Administration of riboflavin improves behavioral outcome and reduces edema formation and glial fibrillary acidic protein expression after traumatic brain injury

Previous studies have shown that administration of riboflavin, vitamin B-2, significantly reduced edema formation following experimental stroke. The present study evaluated the ability of B-2 to improve behavioral function, reduce edema formation, and limit glial fibrillary acidic protein (GFAP) expression following frontal cortex contusion injury. Groups of rats were assigned to B-2 (7.5 mg/kg) or saline (1.0 ml/kg) treatment conditions and received contusion injuries or sham procedures. Drug treatment was administered 15 min and 24 h following injury. Rats were examined on a variety of tests to measure sensorimotor performance (bilateral tactile removal test), and cognitive ability (acquisition of reference and working memory) in the Morris water maze. Administration of B-2 following injury significantly reduced the behavioral impairments observed on the bilateral tactile removal test and improved the acquisition of both reference and working memory tests compared to saline-treated rats. The lesion analysis showed that B-2 reduced the size of the lesion. Examination of GFAP expression around the lesion revealed that B-2 significantly reduced the number of GFAP(+) astrocytes. Edema formation following injury was also significantly reduced by B-2 administration. These findings are the first to show that B-2 administration significantly improved behavioral outcome and reduced lesion volume, edema formation, and the expression of GFAP following traumatic brain injury. These findings suggest that B-2 may have therapeutic potential for the treatment of TBI.