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

Abstract

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 MnCl 2 ) 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. KEY WORDS: escape latency, neurobehavioral test performance, number of errors, oral exposure, stepdown latency Shi X-Q, et al. EFFECT OF DIETARY FIBRE ON MANGANESE

The History, Status, Gaps, and Future Directions of Neurotoxicology in China

“…Manganese also adversely affected astrocytes ( Deng et al 2011 ; Fan X et al 2010 ); activated microglia ( Zhao et al 2009 ); increased tau hyperphosphorylation and α-synuclein expression ( Cai et al 2010 , 2011 ); increased extracellular glutamate and inhibited expression of its N -methyl-D-aspartate (NMDA) receptor subunits in rat striatum ( Xu B et al 2010 ); increased [Ca2+] ( Xu et al 2009 ); induced p21 expression ( Zhao et al 2012b ); and disrupted the Glu-Gln cycling ( Deng et al 2009 ). Interestingly, riluzole, taurine, dextromethorphan, para-aminosalicylic acid and increased dietary fiber antagonized manganese-induced neurotoxicity ( Deng et al 2012 ; Jiang et al 2006 ; Shi et al 2012 ; Xu Z et al 2010 ).…”

Chronic Manganese Administration with Longer Intervals Between Injections Produced Neurotoxicity and Hepatotoxicity in Rats

“…Data are mean + SEM of 3 rats. *Significantly different from Controls, p < 0.05 ◂ non-motor behavior deficits such as the memory and recognition deficits in water maze and step-down tests [38]. The developmental (PND 8-12) exposure to MnCl 2 (5-20 mg/ kg) could result in behavioral deficits during adulthood (PND 60-65) [33].…”

“…Mn intoxication decreases spontaneous locomotor behavior (open field test) and muscle strength (weight test) [ 11 ]. Mn also induces non-motor behavior deficits such as the memory and recognition deficits in water maze and step-down tests [ 38 ]. The developmental (PND 8–12) exposure to MnCl 2 (5–20 mg/kg) could result in behavioral deficits during adulthood (PND 60–65) [ 33 ].…”

“…The developmental (PND 8–12) exposure to MnCl 2 (5–20 mg/kg) could result in behavioral deficits during adulthood (PND 60–65) [ 33 ]. Thus, behavioral impairments are important aspects of chronic Mn intoxication in humans [ 34 , 35 ] and in experimental animals [ 11 , 25 , 33 , 38 ].…”

“…A transportable in vivo neutron activation analysis system was designed and utilized to assess bone Mn as accumulative Mn exposure, and found bone Mn and fingurenail Mn are associated with cognitive dysfunction in Mn-exposed workers [36,37]. In conjunction with these human studies, we have also performed experimental studies on Mn toxicity following oral [38] and peripheral exposures [25]. Subacute Mn injections produced motor deficits and brain damage, but also disrupted circadian clock in the hippocampus and liver [25].…”