Dieckol isolated from Eisenia bicyclis extract suppresses RANKL-induced osteoclastogenesis in murine RAW 264.7 cells

Objective: To demonstrate the effect of dieckol from Eisenia bicyclis on osteoclastogenesis using RAW 264.7 cells. Methods: Murine macrophage RAW 264.7 cells were subjected to dieckol treatment, followed by treatment with receptor activator of nuclear factor kappa-B ligand (RANKL) to induce osteoclastogenesis. Tartrate-resistant acid phosphatase (TRAP) activity was examined using a TRAP activity kit. Western blotting analysis was conducted to examine the level of osteoclast- related factors, including TRAP and calcitonin receptor (CTR), transcriptional factors, including c-Fos, c-Jun, and nuclear factor of activated T cells cytoplasmic 1 (NFATc1), nuclear factor kappa-B (NF-κB), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). Immunofluorescence staining was conducted to examine the expression of c-Fos, c-Jun, and NFATc1. Results: Among the four phlorotannin compounds present in Eisenia bicyclis, dieckol significantly hindered osteoclast differentiation and expression of RANKL-induced TRAP and CTR. In addition, dieckol downregulated the expression levels of c-Fos, c-Jun, NFATc1, ERK, and JNK, and suppressed NF-κB signaling. Conclusions: Dieckol can suppress RANKL-induced osteoclastogenesis. Therefore, it has therapeutic potential in treating osteoclastogenesis- associated diseases.

Effect of Eisenia Bicyclis and Its Pill on Serum Lipid Status in Rats Fed High Fat Diet

In order to investigate whether Eisenia bicyclis (EB) as a functional food material improves serum lipid status, supplementation of EB powder or EB extract to the high fat/cholesterol diet was tested in 6-week old male Sprague-Dawley rats for four weeks. In the first experiment, four kinds of seaweed powder-Eisenia bicyclis (EB), Undaria pinnatifida (UP), Laminaria japonica (LJ), and Ecklonia stolonifera (ES) were compared with alginic acid (ALG) as well as control. In the second experiment, EB water extract and EB ethanol extract and EB pill containing EB and LJ powder were compared with the EB powder. Amounts of dietary fiber contained in experimental diets were adjusted to provide 5% of diets. Serum total cholesterol was significantly lower only in rats fed LJ or EB powder, but HDL cholesterol was higher in rats fed UP, LJ, ES or EB powder. Ratios of HDL-/total cholesterol of all seaweed groups including ALG were significantly higher than that of the control group. Serum triglyceride was lower in LJ, EB and ES powder groups than the control group. In comparison of EB extracts, triglyceride level was decreased in rats fed only EB water extract as compared to control rats, but HDL cholesterol was elevated with both water and ethanol extracts. Serum levels of total cholesterol, triglyceride were decreased and HDL cholesterol was increased by the EB pill. Serum levels of thiobarbituric acid-reactive substances were lower in rats fed ES powder, and EB powder, EB water extract or EB pill, as compared to the control rats. Supplementation of EB powder and EB pill reduced serum level of GOT and GPT, respectively, as compared to the control group. In conclusion, EB and EB pill improve serum lipid status and may be utilized as ingredient of functional foods for the purpose of improving serum lipid profile and inhibiting peroxidation of lipids.

Effects of Eisenia Bicyclis Extracts and Pill on Blood Glucose and Lipid Profile in Streptozotocin-Induced Diabetic Mice

The objectives of this study were to investigate the antihyperglycemic and hypolipidmic effects of sea oak (Eisenia bicyclis, EB) in the diabetic state and to examine the appropriateness of formulated EB pill for the effects. The various test materials obtained from EB were included in the experimental diets with 15% fat/0.5% cholesterol and fed to streptozotocin-induced diabetic mice weighing 35.0 +/- 0.7 g for three weeks but not in the control diet having the same composition. The test materials were EB dry powder, water and ethanol extracts, viscozyme-treated EB water extract (EB enzyme-TR) and formulated pill containing dry powders of the EB, two kinds of seaweed, black soybean, sesame, onion and garlic. BG was measured during feeding period and serum insulin, lipids and thiobarbituric acid reactive substances (TBARS) and intestinal disaccharidase activities were measured at the end of the three weeks of the feeding. BG increase was lower in the EB enzyme-TR group after 10 days of the experimental diet but lower in EB pill group after 15 days compared with the control group. Serum insulin levels were higher in the EB enzyme-TR and EB pill groups. Intestinal maltase but not sucrase activity was higher in EB enzyme-TR fed group than the control group. Serum levels of total cholesterol and triglyceride were reduced by the EB enzyme-TR and EB pill compared with the control diet. HDL-/total cholesterol was increased by all EB test materials. Serum TBARS levels were lower in the EB ethanol extract and EB pill groups than in the control group and tended to be lower in the other EB groups. It is concluded that the EB enzyme-TR is the best among the EB preparations to be utilized as a functional component for improving blood glucose and lipid profile in diabetic subjects in the future. However, the pill containing low level of the EB powder is also regarded as effective and readily usable when formulated with the several other ingredients of the proper composition. (Supported by the RIC Program of MOCIE, Korea).