suggest that enzymatic extracts of the leaves possess antioxidative activity.

Potential Antioxidant Activites of Enzymatic Digests from Benthic Diatoms Achnanthes longipes, Amphora coffeaeformis, and Navicula sp. (Bacillariophyceae)

Abstract: In this study, we focused on natural water-soluble antioxidants from the Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis. They were prepared by enzymatic digestion using five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase) and their potential antioxidant activity was assessed. Among the enzymatic digests, Neutrase digest from A. coffeaeformis exhibited the highest effect in DPPH radical scavenging. Flavourzyme (48.7%), Viscozyme (47.4%) and Celluclast (45.7%) digests from Navicula sp. exhibited higher O.?₂ radical scavenging activity. Viscozyme digest from A. coffeaeformis (45.9%) possessed the highest effects in hydroxyl radical scavenging. Termamyl (89.3%) and Protamex (88.8%) digests from A. coffeaeformis had strong metal chelating activity. Lipid peroxidation was significantly inhibited in Termamyl and Kojizyme digests from A. longipes, AMG and Termamyl digests from Navicula sp. and Kojizyme digest from A. coffeaeformisi. These data suggest that enzymatic digests of the Jeju benthic diatoms might be valuable sources of antioxidant which can be applied in food and pharmaceutical industry.

Simple separation of anticoagulant sulfated galactan from marine red algae

Abstract: In this study, hot water extracts of 22 red algal species were evaluated for their potential anticoagulant activities. The extracts from eight species (Grateloupia elliptica, Sinkoraena lancifolia, Halymenia dilatata, Grateloupia lanceolata, Lomentaria catenata, Martensia denticulata, Schizymenia dubyi, Chondrus crispus) showed potent activated partial thromboplastin time (APTT). Of these eight algae, the crude polysaccharide fraction (CpoF) from the hot water extracts of L. catenata and S. dubyi showed the highest APTT activity. Lomentaria catenata and S. dubyi were selected and an enzymatic digestion process which could effectively separate a crude polysaccharide fraction with higher yields from raw algae materials was applied. The 10 enzymes tested included five carbohydrases and five proteases. The Ultraflo and Celluclast digests of L. catenata and the AMG digest of S. dubyi exhibited the most potent anticoagulant activity. Furthermore, in both species, the active compounds were mainly concentrated in the >30 kDa fraction through ultrafiltration and showed strong APTT (>1000) and thrombin time (TT) >1000 activity. The active compounds were shown to be sulfated galactans with a greater than 80% galactose content and an 0.22 ∼ 0.31 sulfate to total sugar ratio.

Anti-inflammatory Effects of Enzymatic Extract from Ecklonia cava on TPA-induced Ear Skin Edema

Abstract: Anti-inflammatory potential of the enzymatic extract prepared by Kojizyme (ECK), a component of brown seaweeds Ecklonia cava (Alariaceae, Phaeophyta) in vivo was investigated. For the application of mouse ear edema model, 12-O-tetradecanoylphorbol acetate (TPA) was used, a topical inducer of a long-lasting inflammatory response. Our results demonstrated that ECK inhibited ear edema when topically applied to mouse ear skin. In histological evaluation, the inhibition activity of ECK on TPA-induced inflammation is similar to that of dexamethasone, although less strong. In addition, the mRNA expression levels of IL-1β, IFN-γ, TNF-α, and cyclooxygenase-2 (COX2) and the immunoreactivity to inducible nitric oxide synthase (iNOS) and COX2 expressed mainly in inflammatory cells were down-regulated by ECK. These results indicate that ECK has anti-inflammatory effects through the inhibition of Th1 cytokines and 2 inducers of inflammation in TPA-induced ear skin edema.

Evaluation of biomolecular interactions of sulfated polysaccharide isolated from Grateloupia filicina on blood coagulation factors.

