Teratogenicity and brain aromatase-induction of monosodium glutamate in estrogen-responsive mosaic transgenic zebra fish Danio rerio

Abstract

Monosodium glutamate (MSG) has been used as a flavor enhancer for decades. It has various teratogenicity effects on tested animals but has not been examined in zebra fish model to date. This experiment was conducted to study the teratogenic effects of MSG on wild-type zebra fish embryos and also to study the estrogenic potential of MSG on the transient zebrafish embryos with a brain aromatase-based reporter gene. Different concentrations of MSG (0, 10, 50 and 100 μg/ml) were tested. Wild-type and transient embryos were exposed to the solutions at about 2 h post fertilization (hpf). Hatching and survival decreased in all treatments with significant difference (p < 0.05) at 50 and 100 μg/ml concentrations with control. Stunted skeletal structure was observed at 100 μg/ml treatment. At 96 hpf, MSG induced enhanced green fluorescence protein (EGFP) expression in the olfactory bulb at 100 μg/ml treatment. Various malformations were found in all treatments. The current results demonstrate that MSG or MSG-containing foods may harm the human offspring if they take it in a high dose. MSG in high concentration may disrupt the endocrine function. Zebra fish embryo with a brain aromatase-based reporter gene is a good model for the detection of estrogenic potential of any controversial chemical.

Keywords: Monosodium glutamate (MSG), teratogenicity, aromatase, embryos, zebra fish