Vitamin B1 administration attenuates anxiety and depression-like behaviors induced by nicotine abstinence in chronically stressed rats

The present study aimed to assess the effect of treatment by Vitamin B1 (Vit B 1 ) on behavioral manifestations of anxiety and depression in rats exposed to nicotine and/or unpredictable chronic mild stress (UCMS) during adolescence. Furthermore, several biochemical pathways and alcohol drinking behavior was also investigated in these subjects. 120 adolescent male rats (21 days of age) were randomly divided into eight experimental groups: (1) Vehicle (received saline+saline), (2) Nicotine (received Nicotine+saline, 2 mg/kg), (3) UCMS (UCMS+saline), (4) Nicotine-UCMS (Nicotine-UCMS+saline), 5–7) Nicotine-UCMS+ three doses of Vit B 1 (5, 10 and 15 mg/kg) 2) and 8) Vit B1 (received saline + Vit B 1 ). Anxiety- and depression-like behaviors were quantified by open field, elevated plus maze, marble burying and forced swimming tests. Furthermore, ethanol drinking behavior was assessed by the two bottle method. Animals in Nic, UCMS, and Nic-UCMS groups demonstrated heightened anxiety- and depression-like signs as well as increased ethanol consumption, compared to their control counterparts. Interestingly, these observations were associated with biochemical alterations in brain oxidative, inflammatory, neurotrophic and aminergic profile. Treatment with Vit B 1 remarkably restored balance in many of the mentioned behavioral and biochemical findings, particularly when treatment was applied at high dose (i.e. 15 mg/kg). Both nicotine and UCMS adversely affect the mood and reward-related behaviors in rats via affecting brain biochemical pathways and Vit B 1 supplementation could be a potential candidate to improve these complications by restoration of biochemical balance in cortex.