RECIPIENT-MEDIATED EFFECT OF A TRADITIONAL CHINESE HERBAL MEDICINE, REN-SHEN-YANG-RONG-TANG (JAPANESE NAME, NINJIN-YOUEI-TO), ON HEMATOPOIETIC RECOVERY FOLLOWING LETHAL IRRADIATION AND SYNGENEIC BONE-MARROW TRANSPLANTATION

Ren-shen-yang-rong-tang (Japanese name: Ninjin-youei-to, NYT), a traditional Chinese herbal medicine, was evaluated for recipient-mediated effect on hematopoietic recovery in a murine model of syngeneic bone marrow transplantation (BMT). BALB/c recipient mice were preconditioned with a lethal total body irradiation (TBI) at a dose of 6.5 Gy and transplanted with syngeneic bone marrow (BM) cells. NYT treatments, given intraperitoneally (i.p.) once per day for 3 consecutive days in a dose of 0.625 mg, were performed either before or after TBI and BMT to assess any recipient-mediated effect of this compound. NYT pretreatment was effective as NYT posttreatment in enhancing the total number of colony-forming unit erythroid (CFU-E) and colony-forming unit granulocyte-macrophage (CFU-GM) per marrow and spleen after TBI and BMT. NYT pretreatment caused a significant increase in marrow and splenic CFU-E and CFU-GM numbers over a prolonged period following TBI and BMT, and affected late-stage erythropoiesis (CFU-E) more profoundly than early-stage erythropoiesis (burst-forming unit erythroid, BFU-E). NYT pretreatment significantly accelerate recovery of not only erythrocyte and leukocyte counts but also platelet counts after transplantation with a limited number (1 X 10(5)) of BM cells. The same treatment, however, was significantly less effective in hematopoietic recovery after transplantation with a minimal number (1 X 10(4)) of BM cells, indicating that NYT accelerates recovery of donor-derived rather than recipient-derived cells. The data are consistent with the idea that NYT has an enhancing effect on hematopoiesis via the recipient microenvironment, and suggest that NYT may have an important role in the acceleration of hematopoietic recovery of donor-derived cells following BMT.