Chemoprotective properties of rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia) herbal and green and black (Camellia sinensis) teas against cancer promotion induced by fumonisin B-1 in rat liver

The chemoprotective properties of unfermented and fermented rooibos (Aspolathus linearis) and honeybush (Cyclopia intermedia) herbal teas, and green and black teas (Camellia sinensis) were investigated against fumonisin B-1 (FB1) promotion in rat liver utilizing diethylnitrosamine (DEN) as cancer initiator. The various teas differently affected the clinical chemical parameters associated with liver and kidney damage associated with FBI suggesting specific FB1/iron/polyphenolic interactions. Green tea enhanced (P < 0.05) the FB1-induced reduction of the oxygen radical absorbance capacity, while fermented herbal teas and unfermented honeybush significantly (P < 0.05) decreased FB1-induced lipid peroxidation in the liver. The teas exhibited varying effects on FBI-induced changes in the activities of catalase, glutathione peroxidase (GPx) glutathione reductase (GR) as well as the glutathione (GSH) status. Unfermented rooibos and honeybush significantly (P < 0.05) to marginally (P < 0.1) reduced the total number of foci (>10 mu m), respectively, while all the teas reduced the relative amount of the larger foci. Fermentation seems to reduce the protective effect of the herbal teas. Differences in the major polyphenolic components and certain FB1/polyphenolic/tissue interactions may explain the varying effects of the different teas on the oxidative parameters, hepatotoxic effects and cancer promotion in rat liver. (C) 2008 Elsevier Ltd. All rights reserved.