Edible Brown Seaweed Research Articles

In vitro antibacterial and synergistic effect of phlorotannins isolated from edible brown seaweed Eisenia bicyclis against acne-related bacteria

-1 . Furthermore, FF clearly re- versed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromy- cin against P. acnes were dramatically reduced from 2,048 to 1.0 μg mL -1 in combination with MIC of FF (64 μg mL -1 ). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in com- bination with 32 or 64 μg mL -1 of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acne- related bacteria.

Anti-inflammatory potential of monogalactosyl diacylglycerols and a monoacylglycerol from the edible brown seaweed Fucus spiralis Linnaeus.

A monoacylglycerol (1) and a 1:1 mixture of two monogalactosyl diacylglycerols (MGDGs) (2 and 3) were isolated from the brown seaweed Fucus spiralis Linnaeus. The structures were elucidated by spectroscopic means (NMR and MS) and by comparison with the literature. Compound 1 was composed of a glycerol moiety linked to oleic acid (C18:1 Ω9). Compounds 2 and 3 contained a glycerol moiety linked to a galactose unit and eicosapentaenoic acid (C20:5 Ω3) combined with octadecatetraenoic acid (C18:4 Ω3) or linolenic acid (C18:3 Ω3), respectively. The isolated compounds were tested for their cytotoxic and anti-inflammatory activity in RAW 264.7 macrophage cells. All of them inhibited NO production at non-cytotoxic concentrations. The fraction consisting of compounds 2 and 3, in a ratio of 1:1, was slightly more effective than compound 1 (IC50 of 60.06 and 65.70 µg/mL, respectively). To our knowledge, this is the first report of these compounds from F. spiralis and on their anti-inflammatory capacity.

Fucoxanthin Protects Cultured Human Keratinocytes against Oxidative Stress by Blocking Free Radicals and Inhibiting Apoptosis

Fucoxanthin is an important carotenoid derived from edible brown seaweeds and is used in indigenous herbal medicines. The aim of the present study was to examine the cytoprotective effects of fucoxanthin against hydrogen peroxide-induced cell damage. Fucoxanthin decreased the level of intracellular reactive oxygen species, as assessed by fluorescence spectrometry performed after staining cultured human HaCaT keratinocytes with 2',7'-dichlorodihydrofl uorescein diacetate. In addition, electron spin resonance spectrometry showed that fucoxanthin scavenged hydroxyl radical generated by the Fenton reaction in a cell-free system. Fucoxanthin also inhibited comet tail formation and phospho-histone H2A.X expression, suggesting that it prevents hydrogen peroxideinduced cellular DNA damage. Furthermore, the compound reduced the number of apoptotic bodies stained with Hoechst 33342, indicating that it protected keratinocytes against hydrogen peroxide-induced apoptotic cell death. Finally, fucoxanthin prevented the loss of mitochondrial membrane potential. These protective actions were accompanied by the down-regulation of apoptosispromoting mediators (i.e., B-cell lymphoma-2-associated x protein, caspase-9, and caspase-3) and the up-regulation of an apoptosis inhibitor (B-cell lymphoma-2). Taken together, the results of this study suggest that fucoxanthin defends keratinocytes against oxidative damage by scavenging ROS and inhibiting apoptosis.

Deodorizing Effects of Phlorotannins from Edible Brown Alga Eisenia bicyclis on Methyl Mercaptan

In search for new deodorizing compounds, we were identified three phlorotannins; eckol (1), dioxinodehydroeckol (2) and dieckol (3) from edible brown seaweed Eisenia bicyclis and characterized by Fast-atom bombardment mass spectrometry (FAB-MS) and nuclear magnetic resonance (NMR). The deodorizing activity of those compounds was evaluated against methyl mercaptan, which is well known as a major causative material of halitosis and off-flavor. Among them, compound 3 exhibited the highest deodorizing activity against methyl mercaptan at the IC50 values of 26.71 ± 4.16 µg mL-1, followed by compound 2 (40.57 ± 0.63 µg mL-1) and compound 1 (43.62 ± 1.52 µg mL-1). Thus, these results suggest that the phlorotannins derived from E. bicyclis can be an effective deodorizing constituent in the food industry and pharmaceutical industries.

