The effect of tert-butyl hydroperoxide on peritoneal macrophages and the protective effect of protein-bound...

Our previous studies have shown that a protein-bound polysaccharide, polysaccharide krestin (PSK), can protect macrophages from lipoperoxidative injury induced by tert-butyl hydroperoxide (tbOOH) and oxidatively modified low density lipoprotein (O-LDL). PSK was administered intraperitoneally to mice, and the peritoneal macrophages harvested were used as an experimental model. PSK does not reveal any protective effect on macrophages injured by tbOOH when incubated in vitro. In order to elucidate its mode of action, in the present study, the protective effects of PSK were further investigated using morphological changes and viability as indices. It was shown that, compared with the non-PSK group, the viability of macrophages was much higher in the PSK group, and the morphological changes in the PSK group were much less than those in the non-PSK group. The protective effect of PSK administered intraperitoneally and orally on macrophages injured by tbOOH was comparable. Furthermore, the serum of the PSK treated mice had the same protective effect.