Toxicity of a synthetic phenolic antioxidant, butyl hydroxytoluene (BHT), in vertebrate model zebrafish embryo ( Danio rerio )

Abstract

The synthetic antioxidant 3,5-di-tert-butyl-4-hydroxytoluene (BHT) is widely used as an additive in the food, cosmetic and plastic industries to increase the tenability of food and plastic for the past 70 years. BHT is degraded to 3,5-di-test-butyl-4-hydroxybenzaldehyde (BHT-CHO) in mammals, as well as in the natural environment such as in river and water. The average daily intake of BHT for human being is estimated to be 0.3 mg/kg body weight. Even though it is considered safe for human at authorized level, but its ubiquitous presence in the aquatic environment and the controversial toxicological data are of great concern for human as well as aquatic life. The experimental findings of zebrafish embryo toxicity test (ZFET) showed that the acute toxicity of 96-hr (LC50) exposure during the embryogenic stage was found to be 4.388 mg/L and the effective concentration (EC50) was 1.375 mg/L. The reduce heart rate from the sublethal concentrations indicates the chemical to be cardiotoxic but a further review is to be needed. The Teratogenic Index (TI) calculated to be 3.19, which implies the compound may be a potential teratogen in aquatic life. The findings obtained in this study will stretch more evidence regarding developmental toxicity of BHT, which will be of much importance in further risk assessment of ecotoxicological studies.