Beta Glycans
Scientific Name(s):Beta-1,3-glucan, beta-1,3/1,6-glycan
Common Name(s): Beta glycans , beta glucans
Clinical Overview
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Uses of Beta Glycans
Although few studies in humans are available (primarily in HIV patients), beta glycans are sold as supplements to boost the immune system and have also been studied in animals for their antitumor actions.
Beta Glycans Dosing
In an HIV trial, patients were given 2 to 10 mg of the beta-glucan lentinan IV once a week for 8 weeks. In a second trial, 1 to 5 mg of lentinan was given IV twice a week for 12 weeks.
Contraindications
Contraindications have not yet been identified.
Pregnancy/Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking.
Beta Glycans Interactions
None well documented.
Beta Glycans Adverse Reactions
The FDA classifies baker's yeast beta-1,3/1,6-glycan as GRAS (generally recognized as safe), but reports show beta glycans may potentiate airway allergic responses and worsen symptoms in patients with existing disease.
Toxicology
No significant toxicity is associated with this agent.
Beta glycans are carbohydrates. They are natural substances that come from a variety of sources including mushrooms (eg, lentinan [see specific monograph]), oats, barley, baker's yeast, algae, and mannin. 1
History
Beta-1,3/1,6-glycan has been studied for more than 30 years. It has immune system stimulant properties. In the 1980s, beta glycans were used to make salmon more disease resistant. 2
Chemistry
The chemistry of fungal beta-1,3-glucans has been reported. Structures were classified into triple helix, single helix, and random coil, which determined a variety of different pharmacological characteristics. 3
Beta Glycans Uses and Pharmacology
Anti-tumor activityIn vitro testing demonstrated beta glycans induced non-specific macrophage-mediated tumor cell killing. 4 Beta glycans also increased hemagglutinin titers in certain cell lines. 5 Another report on soluble glycan demonstrates enhanced IL-1 and IL-2 production, which can be maintained 12 days post-glycan administration. 6 Beta glycans also cause a rapid decrease in tumor cells as shown in affected mice. 7
Animal dataFungal beta-1,3-glycan orally administered to mice inhibited tumor growth and potentiated immune response. 8 Another report confirms beta glycan's marked antitumor activity and enhanced ability of natural killer cell and macrophage activities in mice. 9 A review on mushroom beta glycans found differences in their effectiveness against certain tumors, primarily in cytokine expression and production. 10 Beta glycans were found to be immunostimulant in postsplenectomy sepsis in mice. Beta glycans increased survival by 75% in certain groups compared with 27% in the control group. 11 In mice with experimental colon and skin wounds, beta glycans increased tensile strength of the wounds by 42% and increased collagen biosynthesis as well. 12 Beta glycans obtained from oats were also found to possess immunostimulatory function in vitro and in vivo. 13 An overdose of a beta glycan preparation (sonifilan) failed to display antitumor activity in another report. 14
Clinical dataResearch reveals no clinical data regarding the use of beta glycan as an anti-tumor agent.
Dietary supplementNorwegian beta glycan is sold as an all-natural dietary supplement to boost the immune system and protect against colds and flu. It is claimed to strengthen the body's ability to fight disease-causing organisms. Because of its molecular shape, it binds specifically to macrophage surfaces, activating the immune system and increasing resistance. 2 In another product claim, beta glycans are said to be acid-resistant and pass through the stomach unchanged. Once in the intestine, macrophages attach to activate them. 1
Research reveals no animal or clinical data regarding the use of beta glycan as a dietary supplement.
Other usesBeta glycan's role in HIV appears promising in phase I and II human trials but needs confirmation. 15 Other product claims include beta glycans' ability to heal bed sores, nail fungus, and ear infections. 16
Dosage
In an HIV trial, patients were given 2 to 10 mg of the beta-glucan lentinan IV once a week for 8 weeks. In a second trial, 1 to 5 mg of lentinan was given IV twice a week for 12 weeks. 15
Pregnancy/Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
Baker's yeast beta-1,3/1,6-glycan has a “GRAS” rating by the FDA, meaning “generally recognized as safe.” 1 A report on Norwegian beta glycans noted that if a patient with an existing disease takes beta glycans, symptoms may actually worsen for a couple of days. 2 In a clinical trial testing beta glycans use in AIDS patients, side effects severe enough to be reported to the FDA were anaphylactoid reaction, back pain, leg pain, depression, rigor, fever, chills, granulocytopenia, and elevated liver enzymes (1 case each); 4 of 98 patients discontinued therapy because of side effects. 15 Beta glycans may potentiate airway allergic responses. 17 , 18
Toxicology
A preclinical safety evaluation of soluble glycan in mice, rats, guinea pigs, and rabbits is available. Data from this report indicate that “administration of soluble glycan over a wide dose range does not induce mortality or significant toxicity.” 19
Bibliography
1. http://www.immunehealthsystems.com/learning_center.htm .2. Levy S. Echinacea, move over; Norwegian beta glucan is here. Drug Topics 2000 Apr 17:73.
3. Yadomae T. Structure and biological activities of fungal beta-1,3-glucans. Yakugaku Zasshi 2000;120(5):413-31. [Japanese.]
4. Artursson P, et al. Macrophage stimulation with some structurally related polysaccharides. Scand J Immunol 1987;25(3):245-54.
5. Rios-Hernandez M, et al. Immunopharmacological studies of beta-1,3-glucan. Arch Med Res 1994;25(2):179-80.
6. Sherwood E, et al. Enhancement of interleukin-1 and interleukin-2 production by soluble glucan. Int J Immunopharmacol 1987;9(3):261-67.
7. Baba H, et al. Rapid tumor regression and induction of tumor-regressing activity in serum by various immune-modulating agents. Int J Immunopharmacol 1986;8(6):569-72.
8. Suzuki I, et al. Immunomodulation by orally administered beta-glucan in mice. Int J Immunopharmacol 1989;11(7):761-69.
9. Suzuki I, et al. Antitumor and immunomodulating activities of a beta-glucan obtained from liquid-cultured Grifola frondosa . Chem Pharm Bull 1989;37(2):410-13.
10. Borchers A, et al. Mushrooms, tumors, and immunity. Proc Soc Exp Biol Med 1999;221(4):281-93.
11. Browder W, et al. Protective effect of nonspecific immunostimulation in postsplenectomy sepsis. J Surg Res 1983;35(6):474-79.
12. Portera C, et al. Effect of macrophage stimulation on collagen biosynthesis in the healing wound. Am Surg 1997;63(2):125-31.
13. Estrada A, et al. Immunomodulatory activities of oat beta-glucan in vitro and in vivo. Microbiol Immunol 1997;41(12):991-98.
14. Miura T, et al. Failure in antitumor activity by overdose of an immunomodulating beta-glucan preparation, sonifilan. Biol Pharm Bull 2000;23(2):249-53.
15. Gordon M, Bihari B, Goolsby E, et al. A placebo-controlled trial of the immune modulator, lentinan, in HIV-positive patients: a phase Ι/ΙΙ trial. J Med . 1998;29:305-330.
16. http://www.immunehealthsystems.com/default1.htm .
17. Wan G, et al. An airborne mold-derived product, beta-1,3-D-glucan, potentiates airway allergic responses. Eur J Immunol 1999;29(8):2491-97.
18. Tarlo S. Workplace respiratory irritants and asthma. Occup Med 2000;15(2):471-84.
19. Williams D, et al. Pre-clinical safety evaluation of soluble glucan. Int J Immunopharmacol 1988;10(4):405-14.
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