Antioxidant activity of brown alga Saccharina bongardiana from Kamchatka (Pacific coast of Russia). A methodological approach

The present study aims to investigate the levels of polyphenols and antioxidant activity in one of the most important commercial species of seaweeds in Kamchatka, an edible brown seaweed Saccharina bongardiana. Six extracts of S. bongardiana, acetone, methanol, ethanol, and the respective 70 % aqueous solutions, were assessed for total phenol content in order to determine the most efficient extracting solvent. The total phenol content was measured by the Folin–Ciocalteu method and expressed as phloroglucinol equivalents (PGE). The antioxidant tests used were 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, linoleic acid-β carotene oxidation inhibiting assay, and Fe2+ ion chelating method. Higher phenolic contents were obtained using aqueous organic solvents, as compared to the respective absolute solvents; 70 % acetone was found to be the most efficient solvent (1.039 mg PGE 100 mg−1 dry algal powder). High significant correlations were noted between total phenol content and the tested antioxidant activities; so the aqueous organic extracts exhibited the highest antioxidant activities versus DPPH radicals (EC50 values of 0.6–1.1 mg dry weight (DW) mL−1), linoleic acid-β carotene oxidation (74–78 % at 0.8 mg DW mL−1), as well as ferrous ions (EC50 values of 5.0–7.9 mg DW mL−1). Some methodological recommendations regarding the assays used and the expression of results are proposed.

Carotenoid Profile of Edible Japanese Seaweeds: An Improved HPLC Method for Separation of Major Carotenoids

An improved multi-step gradient reverse phase high performance liquid chromatography (HPLC) method to simultaneously separate major carotenoids from natural as well as food samples was developed. Quantitative profiling of carotenoid compounds was carried out on three edible brown seaweeds (Sargassum horneri, Cystoseira hakodatensis, and Undaria pinnatifida) and three red seaweeds (Gracilaria vermiculophylla, Grateloupia asiatica, and Grateloupia livida). Fucoxanthin (Fx) was detected in all the brown seaweeds with quantities (mg g−1 dry weight [dwt]) ranging from 1.3 ± 0.3 in C. hakodatensis to 2.4 ± 0.1 in S. horneri. U. pinnatifida, commonly known as wakame, had a Fx content of 2.3 ± 0.1 mg g−1 dwt. In the case of red seaweeds, zeaxanthin (Zx) was the major carotenoid, and G. vermiculophylla had the highest Zx content (80.2 μg g−1 dwt) among the red seaweeds apart from small amounts of Fx (9.1 μg g−1 dwt). Similarly, the other two species of red seaweeds, G. asiatica and G. livida, contained (μg g−1 dwt) lutein (Lut), Fx, and Zx as the major carotenoids (G. asiatica: Lut 10.4, Fx 1.5, Zx 1.1; G. livida: Lut 9.3, Fx 3.5, Zx 1.0). The results suggest the usefulness of edible varieties (barring wakame) of seaweeds as dietary sources of carotenoids.

Capacity of fucoxanthin for scavenging peroxyl radicals and inhibition of lipid peroxidation in model systems

Carotenoids act as physiological antioxidant by scavenging reactive-free radicals as well as quenching singlet oxygen. Fucoxanthin is one of the abundant carotenoids found in edible brown seaweeds. The assessment of radical scavenging capacity of carotenoids has been the subject of extensive studies, which, however, gave inconsistent results. In the present study, the capacity of fucoxanthin for scavenging peroxyl radicals, chain carrying species of lipid peroxidation, was assessed quantitatively by measuring the effect of α-tocopherol on the decay of fucoxanthin induced by peroxyl radicals. It was found that α-tocopherol was 7.1 times more reactive than fucoxanthin in heptane solution, but interestingly fucoxanthin exerted 1.6 times higher reactivity than α-tocopherol in methanol solution. In SDS micelles, the relative reactivity of fucoxanthin and α-tocopherol depended on the site of peroxyl radical formation. The efficacy of lipid peroxidation inhibition by fucoxanthin was much less than that of α-tocopherol.

