Species-specific toxicity of aristolochic acid (AA) in vitro

Differences in toxicity and carcinogenicity of the nephrotoxic compound aristolochic acid between rodents and humans suggest a species-dependent mechanism of action. The goal of this study was to investigate constitutive differences in the susceptibility of renal cortex cells originating from human, rat and porcine origin in vitro. Effects of 24 and 48 h AA exposure on cell number and MTT reduction were studied. Furthermore, using the effective concentrations causing 20 and 50% reduction (cell number), cell cycle, 3H-thymidine incorporation and DNA damage analyses were conducted. AA cytotoxicity was observed in all cell types in a time- and concentration dependent manner with species-specific differences, with porcine cells being the most sensitive. AA had a comparable effect on the cell cycle in primary human and porcine cells and the rat NRK-52E cell line following 48 h exposure, also corroborated by the reduced 3H-thymidine incorporation in NRK-52E cells. In addition, DNA unwinding, suggestive of enhanced DNA damage, was observed in primary porcine cells. These results provide an initial insight into the sensitivity and suitability of different in vitro-systems and suggest that primary porcine renal cortex cells could be a valuable in vitro-system to study AA toxicity.