Safety evaluation of excessive ingestion of mozuku fucoidan in human.

Fucoidan is a sulfated polysaccharide in the brown sea algae. This study was conducted in 20 subjects taking excessive fucoidan up to 4.05 g daily for 2 wk. They recorded questionnaire sheets about their health. Blood and urine were collected before and after 2 wk of ingestion. We found that no disorder was apparent in the test period. Although total cholesterol (P value 0.017) and low-density lipoprotein cholesterol (P value 0.017) showed statistically significant reduction and Cl (P value 0.002) showed significant increase, nothing deviated from the range of normal values. In conclusion, this study showed no abnormalities in the abdominal, fecal states, blood and urine at all.

Effect of fucoidan extracted from mozuku on experimental cartilaginous tissue injury.

We investigated the effect of fucoidan, a sulfated polysaccharide, on acceleration of healing of experimental cartilage injury in a rabbit model. An injured cartilage model was surgically created by introduction of three holes, one in the articular cartilage of the medial trochlea and two in the trochlear sulcus of the distal femur. Rabbits in three experimental groups (F groups) were orally administered fucoidan of seven different molecular weights (8, 50, 146, 239, 330, 400, or 1000 kD) for 3 weeks by screening. Control (C group) rabbits were provided water ad libitum. After the experimental period, macroscopic examination showed that the degree of filling in the fucoidan group was higher than that in the C group. Histologically, the holes were filled by collagen fiber and fibroblasts in the C group, and by chondroblasts and fibroblasts in the F groups. Image analysis of Alcian blue- and safranin O-stained F-group specimens showed increased production of glycosaminoglycans (GAGs) and proteoglycans (PGs), respectively. Some injured holes were well repaired both macroscopically and microscopically and were filled with cartilage tissues; cartilage matrices such as PGs and GAGs were produced in groups F 50, F 146, and F 239. Thus, fucoidan administration enhanced morphologically healing of cartilage injury.

Microbial fucoidan degradation by Luteolibacter algae H18 with deacetylation.

A bacterial strain that assimilates fucoidan from Cladosiphon okamuranus as sole carbon source was isolated as Luteolibacter algae H-18. It was found that it degraded fucoidan by intracellular enzymes, and that the degradation reactions were catalyzed by multiple enzymes. One enzyme, designated fraction B, was established to exhibit the deacetylation reaction of fucoidan. Other enzyme(s), designated fraction A, catalyzed the reaction(s) lowering the molecular weight of fucoidan.

Fucoidan reduces the toxicities of chemotherapy for patients with unresectable advanced or recurrent colorectal cancer.

Combination chemotherapy with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX) or irinotecan plus 5-fluorouracil/leucovorin (FOLFIRI) has become a standard regimen for advanced or recurrent colorectal cancer. Numerous studies have reported that long-term use of FOLFOX or FOLFIRI leads to better survival for these patients. Thus, control of the toxicity of these drugs may be crucial to prolonging survival. Fucoidan is one of the major sulfated polysaccharides of brown seaweeds and exhibits a wide range of biological activities. In the present study, we analyzed the effect of fucoidan on suppressing the toxicity of anti-cancer drugs. A total of 20 patients with unresectable advanced or recurrent colorectal cancer scheduled to undergo treatment with FOLFOX or FOLFIRI were randomly allocated into a fucoidan treatment group (n=10) and a control group without fucoidan treatment (n=10). Results showed that fucoidan regulated the occurrence of fatigue during chemotherapy. Chemotherapy with fucoidan was continued for a longer period than chemotherapy without fucoidan. Additionally, the survival of patients with fucoidan treatment was longer than that of patients without fucoidan, although the difference was not significant. Thus, fucoidan may enable the continuous administration of chemotherapeutic drugs for patients with unresectable advanced or recurrent colorectal cancer, and as a result, the prognosis of such patients is prolonged.

Isolation and characterization of a novel fucoidan-degrading microorganism.

A bacterium utilizing fucoidan from the brown alga Cladosiphon okamuranus as sole carbon source was isolated and identified as Flavobacterium sp. F-31. The strain produced intracellular enzymes involved in fucoidan degradation and desulfation, but desulfation activity was not detected until the molecular weight of fucoidan fell to less than several tens of thousands due to enzymatic degradation. Only fucoidan proved to be an inducible substance for the production of the degrading enzymes.

Cloning and sequencing analysis of alginate lyase genes from the marine bacterium Vibrio sp. O2.

We isolated a new marine bacteria, which displayed alginate-depolymerizing activity in plate assays, from seawater in Mihonoseki Harbor, Japan. Analysis of the 16S ribosomal RNA gene sequence of one of the isolates proved that this alginate-depolymerizing bacterium belonged to the genus Vibrio and it was named Vibrio sp. O2. The alginate lyase genes of Vibrio sp. O2 were cloned and expressed in Escherichia coli. Two alginate lyase-producing clones, pVOA-A4 and pVOA-B5, were obtained. The alginate lyase gene alyVOA from pVOA-A4 was composed of an 858-bp open reading frame (ORF) encoding 285 amino acid residues, while alyVOB from pVOA-B5 was composed of an 828-bp ORF encoding 275 amino acid residues. The degree of identity between the deduced amino acid sequences of AlyVOA or AlyVOB and Photobacterium sp. ATCC43367 alginate poly(ManA)lyase AlxM was 92.3% or 32.6%, respectively. Alginate lyase consensus regions corresponding to the sequences YFKAGXYXQ and RXELR were observed in all three of these sequences. AlyVOA and AlyVOB both degraded polymannuronate in plate assays and were therefore confirmed to be poly(beta-D-mannuronate)lyases.