Antioxidant and prebiotic effects of dietary fiber co-travelers from sugar Kombu in healthy rats

The edible brown seaweed sugar Kombu (Saccharina latissima) is a good source of dietary fiber (DF) and associated compounds. Besides it presents antioxidant capacity in vitro due to their sulfated polysaccharides and polyphenols. The effect of a DF-rich sugar Kombu diet on biochemical parameters and antioxidant and prebiotic effects in healthy rats was evaluated. Thus, rats were fed either a basal diet or a supplemented one with 10 % sugar Kombu for 4 weeks. Several health-promoting effects were found such as a decrease in triglycerides (TGL) and uric acid (UrA), and an increase in antioxidant status both in serum and cecum. Regarding prebiotic effect, higher cecum weight and total short chain fatty acid (SCFA) content were evidenced in the seaweed-fed group, without significant differences on total bacterial count of feces. Sugar Kombu and sulfated polysaccharides from its DF could be used as functional ingredients for further nutraceutical applications.

Fucoxantin: a treasure from the sea.

The World Health Organization (WHO) estimates that 2.3 billion people will be overweight and 700 million obese in 2015. The reasons for this disastrous trend are attributed to the global tendency toward the reduced magnitude of exercise and physical activity and the increased dietary intake of fats, sugars and calories with reduced amount of vitamins and minerals. To prevent life-style-related diseases, like Metabolic Syndrome (MS), researchers’ attention is increasingly focusing on some of the so called “functional foods” which may be useful for their prevention and treatment. One of these functional ingredients is fucoxanthin (FX), a characteristic carotenoid present in edible brown seaweeds, such as Undaria pinnatifida (Wakame), Hijikia fusiformis (Hijiki), Laminaria japonica (Ma-Kombu) and Sargassum fulvellum. The increasing popularity of this molecule is certainly due to its anti-obesity effect, primarily detected by murine studies. These works revealed FX mediated induction of uncoupling protein-1 (UCP-1) in abdominal white adipose tissue (WAT) mitochondria, leading to the oxidation of fatty acids and heat production in WAT. Beyond this important role, in recent studies FX has shown a great antioxidant activity, anti-cancer, anti-diabetic and anti-photoaging properties. The aim of this review is to highlight the main effects of FX on human health.

Depressive effects on the central nervous system and underlying mechanism of the enzymatic extract and its phlorotannin-rich fraction from Ecklonia cava edible brown seaweed.

Marine plants have been reported to possess various pharmacological properties; however, there have been few reports on their neuropharmacological effects. Terrestrial plants have depressive effects on the central nervous system (CNS) because of their polyphenols which make them effective as anticonvulsants and sleep inducers. We investigated in this study the depressive effects of the polyphenol-rich brown seaweed, Ecklonia cava (EC), on CNS. An EC enzymatic extract (ECEE) showed significant anticonvulsive (>500 mg/kg) and sleep-inducing (>500 mg/kg) effects on the respective mice seizure induced by picrotoxin and on the mice sleep induced by pentobarbital. The phlorotannin-rich fraction (PTRF) from ECEE significantly potentiated the pentobarbital-induced sleep at >50 mg/kg. PTRF had binding activity to the gamma aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptors. The sleep-inducing effects of diazepam (DZP, a well-known GABA(A)-BZD agonist), ECEE, and PTRF were completely blocked by flumazenil, a well-known antagonist of GABA(A)-BZD receptors. These results imply that ECEE produced depressive effects on CNS by positive allosteric modulation of its phlorotannins on GABA(A)-BZD receptors like DZP. Our study proposes EC as a candidate for the effective treatment of neuropsychiatric disorders such as anxiety and insomnia.

