Dietary Seaweed Research Articles

Dietary Seaweed Modifies Estrogen and Phytoestrogen Metabolism in Healthy Postmenopausal Women

Seaweed and soy foods are consumed daily in Japan, where breast cancer rates for postmenopausal women are significantly lower than in the West. Likely mechanisms include differences in diet, especially soy consumption, and estrogen metabolism. Fifteen healthy postmenopausal women participated in this double-blind trial of seaweed supplementation with soy challenge. Participants were randomized to 7 wk of either 5 g/d seaweed (Alaria) or placebo (maltodextrin). During wk 7, participants also consumed a daily soy protein isolate (2 mg isoflavones/kg body weight). After a 3-wk washout period, participants were crossed over to the alternate supplement schedule. There was an inverse correlation between seaweed dose (mg/kg body weight) and serum estradiol (E2) (seaweed-placebo = y = 0.28 × dose − 42.8; r = 0.70; P = 0.003), which was linear across the range of weights. Soy supplementation increased urinary daidzein, glycitein, genistein, and O-desmethylangolensin (P = 0.0001) and decreased matairesinol and enterolactone (P < 0.05). Soy and seaweed plus soy (SeaSoy) increased urinary excretion of 2-hydroxyestrogen (2-OHE) (P = 0.0001) and the ratio of 2-OHE:16α-hydroxyestrone (16αOHE1) (P = 0.01). For the 5 equol excretors, soy increased urinary equol excretion (P = 0.0001); the combination of SeaSoy further increased equol excretion by 58% (P = 0.0001). Equol producers also had a 315% increase in 2:16 ratio (P = 0.001) with SeaSoy. Seaweed favorably alters estrogen and phytoestrogen metabolism and these changes likely include modulation of colonic bacteria.

사료 중 미역은 복강내 LPS 주입 육계 병아리에서 영양소 대사, 항산화계 및 면역 반응을 조정한다

Influences of dietary brown seaweed(BSW) on the nutrient metabolism, anti-oxidant enzyme activity and cell-mediated immune response were studied in broiler chicks activated acute phase response. 72 Hatched male broiler chicks(Ross) were divided into 12 pens, 6 heads per pen, and fed the BSW 0.0% (Basal) or 2.0% diet, respectively, and injected with the Salmonella typhimurium lipopoly saccharide(LPS) for activation of the acute phase response three times at 8, 10 and 12 d of age. During 4 wks of experimental feeding, growth performance of broiler chicks was not affected by dietary BSW and the acute phase response. Compared with control birds, the acute phase response did not affect the daily weight gain in birds fed BSW 2.0% diet, decreased nitrogen balance(NB) or metabolizable energy(ME) utilization per metabolic body size(kg0.75), and enhanced activities of peroxidase or extracellular SOD(EcSOD), tumor necrosis factor-alpha and ovotransferrin in plasma and MnSOD and CuZnSOD in erythrocyte cytosol. Compared to BSW 0.0% diet, 2.0% diet enhanced protein retention(NB) per kg0.75 regardless the acute phase response, did not affect uric acid nitrogen excretion(UAN) per kg0.75 in birds during the acute phase response, decreased(p

Prophylactic Effect of Dietary Seaweed Fucoidan against Enteral Prion Infection

Dietary seaweed fucoidan delays the onset of disease of enterally infected mice with scrapie when given orally for 6 days after infection, but not when given before the infection. This effect was not modified at a tested fucoidan dose range and appeared to reach the maximum level at a concentration of 2.5% or less in feed. Daily uptake of fucoidan might be prophylactic against prion diseases caused by ingestion of prion-contaminated materials, although further evaluation of its pharmacology remains to be done.

급성기 반응을 활성화한 육계 병아리에서 사료중 미역 제품 수준이 단백질과 에너지 대사에 미치는 영향

Effects of dietary brown seaweed product levels on performance and metabolism of protein and energy were investigated in broiler chicks that were activated the acute phase response. One day old chicks were fed diets containing either 0.0(basal), 1.0, 2.0 or 4.0 % brown seaweed products for 3 weeks. The acute phase response was activated by injecting i.p. the Salmonella typhimurium lipopolysacharide(LPS) at week of age. The acute phase response lowered nitrogen balance(NB)/ (metabolic body size) and highered dietary ME values in birds fed diets containing brown seaweed product. Increase in dietary brown seaweed products levels lowered daily gain, and NB, uric acid nitrogen(UAN) excretion and ME utilization per in chicks with the acute phase response. But the dietary brown seaweed product level did not affect the performance of 3 Week old broiler chicks that experienced the acute phase response. And the brown seaweed products 1.0 and 2.0 % diets lessened the feed intake reduction caused by the acute phase response in broiler chicks. The brown seaweed 2.0% diet increased NB / g diet or and decreased the excretion of UAN/g diet or . This result indicated that the brown seaweed was able to interact with the acute phase response and increased protein retention via decreased breakdown of protein in birds fed brown seaweed 2.0% diet.

