Abstract
The potential toxicity of enzymatically modified isoquercitrin (EMI) was investigated in groups of 10 F344 rats of each sex given powdered diet containing the compound at 0.3, 0.625, 1.25 or 2.5 % for 13 weeks. Additionally, 10 rats of each sex in 0 and 2.5% satellite groups further received basal diet in a recovery period from weeks 14 to 17. No treatment-related effects were noted regarding clinical signs, survival rate, food consumption, food efficiency, ophthalmology and organ weights. Parameters that showed alteration with EMI treatment included the following; decreased body weight gain in both sexes given 2.5%, increased urinary ketones in the 2.5% males, yellow or yellow-brown discoloration of the urine in both sexes of all EMI-treated groups, mild increased reticulocyte count in the 0.625 and 1.25% females and 0.625 and 2.5% males, mild increased serum γ-GTP in all EMI-treated females and the 1.25 and 2.5% males, mild increased BUN levels in the 1.25 and 2.5% males, yellow coloration of the bone (femur and/or cranium) in the 1.25 and 2.5% females and 0.625, 1.25 and 2.5% males, and a decreased incidence of renal calcification in the 0.625, 1.25 and 2.5% females. Of these, decreased body weight gain in the 2.5% males, increased urinary ketones in the 2.5% males, yellow or yellow-brown discoloration of the urine, increased reticulocytes, increased serum γ-GTP in the females and increased serum BUN had returned to be normal ranges after a 4-week recovery period. In conclusion, the present investigation demonstrated that parameters showed alteration with EMI treatment were negligible for a toxicological significance or returnable to normal ranges. The results indicated the no observed adverse effects level for 13 weeks dietary treatment with EMI to be 0.3% for both male (188mg/kg/day) and female rats (190mg/kg/day).