Abstract: An edible marine red alga, Grateloupia filicina, collected from Jeju Island of Korea was hydrolyzed by cheap food-grade carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, and Ultraflo) to investigate its anticoagulant activity. Among the tested enzymatic extracts of G. filicina, a Termamyl extract showed the highest anticoagulant activity. Anion-exchange chromatography on DEAE-cellulose and gelpermeation chromatography on Sepharose-4B were used to purify the active polysaccharide from the crude polysaccharide fraction of G. filicina. The purified sulfated polysaccharide (0.42 sulfate/total sugar) showed approximately 1,357 kDa molecular mass and was comprised mainly of galactose (98%) and 1-2% of glucose. The sample showed potential anticoagulant activity on activated partial thromboplastin time (APTT) and thrombin time (TT) assays. The purified G. filicina anticoagulant (GFA) inhibited the coagulation factor X (92%), factor II (82%), and factor VII (68%) of the coagulation cascade, and the molecular interaction (protein-polysaccharide) was highly enhanced in the presence of ATIII (antithrombin III). The dissociation constant of polysaccharide towards serine proteins decreased in the order of FXa (58.9 nM) >FIIa (74.6 nM) >FVII (109.3 nM). The low/less cytotoxicity of the polysaccharide benefits its use in the pharmaceutical industry; however, further studies that would help us to elucidate the mechanism of its activity are needed.

Esr spectroscopy investigation of antioxidant activity and protective effect on hydroxyl radical‐induced dna damage of enzymatic extracts from picrorrhiza kurroa

Abstract: The potential antioxidant activity of enzymatic extracts from Picrorrhiza kurroa was evaluated on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical and alkyl radical-scavenging activities using an electron spin resonance spectrometer (JEOL Ltd., Tokyo, Japan). P. kurroa was enzymatically hydrolyzed by seven carbohydrases and five proteases to prepare water-soluble extracts. The DPPH radical-scavenging activities of the pancreatic trypsin and Amyloglucosidase (AMG) (artificial carbohydrase by Novozyme Nordisk, Bagsvaerd, Denmark) extracts from P. kurroa were the highest among protease and carbohydrase extracts, and 50% inhibitory concentration (IC50) values were 35.58 and 29.03 µg/mL, respectively. The hydroxyl radical-scavenging activity of the Protamex and Viscozyme extracts from P. kurroa were the highest scavenging activities, and the IC50 values were 0.46 and 1.89 mg/mL, respectively. In addition, the Protamex and Maltogenase extracts from P. kurroa showed the highest alkyl radical-scavenging activities, and the IC50 values were 18.03 and 10.66 µg/mL, respectively. The protective effect of the Protamex extracts from P. kurroa on DNA damage which was free radical-induced was 92% at 3 mg/mL. These results indicate that enzymatic extracts of P. kurroa show potent antioxidant activity. PRACTICAL APPLICATIONS Picrorrhiza kurroa could be used to produce protein and carbohydrate extracts with antioxidative activity. Many industrial commercial enzymes such as Promozyme, Celluclast 1.5 L FG, Maltogenase L, Viscozyme L, Termamyl SC, Dextrozyme E, AMG 300 L, Protamex, Flavourzyme 500 MG, Neutrase 0.8 L, Pancreatic Trypsin and Alcalase 2.4 L could be also used to attain the extracts processing the high antioxidative activity. The extracts can be used as natural antioxidants.

Effect of Far-infrared Radiation for Dying Citrus By-products and Their Radical Scavenging Activities and Protective Effects Against H₂O₂-induced DNA Damage

Abstract: Efficiency of a far-infrared radiation (FIR) dryer for drying of citrus by-products (CBPs) was evaluated through their antioxidant activities. The CBPs dried through FIR were enzymatically digested by six carbohydrases (AMG, Celluclast, Pectinase, Termamyl, Ultraflo and Viscozyme) to prepare digests for evaluation of the activities. The total polyphenolic and total flavonoid contents of the digests were determined by colorimetric assays. The AMG digest was selected for the further experiments. The antioxidant potential of the digests were evaluated by DPPH, superoxide, hydroxyl and alkyl radical scavenging activities, H₂O₂ scavenging activity, metal chelating, lipid peroxidation inhibition and the reduction of DNA damage. The AMG digest from CBPs dried through FIR at 50℃ showed strong antioxidant activities in DPPH, superoxide, hydrogen peroxide, alkyl and metal chelating assays while all the digests showed strong lipid peroxidation activities. Further, enzymatic digests showed remarkable inhibitory activities against H₂O₂-induced DNA damage. Hence, the data obtained using different in vitro models clearly established the antioxidant potential of enzymatic digests from CBPs dried through FIR. Furthermore, they can be used as a source of natural antioxidants; hence, far-infrared radiation drying is a viable method for transforming wet CBPs into a dried form without destroying the bioactive components.

