Bladderwrack

Bladderwrack (Fucus vesiculosis)

 

marine-algae-bladderwrackCommon Names

Bladderwrack, bladder wrack, bladder fucus, black tang, black tany, cut weed, dyers fucus, red fucus, rockweed, rock wrack, and sea oak.

Natural Habitat

Rocky substrates of intertidal zones in the northern hemisphere. Bladderwrack is found in coastal areas of the Atlantic Ocean in North America (from the Hudson Bay to North Carolina); the Atlantic and North Sea coastal areas of the British Isles and Europe; the Greenland coastal areas; the western Baltic Sea coast; along the coast of the Azores, Canary Islands, Morocco, and Madeira; and coastal areas of Northern Russia.

Key Components

Polysaccharide mucilage; fucoidan; algin; mannitol; carotenoids including beta-carotene and zeaxanthin; numerous minerals, most notably iodine, bromine, and potassium.

Overview

Fucus vesiculosis, a seaweed more commonly known as bladderwrack, is olive brown and easily recognized by its distinctive, spherical air bladders. Fronds of this seaweed, which can reach up to six feet in length, are flat and branched with a distinct midrib running through the length of each frond. The air bladders usually occur symmetrically opposite each other on each side of the midrib. Bladderwrack attaches itself to the rocky substrate found in intertidal areas along coastlines of the northern hemisphere. It grows best in more sheltered areas.

Bladderwrack became popular in the early 19th century, when it was first recognized for its iodine content. It has traditionally been used in herbal medicine to treat thyroid conditions such as underactive thyroid and goiter.1 In the food industry, the algin from bladderwrack is used as a thickener in processed foods such as puddings, ice cream, and salad dressings.2 It is often used as an ingredient in cosmetics and personal care products, in nutritional supplements, and even in fertilizers.3

Seaweed is known for its high antioxidant content, and bladderwrack is no exception, containing a number of helpful carotenoids, including beta carotene, neoxanthin, fucoxanthin, violaxanthin, and zeaxanthin.4 When researchers tested six sulfated polysaccharides for antioxidant function, bladderwrack scored among the highest. The active component identified was fucoidan, which hinders formation of free radicals.5 A second study also demonstrated fucoidan’s potent antioxidant potential. Researchers isolated fractions of the sulfated polysaccharides in bladderwrack; the fraction containing fucoidan performed the best.6 Another study demonstrated the antioxidant activity of bladderwrack, and also showed that it is safe for daily use.7 In recent years, bladderwrack has attracted the attention of anti-aging researchers. One phenomenon associated with aging and lifestyle diseases is the body’s formation of glycation end products, or AGEs. In a recent experiment, researchers tested various fractions of bladderwrack’s phlorotannins against AGEs. They discovered that the phlorotannins neutralize reactive carbonyls and inhibit AGE formation.8 Bladderwrack also may have potential as an ingredient in anti-aging personal care and cosmetic products. When study participants applied an extract of bladderwrack to their skin for five weeks, skin characteristics associated with aging were reversed. Most notably, cheek skin was less thick and skin elasticity was enhanced.9

For many years, nutritionists have believed that one likely explanation for the health and longevity of Japanese women is the soy in their diet. New research suggests it may be seaweed, and not soy, that explains why Japanese women are at lower risk for hormone-related cancers. A pilot study involving pre-menopausal women demonstrated that bladderwrack likely has anti-estrogenic properties. This may be helpful for women who are at risk for estrogen-dependent diseases.10 A study involving female rats also showed similar findings.

