Changes in Spleen Cell Populations in Total Body 60 CO - Gamma Irradiated Mice and Their Modification by SBL - 1 : Implication in Radiation Protection

One time treatment with standardized extract from leaves of Hippophae rhamnoides L. (coded as SBL-1), 30min before irradiation with lethal dose (10 Gy) of Co-gamma rays rendered >90% radioprotection to mice population. The present study was planned to examine the effects of SBL-1 on mouse spleen cell populations in whole body lethally irradiated mice. All non-SBL-1 treated irradiated (10 Gy) mice died by day 12. In comparison to untreated controls, the irradiated mice showed decreases in (i) spleen/body weight (b.w.) ratio; and (ii) spleen cells count on all observation days. Treatment of mice with SBL-1 before irradiation countered the radiation induced changes; the spleen/b.w. ratio; cell numbers (natural killer cells, macrophages and megakaryocytes) were not significantly (P≤0.05) different than the untreated controls at day 15. This study demonstrated that SBL-1 treatment before irradiation could restore the cellularity of spleen to near normal by day 15 and therefore was one of the important mechanisms of radioprotective action by SBL-1.