Objective: This study was conducted to evaluate the acute and subchronic toxicity of gardenia yellow, a natural colorant widely used in China and other Asian countries. An acute toxicity test was performed in S-D rats of both genders and the lethal dose (LD₅₀) of per oral gardenia yellow was estimated to be more than 15.0 g/kg·bw. In the subchronic study, gardenia yellow was orally administered to rats by gavage at doses of 0, 0.50, 1.50 and 4.50 g/kg·bw/day for 90 days followed by a recovery period of 28 days. No appreciable toxic-related changes were observed in the 0.50 g/kg·bw/day group. When the animals received gardenia yellow at 1.50 g/kg·bw/day or more, body weight loss was observed, and pigments began to deposit in several vital organs, resulting in significant changes of several hematological and biochemical indicators related to the nutritional status of the body, liver and kidney function, more severe in the high dose group. In the recovery period, the alterations of the clinical symptoms and parameters were relieved a lot. Based on the results of the current study, the no observed adverse effect level (NOAEL) of gardenia yellow E500 in rats was set to be 0.50 g/kg·bw/day.

(1) Background: a hybrid black rice rich in β-carotene carrying the psy and crtI genes (HJM) was evaluated in Wistar rats by a 90-day feeding study, aiming to assess its dietary safety. (2) Methods: the HJM rice and its parental line HS were included in rats’ diets at levels of 73.5% and 75.5%, respectively. The AIN-93 diet was administered as a nutritional control. No adverse effects on animal behavior or weight gain were observed during the study. Blood samples were collected and analyzed, and standard hematological and biochemical parameters were compared. (3) Results: Some parameters were found to be significantly different, though they remained within the normal range for rats of this breed and age. In addition, upon sacrifice, various organs were weighed, and macroscopic and histopathological examinations were performed, with only minor changes to report. (4) Conclusions: HJM rice exhibited no adverse or toxic effects in Wistar rats in this 90-day study.

The aim of the current study was to evaluate the subchronic toxicity of GmDREB3 gene modified wheat in the third generation rats. SPF Wistar rats were fed with transgenic wheat diet (Gm), parental wheat diet (Jimai22) and AIN-93 rodent diet (Control), respectively, for two generations, to produce the third generation rats which were used for this study. The selected fresh weaned offspring rats (20/sex/group) were given the same diet as their parents for 13 weeks. No toxicity-related changes were observed in rats fed with Gm diet in the following respects: clinical signs, body weights, body weight gains, food consumption, food utilization rate, urinalysis, hematology, serum biochemistry and histopathology. The results from the present study demonstrated that 13 weeks consumption of Gm wheat did not cause any adverse effects in the third generation rats when compared with the corresponding Jimai22 wheat.