Female rats who consumed bladderwrack had longer estrous cycles and lower estradiol levels. Researchers theorized that the seaweed likely blocks production of estradiol or hastens its breakdown.11

Bladderwrack also shows promise as a therapeutic alternative to anticoagulation drugs such as heparin. In one of the earlier studies on this topic, researchers discovered that a fucoidan fraction with a low molecular weight and high sulfate content could act as an anticoagulant. Subsequent research built on this finding. Later studies compared heparin directly to the fucoidan in bladderwrack. When researchers induced thrombosis in mice and compared fucoidan’s effects to heparin, the fucoidan had a greater anti-thrombotic effect.12 In a subsequent study, fucoidan prevented blood clots as well as the prescription drug heparin, but heparin also caused bleeding to continue too long in some cases. Researchers believe that fucoidan could be a safer alternative.13

Cancer researchers are also exploring bladderwrack’s potential as a therapeutic agent. The fucoidan in bladderwrack induced apoptosis (programmed cell death) in lung cancer and melanoma cells in vitro.14 When mice were injected with fucoidans, their natural killer cell activity increased.15 Another series of experiments involved the effects of bladderwrack’s sulfated polysaccharides on melanoma cells. Once again, bladderwrack induced apoptosis.16 The fucoidan from bladderwrack may even be useful in the fight against metastatic cancer, as was shown in an in vitro experiment involving metastatic human lung cancer cells.17

Also of potential use in cancer research is bladderwrack’s potential to protect against the effects of radiation. In one of the earliest studies on the subject, researchers found that the polysaccharides in bladderwrack inhibited the absorption of radioactive strontium into rat femur bones.18 In cancer treatment, radiation not only kills cancer cells, but can also harm healthy cells. This is why the findings in a more recent study are so exciting: Researchers found that fucoidan protects bone marrow cells from the harmful effects of radiation. It also boosts the ability of bone marrow cells to make splenocytes, white blood cells in the spleen that are an important immune defense mechanism.19

Bladderwrack may even be useful in the treatment or prevention of obesity. Once again, fucoidan is the component of this seaweed that shows great promise. Researchers have discovered that fucoidan increases the activity of lipase, an enzyme essential to the breakdown of fat. Fucoidan also inhibits glucose uptake into fat cells, another phenomenon associated with fat loss.20 As a functional food or nutritional supplement, bladderwrack could potentially be of help to the millions of people who struggle with weight management.

 



1 P.R. Bradley, P.R., 1992. British Herbal Compendium 1. Bournemouth, England: British Herbal Medicine Association. ISBN 0-903032-09-0.

4 Haugan, J.A.; Liaaen-Jensen, S. Algal carotenoids 54. Carotenoids of brown algae (phaeophyceae). Biochemical Systematics and Ecology. 1994, 22, 31–41.

5 Rocha de Souza, M.C., et al. Antioxidant activities of sulfated polysaccharides from brown and red seaweeds. Journal of Applied Phycology. 2007. 19:153-160.

6 Ruperez, P., et al. Potential antioxidant capacity of sulfated polysaccharides from the edible marine brown seaweed Fucus vesiculosus. Journal of Agricultural and Food Chemistry. 2002. 50, 840-845.

7 Zaragoza, M.C., et al. Toxicity and antioxidant activity in vitro and in vivoof two Fucus vesiculosus extracts. Journal of Agricultural and Food Chemistry. 2008. 56, 7773-7780.

8 Liu, H., and Gu., L. Phlorotannins from brown algae (Fucus vesiculosus) inhibited the formation of advanced glycation endproducts by scavenging reactive carbonyls.

Journal of Agricultural and Food Chemistry. 2012. 60, 1326-1334.

9 Fujimora, T., et al. Treatment of human skin with an extract of Fucusvesiculosus changes its thickness and mechanical properties. Journal of Cosmetic Science. 2002. 53, 109.

10 Skibola, C.F. The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report. BMC Complementary and Alternative Medicine. 2004.  4 (10).

11 Skibola, C.F., et al.  Brown kelp modulates endocrine hormones in female sprague-dawley rats and in human luteinized granulosa cells. The Journal of Nutrition. 2005. 135, 296-300.

12 Kwak, K.W., et al. Biological effects of fucoidan isolated from Fucus vesiculosus on thrombosis and vascular cells

The Korean Journal of Hematology. 2010. 45 (1), 51-57.

13 Min, S.K., et al. An antithrombotic fucoidan, unlike heparin, does not prolong bleeding time in a murine arterial thrombosis model: a comparative study of Undaria pinnatifida sporophylls and Fucus vesiculosus. Pharmacology Research & Perspectives. 2012. 26 (5), 752-757.

