Specification :

INTRODUCTION:

Yeast beta-D-glucan is marketed as a nutritional supplement. The yeast beta-D-
glucan in the supplement is a polyglucose polysaccharide derived from the cell
walls of baker's yeast or Saccharomyces cerevisiae. Yeast beta-D-glucan, usually
referred to as yeast beta-glucan, consists of straight-chain and branched
polymers. The straight-chain structures are (1/3)-beta-D-linked glucose polymers
and (1/6)-beta-D-linked glucose polymers. Yeast beta-glucan appears to have
immunomodulatory properties. It is being evaluated in clinical studies as an
immunomodulatory agent and a biological response modifier.

ACTIONS:

Yeast beta-glucan may have immunomodulatory and lipid-lowering activity.

MECHANISM ACTIONS:

Yeast beta-glucan can bind to a beta-glucan receptor in macrophages and stimulate
the production of such cytokines as TNF (tumor necrosis factor)-alpha and IL
(interleukin)-I beta. Binding to the beta-glucan receptor may also induce the release
such reactive oxygen species as superoxide anions and hydrogen peroxide. Yeast
of beta-glucan may also stimulate such cells as neutrophils NK (natural killer cells)
and LAK (lymphokine-activated killer) cells. All of the above stimulation effects may
result in antimicrobial and tumoricidal activities.yeast beta-glucan may be
considered an immune system primer.

Yeast beta-glucan is an indigestible polysaccharide and very little hydrolysis of it
takes place in the stomach or small intestine. There is some digestion of yeast
beta-glucan that does take place in the large intestine via bacterial beta-
glucosidases, and some remnants of this digestion, oligosaccharides with
molecular weights of up to 20,000 daltons, have been detected in the serum of
animals, as well as of humans, Yeast beta-glucan has been found to lower total
cholesterol levels as well as to increase levels of HDL-cholesterol. Yeast beta-glucan may also promote the excretion of bile acids.