Genotoxicity testing chromosomal mutations

Data indicate butyric acid is not genotoxic. Negative results were observed in assays assessing for both mutations (Ames test) and chromosomal aberrations. 

Because the liver is the major organ of xenobiotic metabolism, hepatocytes are an appropriate cell in which to conduct genotoxicity tests. Because they do not divide readily in culture, they are not so useful in tests for chromosomal aberrations or mutations, but they can be used to detect DNA damage or repair where dividing cells are not needed. In studies with fresh hepatocytes, it is not necessary to include S9 mix. 

Genotoxicity tests were performed with senna fruit, senna leaf extract, sennosides, rhein, and aloe-emodin. Senna fruit, sennosides, and rhein did not increase mutation frequencies in the following test systems bacterial systems, mammalian cell culture tests, mouse lymphoma test, chromosome aberration test with Chinese hamster ovary (CHO) cells, bone marrow micronucleus test, chromosome aberration tests, and melanoblast cell test. With aloe-emodin, mutagenic effects were observed only in vitro in the chromosome aberration test with CHO cells and in the Salmonella reverse mutation test. In the in vitro gene mutation test with V79 cells, no mutagenic potential of aloe-emodin was observed. In vivo studies indicated no mutagenic activity of aloe-emodin, and aloe-emodin did not induce unscheduled DNA synthesis in an ex vivo assay performed with hepato-cytes of male rats (Heidemann et al. 1993). 

Genotoxicity testing evaluates the test article s ability to cause damage to DNA, genes, and chromosomes. Because of this, genotoxicity testing is performed as a battery, which typically consists of a bacterial reverse mutation assay, also known as the Ames assay, a mouse micronucleus test, and a mouse lymphoma or chromosomal aberration test. 

Literature reports iadicate that sodium sorbate causes weak genotoxic effects such as chromosomal aberrations and mutations ia mammalian cells (172,173). This effect is thought to be caused by oxidative products of sodium sorbate ia stored solutions (173—175). The main oxidation product of sodium sorbate, 4,5-oxohexenoate, is mutagenic ia a Salmonella mammahan-microsome test (176). Sorbic acid and potassium sorbate were not genotoxic under the same test procedures (167,172,174—177). 

Genotoxicity studies are required to identify compounds that can induce genetic damage ranging from single point gene mutations to gross alterations of chromosomal structure. Such effects are taken as indicative of the potential to cause cancer or heritable defects in humans. A standard battery of three types of test is recommended ... 

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