The role of NK cells in antitumor activity of dietary fucoidan from Undaria pinnatifida sporophylls (Mekabu).
Fucoidan from Mekabu (sporophyll of Undaria pinnatifida), a dietary alga, exerts antitumor activity possibly through enhancing the immune response. The present report describes the effects of dietary Mekabu fucoidan on the tumor growth of mouse A20 leukemia cells and on T cell-mediated immune responses in T cell receptor transgenic (DO-11 - 10 - Tg) mice. The animals were fed with a diet containing 1% Mekabu fucoidan (0.034 +/- 0.003 g/mouse/day) for 10 days and subcutaneously (s. c.) inoculated with A20 leukemia cells. Thereafter, the mice were fed with the diet containing fucoidan for 40 days. Mekabu fucoidan inhibited tumors by 65.4 %. We studied how the killer activities of T cell-mediated and natural killer (NK) cells are augmented in DO-11 - 10 mice fed with Mekabu fucoidan. The cytolytic activities of ovalbumin (OVA), which is specific against OVA-transfected A20 (OVA-A20) B lymphoma cells, and NK cells against YAC-1 were significantly enhanced in the mice fed with fucoidan compared with a basic diet. Thus, these findings suggested that Mekabu fucoidan mediates tumor destruction through Th1 cell and NK cell responses.
Planta Med. 2006 Dec;72(15):1415-7
Low molecular weight fucoidan prevents neointimal hyperplasia after aortic allografting.
BACKGROUND: Fucoidan, a new low molecular weight sulfated polysaccharide (LMWF), has previously been shown to mobilize bone marrow-derived progenitors cells via stimulation of stromal derived factor (SDF)-1 release. Mobilized progenitor cells have been suggested to repair intimal lesions after immune-mediated endothelial injury and thus prevent intimal proliferation. The aim of this study was to evaluate the effect of LMWF treatment in a rat aortic allograft model of transplant arteriosclerosis (TA). METHODS: Aortic grafts were performed in Brown Norway (BN, donor) and Lewis (Lew, recipient) rats. The recipient rats were treated with LMWF (5 mg/kg/day) and sacrificed at 30 days. To determine the role of SDF-1 in mediating the effects of LMWF, a specific inhibitor of the SDF-1 receptor CXCR4, AMD 3100 (20 microg/kg/day), was used. The grafted segments were evaluated by morphometric (histochemical) analyses. RESULTS: Untreated aortic allografts exhibited severe intimal proliferation, indicative of TA. In contrast, LMWF treatment significantly prevented allograft intimal proliferation as compared with controls (5.7+/-3 vs. 66.2+/-6 microm, P<0.01) and permitted a normalization of the intima/media ratio (0.1+/-0.1 vs. 1.7+/-0.3, P<0.01). Further, LMWF treatment stimulated allograft reendothelialization, as evidenced by strong intimal endothelial nitric oxide synthase antibody and CD31 signals. Unexpectedly, AMD treatment failed to prevent the protective effect of LMWF on intimal thickening and AMD treatment alone was found to reduced intimal proliferation in allografts. CONCLUSIONS: We found that LMWF treatment reduced intimal thickness and induced the presence of an endothelial cell lining in the vascular graft at 30 days. Our findings may suggest a novel therapeutic strategy in the prevention of TA.
Transplantation. 2007 May 15;83(9):1234-41
Induction of hepatocyte growth factor by fucoidan and fucoidan-derived oligosaccharides.
Fucoidan, which is extracted from brown seaweed, is a complex sulphated polysaccharide that is mostly composed of L-fucose and sulphated ester groups. The structural and anionic characteristics of fucoidan are similar to those of heparin. Heparin stimulates production of hepatocyte growth factor (HGF), which has key roles in tissue regeneration. We have shown that fucoidan and fucoidan-derived oligosaccharides have similar ability to stimulate production of HGF as heparin and heparin-derived oligosaccharides. This induction of HGF by heparin or fucoidan and their oligosaccharide derivates occurs primarily at the level of translation, probably via the same mechanism. Fucoidan may thus be useful to protect tissues and organs from various injuries and diseases, via mechanisms involving HGF.
J Pharm Pharmacol. 2008 Apr;60(4):499-503
Sulfated polysaccharide fucoidan ameliorates experimental autoimmune myocarditis in rats.
