Monosodium glutamate influences depressive behavior of two age groups of mice in forced swimming test: Vitamin B6 could remedy the situation

Abstract

Monosodium glutamate (MSG) could cause metabolic and neurotransmitters disturbance, and according to animal studies, it may cause neuronal damage. Vitamin B6 is a cofactor for various enzymes and can alter neurotransmitter levels. The aim was observing the effects of MSG administration alone and in combination with vitamin B6 on mood in two age groups of mice. MSG was administered either a single dose or long-term for 7, and 14 days in two age groups of mice (4–5 weeks or 9–10 weeks). Vitamin B6 (100 mg/kg) was administered six days consecutively. Depression was assessed by the forced swimming test (FST), higher immobility time denotes depressive-like behavior. A single dose of MSG (2.5 g/kg) increased immobility during the FST only in younger mice 179 sec ± 17 (p < 0.05, vs control 159 sec ± 8.5). Immobility time was higher than normal in young animals (191 sec ± 1.7) after seven or fourteen days of MSG exposure, it was also higher than control in adult animals on the 7th and 14th days (195 sec ± 8.7 and 203.6 sec ± 8 respectively). Vitamin B6 decreased the immobility time during FST in both age groups when it was administered prior to MSG single dose or in combination with MSG for the long term. In conclusion, MSG effects on depressive behavior depend on age and duration of exposure. Vitamin B6 as a cofactor of various neurotransmitter enzymes is promising in preventing the possible harmful effects of MSG on mood. © 2019