RESUMEN
Objective To study the antidepressant-like effect of Butanol Extract from Stevia (BEFS) and its possible corresponding mechanisms.Methods Forty-five mice were randomly divided into control group,model group,model + Fluoxetine group,model + BEFS-3 g/kg group and model + BEFS-6 g/kg group.The chronic unpredictable mild stress(CUMS) for 3 weeks was used to make up depressive animal model.It was based on body weight,crossing numbers,rearing numbers and sucrose preference to assess whether the model was a success.After continuous lavage giving BEFS and fluoxetine for 2 weeks and subsequent behavioral test,the mRNA transcription of Single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) and nuclear factor kappa-B (NF-κB) in liver tissue of mice were detected by using quantitative real time-PCR.Results Three weeks after CUMS,behavior parameters were significantly decreased in mice exposed to CUMS compared with control group[(17.28 ±0.49) g vs (22.47 ± 0.82) g,P =0.000;(43.35 ± 1.68) scores vs (125.25 ± 3.07) scores,P =0.000;(3.92 ± 0.18) scores vs (15.92 ± 1.78) scores,P =0.000;(49.39 ± 2.05) ％ vs (67.18 ± 4.46) ％,P =0.001].However,2 weeks after dosing,body weight,crossing numbers,rearing numbers and sucrose preference were (19.03 ± 0.44) g,(70.50 ± 6.56) scores,(3.08 ± 0.77) scores and (41.27 ± 7.59) ％,respectively in model group.Compared to model group,behavior parameters of BEFS (3 and 6 g/kg BEFS) groups were significantly increased [BEFS-6 g/kg group:(24.42 ± 1.46) g,(99.75 ± 5.07) scores,(13.08 ± 1.60) scores,(64.31 ± 1.92) ％,all P ＜ 0.05;BEFS-3 g/kg group:(23.82 ± 1.72) g,(91.67 ± 5.69) scores,(6.92 ± 1.05) scores,(59.56 ± 5.31) ％,respectively,all P ＜ 0.05].Correspondingly,BEFS could reverse the mRNA expression of SIGIRR lowering and NF-κB rising in the liver of mice exposed to CUMS(BEFS-6 g/kg group:1.208 1 ± 0.102 2,1.437 7 ± 0.352 9;BEFS-3 g/kg group:0.768 0 ± 0.108 6,2.186 2 ± 0.203 8,all P ＜ 0.05).Conclusions BEFS can remarkably improve depression-like behaviors in CUMS mice and its antidepressant activity is mediated,at least in part,by upregulating SIGIRR and downregulating NF-κB in the liver.