Protective effects of beta-glucan extracted from barley against benzo[a]pyrene-induced DNA damage in hepatic cell HepG2

The aim of the present study was to assess the genotoxic and antigenotoxic effect of beta-glucan (BG) extracted from barley. The genotoxicity of BG was tested in the single-cell gel electrophoresis assays (SCGE)/HepG2 test system. Moreover. the protective effects of BG against the genotoxicity of B[a]P were studied to delineate its mechanism of antigenotoxicity using four different treatment protocols - pre-treatment, simultaneous simple, simultaneous with pre-incubation. and post-treatment. The results showed that the compound itself was devoid of mutagenic activity at the three lower concentrations studied (1, 5, and 25 mu g/mL) however, genotoxic and cytotoxic effects were seen at 100 and 200 mu g/mL, respectively. In combination experiments with B[a]P, pronounced inhibition of DNA Migration in the SCGE assay was observed in the two simultaneous treatments, and a smaller reduction was observed in the two other treatments. Thus, the data suggest that BG acts through binding to the genotoxic compound or capturing free radicals produced during its activation. However, the protective effects observed with pre-treatment and post-treatment suggest that the BG may be modulating cell metabolism. (C) 2008 Elsevier GmbH. All rights reserved.