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.

BACKGROUND AND PURPOSE: 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, determine whether it induces nerve cell damage in susceptible brain structures and identify the mechanism of its action in the CNS.

EXPERIMENTAL APPROACH: 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 was assayed in the brain and peripheral tissues. In brain structures, selected markers of brain damage were measured.

KEY RESULTS: The study showed that BP-3 is absorbed through the rat skin, passes through the blood-brain barrier. 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.

CONCLUSIONS AND IMPLICATIONS: 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.