Bae-Jin Lee

Fish-bone peptide increases calcium solubility and bioavailability in ovariectomised rats.

Fish-bone peptides (FBP) with a high affinity to Ca were isolated using hydroxyapatite affinity chromatography, and FBP II with a high ratio of phosphopeptide was fractionated in the range of molecular weight 5.0-1.0 kDa by ultramembrane filtration. In vitro study elucidated that FBP II could inhibit the formation of insoluble Ca salts in neutral pH. In vivo effects of FBP II on Ca bioavailability were further examined in the ovariectomised rat. During the experimental period, Ca retention was increased and loss of bone mineral was decreased by FBP II supplementation in ovariectomised rats. After the low-Ca diet, the FBP II diet, including both normal level of Ca and vitamin D, significantly decreased Ca loss in faeces and increased Ca retention compared with the control diet. The levels of femoral total Ca, bone mineral density, and strength were also significantly increased by the FBP II diet to levels similar to those of the casein phosphopeptide diet group (no difference; P>0.05). In the present study, the results proved the beneficial effects of fish-meal in preventing Ca deficiency due to increased Ca bioavailability by FBP intake.

Antioxidant effects of fermented sea tangle (Laminaria japonica) by Lactobacillus brevis BJ20 in individuals with high level of γ-GT: A randomized, double-blind, and placebo-controlled clinical study

A randomized, double-blind, and placebo-controlled clinical study was performed to evaluate the antioxidant effects of fermented sea tangle (FST) on healthy volunteers with high levels of γ-glutamyltransferse (γ-GT). Forty-eight participants were divided into a placebo group and an FST group that received FST (1.5 g/day) for 4 weeks. Serum γ-GT, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were determined before and after the trial. Administering FST significantly decreased serum levels of γ-GT and MDA. Additionally, SOD and CAT activities were significantly augmented compared to those in the placebo group after 4 weeks, but no significant alteration was observed in GPx activity compared to that in the placebo group. Our findings indicate that FST enhanced the antioxidant defense system in a healthy population and may be useful as a functional food ingredient.

Potential of Benthic Diatoms Achnanthes longipes, Amphora coffeaeformisand Navicula sp. (Bacillariophyceae) as Antioxidant Sources

Reactive oxygen species (ROS) such as hydrogen peroxide, hydroxyl radicals and superoxide anions, which are produced because of exogenous factors (tobacco smoke, ionizing radiation and certain pollutants) and endogenous factors (normal aerobic respiration) have been implicated in cellular processes such as mutagenesis, carcinogenesis and premature aging. ROS have the ability to react with a large variety of easily oxidisable cellular components, such as proteins, lipids and lipoproteins (Fridovich 1995). Oxidation is one of the major reasons of food deterioration, resulting to the destruction of fat-soluble vitamins and development of off colors and toxicants (Yang et al. 2000; Ukeda et al. 2002). Besides, in the food industry lipid peroxidation is an important deteriorative reaction during processing and storage. Commercial antioxidant supplements such as butylated hydroxyl anisole (BHA), butylated hydroxy tolouene (BHT), α-tocopherol and propyl gallate (PG) have been used in order to reduce oxidative damages in human body (Sherwin 1990; Gulcin et al. 2002). However, it is suspected that those antioxidants are responsible for some side effects such as liver damage and carcinogenesis. Antioxidants are involved with the oxidation mechanism by scavenging free radicals, chelating catalytic metals and by acting as oxygen scavengers (Shahidi and Wanasundara 1992; Buyukokuroglu et al. 2001). As a natural antioxidant source, plants have an ability to absorb the sun’s radiation for generating high levels of oxygen as secondary metabolites of photosynthesis. Oxygen is easily activated by ultra violet (UV) radiation and heat from the sunlight to produce toxic ROS. Therefore, plants produce various antioxidative comAlgae Volume 24(1): 47-55, 2009

A Polysaccharide Isolated from Ecklonia cava Fermented by Lactobacillus brevis Inhibits the Inflammatory Response by Suppressing the Activation of Nuclear Factor-κB in Lipopolysaccharide-Induced RAW 264.7 Macrophages

