Treatment of chemotherapy-induced leukopenia in a rat model with aqueous extract from Uncaria tomentosa

The Uncaria tomentosa water extracts (C-Med-100(R)) depleted of indole alkaloids (< 0.05%, w/w) have been shown to induce apoptosis and inhibit proliferation in tumor cells in vitro and to enhance DNA repair, mitogenic response and white blood cells in vivo. In this study, the effect of C-Med-100(R) in the treatment of chemically induced leukopenia was evaluated in a rat model. W/Fu rats were treated first with doxorubicin (DXR) 2 mg/kg x 3 (i.p. injection at 24 hour-intervals) to induce leukopenia. Twenty-four hours after the last DXR treatment, the rats were daily gavaged with C-Med-100(R) for 16 consecutive days. As a positive control, Neupogen(R), a granulocyte colony stimulator was also administered by subcutaneous injection at a dose of 5 and 10 mu g/ml for 10 consecutive days. The results showed that both C-Med-100(R) and Neupogen(R) treatment groups recovered significantly sooner (p < 0.05 by Duncan test) than DXR group. However, the recovery by C-Med-100(R) treatment was a more natural process than Neupogen(R) because all fractions of white blood cells were proportionally increased while Neupogeno(R) mainly elevated the neutrophil cells. These results were also confirmed by microscopic examination of the blood smears. The mechanism of the C-Med-100(R) effect on WBC is not known but other data showing enhanced effects on DNA repair and immune cell proliferative response support a general immune enhancement.