Effect of vitamins B 1 , B 6, and B 12 (Neurobion) on Diisopropylfluorophosphate-induced Delayed Neuropathy in Mice.

Certain organophosphorus esters, such as diisopropylfluorophosphate (DFP), cause delayed neuropathy by inhibition of neuropathy target esterase (NTE) keeping the neuron in normal function. In this study, effects of neurobion alone and in combination with dexamethasone on DFP-induced delayed neuropathy were evaluated. Thirty-five mice were divided into five groups, each consisting of 7 mice. Except group1 (Normal group), group 2 received normal saline and 1h later, 1 mg/kg DFP; groups 3, 4 and 5 received 150 mg/kg neurobion, 2 mg/kg dexamethasone and 150 mg/kg neurobion plus 2 mg/kg dexamethasone, respectively and 1h later 1mg/kg DFP. Twenty one days after the last injection, the mice were killed by decapitation under deep anesthesia. NTE level was determined in the brain and though there was no significant difference between the groups, neurobion and neurobion plus dexamethasone partly- not significantly ( p > 0.05)- were able to prevent reduction of NTE in the brain caused by DFP. Histopathological evaluation of sciatic nerves showed that neurobion and neurobion plus dexamethasone significantly suppressed the harmful effect of DFP. We also evaluated the activity of acetylcholine esterase (AChE), concentration of glutathione (GSH), and malondialdehyde (MDA) levels in the serum. Results showed dexamethasone ( p < 0.001) and dexamethasone in combination with neurobion ( p < 0.01) diminished AChE activity significantly compared to the DFP group. Neurobion caused a significant increase in the GSH level ( p < 0.05). No significant change was seen in MDA. It is suggested that neurobion should be added and used in the first aid equipment and techniques for exposure to organophosphorus compounds, e.g. pesticides and chemical warfare.