The in vitro enzyme-inducing and cytotoxic properties of South African laboratory animal contact bedding and nesting materials.

Enzyme-inducing and cytotoxic effects of South African bedding materials were investigated using a mouse hepatoma cell line, Hepa-1, cell culture system. This cell culture system is a convenient and sensitive method for the screening of bedding materials for the presence of compounds that could be potentially harmful to animals and thus the experimental outcome. Cells were exposed to acetone extracts of the different materials or their components. Corn cobs displayed very little or no CYP1A1-inducing or cytotoxic effects, whilst vermiculite and unbleached pulp from pine and eucalyptus showed greater induction and cytotoxic properties. The latter properties were lower than those produced by the different recycled paper extracts. Pine shavings (Pinus elliottii) and the different wood components making up industrial sawdust expressed the highest cytotoxic and CYP1A1-inducing properties.