Safety assessment of DHA-rich microalgae from Schizochytrium sp.: III.: Single-generation rat reproduction study

Schizochytrium sp. dried microalgae (DRM) contains oil rich in highly unsaturated fatty acids (PUFAs). Docosahexaenoic acid (DHA n-3) is the most abundant PUFA component of the oil. DHA-rich oil extracted from Schizochytrium sp. is intended for use as a nutritional ingredient in foods. As part of a comprehensive safety assessment program, the reproductive toxicity of DRM was examined in Sprague-Dawley-derived rats Crl:CD(SD)BR (30/sex/group) provided DRM in the diet at concentrations of 0, 0.6, 6.0, and 30%. These dietary levels corresponded to overall average dosages of approximately 400, 3900, and 17,800 mg/kg/day for F-0 males (premating) and 480, 4,600, and 20,700 mg/kg/day for F-0 females, respectively. Prior to mating, males and females of the F-0 generation were treated for 10 and 2 weeks, respectively. Treatment of males continued throughout mating and until termination (approximately 3 weeks after mating). Treatment of the females was continued throughout gestation and through lactation day 21. The females were killed after raising their young to weaning at 21 days of age. Food consumption was measured weekly throughout the study (except during mating) and body weights were recorded at least weekly during premating, gestation, and lactation. Reproductive parameters including estrus cycle duration, mating performance, fertility, gestation length, parturition, and gestation index were evaluated. Litter size and offspring body weights were recorded, offspring viability indices were calculated, and physical development (vaginal opening and preputial separation) was assessed for the F-1 generation. All adult F-0 and F-1 animals were subjected to a detailed necropsy DRM treatment had no effect on estrus cycles or reproductive performance including mating performance, fertility, gestation length, parturition, or gestation index. Litter size, sex ratio, and offspring viability indices were similarly unaffected and there were no effects of DRM treatment on the physical development of F-1 animals. (C) 2001 Academic Press.