Protective effects of dietary fibre against manganese-induced neurobehavioral aberrations in rats

We tested the hypothesis that dietary fi bre (DF) has protective effects against manganese (Mn)-induced neurotoxicity. Forty-eight one-month old Sprague-Dawley rats were randomly divided into six groups: control, 16 % DF, Mn (50 mg kg-1 body weight), Mn+ 4 % DF, Mn+ 8 % DF, and Mn+ 16 % DF. After oral administration of Mn (as MnCl2) by intragastric tube during one month, we determined Mn concentrations in the blood, liver, cerebral cortex, and stool and tested neurobehavioral functions. Administration of Mn was associated with increased Mn concentration in the blood, liver, and cerebral cortex and increased Mn excretion in the stool. Aberrations in neurobehavioral performance included increases in escape latency and number of errors and decrease in step-down latency. Irrespective of the applied dose, the addition of DF in forage decreased tissue Mn concentrations and increased Mn excretion rate in the stool by 20 % to 35 %. All neurobehavioral aberrations were also improved. Our fi ndings show that oral exposure to Mn may cause neurobehavioral abnormalities in adult rats that could be effi ciently alleviated by concomitant supplementation of DF in animal feed.