The aryloxyalkanoate dioxygenase-12 (AAD-12) protein is not acutely toxic in mice

Typically, when a protein is orally toxic, it acts via acute mechanisms, especially at high doses. Therefore, an acute oral toxicity study is considered appropriate for evaluating the safety of transgenic proteins. Soybean plants (events DAS-68416-4 and DAS-444 empty set6-6) have been genetically modified to express the aryloxyalkanoate dioxygenase-12 (AAD-12) protein. The AAD-12 protein provides tolerance to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). This paper summarizes the study designs of two acute oral toxicity studies evaluating the AAD-12 protein and reports the results of these studies. No mortalities or adverse effects were observed in mice when AAD-12 was tested up to a limit dose of 5000 mg/kg body weight. Based on the results of these studies, it can be concluded that AAD-12 protein, as expressed in genetically modified DAS-68416-4 and DAS-444 empty set6-6 soybeans, lacks acute toxicity via the oral route.