Objective To explore the mechanism of malt alcohol extract improving depression-like behavior induced by CUMS in rats by regulating gut microbiota.Methods The depression model of rats was established using an 8-weeks CUMS procedure,and the administration group was given low(59.6 mg·kg-1)and high(178.8 mg·kg-1)doses of malt alcohol extract,respectively.The depression-like behavior of rats was evaluated by classic behavioral test.The composition of intestinal microbiota of rats was analyzed by 16S rRNA sequencing.The morphological changes of colon were observed by hematoxylin and eosin(HE),the expression of ZO-1 and Occludin in colon was detected by immunofluorescence(IF),and the expression of IL-10,IL-1βand 5-HT were detected by ELISA.Results The low dose of malt alcohol extract attenuated the depressive behavior and restored the expression of 5-HT in the brain of CUMS rats.16S rRNA sequencing results showed that the diversity and relative abundance of gut microbiota changed after treatment with the low dose of malt alcohol extract.ELISA results showed that the low dose of malt alcohol extract significantly reversed the CUMS-induced reduction of IL-10 and elevation of IL-1 β.HE results showed that the low dose of malt alcohol extract significantly ameliorated CUMS-induced structural damage in colon.IF results showed increased protain expression of intestinal epithelial barrier tight junction proteins ZO-1 and Occludin by the low dose of malt alcohol extract.Conclusion The low dose of malt alcohol extract can ameliorate CUMS-induced depressive-like behavior in rats by modulating intestinal flora,restoring 5-HT expression in the brain,inhibiting inflammation,and repairing the intestinal barrier.

Objective To explore the mechanism of malt alcohol extract improving depression-like behavior induced by CUMS in rats by regulating gut microbiota.Methods The depression model of rats was established using an 8-weeks CUMS procedure,and the administration group was given low(59.6 mg·kg-1)and high(178.8 mg·kg-1)doses of malt alcohol extract,respectively.The depression-like behavior of rats was evaluated by classic behavioral test.The composition of intestinal microbiota of rats was analyzed by 16S rRNA sequencing.The morphological changes of colon were observed by hematoxylin and eosin(HE),the expression of ZO-1 and Occludin in colon was detected by immunofluorescence(IF),and the expression of IL-10,IL-1βand 5-HT were detected by ELISA.Results The low dose of malt alcohol extract attenuated the depressive behavior and restored the expression of 5-HT in the brain of CUMS rats.16S rRNA sequencing results showed that the diversity and relative abundance of gut microbiota changed after treatment with the low dose of malt alcohol extract.ELISA results showed that the low dose of malt alcohol extract significantly reversed the CUMS-induced reduction of IL-10 and elevation of IL-1 β.HE results showed that the low dose of malt alcohol extract significantly ameliorated CUMS-induced structural damage in colon.IF results showed increased protain expression of intestinal epithelial barrier tight junction proteins ZO-1 and Occludin by the low dose of malt alcohol extract.Conclusion The low dose of malt alcohol extract can ameliorate CUMS-induced depressive-like behavior in rats by modulating intestinal flora,restoring 5-HT expression in the brain,inhibiting inflammation,and repairing the intestinal barrier.

Objective: To assess the effects of acute exposure to electronic cigarette ( e-cigarette ) on leukocyte and total protein levels in bronchoalveolar lavage fluid ( BALF ) and pulmonary surfactant protein expression in a mouse model, so as to provide insights into the elucidation of the mechanism underlying the damages to the respiratory system caused by e-cigarette. Methods: Twenty-one C57BL/6N female mice were randomly divided into the blank control group, the solvent control group and the nicotine group. Mice in the solvent control group and the nicotine group were exposed to the solvent aerosol or e-cigarette aerosol containing 25 mg/mL nicotine for 3 hours daily, while mice in the blank control group were bred in clean air. Following 3-day exposure, mouse BALF and lung specimens were collected. The cell morphology was observed using microscopy following Wright-Giemsa staining and the leukocyte count was estimated in BALF, while the total protein expression was quantified using bicinchoninic acid ( BCA ) assay. In addition, the mRNA expression of pulmonary surfactant protein genes was detected in mouse lung specimens using quantitative real-time PCR ( qPCR ) assay. Results: All mice in three groups grew well without obvious abnormality or death seen. Wright-Giemsa staining showed a higher number of mononuclear macrophages in mouse BALF in the nicotine group than in the blank control group and the solvent control group. The leukocyte counts were ( 2.00±0.77 )×107, ( 1.79±0.99 )×107 and ( 4.00±1.35 )×107 cells/L ( F=9.199, P=0.002 ), and the total protein levels were ( 0.16±0.03 ), ( 0.12±0.02 ) and ( 0.16±0.04 ) mg/mL in mouse BALF in the blank control group, solvent control group and nicotine group ( F=3.610, P=0.048 ), and the relative mRNA expression of pulmonary surfactant protein B (SP-B) and SP-D was 1.00±0.14, 0.82±0.12 and 0.74±0.07 ( F=5.491, P=0.028 ), and 1.00±0.06, 0.90±0.02 and 0.71±0.15 in mouse lung specimens, respectively ( F=10.460, P=0.005 ). The leukocyte count was significantly higher in the nicotine group than in the blank control group and solvent control group (P=0.007, 0.003), and the total protein content was higher in the nicotine group than in the solvent control group ( P=0.060 ), while the relative SP-B mRNA expression was lower in the nicotine group than in the blank control group ( P=0.025 ), and the relative SP-D mRNA expression was lower in the nicotine group than in the blank control group and solvent control group ( P=0.004, 0.041 ). Conclusion Acute exposure to e-cigarette results in elevated intrapulmonary inflammatory responses, pulmonary capillary barrier impairment and reduced pulmonary surfactant protein expression.