The effects of Clostridium butyricum on Ira rabbit growth performance, cecal microbiota and plasma metabolome.

Clostridium butyricum (C. butyricum) can provide many benefits for animals' growth performance and gut health. In this study, we investigated the effects of C. butyricum on the growth performance, cecal microbiota, and plasma metabolome in Ira rabbits. A total of 216 Ira rabbits at 32 days of age were randomly assigned to four treatments supplemented with basal diets containing 0 (CG), 200 (LC), 400 (MC), and 600 mg/kg (HC) C. butyricum for 35 days, respectively. In comparison with the CG group, C. butyricum supplementation significantly improved the average daily gain (ADG) and feed conversion rate (FCR) at 53 and 67 days of age (P < 0.05) and digestibilities of crude protein (CP) and crude fiber (CF) at 67 days of age (P < 0.05). The cellulase activity in the HC group was higher respectively by 50.14 and 90.13% at 53 and 67 days of age, than those in the CG groups (P < 0.05). Moreover, at 67 days of age, the diet supplemented with C. butyricum significantly increased the relative abundance of Verrucomicrobia at the phylum level (P < 0.05). Meanwhile, the concentrations of different metabolites, such as amino acids and purine, were significantly altered by C. butyricum (P < 0.05). In addition, 10 different genera were highly correlated with 52 different metabolites at 53-day-old and 6 different genera were highly correlated with 18 different metabolites at 67-day-old Ira rabbits. These findings indicated that the C. butyricum supplementation could significantly improve the growth performance by modifying the cecal microbiota structure and plasma metabolome of weaned Ira rabbits.

[Effects of SIRT1 in amygdala on chronic restraint stress-induced depression-like behaviors in rats].

OBJECTIVE: To investigate the effects of silent information regulator 1 (SIRT1) in amygdala on depression-like behaviors in rats using chronic restraint stress (CRS) as a model of depression. METHODS: Sixty male SD rats were randomly divided into six groups (n=10 per group): control group (Control), chronic restraint stress group (CRS), CRS + fluoxetine-treated group (CRS + FLU), CRS + saline-treated group (CRS + NaCl), CRS + SIRT1-overexpression group (CRS + AAV-SIRT1), and CRS + empty vector group (CRS + AAV-EGFP). Except for the control group, rats from the other groups were exposed to chronic restraint stress for 21 days. After the modeling, rats in fluoxetine-treated group and saline-treated group were, respectively, treated with fluoxetine (10 mg/kg) or saline (10 mg/kg) by gavage every day for 3 weeks; AAV-SIRT1 or AAV-EGFP was, respectively, stereotaxically injected into the amygdala of rats in SIRT1-overexpression group and empty vector group, and the virus was expressed for 3 weeks. Rats in normal control group and CRS model group were not given any drug treatment. The depression-like behaviors of rats in each group were evaluated by sugar preference test (SPT), open field test (OFT) and forced swimming test (FST). SIRT1 expression in amygdala of rats was assessed by using immunoblot blotting. The number of SIRT1-positive cells in amygdala of rats was detected by immunofluorescence technique. RESULTS: Compared with the normal control group, the level of SIRT1 protein and the number of SIRT1+ cells in amygdala of the CRS-exposed rats were decreased significantly (P＜0.01), and CRS-exposed rats showed a significant decrease in sucrose preference (P＜0.01), less total horizontal distance (P＜0.01) and less time entered the center field (P＜0.01) in the OFT, a significant increase in the immobility time of the FST (P＜0.01). Fluoxetine treatment (P＜0.05, P＜0.01) or SIRT1 overexpression (P＜0.01) partially reversed the down-regulation of SIRT1 protein and SIRT1+ cells in amygdala of CRS-exposed rats and significantly improved the depression-like behaviors of CRS rats. CONCLUSION: Fluoxetine treatment partially reversed the down-regulation of SIRT1 level and the number of SIRT1+ in CRS rats, and significantly improved the depression-like behaviors. The antidepressant effect of fluoxetine treatment may be related to the up-regulation of SIRT1 in the amygdala of CRS-exposed rats.

12-lipoxygenase induces apoptosis of human gastric cancer AGS cells via the ERK1/2 signal pathway.

12-Lipoxygenase (12-LOX) is over-expressed in a variety of human tumors, but its exact effect on the tumorogenesis of gastric cancer remains largely obscure. To investigate the effect of 12-LOX and its inhibitor baicalein on proliferation and apoptosis of human gastric cancer, AGS cells were separately treated with 12-hydroxyeicosatetraenoic acid (12-HETE, a metabolite of 12-LOX) and baicalein. MTT assay revealed that the absorbance of the 12-HETE-treated group was significantly (P < 0.01) higher than that of control group and that the absorbance of baicalein-treated group was significantly (P < 0.01) less than that of the control group, and that 48 h after treatment the apoptosis index of the baicalein-treated group was significantly (P < 0.01) higher than that of the untreated group and was significantly (P < 0.01) lower in the 12-HETE-treated group. Western blotting analysis was used to investigate the mechanism of these effects. The results revealed that the concentration of phosphorylated ERK in cells treated with 100 nmol L(-1) 12-HETE was significantly (P < 0.05) higher than in the untreated group and that the concentration of phosphorylated ERK1/2 in cells treated with 40 micromol L(-1) baicalein was significantly (P < 0.05) lower than in the untreated group. The expression level of bcl-2 was up-regulated and down-regulated after separate treatment with 12-HETE and baicalein, respectively, and both of these effects could be blocked by PD98059. Protein kinase C (PKC) activity was increased by treatment with 12-HETE and reduced by treatment with baicalein (P < 0.05). The PKC inhibitor BIM (bisindolymaleimide-I) blocked the phosphorylation of ERK1/2 and activation of PKC induced by 12-LOX. When pretreated with BIM, the concentration of phospho-ERK1/2 or bcl-2 in the BIM + 12-HETE-treated group was significantly (P < 0.05) lower than in that treated with 12-HETE only, and the concentration in the BIM + baicalein-treated group was significantly (P < 0.05) higher than in that treated with baicalein only. On the basis of these data we conclude that, via its metabolite 12-HETE, 12-LOX abolishes proliferation of AGS cells and protect cells from apoptosis by activating the ERK1/2 pathway and, eventually, enhances expression of bcl-2. Because PKC is also involved in the activation of ERK1/2 induced by 12-LOX, 12-LOX inhibitors would be potentially powerful anticancer agents for prevention and cure of human gastric cancer.