Therapeutic effects of Lycium barbarum polysaccharide (LBP) on irradiation or chemotherapy-induced myelosuppressive mice.

OBJECTIVE

The aim of this study was to investigate the effects of Lycium barbarum polysaccharide (LBP) on irradiation- or chemotherapy-induced myelosuppressive mice and cultured peripheral blood mononuclear cells (PBMCs).

METHODS

In an in vivo experiment, mice were irradiated with a sublethal dose of 550 cGy X-ray or intraperitoneally (i.p.) injected with carboplatin (CB) 125 mg/kg to produce severe myelosuppression. Four to 6 hours after the irradiation or injection, mice were subcutaneously (s.c.) injected with LBP (50, 100, and 200 mg/kg) daily from day 0 to day 6. Blood samples were collected from the tail veins of mice at different time points, and peripheral white blood cells (WBC), red blood cells (RBC), and platelet (PLT) counts were monitored. In an in vitro experiment, human PBMCs were incubated with LBP at different concentrations in combination with phytohemagglutinin (PHA), and the production of granulocyte colony-stimulating factor (G-CSF) was tested.

RESULTS

Compared to the control, 50 mg/kg LBP (LBP-L) significantly ameliorated the decrease of peripheral WBC of irradiated myelosuppressive mice on day 13, and 100 mg/kg LBP (LBP-M) did the same on days 17 and 21. All dosages of LBP significantly ameliorated the decrease of peripheral RBC of irradiated myelosuppressive mice on days 17 and 25. Two-hundred mg/kg LBP (LBP-H) and LBP-M significantly enhanced peripheral PLT counts of irradiated myelosuppressive mice on days 10, 13, 17, and 21, as did LBP-L on days 13 and 17. All dosages of LBP increased peripheral WBC counts of chemotherapy-induced myelosuppressive mice to some extent, but there was no statistic difference when compared to the control. LBP-H significantly ameliorated the decrease of peripheral RBC of chemotherapy-induced myelosuppressive mice on days 13, 15, 17, and 20, and LBP-M and LBP-L did the same on days 15 and 17. All dosages of LBP significantly enhanced peripheral PLT counts of chemotherapy-induced myelosuppressive mice on days 7 and 10, as did LBP-H on days 13, 15, and 17, and LBP-M on days 13 and 15. Also, LBP could obviously stimulate human PBMCs to produce G-CSF.

CONCLUSIONS

LBP promoted the peripheral blood recovery of irradiation or chemotherapy-induced myelosuppressive mice, and the effects may be the result of the stimulation of PBMCs to produce G-CSF.