Antioxidant activity of enzymatic extracts from Stellaria dichotoma.

Abstract: The antioxidant properties of enzymatic extracts from Stellaria dichotoma were evaluated using seven carbohydrases (Promozyme, Celluclast, Maltogenase, Viscozyme, Termamyl, Dextrozyme, and AMG 300L) and five proteases (Protamex, Flavourzyme, Neutrase, pancreatic trypsin, and Alcalase) (all from Novo Co., Novozyme Nordisk, Bagsvaerd, Denmark) for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical, and alkyl radical scavenging activity using an electron spin resonance spectrometer. The DPPH radical scavenging activities of pancreatic trypsin and Celluclast extracts from S. dichotoma were the highest among various protease and carbohydrate extracts, and the 50% inhibitory concentration (IC(50)) values were 10.45 and 13.80 microg/mL, respectively. The Flavourzyme and Promozyme extracts of S. dichotoma showed the highest hydroxyl radical scavenging activities among the tested protease and carbohydrase extracts, with IC(50) values of 1.51 and 1.23 microg/mL, respectively. The S. dichotoma enzymatic extracts also exhibited alkyl radical scavenging activity in a dose-dependent manner. In addition, the ability of the enzymatic extracts to inhibit the oxidative damage of DNA was assessed in vitro by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that the enzymatic extracts could significantly and dose-dependently protect against hydroxyl radical-induced DNA damage. These results indicate that enzymatic extracts of S. dichotoma possess potent antioxidant activity.

Protective effects of fermented onion juice containing higher amount of querectin aglycone against oxidative stress by 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH) treatment in Sprague–Dawley rats

Abstract: It has been reported on beneficial effects of onion extracts containing a large amount of quercetin glucosides for several decades This study was performed to investigate antioxidative and hepatoprotective effects of fermented onion (Allium cepa L) extracts containing higher amount of quercetin aglycone (FOQ) against oxidative stress by 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH) treatment in rats RP-HPLC analysis elucidated that the fermented onions contain larger amount of quercetin aglycone than that of fresh onions, and the content of quercetin aglycone in 10 kg of fresh and fermented onion pickles was 26134 ± 1947 and 36025 ± 2732 mg, respectively In vitro free radical scavenging assay showed potently radical-quenching ability of FOQ against reactive oxygen species (ROS) such as hydroxyl, superoxide, and carbon-centered radical using electron spin resonance (ESR) spectroscopy Biological parameters in plasma and liver tissue were evaluated with 36 healthy Sprague–Dawley rats in the experimental groups (n = 6); control (basal diet), AAPH treated, quercetin aglycone treated, ascorbate-AAPH treated, quercetin aglycone-AAPH treated and FOQ-AAPH treated group The results revealed that quercetin aglycone or FOQ intakes could increase the level of glutathione (GSH), enzymatic activity of glutathione reductase (GSSG-R), and catalase (CAT), but could decrease the level of glutamate oxaloacetic transaminase (GOT), glutamate pyruvate transaminase (GPT), thiobarbituric acid reactive substance (TBARS) production with the abnormal levels caused by AAPH induced oxidative stress Moreover, histological study for central vein (CV) area of hepatic lobule was illustrated that cytoplasmic phase near the CV in the qurecetin and FOQ pretreated before AAPH injection could be maintained with normal morphology like that of the control The present study illustrated that the fermented onion extracts containing larger amount of quercetin aglycone (FOQ) have antioxidative activities against AAPH-induced carbon-centered radical, and its activity can present the protective effect against hepatic damage by oxidative stress similar with the ability of ascorbate (vitamin C)