Homing of cardiac myosin-specific CD4-positive T cells into the myocardium is the initial pathologic event of experimental autoimmune myocarditis (EAM). Subsequently, various bystander inflammatory cells are recruited into the myocardium crossing vascular endothelial cell walls. Sulfated polysaccharide fucoidan binds selectin nonselectively and blocks its function. Therefore, this study was designed to evaluate whether in vivo fucoidan treatment can improve EAM. A 21-day infusion of physiological saline or fucoidan was administrated intraperitoneally to the rats with sham operation (sham-saline, n = 5; sham-fucoidan, n = 6) or those with cardiac myosin injection (EAM-saline, n = 10; EAM-fucoidan, n = 10). After 3 weeks, fucoidan treatment improved left ventricular ejection fraction (79.04 ± 2.81 vs 65.94% ± 3.22%; P < .01 vs EAM-saline) with a reduced ratio of heart weight to body weight (4.016 ± 0.239 vs 4.975 ± 0.252 mg/g; P < .05 vs EAM-saline) in EAM. Furthermore, fucoidan treatment decreased serum levels of BNP (292.0 ± 53.4 vs 507.4 ± 89.2 ng/mL; P < .05 vs EAM-saline) and the myocarditis area (31.66 ± 1.53 vs 42.51% ± 3.24%; P < .01 vs EAM-saline) in EAM. These beneficial effects of fucoidan were accompanied by inhibition of both macrophage and CD4-positive T-cell infiltration into the myocardium. Fucoidan, a nonselective selectin blocker, attenuates the progression of EAM. This observation may be explained, at least in part, by blocking the extravasation of inflammatory cells into the myocardium.
J Cardiovasc Pharmacol Ther. 2011 Mar;16(1):79-86
Immunostimulating and anticoagulating activity of fucoidan from brown algae Fucus evanescens of Okhotskoe sea.
Fucoidan—nontoxic sulfated polysaccharide was isolated from brown algae Fucus evanescens in Okhotskoe Sea. Chemical analysis of the compound was performed, it was shown that fucoidan is freely soluble in water and acid solutions. Immunotropic and anticoagulating properties of the compound were evaluated in comparison with heparin. It was demonstrated that fucoidan in wide range of doses stimulated phagocytic and bactericidic activity at leucocytes of mice peritoneal exudate. Heparin on the contrary demonstrated depressive effect on these functions at high dose. It was shown that fucoidan has dose-dependent anticoagulating activity in vitro and in vivo comparable with heparin activity. The results of investigation demonstrated possibility of fucoidan application as immunomodulating and anticoagulating agent of plant origin.
Antibiot Khimioter. 2003;48(4):11-3
Immunological analysis of inhibition of lung metastases by fucoidan (GIV-A) prepared from brown seaweed Sargassum thunbergii.
The antimetastatic effect of GIV-A (fucoidan) and/or 5-FU was examined in an experimental model of lung metastases induced by Lewis lung carcinoma in mice. Injection of GIV-A i.p. after removal of the implanted primary tumor inhibited the development of lung metastases. Combination treatment with GIV-A and 5-FU inhibited significantly the lung metastases. The number of peritoneal macrophages, total cells and macrophages in the lung increased in mice treated with GIV-A. Binding of the third component of complement (C3) cleavage products (C3b) to the C3 receptor on peritoneal macrophages after i.v. injection of GIV-A was enhanced, as shown by the fluorescent antibody technique. Lung metastases were inhibited by i.v. injection of peritoneal macrophages activated with GIV-A. GIV-A depressed aniline hydroxylase and aminopyrine demethylase activities of the hepatic microsomal drug-metabolizing system in tumor-bearing mice. Moreover, the concentration of 5-FU in the tissues (lung, liver, kidney, spleen and blood) was increased significantly by coadministration of GIV-A. The picryl chloride-induced delayed type hypersensitivity (PC-DTH) response in mice was depressed after the implantation of tumor and treatment with 5-FU. GIV-A restored the suppression of PC-DTH by 5-FU, but did not increase the PC-DTH of normal mice. GIV-A not only enhanced the degree of spleen cell-mediated sheep red blood cell (SRBC) hemolysis (quantitative hemolysis of SRBC), the indexes of the spleen and thymus and the number of spleen cells, but also restored the suppressive effect of 5-FU. In the group receiving GIV-A, the percentages of splenic Thy1.2-, L3T4- and asialo GM1-positive cells were significantly increased as compared with the tumor-bearing mice treated with saline. Furthermore, the L3T4+/Lyt2+ ratio showed a tendency to increase, and the Lyt2+/Thy1.2+ ratio was decreased. These results suggest that the antitumor effect of GIV-A may be correlated with the changing pattern of the Thy1.2-, L3T4- and asialo GM1-positive cells, C3 activation, macrophage activation and depression of the hepatic microsomal drug-metabolizing system. These findings raise the possibility that GIV-A may have clinical value in the prevention of cancer metastasis.