Benefit of dietary seaweed ( Ascophyllum nodosum) extract in reducing heat strain and fescue toxicosis: a comparative evaluation

Much of the fescue throughout the world contains an endophytic fungus which protects the plant from heat and drought, but produces a condition known as fescue toxicosis when consumed by animals. Major symptoms include reduced feed intake and growth, and increased hyperthermia during heat stress. Seaweed extract was tested, using both rodent and bovine models, to determine potential for reduction of fescue toxicosis-induced hyperthermia. Results show that the seaweed extract reduces hyperthermia associated with fescue toxicosis.

미역첨가 식이가 당뇨 유발쥐의 혈청지질과 혈당 및 항산화 효소에 미치는 영향

미역 첨가식이가 당뇨쥐의 당질과 지질대사 및 항산화효 소계에 미치는 영향을 규명하기 위하여 SD계 흰쥐에 식이 무게량의 20% 미역 분말을 급여하여 7주간 실험 사육한 후 혈청의 포도당 및 지질농도와 주요 장기의 항산화효소의 활성도를 관찰하였다. 미역 당뇨군에서 미역의 섭취는 당뇨에 의한 체중감소 현상을 보였다. 당뇨군의 혈당 농도는 미역섭취에 의한 혈당강하 효과는 2주째에 나타났으나 7주째는 보이지 않았다. 혈청지질중 총 콜레스테롤과 LDL-콜레스테롤은 변화가 없었으나 중성지방은 미역 당뇨군에서 감소하는 경향이고 HDL-콜레스테롤은 증가하는 경향으로 나타났다. 일반적으로 당뇨시 증가하는 신장의 G6Pase 활성도는 MD군에서 미역의 섭취에 의해 유의적(p<0.05)으로 감소했다. 대조군에서 증가된 간장의 GST 활성도는 미역 섭취에 의해 유의적(p<0.05)으로 감소했다. 간장의 GPX 활성도의 경우, 미역 섭취에 의해 증가하는 경향이었다. 간장의 GR 활성도는 미역 당뇨쥐에서 미역 섭취에 의해 감소하는 경향이나 신장에서는 상반되는 경향으로 나타났다. 간장의 TBARS는 미역 당뇨군에서 증가하는 경향이었다. 따라서 7주간의 미역첨가 섭취로 당뇨쥐의 고혈당이 강하되는 것은 2주에 나타났고 7주에는 관찰하지 못하였으나, 당뇨에 의한 산화적 스트레스로 인해 증가한 간장의 항산화 효소 활성도(GST)가 미역 섭취로 인해 저하됨으로써 미역의 섭취가 당뇨시 항산화적 반응을 제공할 수 있음을 유추할 수 있었다. 또한 중성지방이 감소하고 HDL-콜레스테롤의 증가하는 경향으로 심혈관계와 관련되는 당뇨합병증의 억제 가능성을 제시하였다.

Antileukemic activity of Viva-Natural, a dietary seaweed extract, on Rauscher murine leukemia in comparison with anti-HIV agents, azidothymidine, dextran sulfate and pentosan polysulfate

An antileukemic activity of partially purified polysaccharide of an edible seaweed, Viva-Natural, against Rauscher murine retrovirus-induced erythroleukemia has been demonstrated. This antileukemic effect is compared with standard anti-human immunodeficiency virus (HIV) agents, azidothymidine (AZT), dextran sulfate and pentosan polysulfate. Pretreatment with Viva-Natural, as an immunomodulator, on day 3 prior to the virus inoculation demonstrated definite prophylactic activity, while pretreatment with the other three anti-HIV agents showed no prophylactic activity. The replication of Rauscher virus in BALB 3T3 cell cultures accompanied by direct cytopathic effect (syncytia formation) was suppressed in the presence of Viva-Natural or the other anti-HIV agents in the culture medium. In spite of the antiviral potentials of the four agents in vitro, only Viva-Natural and AZT demonstrated therapeutic efficacy against Rauscher leukemia in mice.

Antitumor potential of low-dose chemotherapy manifested in combination with immunotherapy of Viva-Natural, a dietary seaweed extract, on Lewis lung carcinoma

Beneficial antitumor effects of low-dose chemotherapy (Adriamycin ®, BCNU, cisplatin, 5-fluorouracil, methotrexate, 6-thioguanine or vincristine) combined with an immunotherapy with a partially purified polysaccharide of Viva-Natural, an edible seaweed extract, have been demonstrated against intraperitoneally implanted Lewis lung carcinoma in syngeneic mice. Adriamycin ®, cisplatin, 5-fluorouracil and vincristine at low doses, that were not effective when given alone, manifested antitumor activity when combined with the polysaccharide fraction of Viva-Natural. Other three drugs (BCNU, methotrexate and 6-thioguanine) at the non-effective low doses exhibited no further antitumor activity when combined with Viva-Natural. Cytotoxic activation of peritoneal macrophages in mice has been induced by single administration of the polysaccharide fraction of Viva-Natural, but the combined regimen of low dose drugs plus viva-Natural was no more effective than Viva-Natural alone. Therefore, the mechanism of action of the beneficial combination is not clear yet.