14 Ale, M.T., et al. Fucoidan from Sargassum sp. and Fucus vesiculosus reduces cell viability of lung carcinoma and melanoma cells in vitro and activates natural killer cells in mice in vivo. International Journal of Biological Macromolecules. 2011. 49, 331-336.

15 Ibid.

16 Ale, M.T., et al. Fucose-containing sulfated polysaccharides from brownseaweeds inhibit proliferation of melanoma cells and induce apoptosis by activation of caspase-3 in vitro. Marine Drugs. 2011. 9, 2605-2621.

17 Lee, H., et al. Fucoidan from seaweed Fucus vesiculosus inhibits migration and invasion of human lung cancer cell via PI3K-Akt-mTOR pathways. PLoS ONE. 2012. 7 (11).

18 Tanaka, Y., et al. Studies on inhibition of intestinal absorption of radioactive strontium: VII. Relationship of biological activity to chemical composition of alginates obtained from North American seaweeds. Canadian Medical Association Journal. 1968. 99, 169-175.

19 Byon, Y.Y., et al. Radioprotective effects of fucoidan on bone marrow cells: improvement of the cell survival and immunoreactivity. Journal of Veterinary Science. 2008. 9 (4), 359-365.

20 Park, M.K., et al. Fucoidan from marine brown algae inhibits lipid accumulation.

Marine Drugs. 2011. 9, 1359-1367.

 

Research

1. An antithrombotic fucoidan, unlike heparin, does not prolong bleeding time in a murine arterial thrombosis model: a comparative study of Undaria pinnatifida sporophylls and Fucus vesiculosus

Min, S.K., et al. Pharmacology Research & Perspectives. 2012. 26 (5), 752-757.

The blood thinning drug heparin was compared to fucoidan, a component of bladderwrack, in mice. Researchers induced blood clots in mice and then administered either fucoidan or the drug heparin, in varying dose amounts. Blood flow was monitored for an hour after dosing. As expected, the effects of the substances were dose dependent. When fucoidan was used, clot formation was inhibited and bleeding continued for several minutes. When heparin was used, clot formation was also inhibited, but bleeding continued for an hour. Researchers conclude that while both substances prevent clots, heparin may cause bleeding to continue for too long. Fucoidan from bladderwrack may offer a safe alternative.

2. Biological effects of fucoidan isolated from Fucus vesiculosus on thrombosis and vascular cells

Kwak, K.W., et al. The Korean Journal of Hematology. 2010. 45 (1), 51-57.

In this series of in vitro and in vivo experiments, researchers looked at the effects of fucoidan, a component of bladderwrack, on thrombosis (formation of a blood clot which can block blood flow). Researchers treated vascular cells with fucoidan in vitro. Proinflammatory cytokines, chemokine production, and proliferation were all reduced. In vivo, researchers induced thrombosis in mice and compared the anti-thrombotic effects of fucoidan to heparin. Fucoidan demonstrated a greater anti-thrombotic effect in the mice than heparin.

3. Antioxidant activities of sulfated polysaccharides from brown and red seaweeds

Rocha de Souza, M.C., et al. Journal of Applied Phycology. 2007. 19:153-160.

Six sulfated polysaccharides, including fucoidan from bladderwrack, were examined in vitro for their antioxidant effects. Tests included fucoidan’s ability to inhibit the formation of superoxide radicals and hydroxyl radicals. Of the six polysaccharides tested, fucoidan was one of two with the highest antioxidant activity. Researchers believe the high sulfate content is responsible for the increased antioxidant effect. They also conclude that fucoidan may be helpful as a food additive to inhibit food spoilage.

4. Anticoagulant fucoidan fractions from Fucus vesiculosus induce platelet activation in vitro

Durig, J., et al. Thrombosis Research. 1997. 85 (6), 479-491.

In this in vitro study, researchers evaluated various fucoidan fractions of differing sulfate content and differing molecular weights from the seaweed bladderwrack. They looked in particular at fucoidan’s effectiveness as an anticoagulant. Testing revealed that a fucoidan fraction with a low molecular weight and high sulfate content acts as an anti-coagulant, anti-clotting agent. Researchers believe further studies regarding this substance’s potential for pharmacological applications would be useful.

