Clostridium butyricum attenuates cerebral ischemia/reperfusion injury in diabetic mice via modulation of gut microbiota.

Diabetes is known to exacerbate cerebral ischemia/reperfusion (I/R) injury. Here, we investigated the effects of Clostridium butyricum on cerebral I/R injury in the diabetic mice subjected to 30min of bilateral common carotid arteries occlusion (BCCAO). The cognitive impairment, the blood glucose level, neuronal injury, apoptosis, and expressions of Akt, phospho-Akt (p-Akt), and caspase-3 level were assessed. Meanwhile, the changes of gut microbiota in composition and diversity in the colonic feces were evaluated. Our results showed that diabetic mice subjected to BCCAO exhibited worsened cognitive impairment, cell damage and apoptosis. These were all attenuated by C. butyricum. Moreover, C. butyricum reversed cerebral I/R induced decreases in p-Akt expression and increases in caspase-3 expression, leading to inhibiting neuronal apoptosis. C. butyricum partly restored cerebral I/R induced decreases of fecal microbiota diversity, changes of fecal microbiota composition. Together, these findings highlight the important role of bacteria in the bidirectional communication of the gut-brain axis and suggest that certain probiotics might prove to be useful therapeutic adjuncts in cerebral I/R injury with diabetes.

Sodium butyrate exerts neuroprotective effects by restoring the blood-brain barrier in traumatic brain injury mice.

Sodium butyrate (SB) has been widely used to treat cerebral diseases. The aim of the present study is to examine the neuroprotective effects of SB on early TBI in mice and to explore the underlying mechanisms of these effects. TBI was induced using a modified weight-drop method. Neurological deficits were evaluated according to the neurological severity score (NSS), brain oedema was measured by brain water content, and blood-brain barrier (BBB) permeability was evaluated by Evans blue (EB) dye extravasation. Neuronal injury was assessed by hematoxylin and eosin (H&E) staining and Fluoro-Jade C staining. The expression of tight junction-associated proteins, such as occludin and zonula occludens-1 (ZO-1), was analysed by western blotting and immunofluorescence. Our results showed that mice subjected to TBI exhibited worsened NSS, brain oedema, neuronal damage and BBB permeability. However, these were all attenuated by SB. Moreover, SB reversed the decrease in occludin and ZO-1 expression induced by TBI. These findings suggest that SB might attenuate neurological deficits, brain oedema, neuronal change and BBB damage, as well as increase occludin and ZO-1 expression in the brain to protect against TBI. The protective effect of SB may be correlated with restoring the BBB following its impairment.

Antidepressant-like effects of sodium butyrate and its possible mechanisms of action in mice exposed to chronic unpredictable mild stress.

Sodium butyrate (NaB) has exhibited neuroprotective activity. This study aimed to explore that NaB exerts beneficial effects on chronic unpredictable mild stress (CUMS)-induced depression-like behaviors and its possible mechanisms. The behavioral tests including sucrose preference test (SPT), open field test (OFT), tail suspension test (TST) and forced swimming test (FST) were to evaluate the antidepressant effects of NaB. Then changes of Nissl's body in the hippocampus, brain serotonin (5-HT) concentration, brain-derived neurotrophic factor (BDNF) and tight junctions (TJs) proteins level were assessed to explore the antidepressant mechanisms. Our results showed that CUMS caused significant depression-like behaviors, neuropathological changes, and decreased brain 5-HT concentration, TJs protein levels and BDNF expression in the hippocampus. However, NaB treatment significantly ameliorated behavioral deficits of the CUMS-induced mice, increased 5-HT concentration, increased BDNF expression, and up-regulated Occludin and zonula occludens-1(ZO-1) protein levels in the hippocampus, which demonstrated that NaB could partially restore CUMS-induced blood-brain barrier (BBB) impairments. Besides, the pathologic changes were alleviated. In conclusion, these results demonstrated that NaB significantly improved depression-like behaviors in CUMS-induced mice and its antidepressant actions might be related with, at least in part, the increasing brain 5-HT concentration and BDNF expression and restoring BBB impairments.

Clostridium butyricum pretreatment attenuates cerebral ischemia/reperfusion injury in mice via anti-oxidation and anti-apoptosis.

