PSK PROTECTS MACROPHAGES FROM LIPOPEROXIDE ACCUMULATION AND FOAM CELL-FORMATION CAUSED BY OXIDATIVELY MODIFIED LOW-DENSITY-LIPOPROTEIN

In previous works, it has been evidenced that lipoperoxidative injury to macrophages caused by oxidatively modified low-density lipoprotein (O-LDL) plays an important role in foam cell formation, and that PSK, a protein bound polysaccharide extracted from the class Basidiomycetes Coriolus Versicolor, can protect macrophages from lipoperoxidative in jury induced by tert-butyl hydroperoxide (tbOOH). In this paper PSK pr otection of macrophages from lipoperoxide (LPO) accumulation and foam cell formation caused by O-LDL and its action mechanism were further s tudied, The LPO accumulation was determined by using ACAS 570. Dynamic assay of the LPO level in eight single cells after adding O-LDL or de termination of the average LPO content in a lot of cells incubated in advance with O-LDL for 12 h, both indicated that O-LDL might induce LP O accumulation in macrophages and the effects of O-LDL could be preven ted by PSK. O-LDL might cause the changes of morphological structure i n macrophages and the transformation of macrophages into foam cells, a nd the effects could also be prevented by PSK, The determination of, s elenium-dependent glutathione peroxidase (SeGSHPx) activities and mRNA contents of macrophages and changes of SeGSHPx activity and mRNA cont ent after incubation with tbOOH showed that PSK might increase the SeG SHPx activity of macrophage and the enhanced SeGSHPx activity may occu r at the level of gene transcription.