5. Fucoidan from marine brown algae inhibits lipid accumulation

Park, M.K., et al. Marine Drugs. 2011. 9, 1359-1367.

In this in vitro study, researchers looked at the effects of fucoidans from brown algae, including bladderwrack, on fat cells. The fucoidan increased the activity of lipase, an enzyme that breaks down fats, and decreased glucose uptake into the fat cells. Both of these phenomena are already associated with the breakdown of fat. Researchers conclude that fucoidans may be useful in weight loss and weight maintenance.

6. Fucoidan from Sargassum sp. and Fucus vesiculosus reduces cell viability of lung carcinoma and melanoma cells in vitro and activates natural killer cells in mice in vivo

Ale, M.T., et al. International Journal of Biological Macromolecules. 2011. 49, 331-336.

In a series of in vitro experiments, researchers evaluated the effects of fucoidan from Sargassum sp. and Fucus vesiculosus (bladderwrack) on two types of cancer cells. Fucoidans from both seaweeds were effective in a dose-dependent manner against lung cancer cells and melanoma cells. Tests showed that the fucoidans induced cell death. In an in vivo experiment, mice were injected with one of the two types of seaweed fucoidans. Both types of fucoidans enhanced the cancer cell-destroying activity of natural killer cells in mice.

7. Fucose-containing sulfated polysaccharides from brown seaweeds inhibit proliferation of melanoma cells and induce apoptosis by activation of caspase-3 in vitro

Ale, M.T., et al. Marine Drugs. 2011. 9, 2605-2621.

This series of in vitro experiments involved the sulfated polysaccharides from several types of seaweed, including bladderwrack. Researchers looked at their effects on melanoma cells. Both seaweeds inhibited melanoma cell proliferation by inducing apoptosis (cell death). Bladderwrack was found to be more effective at higher doses while another variety of seaweed, Sargassum, was more effective at lower doses.

8. Treatment of human skin with an extract of Fucus vesiculosus changes its thickness and mechanical properties

Fujimora, T., et al. Journal of Cosmetic Science. 2002. 53, 109.

As one ages, the skin on the cheeks thickens and becomes less elastic. In this study, researchers looked at the effects on cheek skin of a topical gel that contained an extract of bladderwrack. Twice a day for five weeks, study participants applied the gel. Before and after measurements revealed that skin thickness decreased and elasticity increased. Researchers conclude that an extract of bladderwrack may have potential applications in anti-aging cosmetics.

9. Fucoidan from seaweed Fucus vesiculosus inhibits migration and invasion of human lung cancer cell via PI3K-Akt-mTOR pathways

Lee, H., et al. PLoS ONE. 2012. 7 (11).

In this study, researchers looked at the fucoidan from bladderwrack as a potential anti-cancer agent. They sought to demonstrate its anti-metastatic properties and mechanism of action. In this in vitro experiment, they used a line of human lung cancer cells, A549, that are exceedingly metastatic. At lower doses, the fucoidan slowed down the invasion and migration of cancer cells by inhibiting MMP-2 activity. (MMP-2 is an enzyme that is involved in inflammatory response and the breakdown of tissue.) At higher doses, it slowed or stopped the cancer cell growth. Researchers discovered that fucoidan worked by down-regulating the signaling pathways for ERK1/2 (a signaling molecule), Akt-mTOR (especially important for cancer cell apoptosis), and NF-kB (which helps regulate immune response).

10. The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report

Skibola, C.F. BMC Complementary and Alternative Medicine. 2004.  4 (10).

In a pilot study involving pre-menopausal women, researchers investigated whether bladderwrack has therapeutic potential for women at risk for, or currently experiencing, estrogen-dependent diseases. The study participants all had histories of abnormal menstrual issues. Study results revealed that bladderwrack may have anti-estrogenic properties and may stimulate release of more progesterone. All study participants experienced longer menstrual cycles (from 5 to 14 days longer) while using bladderwrack. Researchers believe that larger scale clinical trials are warranted.

