Is the commonly used UV filter benzophenone-3 a risk factor for the nervous system?

ABSTRACT

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone, oxybenzone, or BP-3) is one of the most frequently used UV radiation absorbents, which are commonly referred to as sunscreen filters. Its widespread use in industrial applications provides protection against the photodegradation of a wide range of products but at the same time creates the risk of human exposure to benzophenone-3 unbeknownst to the individuals exposed. Topically applied benzophenone-3 penetrates individual skin layers, enters the bloodstream, and is excreted in the urine. In addition, benzophenone-3 easily crosses the placental barrier, which creates the risk of exposure to this substance in the prenatal period. Despite the widespread use and occurrence of benzophenone-3 in the human environment, little knowledge of the mechanisms underlying the effect of benzophenone-3 on the nervous system was available until recently. Only the most recent research, including studies by our group, has enabled the identification of new molecular mechanisms through which benzophenone-3 affects embryonic neuronal cells and the developing mammalian brain. Benzophenone-3 has been shown to induce neurotoxicity and apoptotic processes and inhibit autophagy in embryonic neuronal cells. Benzophenone-3 also alters expression and impairs function of receptors necessary for the proper development and function of the nervous system. The most worrying finding seems to be that benzophenone-3 contributes to an increased risk of developmental abnormalities and/or epigenetically based degeneration of neuronal cells by changing the epigenetic status of neuronal cells.