Investigations into the genotoxic potential of olive extracts

Publication date: Available online 8 November 2014 Source:Mutation Research/Genetic Toxicology and Environmental Mutagenesis Author(s): David Kirkland , James Edwards , Tina Woehrle , Paul Beilstein The phenolic anti-oxidant 3-hydroxytyrosol (HT) is a major constituent of olives and olive oil. Published data showed it was negative in the Ames test at concentrations up to 5μL per plate, but did induce chromosomal aberrations in human lymphocytes. HIDROX, an olive extract containing approximately 2.4% HT, was reported as both positive and equivocal in an Ames test in different papers from the same laboratory. Negative results for micronucleus induction in vivo in both an acute study and as part of a 90-day rat toxicity study were also reported for HIDROX. Given the widespread use and consumption of olives, olive oil and olive extracts, it was important to obtain more data. Here we confirm that pure HT, and an olive extract containing 15% HT, both induced micronuclei in cultured cells in vitro, but show that these responses were either due to high levels of cytotoxicity or to reaction of HT with culture medium components to produce hydrogen peroxide. Another extract (H40) containing 40% HT also induced micronuclei in vitro, probably via the same mechanism. However, both extracts were negative in robust Ames tests. The 15% HT formulated extract did not induce micronuclei in rat bone marrow after 4 weeks of dosing up to 561mg HT/kg/day. H40 produced increased rat bone mar...
Source: Mutation Research Genetic Toxicology and Environmental Mutagenesis - Category: Genetics & Stem Cells Source Type: research