Safety evaluation of phytosterol esters. Part 3. Two-generation reproduction study in rats with phytosterol esters - a novel functional food

Phytosterol esters (PE) are intended for use as a novel food ingredient wit h plasma cholesterol lowering activity which works by inhibiting the absorp tion of cholesterol from the gut. Although PE are naturally present in the normal diet, the levels are insufficiently large to ensure lowering of plas ma cholesterol levels. Therefore PE may be added to spreads to achieve the desired cholesterol lowering activity. As part of an extensive programme of safely evaluation studies a two-generation reproduction study has been con ducted in Wistar rats, in which the possible effect of PE on male and femal e reproductive performance and on the growth and development of the offspri ng was studied. Rats were fed diets containing PE at levels of 0, 1.6, 3.2 and 8.1% (w/w) PE over two successive generations, and a wide range of repr oductive and developmental parameters, including sexual maturation paramete rs and oestrous cycle length, were determined. Macroscopic and microscopic examinations were conducted including a histological examination of selecte d organs from F-1- and F-2-weanlings and from F-0- and F-1-parental animals . Daily clinical observations did not reveal any unusual findings. In both generations, no effects of PE were observed on pup mortality (calculated on litter basis), precoital time, mating index, male and female fertility ind ex, female fecundity index, gestation index, duration of gestation, number of females with stillborn pups, post-implantation loss and pup development. Furthermore, PE had no effect on sexual maturation parameters (preputial s eparation and vaginal opening) and oestrous cycle length. In addition, ther e were no dose-related effects on selected organs following histological ex amination. In conclusion, dietary administration of up to 8.1% PE (equivale nt to a dose of 2.5 to 9.1 g PE/kg body weight/day, dependent on the period of the study) during two generations had no effect on reproduction of pare ntal F-0- and F-1-generation Wistar rats, nor on the development of the F-1 - and F-2-pups, nor on the sexual maturation of the F-1-weanlings. Therefor e, a nominal dietary PE concentration of 8.1% (equivalent to a dose of 2.5- 9.1 g PE/kg body weight/day or 1.54-5.62 g phytosterol/kg body weight/day d ependent on the period of the study) was considered to be the no-observed-a dverse-effect level following daily oral administration of PE for two succe ssive generations. (C) 1999 Elsevier Science Ltd. All rights reserved.