Safety evaluation of ice-structuring protein (ISP) type III HPLC 12 preparation. Lack of genotoxicity and subchronic toxicity

Ice-structuring proteins (ISPs) naturally occur in a range of species (including edible plants and fish) that need to protect themselves against freeze damage. ISPs have potential applications in a number of areas including cryopreservation and frozen foods manufacture. However, these materials are not currently generally available for commercial use. ISP type III HPLC 12 is of particular interest and although it is likely to be consumed naturally, its toxicological safety has not previously been assessed. This paper presents data from a set of in vitro and in vivo genotoxicity assays (bacterial mutation, chromosome aberration, mammalian cell gene mutation and rat bone marrow micronucleus) and a 3-month repeat-dose gavage study in the rat using high levels of ISP type III HPLC 12 preparation produced by recombinant bakerʹs yeast. No evidence was seen of a genotoxic potential (using levels accepted as limit concentrations for the assays used) or notable subchronic toxicity following oral administration for 3 months in the rat at up to 580 mg ISP type III HPLC 12/kg/day, the highest dose tested (which was considered to be a NOAEL).