We previously reported that the increment of carbohydrate content in the Viscozyme(®) L (Novozyme Corp., Oklahoma City, OK, USA) extract of Lactobacillus brevis-fermented Ecklonia cava affected the inhibition of nitric oxide (NO) production and that it might be related to the polysaccharide compound. However, there is no report of anti-inflammatory effects of the polysaccharide or its biological mechanism. Here, we investigated the anti-inflammatory effects of the polysaccharide and its biological mechanism in lipopolysaccharide (LPS)-activated RAW 264.7 cells. The polysaccharide isolated from the Viscozyme extract of L. brevis-fermented E. cava (VLFEP) dose-dependently decreased LPS-stimulated NO production without cytotoxicity. Also, VLFEP significantly decreased the production of prostaglandin E(2) (PGE(2)) at the 100 μg/mL concentration. In addition, VLFEP dose-dependently decreased the protein and mRNA expressions of inducible NO synthase, whereas it slightly decreased those of cyclooxygenase 2 and only at the 100 μg/mL concentration. Moreover, VLEFP dose-dependently decreased the productions and/or mRNA expressions of tumor necrosis factor-α and interleukin-6, compared with those of LPS only-stimulated cells. In further experiments, VLFEP considerably reduced the phosphorylation and degradation of inhibitory κB as well as the translocation of nuclear transcription factor-κB (NF-κB) p65 into the nucleus, and its DNA binding was markedly induced by LPS stimulation. This study suggests that VLFEP exerts anti-inflammatory effects by down-regulating the production and expression of pro-inflammatory cytokines and mediators via inhibiting the NF-κB pathway in LPS-stimulated RAW 264.7 cells.

GABA-enriched Fermented Laminaria japonica Protects against Alcoholic Hepatotoxicity in Sprague-Dawley Rats

The sea tangle, Laminaria japonica has long been used in Korea as a folk remedy to promote health. Gamma-amino butyric acid-enriched (5.56% of dry weight) sea tangle was obtained by fermentation with Lactobacillus brevis BJ-20 (FLJ). A suppressive effect of FLJ on carbon tetrachloride-induced hepatotoxicity has been shown previously. Alcohol administration to Sprague-Dawley rats leads to hepatotoxicity, as demonstrated by heightened levels of hepatic marker enzymes as well as increases in both the number and volume of lipid droplets as fatty liver progresses. However, FLJ attenuated alcohol-induced hepatotoxicity and the accumulation of lipid droplets following ethanol administration. Additionally, FLJ increased the activities and transcript levels of major alcohol-metabolizing enzymes, such as alcohol dehydrogenase and aldehyde dehydrogenase, and reduced blood concentrations of alcohol and acetaldehyde. These data suggest that FLJ protects against alcohol-induced hepatotoxicity and that FLJ could be used as an ingredient in functional foods to ameliorate the effects of excessive alcohol consumption.

Production of gamma-Aminobutyric Acid (GABA) by Lactobacillus plantarum subsp. plantarum B-134 Isolated from Makgeolli, Traditional Korean Rice Wine

This study is to isolate and identify γ-amino butyric acid (GABA) producing lactic acid bacteria (LAB) from Makgeolii, traditional Korean rice wine and then establish the optimal culture conditions for GABA production. Sixty four LAB from Makgeolli were isolated according to the characteristics of the shape and color of the colony grown on MRS agar plate. The GABA production of the isolated strain cultured in MRS broth contained 1% MSG (mono-sodium glutamate) were determined and evaluated by TLC and HPLC analysis. Strain B-134 was selected for highest GABA production. From the analysis of 16S rRNA and glutamate decarboxylase B (gadB) gene sequences, strain B-134 was tentatively identified as a Lactobacillus plantarum subsp. plantarum B-134. Effects of culture parameters, including glutamic acid level, culture temperature, NaCl level, and pH on GABA production were investigated for culture optimization. The optimum culture condition for GABA production by B-134 were culture temperature of 37℃, pH of 5.7, NaCl content of 0% (w/v) and MSG content of 3% (w/v), which produced 25 mM of GABA during cultivation time of 48 hr. From these results, strain B-134 is expected to be utilized as useful microorganisms for GABA-enriched health beneficial food.

Fermented Sea Tangle Attenuates Oxidative Stress in Individuals with a High Level of γ-Glutamyltransferase: a Randomized, Double-Blind, and Placebo-controlled Clinical Study

A randomized, double-blind, placebo-controlled study of fermented sea tangle (FST) was conducted using 48 healthy volunteers with high levels of γ-glutamyltransferase (GGT). Participants (n=48) were divided into a placebo group and a FST group, which consumed FST (1.5 g/day) for 4 weeks. Serum GGT, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined. Plasma 8-isoprostane, 8-hydroxydeoxyguanosine (8-OHdG), and protein carbonyl contents, which indicate lipid peroxidation, DNA damage, and oxidation of protein, were determined. Decreased serum GGT was found in FST consumption group, compared to the placebo group [mean values (IU/L): 78.71±19.14 and 116.75±38.55, respectively, p<0.001]. Administration of FST significantly (p<0.05) decreased levels of serum AST [mean values (IU/L): 31.08±7.25 and 26.79±6.53 respectively, p<0.001] and ALT [mean values (IU/L): 42.63±18.99 and 31.83±14.21, respectively, p=0.001], compared to the placebo group, and significantly (p<0.05) decreased concentrations of plasma 8-isoprostane, 8-OHdG, and protein carbonyl levels.