Difference in the effects of radioprotection between aerial and root parts of Lycium chinense

Radiation protection from bone marrow death by consecutive injections of crude extracts from different parts of Lycium chinense (LC), root (LCR) and aerial part (LCA), before whole body X-irradiation was confirmed by tests with ICR strain mice. Both extracts were effective after intraperitoneal injection of a high dose, once a day, for seven consecutive days before irradiation. Based on the studies of endogenous hematopoietic spleen colony formation (CFUs), and the postirradiation behavior of hematograms and hematocrits, it was demonstrated that the LCR protects mice more effective when given in a dose of 500 mg/kg. Enhanced CFUs was found in the irradiation range of 4-8 Gy by various treatments. Recovery of leukocyte, erythrocyte and thrombocyte counts was significantly stimulated by the extract of LCR with 500 mg/kg administration. Stimulated recovery by the extract from the LCR was also observed in hematocrit. On the contrary, the extracts of both LCA and LCR did not markedly affect recovery of leukocyte, erythrocyte, thrombocyte counts and hematocrits by 250 mg/kg administration. It could be deduced that the uncertainly radioprotective action is induced by a possible process of enhanced regeneration of the hematopoietic stem cells due to either enhanced postirradiation repair or an increased proliferation of the hematopoietic stem cells under the suitable extract administration. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.