Probiotics participate actively in the neuropsychiatric disorders. However, their roles on ischemic stroke remain unclear. This study aims to determine whether Clostridium butyricum (C. butyricum) could attenuate cerebral ischemia/reperfusion (I/R) injury and its possible mechanisms. Male ICR mice were intragastrically pretreated with C. butyricum for 2 successive weeks, and then subjected to cerebral I/R injury induced by the bilateral common carotid artery occlusion (BCCAO) for 20min. After 24h of the reperfusion, neurological deficit scores were evaluated. Histopathological changes of the hippocampus neurons were observed using Hematoxylin and eosin (H&E) and TUNEL staining. Malondialdehyde (MDA) contents and superoxide dismutase (SOD) activities in the brain were detected. The expression of Caspase-3, Bax and Bcl-2 were investigated by Western blot and immunohistochemistry analysis. The butyrate contents in the brain were determined. Our results showed that cerebral I/R injury led to neurological deficit, increased levels of Caspase-3 and Bax and decreased Bcl-2/Bax ratio. C. butyricum significantly improved neurological deficit, relieved histopathologic change, decreased MDA contents and increased SOD activities in the I/R injury mice. After C. butyricum pretreatment, the expression of Caspase-3 and Bax were significantly decreased, the Bcl-2/Bax ratio was significantly increased, and butyrate contents in the brain were significantly increased. These findings suggested that C. butyricum is able to exert neuroprotective effects against I/R injury mice through anti-oxidant and anti-apoptotic mechanisms, and reversing decrease of butyrate contents in the brain might be involved in its neuroprotection.

Neuroprotective Effects of Clostridium butyricum against Vascular Dementia in Mice via Metabolic Butyrate.

Probiotics actively participate in neuropsychiatric disorders. However, the role of gut microbiota in brain disorders and vascular dementia (VaD) remains unclear. We used a mouse model of VaD induced by a permanent right unilateral common carotid arteries occlusion (rUCCAO) to investigate the neuroprotective effects and possible underlying mechanisms of Clostridium butyricum. Following rUCCAO, C. butyricum was intragastrically administered for 6 successive weeks. Cognitive function was estimated. Morphological examination was performed by electron microscopy and hematoxylin-eosin (H&E) staining. The BDNF-PI3K/Akt pathway-related proteins were assessed by western blot and immunohistochemistry. The diversity of gut microbiota and the levels of butyrate in the feces and the brains were determined. The results showed that C. butyricum significantly attenuated the cognitive dysfunction and histopathological changes in VaD mice. C. butyricum not only increased the levels of BDNF and Bcl-2 and decreased level of Bax but also induced Akt phosphorylation (p-Akt) and ultimately reduced neuronal apoptosis. Moreover, C. butyricum could regulate the gut microbiota and restore the butyrate content in the feces and the brains. These results suggest that C. butyricum might be effective in the treatment of VaD by regulating the gut-brain axis and that it can be considered a new therapeutic strategy against VaD.

Neuroprotective Effect of Sodium Butyrate against Cerebral Ischemia/Reperfusion Injury in Mice.

Sodium butyrate (NaB) is a dietary microbial fermentation product of fiber and serves as an important neuromodulator in the central nervous system. In this study, we further investigated that NaB attenuated cerebral ischemia/reperfusion (I/R) injury in vivo and its possible mechanisms. NaB (5, 10 mg/kg) was administered intragastrically 3 h after the onset of reperfusion in bilateral common carotid artery occlusion (BCCAO) mice. After 24 h of reperfusion, neurological deficits scores were estimated. Morphological examination was performed by electron microscopy and hematoxylin-eosin (H&E) staining. The levels of oxidative stress and inflammatory cytokines were assessed. Apoptotic neurons were measured by TUNEL; apoptosis-related protein caspase-3, Bcl-2, Bax, the phosphorylation Akt (p-Akt), and BDNF were assayed by western blot and immunohistochemistry. The results showed that 10 mg/kg NaB treatment significantly ameliorated neurological deficit and histopathology changes in cerebral I/R injury. Moreover, 10 mg/kg NaB treatment markedly restored the levels of MDA, SOD, IL-1ß, TNF-α, and IL-8. 10 mg/kg NaB treatment also remarkably inhibited the apoptosis, decreasing the levels of caspase-3 and Bax and increasing the levels of Bcl-2, p-Akt, and BDNF. This study suggested that NaB exerts neuroprotective effects on cerebral I/R injury by antioxidant, anti-inflammatory, and antiapoptotic properties and BDNF-PI3K/Akt pathway is involved in antiapoptotic effect.