Immunomodulation Effect Of Gingerol On Immunosuppression Induced Via Gamma-ray Radiation In The Kunming Mice

Exposure to ionizing radiation damages cells and tissues depending on the total radiation dose and dose rate. Cells having proliferative activity/potential constitute the most radio-sensitive compartment. The magnitude of damage by ionizing radiation depends upon the nature and function of cells/tissues generated by stem cells. The ionizing radiations with low linear energy transfer cause bone marrow suppression and depletion of peripheral blood lymphocytes leading to immunosuppression. The exposed animals, therefore, become susceptible to opportunistic pathogens and some of these infections could be lethal.Hydroalcoholic extract of ginger rhizome , which has been reported to ameliorate the severity of symptoms of radiation sickness and mortality induced at the 11 Gy gamma-irradiation in mice, was further investigated for its immunomodulatory potential. In this study, mice were given 400mg/kg gingerol orally once daily for 7 consecutive days before exposure to 5 Gy of gamma-radiation and were sacrificed at 48h post-irradiation. Pretreatment of gingerol significantly (P<0.01) enhanced the spleen relative weight as compared to irradiation control group. gingerol treatment before whole body irradiation enhanced macrophage survival significantly (P<0.01) as compared to the irradiated control mice, and there was significant (P<0.01) reduction in splenocyte survival and proliferation as revealed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method in irradiation mice. As compared to irradiated control group, gingerol treatment alone or before irradiation countered the decrease in survival of splenocytes and proliferation significantly (P<0.01). Whole body irradiation also significantly (P<0.01) reduced the population of CD4~+ and CD8~+ T cells at 48h post-irradiation, as compared to unirradiated control. gingerol treatment before whole body irradiation countered the decrease in CD4+ and CD8+ T cells population. Whole body irradiation (5 Gy) also reduced the serum titres of IL-3, IL-1βand various IgG isotypes observed at 48h post-irradiation. Gingerol treatment alone or before whole body irradiation countered radiation induced decrease in the titre of IL-1β, IL-3 and IgG's in the serum of mice. Pretreatment of gingerol before irradiation significantly reduced the numbers of micronuclei(MN) in bone marrow polychromatic erythrocytes (PCEs). These findings indicate that gingerol has immunostimulatory potential against suppression induced by the radiation.