Application of response surface methodology to study the influence of hydrothermal processing on phytochemical constituents of the Irish edible brown seaweed Himanthalia elongata

Abstract We used response surface methodology to investigate the effect of time and temperature of hydrothermal processing (blanching) on the phytochemical content, texture and colour of a semi-dried brown seaweed (Himanthalia elongata). A central composite design was employed with a hydrothermal processing time of 10–30 min and temperature of 60–90°C. Predicted models were found to be significant for total phenolic content, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, total flavonoids, total condensed tannins, texture and colour. The predicted values for each of the responses were in good agreement with experimental values. Processing time had the most significant effect on phytochemical constituents of H. elongata. An acceptable edible texture and colour of seaweed was also achieved during the blanching procedure. Thus, central composite design and response surface methodology can be used to model phytochemical content, texture and colour of H. elongata while minimising the number of experiments required. Multiple response optimisation demonstrated that the phytochemical content of H. elongata may be maximised by blanching for 20.4 min at 80.5°C.

Phlorotannins of the edible brown seaweed Ecklonia cava Kjellman induce sleep via positive allosteric modulation of gamma-aminobutyric acid type A–benzodiazepine receptor: A novel neurological activity of seaweed polyphenols

The primary objective was to investigate whether seaweeds have hypnotic activity. Methanol extracts of 30 seaweeds were screened for their binding activity at the GABA type A–benzodiazepine (GABAA–BZD) receptor, a well-characterised molecular target for sedative–hypnotics. The most active seaweed was Ecklonia cava Kjellman (ECK). An ethanol extract of ECK (ECK-E) significantly potentiated pentobarbital-induced sleep in mice. In four solvent fractions separated from ECK-E, hypnotic activity was proportional to contents of total phenols and total phlorotannins, known as seaweed polyphenols. Major phlorotannins of the ethyl acetate (EtOAc) fraction with the highest activity were eckol, eckstolonol, dieckol, and triphlorethol-A, and their Ki (binding affinity, μM) values for [3H]-flumazenil binding were 1.070, 1.491, 3.072, and 4.419, respectively. Hypnotic effects of ECK-E and the EtOAc fraction were fully inhibited by flumazenil, a specific GABAA–BZD receptor antagonist. These results imply that phlorotannins of ECK induce sleep by positive allosteric modulation of the GABAA–BZD receptor.

Fucoxanthin exerts differing effects on 3T3-L1 cells according to differentiation stage and inhibits glucose uptake in mature adipocytes

Progression of 3T3-L1 preadipocyte differentiation is divided into early (days 0–2, D0–D2), intermediate (days 2–4, D2–D4), and late stages (day 4 onwards, D4-). In this study, we investigated the effects of fucoxanthin, isolated from the edible brown seaweed Petalonia binghamiae, on adipogenesis during the three differentiation stages of 3T3-L1 preadipocytes. When fucoxanthin was applied during the early stage of differentiation (D0–D2), it promoted 3T3-L1 adipocyte differentiation, as evidenced by increased triglyceride accumulation. At the molecular level, fucoxanthin increased protein expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), sterol regulatory element-binding protein 1c (SREBP1c), and aP2, and adiponectin mRNA expression, in a dose-dependent manner. However, it reduced the expression of PPARγ, C/EBPα, and SREBP1c during the intermediate (D2–D4) and late stages (D4–D7) of differentiation. It also inhibited the uptake of glucose in mature 3T3-L1 adipocytes by reducing the phosphorylation of insulin receptor substrate 1 (IRS-1). These results suggest that fucoxanthin exerts differing effects on 3T3-L1 cells of different differentiation stages and inhibits glucose uptake in mature adipocytes.

