Teratology studies on food colourings. Part II. Embryotoxicity of R salt and metabolites of amaranth (FD & C red no. 2) in rats

Abstract

Two metabolites (sodium naphthionate and the R-amino salt) and one intermediate (R salt) of the red dye, amaranth (FD & C Red No. 2), were tested for their effects on rat reproductive processes and progeny development. Dose levels of 15, 30, 100 or 200 mg/kg/day were administered by stomach tube to Osborne-Mendel females during days 0–19 of pregnancy. No adverse clinical signs were observed in any dams, and no adverse effects on implantation were observed after treatment with any compound. A significant increase in the number of litters with multiple resorptions followed treatment with R salt at the 100 and 200 mg/kg dose levels and with sodium naphthionate at 200 mg/kg. The number of offspring with skeletal, sternebral or soft-tissue abnormalities was not dose-related with any of the compounds. Sodium naphthionate at the 100 mg/kg dose level produced a significant increase in the percentage of foetuses with sternebral abnormalities, but did not affect the incidence of soft-tissue abnormalities at any dose level. R-amino salt at 200 mg/kg significantly increased the incidence of litters with one or more foetuses bearing skeletal abnormalities, but did not increase sternebral or soft-tissue abnormalities. The R salt did not affect skeletal, sternebral or soft-tissue development.