11. Toxicity and antioxidant activity in vitro and in vivo of two Fucus vesiculosus extracts

Zaragoza, M.C., et al. Journal of Agricultural and Food Chemistry. 2008. 56, 7773-7780.

Researchers examined the effects of two bladderwrack extracts for safety and for antioxidant function. One extract contained 28.8% polyphenols; the other contained 18% polyphenols and 0.0012% fucoxanthin. Tests revealed the extracts to be non-toxic in mice. Furthermore, both extracts showed antioxidant activity, although the second extract was more easily metabolized. Researchers conclude that daily intake of bladderwrack may have potential health benefits.

12. Radioprotective effects of fucoidan on bone marrow cells: improvement of the cell survival and immunoreactivity

Byon, Y.Y., et al. Journal of Veterinary Science. 2008. 9 (4), 359-365.

In a series of experiments, researchers looked at the ability of fucoidan (from bladderwrack) to protect bone marrow cells from the harmful effects of radiation. Bone marrow cells treated with fucoidan were more viable than those not treated. Test results suggest that the fucoidan inhibited cell death that would normally be caused by radiation. Fucoidan also boosted the ability of bone marrow cells to stimulate splenocytes, which are white blood cells in the spleen that are part of the body’s immune defenses. Researchers conclude that fucoidan helps protect the body against the negative effects of radiation and supports the body’s immune system to react properly when needed. These findings may have potential applications for patients undergoing radiation treatments.

13. Potential antioxidant capacity of sulfated polysaccharides from the edible marine brown seaweed Fucus vesiculosus

Ruperez, P., et al. Journal of Agricultural and Food Chemistry. 2002. 50, 840-845.

In this series of experiments, researchers isolated fractions of sulfated polysaccharides from bladderwrack and tested them for their antioxidant potential. All the polysaccharides tests showed antioxidant potential, especially one fraction designated F3, which also contained fucoidan. Researchers conclude that the polysaccharides (and especially fucoidan) from bladderwrack and other brown seaweeds may be of interest as functional food ingredients.

14. Phlorotannins from brown algae (Fucus vesiculosus) inhibited the formation of advanced glycation endproducts by scavenging reactive carbonyls

Liu, H., and Gu., L. Journal of Agricultural and Food Chemistry. 2012. 60, 1326-1334.

Researchers sought to determine whether the phlorotannins present in bladderwrack could mitigate the effects of advanced glycation end products. Advanced glycation end products, or AGEs, are associated with aging and lifestyle diseases. After extracting and testing various fractions of the phlorotannins, researchers determined that they inhibit AGE formation partly by neutralizing reactive carbonyls. These test results suggest that bladderwrack or its phlorotannins show potential as an anti-aging and therapeutic substance.

15. Brown kelp modulates endocrine hormones in female sprague-dawley rats and in human luteinized granulosa cells

Skibola, C.F., et al.  The Journal of Nutrition. 2005. 135, 296-300.

This study was a follow up to an earlier pilot study of premenopausal women who consumed bladderwrack and experienced anti-estrogenic effects, which may be of benefit in estrogen-dependent diseases. This study looked at the administration of bladderwrack to female rats, which resulted in longer estrous cycles and reduced estradiol levels. In comparison with soy, the bladderwrack had a significantly greater effect on female cycle length. These findings suggest that seaweed, not soy, is responsible for lowering hormone-related cancers in Japanese women. In a related in vitro experiment, researchers demonstrated that the seaweed extract may work by either blocking production of estradiol or boosting its breakdown.

16. Studies on inhibition of intestinal absorption of radioactive strontium: VII. Relationship of biological activity to chemical composition of alginates obtained from North American seaweeds

Tanaka, Y., et al. Canadian Medical Association Journal. 1968. 99, 169-175.

Researchers evaluated the polysaccharides in 19 different varieties of marine plants for their potential protective effects against radioactive strontium. Of the plants studied, bladderwrack was among the most effective. It inhibited the absorption of strontium into rat femur bones by 70%.

 

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