톳 분획물이 조골세포의 증식 및 분화에 미치는 영향

Osteoporosis is a disease involving a decrease in bone mineral density and increased risk of fractures. Osteoblast and osteoclast activities are important for bone formation. The MC3T3-E1 osteoblastic cell line is a well-accepted model of osteogellsis in vitro. Hijikia fusiforme is a kind of edible brown seaweed that grows mainly in the Northwest Pacific region, including the countries of Korea, Japan and China, and it has been widely used as a medicinal and health food in Korea. In this study, by using osteoblasts, the effects of Hijikia fusiforme fractions on proliferation, alkaline phosphatase (ALP) activity, collagen synthesis and mineralization of cells were investigated. Hijikia fusiforme were subjected to fractionation by using hexane, methanol, butanol and aqueous. Proliferation of the MC3T3-E1 osteoblastic cells that were treated with Hijikia fusiforme fractions increased by approximately 120%. Regarding effects of Hijikia fusiforme fractions on ALP activity, 1 ㎍/ml butanol fraction showed the highest activity. The synthesis of collagen increased significantly in response to treatment with Hijikia fusiforme fractions, with the exception of the hexane fraction. Moreover, mineralization in the MC3T3-E1 cells that were treated with 100 ㎍/ml butanol fraction increased by 281%. Also, when 100 ㎍/ml aqueous fraction was added, mineralization increased by 240%. These results indicate that Hijikia fusiforme fractions have anabolic effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases.

FTIR-ATR spectroscopy as a tool for polysaccharide identification in edible brown and red seaweeds

Phycocolloids present in three brown ( Himanthalia elongata, Bifurcaria bifurcata, Saccharina latissima) and five red edible seaweeds ( Mastocarpus stellatus, Gigartina pistillata, Chondracanthus acicularis, Nemalion helminthoides and Dumontia contorta) were studied by FTIR-ATR spectroscopy. Infrared spectra of polysaccharide standards (alginate, agar, iota-, kappa- and lambda-carrageenan) were obtained for comparison. The main polysaccharide found in brown seaweeds was alginate, a linear copolymer of mannuronic (M) and guluronic acid (G). Alginate M/G ratio was tentatively estimated from specific absorption bands (808/787 cm −1 and 1030/1080 cm −1) in infrared spectra, suggesting higher values of mannuronic than guluronic acid blocks (M/G > 1) for brown seaweeds. According to their infrared spectra, all the red seaweeds studied were mainly carrageenan producers. Thus, M. stellatus showed absorption bands at 929.0, 844.7 and 803.2 cm −1 of a typical hybrid kappa/iota/mu/nu-carrageenan, meanwhile G. pistillata and C. acicularis, showed the characteristic broad band (830–820 cm −1) of lambda-type carrageenan. Moreover, when the second-derivative was obtained to improve resolution of overlapped bands in the original FTIR spectra, this band was divided into several sharper signals, indicating the presence of lambda-/theta-/xi-carrageenans. Accordingly with their FTIR spectra, N. helminthoides contained sulphated polysaccharides, such as carrageenan or mannans, while D. contorta produced lambda- with lesser amounts of kappa-carrageenan. Therefore, FTIR-ATR spectroscopy is proposed as a useful tool for the food, pharmaceutical and cosmetics industry to check the phycocolloid quality of a raw seaweed material by a quick and non-destructive method.

