Boric acid as a protector against paclitaxel genotoxicity

Paclitaxel (PAC) is an anticancer drug used for treatments of breast, ovarian and lung cancers. However, little data is available in the literature on its potential genotoxicity on healthy human cells. On the other hand, boron deficiency and supplementation exert important biological effects in human and animal tissues. The biological effects of dietary boron are defined, but its interaction with PAC is not known for therapeutic uses. The aim of the present study was to determine whether boric acid (BA) confer a protection against PAC genotoxicity. After the application of PAC (10 or 20 mu g/l) and BA (2.5 or 5 mg/l), the genotoxic effects were assessed by sister chromatid exchange (SCE) and micronucleus (MN) tests in human blood cultures. We also analyzed nuclear division index (NDI) in peripheral lymphocytes. Our results showed that PAC significantly (P<0.05) increased the frequencies of SCEs and the formations of MNs in peripheral lymphocytes as compared to controls. PAC decreased the nuclear division index in lymphocyte cultures. Boric acid did not show cytotoxic or genotoxic effects at the concentrations tested. Furthermore, the PAC-induced increases in the genotoxicity and cytotoxicity indices were diminished by the addition of BA. The present study suggests for the first time that BA can prevent the genotoxicity of PAC on human lymphocytes.