Evaluation of anti-depressant properties of ethanol extract of Zingiber officinale rhizome in mice

Abstract

Depression, a common psychiatric disease, is associated with moodiness, disinterest, and anhedonia. Zingiber officinale is a traditional herb used to treat various disorders. This study evaluated the effect of ethanol extract of Zingiber officinale (EEZO) rhizome on depression in mice. Forty-eight male mice (28±2 g) were used and divided into six groups of 8 mice each. Depression was induced using the chronic mild stress model and then treated for three days afterwards. Group 1: control (normal saline), group 2: depressed, group 3: standard drug (diazepam; 1 mg/kg), groups 4, 5 and 6: treatment (50 mg/kg, 100 mg/kg and 200 mg/kg) body weight of EEZO respectively. Behavioural tests (open field, tail suspension, sucrose preference, dark and light box, hole maze and object exploration) were carried out on the mice before and after treatment. Concentration of inflammatory cytokines such as prostaglandins E₂, interleukin-1, tumour necrosis factor-α, interferon gamma, cyclooxygenase and nitric oxide was determined. The extract significantly (p < 0.05) improved behavioural pattern of mice and reduced the level of the inflammatory biomarkers, relative to the depressed mice. The results implied that EEZO reduced stress-induced depression in mice and could be a potential alternative for anti-depressant drug formulation.