Effect of water motion on the cultivation of the commercial seaweed Undaria pinnatifida in a coastal bay of Galicia, Northwest Spain

Undaria pinnatifida is an edible brown seaweed, and its cultivation is being considered in Northwest Spain. Water motion is considered to be a key factor in growth and production of macroalgae; however, little is known about their influence on the farming of commercial seaweeds. In this study we investigated water motion effects on the cultivation of U. pinnatifida in a coastal bay of Galicia (Northwest Spain). Growth and morphological features of fronds and biomass yield were compared between two locations with different degrees of water motion (moderately exposed site vs. sheltered site). Growth rate, which was measured either as length and weight changes of fronds, was significantly higher for the moderately exposed site compared to the sheltered site. Fronds in the moderately exposed site were larger and had significantly more area and biomass of blades. The highest biomass yield was obtained at the moderately exposed site. Whether the environmental conditions at these locations were responsible for these results was explored. We suggest that the different hydrodynamic conditions may be the main environmental factor responsible for the results, as different hydrodynamics can affect the uptake of nutrients and carbon dioxide by reducing the diffusion boundary layer around the algal surface. According to this view, the degree of water motion at a culture site is a key factor that should be considered when identifying optimal locations for the cultivation of U. pinnatifida and other kelps in coastal bays.

Antioxidant compounds in edible brown seaweeds

Seaweeds are an excellent source of compounds with biological activity. Among the bioactive substances identified, antioxidants have received particular interest due to their beneficial effects on health. In the present study, the total phenolic content and the pigment contents in edible seaweeds were evaluated. The total phenolic content was determined by Folin-Ciocalteu’s method for four species of brown algae included Himanthalia elongata, Laminaria sp., Laminaria saccharina and Undaria pinnatifida. The total polyphenol content varied between 1.3 and 10.0 g phloroglucinol/kg wet weight of sample. The components responsible of the colour (carotenoids and chlorophylls) of the seaweeds were evaluated by using a spectrophotometric method. In addition, pigments were separated and identified by on line HPLC coupled with UV–Vis and fluorescence detectors and confirmed by liquid chromatography coupled to mass spectrometry (LC–MS APCI). Fucoxanthin, β-carotene, chlorophyll a and phaeophytin a were identified in the samples analysed.

Fucoxanthin regulates adipocytokine mRNA expression in white adipose tissue of diabetic/obese KK- A y mice

Fucoxanthin, a marine carotenoid found in edible brown seaweeds, attenuates white adipose tissue (WAT) weight gain and hyperglycemia in diabetic/obese KK- A y mice, although it does not affect these parameters in lean C57BL/6J mice. In perigonadal and mesenteric WATs of KK- A y mice fed fucoxanthin, mRNA expression levels of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α), which are considered to induce insulin resistance, were markedly reduced compared to control mice. In contrast to KK- A y mice, fucoxanthin did not alter MCP-1 and TNF-α mRNA expression levels in the WAT of lean C57BL/6J mice. Interleukin-6 (IL-6) and plasminogen activator inhibitor-1 mRNA expression levels in WAT were also decreased by fucoxanthin in KK- A y mice. In differentiating 3T3-F442A adipocytes, fucoxanthinol, which is a fucoxanthin metabolite found in WAT, attenuated TNF-α-induced MCP-1 and IL-6 mRNA overexpression and protein secretion into the culture medium. In addition, fucoxanthinol decreased TNF-α, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) mRNA expression in RAW264.7 macrophage-like cells stimulated by palmitic acid. These findings indicate that fucoxanthin regulates mRNA expression of inflammatory adipocytokines involved in insulin resistance, iNOS, and COX-2 in WAT and has specific effects on diabetic/obese KK- A y mice, but not on lean C57BL/6J mice.

