Benzophenone-3 passes through the blood-brain barrier, increases the level of extracellular glutamate and induces apoptotic processes in the hippocampus and frontal cortex of rats.

Benzophenone-3 is the most commonly used UV filter. It is well absorbed through the skin and gastrointestinal tract. Its best-known side effect is the impact on the function of sex hormones. Little is known about the influence of BP-3 on the brain. The aim of this study was to show whether BP-3 crosses the blood-brain barrier (BBB), to determine whether it induces nerve cell damage in susceptible brain structures, and to identify the mechanism of its action in the central nervous system. BP-3 was administered dermally during the prenatal period and adulthood to rats. BP-3 effect on short-term and spatial memory was determined by novel object and novel location recognition tests. BP-3 concentrations were assayed in the brain and peripheral tissues. In brain structures, selected markers of brain damage were measured. The study showed that BP-3 is absorbed through the rat skin, passes through the BBB. BP-3 raised oxidative stress and induced apoptosis in the brain. BP-3 increased the concentration of extracellular glutamate in examined brain structures and changed the expression of glutamate transporters. BP-3 had no effect on short-term memory but impaired spatial memory. The present study showed that dermal BP-3 exposure may cause damage to neurons what might be associated with the increase in the level of extracellular glutamate, most likely evoked by changes in the expression of GLT-1 and xCT glutamate transporters. Thus, exposure to BP-3 may be one of the causes that increase the risk of developing neurodegenerative diseases.