Anticancer Res. 1995 Sep-Oct;15(5B):1937-47
Immunomodulating activity of arabinogalactan and fucoidan in vitro.
Many polysaccharides obtained from natural sources are considered to be biological response modifiers and have been shown to enhance various immune responses. Here, we investigated the immunomodulating effects of arabinogalactan (AG) and fucoidan (FU) in vitro. Mouse spleen lymphocytes became cytotoxic to tumor cells after culture with AG and FU at concentrations of 10-100 microg/mL. Also, AG and FU were mitogenic in spleen lymphocytes and peripheral macrophages. Macrophages treated with AG and FU (10-100 microg/mL) exhibited induced tumoricidal activity and increased phagocytosis, lysosomal enzyme activity, and production of nitrite, H2O2, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6. However, AG and FU had little effect on the level of IL-1beta. Thus, the tumoricidal effect of AG- and FU-activated macrophages appeared to be mainly mediated by production of free radicals (NO and H2O2) and cytokines (TNF-alpha and IL-6). These data suggest that AG and FU are activators of lymphocytes and macrophages. This property may contribute to their effectiveness in the immunoprevention of cancer.
J Med Food. 2005 Winter;8(4):446-53
Immunostimulatory effects of fucoidan on bone marrow-derived dendritic cells.
Fucoidan is a polysaccharide purified from the brown seaweed Fucus vesiculosus. Although some effects of fucoidan on immune functions have been elucidated, there have been no studies concerning the immunomodulatory effects of fucoidan on dendritic cells (DCs), which are powerful antigen-presenting cells. In this study, fucoidan increased the viability of DCs, the production of interleukin-12 and tumor necrosis factor-alpha, and the expression of major histocompatibility complex class I, class II, CD54, and CD86 molecules. Furthermore, fucoidan-treated DCs showed decreased antigen uptake and increased proliferation of allogeneic splenocytes. In a study of the transcriptional regulation effects of fucoidan, translocation of p65 molecules of nuclear factor-kappaB (NF-kappaB) from the cytosol to the nucleus was clearly observed in fucoidan-treated DCs. Taken together, the results suggest that fucoidan has immunostimulating and maturing effects on DCs, via a pathway involving at least NF-kappaB.
Immunol Lett. 2008 Jan 29;115(2):138-43
Antitumor activity and immune response of Mekabu fucoidan extracted from Sporophyll of Undaria pinnatifida.
BACKGROUND: We showed that fucoidan, extracted from dietary seaweed, could inhibit tumor growth. However, the mechanism of Mekabu (Sporophyll of Undaria pinnatifida) fucoidan antitumor activity and how it enhances the immune response remains unknown. MATERIALS AND METHODS: We examined the effect of Mekabu fucoidan in P-388 tumor-bearing mice and in T cell-mediated NK cell activity in normal mice. RESULTS: The survival of mice was prolonged when Mekabu fucoidan was administered for 4 days before tumor cell inoculation, compared with non-treated mice. Fucoidan significantly enhanced the cytolytic activity of NK cells and increased the amount of IFN-gamma produced by T cells up to about 2-fold compared with non-treated mice. CONCLUSION: The anti-tumor effect of Mekabu fucoidan appears to be mediated by IFN-gamma-activated NK cells
In Vivo. 2003 May-Jun;17(3):245-9
Novel antiviral fucoidan from sporophyll of Undaria pinnatifida (Mekabu).
