Acute and Subchronic Oral Toxicity Study of Gardenia Yellow E500 in Sprague-Dawley Rats.

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.