Effects of rosmarinic acid against aflatoxin B1 and ochratoxin-A-induced cell damage in a human hepatoma cell line (Hep G2)

Recent findings have suggested that oxidative damage might contribute to the cytotoxicity and carcinogenicity of aflatoxin B1 (AFB1). The induction of oxidative stress also plays an important role in the toxicity of another mycotoxin: ochratoxin A (OTA). In this study, the protective effect of rosmarinic acid (Ros A) against AFB1 and OTA‐induced cytotoxicity was investigated in a human hepatoma‐derived cell line (Hep G2). Rosmarinic acid, a natural phenolic compound contained in many Lamiaceae herbs such as Perilla frutescens, sage, basil and mint, inhibits complement‐dependent inflammatory processes and may have therapeutic potential. The ability of Ros A to reduce radical oxygen species (ROS) production, protein and DNA synthesis inhibition and apoptosis caused by the two mycotoxins was also investigated. Our experiments proved the significant cytoprotective effect of Ros A in vitro from OTA‐ and AFB1‐induced cell damage. In particular, 24‐h pretreatment with 50 µM Ros A inhibited the cytotoxicity of 10 µM AFB1 (by 45%) and 10 µM OTA (by 35%) in Hep G2 cells (P < 0.001). Moreover, Ros A dose dependently attenuated ROS production and DNA and protein synthesis inhibition induced by both of the toxins. Similarly, apoptosis cell death was prevented, as demonstrated by reduction of DNA fragmentation and inhibition of caspase‐3 activation (P < 0.001). Copyright © 2004 John Wiley & Sons, Ltd.