The effect of acid and base hydrolysis on immunomodulatory activities of higher mushroom glucans, in vitro

Abstract

Immunomodulatory activities of higher mushroom glucans depend on such chemical properties as their molecular weight, branching patterns, water solubility and tertiary structure. The aim of the study was to examine how glucans size and conformation affect their in vitro immunomodulatory properties. Measurements of the immunomodulatory capacity of Agaricus blazei and Phellinus linteus native glucans showed that A. blazei glucans expressed an immunostimulating effect on activated peripheral blood mononuclear cells (PBMCs) and the synthesis of interferon-gamma (IFN-γ). P. linteus glucans showed a characteristic immunosuppressive effect. The results obtained after the stimulation of cells with 1M H2SO4 and 1M NaOH treated glucans confirmed that the immunomodulatory activity of glucans was due to the size and conformation. Glucans of a lower molecular weight obtained after acid hydrolysis appeared to be effective immunostimulators of PBMCs. Obtained results indicated that the primary structure of glucans was of more importance then the tertiary structure of the triple helix for their immunostimulating activity. The study confirmed that the size and conformation of native P. linteus glucans were of a primary importance for their immunosupressive effect.

Imunomodulatorska aktivnost glukana viših gljiva u funkciji je od njihovih hemijskih karakteristika, kao što su molekulska masa, stepen grananja, rastvorljivost u vodi i tercijarna struktura. Cilj ovog rada bio je da se ispita uticaj veličine i konformacije miko glukana na njihova imunomodularska svojstva, in vitro. Merenjem imunomodulatorskog kapaciteta Agaricus blazei i Phellinus linteus nativnih glukana pokazano je da A. blazei glukani imaju izraženo imunostimulativno dejstvo na aktivirane mononuklearne ćelije krvi iz perifernog krvotoka (PBMC-Peripheral Blood Mononuclear Cell) i stimulaciju sinteze interferona-gama (IFN-γ). P. linteus glukani su ispoljili izraženo imunosupresivno dejstvo. Stimulacijom ćelija glukanima koji su prethodno hidrolizovani 1M H2SO4 i 1M NaOH zaključeno je da su veličina i konformacija molekula bitne hemijske karakteristike od kojih zavisi njihova imunomodulatorska aktivnost. Glukani manjih molekulskih masa, nastali nakon kisele hidrolize, pokazali su se kao efikasni imunostimulatori PBMC ćelija. Ukazano je da je za imunostimulativnu aktivnost ovih molekula bitna primarna struktura, a ne konformacija trostrukog heliksa nativnih molekula. Ispitivanjem imunosupresivnog efekta P. linteus glukana na sintezu IFN-γ pokazano je da su za ovaj efekat bitna veličina molekula kao i konformacija nativnih molekula.