Evaluation of Antidepressant Effect of Minocycline in Alcohol Abstinence-Induced Depression Model in Mice

Introduction Depression is one of the common comorbidities seen in chronic alcohol use disorder. Also, alcohol withdrawal induces depression and anxiety, which is associated with relapse in alcohol consumption. Minocycline, a tetracycline derivative, has shown an antidepressant effect in preclinical models. However, their effect on alcohol withdrawal-induced depression has not been studied. Therefore, the current study has been undertaken to evaluate the effect of minocycline on alcohol abstinence-induced depression models in mice. Method We conducted the study in two models. C57bl/6 mice were given a two-bottle choice (alcohol + water) for 28 days. During alcohol abstinence of 14 days, mice were treated with 10 mg/kg, 30 mg/kg, and 50 mg/kg of minocycline and were evaluated for behavioral changes using the forced swim test (FST) and tail suspension test (TST). A sucrose preference test was carried out where mice were exposed to binge alcohol drinking protocol for 12 days, where a two-bottle choice (alcohol or water) was given. This was followed by exposing the mice to a two-bottle choice paradigm (alcohol + sucrose) and they were divided into groups - no treatment group, vehicle-treated, minocycline 30 mg/kg or minocycline 50 mg/kg treated - and consumption of sucrose was assessed. Result In the forced swim test, a significant decrease in immobility time (p<0.05) was observed in the high-dose minocycline group (82.75±19.09) as compared to the vehicle control group (128.12±35.44). In the tail suspension test also, a significant decrease in immobility time (p<0.05) was seen in the high-dose minocycline group (83.75±18.61) as compared to the vehicle control group (122.25±18.51). The water and alcohol intake were comparable among all groups. In the sucrose preference test, it was found that the minocycline 50 mg/kg group had the highest sucrose preference (55%) followed by the minocycline 30 mg/kg group (50%) as compared to 42% in the vehicle control group. Significant reduction in brain-derived neurotrophic factor (BDNF) levels was seen with minocycline 50 mg/kg (p<0.05) and minocycline 30 mg/kg group (p<0.05) in BDNF levels when compared to the normal control group. Conclusion Minocycline in a higher dose (50 mg/kg) has shown an effect in alcohol withdrawal-induced depression in the abstinence-induced two-bottle choice model in mice. Both doses of minocycline have shown an effect in the sucrose preference test in the alcohol withdrawal-induced depression model.