Study of the microbial diversity and antimicrobial properties of Irish edible brown seaweeds

SummaryBrown Irish edible seaweeds, Himanthalia elongata, Laminaria sachharina and Laminaria digitata, were evaluated for the microbiota in raw and heat processed form. Raw seaweeds showed complete absence of aerobic mesophiles, halophiles, yeasts and molds. However, heating at 85 °C for 15 min resulted in spore germination. Bacterial counts as high as 107 were observed for aerobic mesophiles and halophiles. Heating above 95 °C for 15 min resulted in complete inactivation of surface microflora. Bacteria belonging to Bacillaceae, Paenibacillaceae, Moraxellaceae and Enterobacteriaceae family were identified by 16S rRNA sequencing. In vitro antimicrobial activity of the methanolic extracts of the seaweed on food pathogenic and food spoilage bacteria were also evaluated. The seaweeds in their raw state had almost 100% inhibition against Listeria monocytogenes; 98% and 93% inhibition was achieved against Pseudomonas aeruginosa by H. elongata and L. saccharina extracts, respectively. Heating the seaweeds resulted in the reduction of antimicrobial activity as compared to raw. The effect was more pronounced against Gram negative bacteria.

PMA에 의한 cyclooxygenase-2 발현 및 prostaglandin E2의 생성 증가에 미치는 톳 추출물의 영향

본 연구에서는 갈조류의 일종인 톳(H. fusiforme)의 항염증 효과에 관한 생화학적 기전 해석을 위하여 U937 단핵구 세포를 이용하였으며, PMA에 의하여 인위적으로 유발된 COX-2의 발현 및 <TEX>$PGE_2$</TEX>의 생성 증가에 미치는 몇 가지 톳 추출물의 영향을 조사하였다. PMA는 U937 세포에서 처리 농도 의존적으로 COX-2의 전사 및 번역수준의 발현을 증가시켰으나, COX-1의 발현에는 큰 변화가 없었다. PAM에 의한 COX-2의 발현 증가는 <TEX>$PGE_2$</TEX> 생성 증가와 연관성이 있었고, 톳의 열수 추출물에 비하여 에탄올 및 메탄올 추출물은 COX-2의 발현 증가는 <TEX>$PGE_2$</TEX> 생성 증가를 매우 억제시켰으나, COX-1의 발현에는 영향을 주지 않았다. 아울러 PMA에 의한 NF-<TEX>$\kappa$</TEX>B의 핵내 이동 및 I<TEX>$\kappa$</TEX>B의 분해를 톳의 에탄올 및 메탄올 추출물이 완벽하게 차단시켰다. 본 연구의 결과는 톳의 에탄올 및 메탄올 추출물이 NF-<TEX>$\kappa$</TEX>B의 활성을 차단함으로서 COX-2의 발현 및 <TEX>$PGE_2$</TEX> 생성을 저해하였음을 의미하며, 이는 톳이 강력한 항염증 효능을 가지고 있음을 뒷받침하여 주는 것이다. Hizikia fusiforme is a kind of edible brown seaweed that grows mainly in the northwest Pacific including Korea, Japan and China, and has been widely used as food in Korea. Induction of cyclooxygenase-2 (COX-2) expression and prostaglandin <TEX>$E_2$</TEX> (<TEX>$PGE_2$</TEX>) production is thought to have beneficial immunomodulatory effects in acute and chronic inflammatory disorders. In this study, we investigated the effects of extracts of H. fusiforme on the expression of COX-2 and production of <TEX>$PGE_2$</TEX> in U937 human pre-monocytic cell models. In U937 cells stimulated with phorbol 12-myristate 13-acetate (PMA) to mimic inflammation, methanol extract of H. fusiforme (MEHF) and ethanol extract of H. fusiforme (EEHF), but not water extract of H. fusiforme (WEHF), inhibited PMA-induced expression of both COX-2 protein and mRNA, which was associated with inhibition of <TEX>$PGE_2$</TEX> production. To investigate the mechanism by which MEHF and EEHF inhibit COX-2 gene expression and <TEX>$PGE_2$</TEX> production, we examined the activation of nuclear factor-kappaB (NF-<TEX>$\kappa$</TEX>B) in U937 cells. Pre-treatment with MEHF and EEHF significantly attenuated the PMA-induced IkappaB degradation and prevented nuclear translocation of NF-<TEX>$\kappa$</TEX>B. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-inflammatory activity of H. fusiforme.