Structural characterization and antiviral activities of fucoidan from sporophyll of Undaria pinnatifida (Mekabu) was examined. The fucoidan was composed of fucose and galactose with an approximately ratio of 1.0:1.1. Degree of substitution of sulfate was 0.72 and its apparent molecular weight was 9,000. Methylation analyses showed that fucoidan had various sugar linkages, and revealed that the fucoidan might have complicated structure. This fucoidan showed potent antiviral activities against herpes simplex virus type 1 (HSV-1), HSV-2, and human cytomegalovirus.
Chem Pharm Bull (Tokyo). 2004 Sep;52(9):1091-4
Defensive effects of a fucoidan from brown alga Undaria pinnatifida against herpes simplex virus infection.
Fucoidan, a sulfated polysaccharide isolated from an edible brown alga Undaria pinnatifida, was previously shown to be a potent inhibitor of the in vitro replication of herpes simplex virus type 1 (HSV-1). HSV-1 is a member of herpes viruses that cause infections ranging from trivial mucosal ulcers to life-threatening disorders in immunocompromised hosts. In the in vivo conditions, the replication of HSV-1 is controlled under the immunoresponse coordinated by both the innate and adaptive immune systems. In the present study, the effects of the fucoidan were examined on in vivo viral replication and the host’s immune defense system. Oral administration of the fucoidan protected mice from infection with HSV-1 as judged from the survival rate and lesion scores. Phagocytic activity of macrophages and B cell blastogenesis in vitro were significantly stimulated by the fucoidan, while no significant change in the release of NO(2)(-) by macrophages was observed. In in vivo studies, oral administration of the fucoidan produced the augmentation of NK activity in HSV-1-infected mice immunosuppressed by 5-fluorouracil treatment. CTL activity in HSV-1-infected mice was also enhanced by oral administration of the fucoidan. The production of neutralizing antibodies in the mice inoculated with HSV-1 was significantly promoted during the oral administration of the fucoidan for 3 weeks. These results suggested that oral intake of the fucoidan might take the protective effects through direct inhibition of viral replication and stimulation of both innate and adaptive immune defense functions.
Int Immunopharmacol. 2008 Jan;8(1):109-16
Growth-inhibitory effect of a fucoidan from brown seaweed Undaria pinnatifida on Plasmodium parasites.
The present study was undertaken to investigate the inhibitory effects of fucoidan, a sulfated polysaccharide isolated from the edible brown seaweed Undaria pinnatifida, on the growth of Plasmodium parasites. In order to assess the anti-malarial activity of fucoidan, growth inhibition activities were evaluated using cultured Plasmodium falciparum parasites in vitro and on Plasmodium berghei-infected mice in vivo. Fucoidan significantly inhibited the invasion of erythrocytes by P. falciparum merozoites, and its 50% inhibition concentration was similar to those for the chloroquine-sensitive P. falciparum 3D7 strain and the chloroquine-resistant K1 strain. Four-day suppressive testing in P. berghei-infected mice with fucoidan resulted in a 37% suppressive effect versus the control group and a delay in death associated with anemia (P < 0.05). In addition, fucoidans had no toxic effect on RAW 264.7 cells. These findings indicate that fucoidans from the Korean brown algae U. pinnatifida inhibits the invasion of Plasmodium merozoites into erythrocytes in vitro and in vivo.
Parasitol Res. 2009 Jan;104(2):245-50
Seaweed prevents breast cancer?
To investigate the chemopreventive effects of seaweed on breast cancer, we have been studying the relationship between iodine and breast cancer. We found earlier that the seaweed, wakame, showed a suppressive effect on the proliferation of DMBA (dimethylbenz(a)anthracene)-induced rat mammary tumors, possibly via apoptosis induction. In the present study, powdered mekabu was placed in distilled water, and left to stand for 24 h at 4 degrees C. The filtered supernatant was used as mekabu solution. It showed an extremely strong suppressive effect on rat mammary carcinogenesis when used in daily drinking water, without toxicity. In vitro, mekabu solution strongly induced apoptosis in 3 kinds of human breast cancer cells. These effects were stronger than those of a chemotherapeutic agent widely used to treat human breast cancer. Furthermore, no apoptosis induction was observed in normal human mammary cells. In Japan, mekabu is widely consumed as a safe, inexpensive food. Our results suggest that mekabu has potential for chemoprevention of human breast cancer.
Jpn J Cancer Res. 2001 May;92(5):483-7