Anticancer Potential of Viva-Natural, a Dietary Seaweed Extract, on Lewis Lung Carcinoma in Comparison with Chemical Immunomodulators and on Cyclosporine-Accelerated AKR Leukemia

Viva-Natural, extracted from a dietary seaweed, containing a macrophage-activating polysaccharide, has been confirmed to be active against intraperitoneally implanted Lewis lung carcinoma (LLC) and spontaneous AKR T cell leukemia. The antitumor potential against LLC has been evaluated in comparison with standard synthetic immunomodulators such as pyran copolymer (MVE-2), isoprinosine, levamisole, and tilorone while manipulating the immune systems by immunosuppressive agents, cyclophosphamide (CY) and 2-chloroadenosine. The anti-LLC activity of Viva-Natural has been found to be superior to that of isoprinosine but inferior to that of MVE-2. LLC-enhancing effect of CY could be partially reserved by the subsequent administration of Viva-Natural or MVE-2 but not by isoprinosine. 2-Chloroadenosine, a specific macrophage inhibitor, abrogated the anti-LLC activity of Viva-Natural and isoprinosine but not the activity of MVE-2. Levamisole and tilorone showed no anti-LLC activity. Ethanol-precipitable fraction of water-soluble part of Viva-Natural (crude polysaccharide) demonstrated curative activity similar to that of MVE-2. Viva-Natural reversed the potentiation effect of ciclosporin on the development of leukemia in AKR mice at preleukemic stage.

Effect of dietary seaweed preparations on 1,2-dimethylhydrazine-induced intestinal carcinogenesis in rats.

Nineteen preparations from 8 species of edible seaweeds, sodium alginate and cellulose powder were incorporated into a basic diet in proportions ranging from 0.05% to 2.0%, and used as experimental diets. Experimental rats were fed these diets and controls were fed the basic diet for 12 weeks. All rats also received the carcinogen, 1,2-dimethylhydrazine, during above period. After 20 weeks, all rats were autopsied and the incidence of intestinal tumors induced were examined. There was a significant decrease in incidence in rats fed 6 preparations from Eisenia bicyclis, Laminaria angustata, L. angustata var. longissima and Porphyra tenera (P less than 0.05).

Effect of dietary Laminaria angustata (brown seaweed) on azoxymethane-induced intestinal carcinogenesis in male F344 rats.

The effect of dietary Laminaria angustata (brown seaweed) on azoxymethane (AOM)-induced intestinal carcinogenesis was studied in male F344 rats. Five-week old rats were fed semipurified diets containing 0 and 10% seaweed. When the rats were 7 weeks old, all except the vehicle-treated groups received weekly subcutaneous injections of AOM in normal saline for two weeks (20 mg/kg body wt/week). All animals were fed the experimental diets until the termination of the experiment, which was 28 weeks after the last AOM injection. The incidence (percent of animals with tumors) and multiplicity (tumors/animal) of small intestinal tumors did not differ significantly between the control and seaweed groups. The incidence and multiplicity of colon adenomas along with the size of colon tumors were increased in rats fed the seaweed diet compared with those fed the control diet. Dietary seaweed had no major effect on the concentration of fecal bile acids; however, the concentration of fecal cholesterol and total neutral sterols was decreased in the seaweed group. These results suggest that dietary seaweed increases the risk for colon tumors.

Anticancer activity of a natural product, viva-natural, extracted from Undaria pinnantifida on intraperitoneally implanted Lewis lung carcinoma.

A natural product, named Viva-Natural, extracted from a dietary seaweed Undaria pinnantifida has been found to be therapeutically active against Lewis lung carcinoma (LLC). Viva-Natural also demonstrated moderate prophylactic activity against LLC in allogeneic mice. The active principle(s) which was concentrated in the water-insoluble fraction of Viva-Natural was essentially noncytotoxic in KB cell cultures, and probably a polysaccharide. Viva-Natural was found to be significantly effective in enhancing the natural cytolytic activity of peritoneal macrophages against KB cells as targets in in vitro assay, suggesting that the antitumor action of Viva-Natural might be indirect through the activation of nonspecific immune systems. A combination therapy of Viva-Natural and standard anticancer drugs was additively or synergistically effective.