Approaches to ablating the myelotoxicity of chemotherapy

Protective effect of (+)-catechin against 5-fluorouracil-induced myelosuppression in mice

The object of this study was to investigate the efficacy of (+)-catechin, which was isolated from Actinidia arguta Planch (Actinidiaceae), as a bone marrow cell proliferation-promoting compound against the hematotoxicity of 5-fluorouracil (5-FU) in mice. Intraperitoneally injected (+)-catechin (1 and 10 mg/kg per day) accelerated the recovery of the number of white blood cells (WBC) and platelets (PLT) but did not affect the number of circulating red blood cells (RBC). (+)-Catechin also augmented the number of myelocytes and splenocytes. Dual color flow cytometric analysis revealed that (+)-catechin reversed the reduction of the population of leukocytes (CD11b+ monocytes, Gr-1+ granulocytes and CD3+ T and CD45RA+ B lymphocytes) in whole blood, spleen and bone marrow caused by 5-FU. (+)-Catechin (1 and 10 mg/kg per day) showed remarkable recovery of Gr-1+ cells in all three types of tissues and of CD11b+ cells in the bone marrow cells. These findings suggest that (+)-catechin selectively enhances the recovery of the population of granulocytes reduced by 5-FU in mice.

Bone marrow protection with amifostine in the treatment of high-risk malignant lymphoma

Based on preclinical and clinical studies which suggested that amifostine can protect against haematological toxicity of cyclophosphamide, we conducted a clinical trial of amifostine and intermediate doses of cyclophosphamide in patients with high-risk malignant lymphoma. 40 patients were enrolled to receive amifostine (910 mg/m2) before cyclophosphamide (1500 mg/m2) for two cycles (10 patients); 20 patients were allocated to receive amifostine/cyclophosphamide only on one cycle (patients were their own control) and 10 patients received cyclophosphamide alone without amifostine protection. Patients who received amifostine had fewer days of severe granulocytopenia (grade III or IV) and infectious episodes, and delay on treatment was minimal. Amifostine was well tolerated; only 2 patients developed transient and mild hypotension. The complete response rate was 72% (29/40). We conclude that amifostine is a good protector against haematological toxicity of cyclophosphamide and did not interfere with tumour response. Clinical trials with increasing doses of cytotoxic drugs or combination chemotherapy are needed to define the role of this myeloprotector agent in the treatment of patients with malignant lymphoma.