LACK OF GENOTOXIC EFFECTS OF SUCROSE ACETATE ISOBUTYRATE (SAIB)

Sucrose acetate isobutyrate (SAIB) was tested for potential genotoxic activity in four different in vitro assay systems. Two independent tri als of a Salmonella reverse mutation Essay (using strains TA98, TA100, TA1535, TA1537 and TA1538) showed no increases in revertant frequenci es at doses up to 10,000 mu g/plate which was non-toxic but exceeded t he solubility limit. Similarly, no mutagenic response was observed at doses up to 1000 mu g/ml at the HGPRT locus in cultured CHO cells; SAI B was toxic and its solubility limit was exceeded at 50 mu g/ml. No cl astogenic activity was detected in cultured CHO cells at concentration s up to 2000 mu g/ml. All three preceding in vitro tests were conducte d both in the presence and absence of Aroclor 1254-induced rat liver S -9 metabolic activation systems. An unscheduled DNA synthesis assay al so was performed using rat primary hepatocyte cultures with doses up t o 1000 mu g/ml, and no DNA repair was detectable. Thus, SAIB was strin gently tested at doses exceeding the solubility limit in culture mediu m and causing toxicity to CHO cells without obtaining any evidence for genotoxic activity as a mutagen, clastogen, or DNA-damaging agent. (C ) 1998 Elsevier Science Ltd. All rights reserved.