Shark Derivatives

Scientific Name(s): Squalus acanthias (spiny dogfish shark), Sphyrna lewini (Hammerhead Shark) and other shark species

Common Name(s): Spiny dogfish shark , hammerhead shark and other species

Uses

The shark cartilage was thought to be a cancer control agent, but no studies have proven this theory. Squalamine has been used as a potent antibiotic with fungicidal and antiprotozoal activity.

Dosing

A standardized shark cartilage product has been marketed under the name Neovastat (AE-941). Clinical trials in cancer angiogenesis have used doses of 60 to 240 mL daily, while another trial of a liquid shark cartilage product used only 7 to 21 mL daily.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Research reveals little or no information regarding adverse reactions with the use of shark derivatives.

Toxicology

Research reveals little or no information regarding toxicology with the use of shark derivatives.

History

Shark cartilage is prepared from the cartilage of freshly caught sharks in the Pacific Ocean. The cartilage is cut from the shark, cleaned, shredded, and dried. One of the main processing plants for dogfish shark is in Costa Rica. The finely ground cartilage is uniformly pulverized (in a 200 mesh screen), sterilized, and encapsulated. Gelatin capsules contain 740 mg, usually without additives or fillers, and are claimed to be “all natural.” Shark cartilage is also available in 200 g and 500 g capsules (eg, Cartilade ©). 1 , 2

Squalamine was originally isolated from shark stomachs, but has subsequently been synthesized. 1 This compound is still in the experimental stage and is not yet commercially available.

Chemistry

Early claims were made that extracts of shark cartilage inhibited tumor angiogenesis when implanted in rabbit corneas. The active principle(s) has not been found, although some believe it might be a protein. 1 , 2 Several studies have been done on various sharks. Pettit and Ode 3 isolated and characterized sphyrnastatin 1 and 2 from the hammerhead shark. Neame et al 4 recently reported on the isolation of a protein from reef shark ( Carcharhinus springeri ) cartilage which bears a striking resemblance to human tetranectin. Moore et al 5 discovered a broad-spectrum steroidal antibiotic from the dogfish shark which they nemed squalamine; chemically it is 3-beta-N-1-(N-[3–(4–aminobutyl)]-1,3-diamino-propane)-7 alpha, 24 zeta-dihydroxy-5 alpha-cholestane 24-sulfate.

Uses and Pharmacology

Cancer

Many claims have been made that shark cartilage can cure cancer. The rationale includes the fact that sharks rarely get cancer, that sharks are cartilaginous fish and that cartilage is avascular and contains agents that inhibit vascularization (angiogenesis). The reasoning then follows that sharks do not get cancer because the inhibited vascularization prevents the formation of tumors; hence, giving it to humans may inhibit tumor angiogenesis and thus cure cancer. 1

Animal data

Research reveals no animal data regarding the use of shark derivatives for cancer.

Clinical data

In late 1992, incomplete and since nonreplicated clinical studies (unpublished) in Havana, Cuba, purported to show some progress in terminally ill cancer patients. The National Cancer Institute reviewed these studies and decided against researching shark cartilage. 1 Recently, however, the FDA granted an IND application for a shark cartilage product, Benefin , by Lane Labs-USA, Inc. to investigate benefits in prostate cancer and AIDS-associated Kaposi's sarcoma. 6

Certainly, future work should continue to focus on the isolation of the responsible proteins or small molecules. The tetranectin-like protein from the reef shark is important since, in man, tetranectin enhances plasminogen activation catalyzed by the tissue plasminogen activator. It may also play a role in cancer metastasis.

Other uses
Antimicrobial

Research along these lines by Moore et al 5 has demonstrated the presence of a broad-spectrum aminosterol antibiotic in the dogfish shark which they named squalamine. It shows significant bactericidal activity against both Gram-negative and Gram-positive bacteria. It is also fungicidal and induces activity against protozoa. 5 This discovery implicates a unique steroid acting as a potential host-defense agent in vertebrates and provides for a new family broad-spectrum antibiotics.

Dosage

A standardized shark cartilage product has been marketed under the name Neovastat (AE-941). Clinical trials in cancer angiogenesis have used doses of 60 to 240 mL daily, while another trial of a liquid shark cartilage product used only 7 to 21 mL daily. 7 , 8

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Research reveals little or no information regarding adverse reactions with the use of shark derivatives.

Toxicology

Research reveals little or no information regarding toxicology with the use of shark derivatives.

Bibliography

1. Masslo Anderson J. Biotech Discovers the Shark. MD Magazine 1993;37:43.
2. Moss RW. Cancer Therapy: The Independent Consumers Guide to Non-Toxic Treatment & Prevention. New York: Equinox Press, 1992.
3. Pettit GR, Ode RH. Antineoplastic agents L: isolation and characterization of sphyrnastatins 1 and 2 from the hammerhead shark Sphyrna lewini . J Pharm Sci 1977:66:757.
4. Neame PJ, et al. Primary structure of a protein isolated from reef shark (Carcharhinus springeri) cartilage that is similar to the mammalian C-type lectin homolog, tetranectin. Protein Sci 1992:1(1):161.
5. Moore KS, et al. Squalamine: an aminosterol antibiotic from the shark. Proc Nat Acad Sci USA 1993;90(4):1354.
6. Hunt TJ, Connelly JF. Shark cartilage for cancer treatment. Am J Health-Syst Pharm 1995;52:1756.
7. Berbari P, Thibodeau A, Germain L, et al. Antiangiogenic effects of the oral administration of liquid cartilage extract in humans. J Surg Res . 1999;87:108-113.
8. Falardeau P, Champagne P, Poyet P, Hariton C, Dupont E. Neovastat, a naturally occurring multifunctional antiangiogenic drug, in phase III clinical trials. Semin Oncol . 2001;28:620-625.

Copyright © 2009 Wolters Kluwer Health

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