Restoration of electric footshock-induced immunosuppression in mice by Modified Aloe Polysaccharide (INC2P.411)

Abstract

Abstract A mutual relationship between stress and immune system has long been studied. To investigate the immunomodulatory effects of MAP (modified aloe polysaccharide) on stressed model, we induced electric foot shock on mice for 17days. Oral administration of MAP was found to prevent the atrophy of body weight and immune apparatus weights. The stress-induced disturbances in cellularity were also restored by MAP administration in both thymus and spleen. In addition, MAP treatment improved lymphocytes proliferation induced by several antigens. The model antigen OVA-peptide was designed to examine the restoration effects of MAP in terms of specific immunity. The oral administration of MAP considerably improved the proliferation of OVA-specific CD4+T cells. We also found that MAP treated mice generated more potent ova specific cytotoxic T cells compared to MAP untreated group. In a sense of humoral immunity, OVA specific IgG production level was increased by the oral administration of MAP. According to the analysis of stress-related hormones including dopamine, serotonin and corticosterone, the oral administration of MAP tends to reduce the changes in hormone levels between the stressed and unstressed groups. Lastly, elevated plus-maze (EPM) test showed the anxiolytic effects of MAP in stressed mice. These results consistently demonstrate that oral administration of MAP could increase host defense toward chronic stress induced by electric foot shock.