The genotoxic potential of GutGard® was evaluated in bacterial reverse mutation test, chromosome aberration (CA) test and micronucleus (MN) test. Study was carried out in compliance with the Test Guidelines of the Organization for Economic Cooperation and Development.
Bacterial reverse mutation test (Ames II™ tests)
Ames II™ tests determine the ability of test substance to induce the reversion of histidine auxotrophy to prototrophy.
GutGard® did not induce significant number of revertant colonies in two bacterial strains (TA98 and TAMix) both in the presence and absence of metabolic activation. Positive controls, 2-NF (2-Nitrofluorene) and 4-NQO (4-Nitroquinoline-N-oxide) significantly amplified the number of histidine revertants in the absence of metabolic activation. The Ames II™ test for GutGard® was negative.
In vitro chromosome aberration analysis in CHO-K1 cells
Clastogenic effect of GutGard® was evaluated using mammalian chromosome aberration test using Chinese Hamster Ovary (CHO-K1) cells.
GutGard® both in presence and absence of S9-mix did not induce significant number of structural chromosomal aberrations. The chromosome aberration test for Gutgard® was negative.
In vitro micronucleus analysis in CHO-K1 cells
Micronucleus analysis revealed that GutGard® did not produce significant aneugenic activity after treatment with any of the tested concentrations when compared to the concurrent vehicle control cells (p < 0.05) both with and without metabolic activation. The micronucleus analysis test for GutGard® was negative.
Reference: Chandrasekaran CV et al., Regulatory Toxicology and Pharmacology 2011; 61:373-380.