Berberine alleviates visceral hypersensitivity in rats by altering gut microbiome and suppressing spinal microglial activation.

Accumulating evidence shows that agents targeting gut dysbiosis are effective for improving symptoms of irritable bowel syndrome (IBS). However, the potential mechanisms remain unclear. In this study we investigated the effects of berberine on the microbiota-gut-brain axis in two rat models of visceral hypersensitivity, i.e., specific pathogen-free SD rats subjected to chronic water avoidance stress (WAS) and treated with berberine (200 mg· kg-1 ·d-1, ig, for 10 days) as well as germ-free (GF) rats subjected to fecal microbiota transplantation (FMT) from a patient with IBS (designated IBS-FMT) and treated with berberine (200 mg· kg-1 ·d-1, ig, for 2 weeks). Before the rats were sacrificed, visceral sensation and depressive behaviors were evaluated. Then colonic tryptase was measured and microglial activation in the dorsal lumbar spinal cord was assessed. The fecal microbiota was profiled using 16S rRNA sequencing, and short chain fatty acids (SCFAs) were measured. We showed that berberine treatment significantly alleviated chronic WAS-induced visceral hypersensitivity and activation of colonic mast cells and microglia in the dorsal lumbar spinal cord. Transfer of fecal samples from berberine-treated stressed donors to GF rats protected against acute WAS. FMT from a patient with IBS induced visceral hypersensitivity and pro-inflammatory phenotype in microglia, while berberine treatment reversed the microglial activation and altered microbial composition and function and SCFA profiles in stools of IBS-FMT rats. We demonstrated that berberine did not directly influence LPS-induced microglial activation in vitro. In both models, several SCFA-producing genera were enriched by berberine treatment, and positively correlated to the morphological parameters of microglia. In conclusion, activation of microglia in the dorsal lumbar spinal cord was involved in the pathogenesis of IBS caused by dysregulation of the microbiota-gut-brain axis, and the berberine-altered gut microbiome mediated the modulatory effects of the agent on microglial activation and visceral hypersensitivity, providing a potential option for the treatment of IBS.

Physiology and cell biology of acupuncture observed in calcium signaling activated by acoustic shear wave.

This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100 Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca(2+) transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency-amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd(3+) were observed; and increased Ca(2+) fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system.

Up-regulation of the expression of cocaine and amphetamine-regulated transcript peptide by electroacupuncture in the arcuate nucleus of diet-induced obese rats.

It was reported that acupuncture or electro-acupuncture (EA) is effective in reducing the body weight for obese patients, although the mechanisms remain obscure. In a previous study, we have found that rats fed with high-fat (HIF) diet developed diet-induced obesity (DIO) with a concomitant decrease in the hypothalamic content of the cocaine and amphetamine-regulated transcript (CART) peptide, a peptide with anorexiogenic effect. To assess the central effect of EA on DIO rat, we revealed that EA up-regulated the expression of CART peptide in the arcuate nucleus (ARC) of the DIO rats. After feeding with HIF diet for 14 weeks, the DIO rats received EA stimulation three times per week for 4 weeks. The expression of CART peptide in ARC was measured using immunohistochemistry. The plasma ACTH was measured with ELISA. EA caused a reduction of both body weight and energy intake in DIO rats and increased the expression of CART peptide in ARC. The plasma ACTH was increased in response to restraint stress, but EA produced no further increase in ACTH levels. The results suggest that EA can up-regulate the expression of CART peptide to approach normal level, resulting in an inhibition of food intake and a reduction of body weight in DIO rats.

Triptolide protects dopaminergic neurons from inflammation-mediated damage induced by lipopolysaccharide intranigral injection.

Converging lines of evidence suggest that neuroinflammatory processes may account for the progressive death of dopaminergic neurons in Parkinson's disease (PD). Therefore, anti-inflammatory strategies have attracted much interest for their potential to prevent further deterioration of PD. Our previous study showed that triptolide, a traditional Chinese herbal compound with anti-inflammatory and immunosuppressive properties, protected dopaminergic neurons from lipopolysaccharide (LPS)-induced damage in primary embryonic midbrain cell cultures. To examine further if triptolide can protect dopaminergic neurons from inflammation-mediated damage in vivo, microglial activation and injury of dopaminergic neurons were induced by LPS intranigral injection, and the effects of triptolide treatment on microglial activation and survival ratio and function of dopaminergic neurons were investigated. Our results demonstrated that microglial activation induced by a single intranigral dose of 10 mug of LPS reduced the survival ratio of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra pars compacta (SNpc) to 29% and the content of dopamine (DA) in striatum to 37% of the non-injected side. Intriguingly, treatment with triptolide of 5 mug/kg for 24 days once per day dramatically improved the survival rate of TH-ir neurons in the SNpc to 79% of the non-injected side. Meanwhile, treatment with triptolide of 1 or 5 mug/kg for 24 days once per day significantly improved DA level in striatum to 70% and 68% of the non-injected side, respectively. Complement receptor 3 (CR3) immunohistochemical staining revealed that triptolide treatment potently inhibited LPS-elicited deleterious activation of microglia in SNpc. The excessive production of cytokines, such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, was significantly abolished by triptolide administration. These results, together with our previous data in vitro, highly suggest the effectiveness of triptolide in protecting dopaminergic neurons against inflammatory challenge.

Electro-acupuncture stimulation protects dopaminergic neurons from inflammation-mediated damage in medial forebrain bundle-transected rats.

Through producing a variety of cytotoxic factors upon activation, microglia are believed to participate in the mediation of neurodegeneration. Intervention against microglial activation may therefore exert a neuroprotective effect. Our previous study has shown that the electro-acupuncture (EA) stimulation at 100 Hz can protect axotomized dopaminergic neurons from degeneration. To explore the underlying mechanism, the effects of 100 Hz EA stimulation on medial forebrain bundle (MFB) axotomy-induced microglial activation were investigated. Complement receptor 3 (CR3) immunohistochemical staining revealed that 24 sessions of 100 Hz EA stimulation (28 days after MFB transection) significantly inhibited the activation of microglia in the substantia nigra pars compacta (SNpc) induced by MFB transection. Moreover, 100 Hz EA stimulation obviously inhibited the upregulation of the levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA in the ventral midbrains in MFB-transected rats, as revealed by reverse transcriptase polymerase chain reaction (RT-PCR). ED1 immunohistochemical staining showed that a large number of macrophages appeared in the substantia nigra (SN) 14 days after MFB transection. The number of macrophages decreased by 47% in the rats that received 12 sessions of EA simulation after MFB transection. These data indicate that the neuroprotective role of 100 Hz EA stimulation on dopaminergic neurons in MFB-transected rats is likely to be mediated by suppressing axotomy-induced inflammatory responses. Taken together with our previous results, this study suggests that the neuroprotective effect of EA on the dopaminergic neurons may stem from the collaboration of its anti-inflammatory and neurotrophic actions.

[Effect of Chinese herb Tripterygium wilfordii Hook F monomer triptolide on apoptosis of PC12 cells induced by Abeta1-42].

Recent studies indicate that beta-amyloid (Abeta) is the key factor to cause neuronal degeneration in Alzheimer's disease (AD). In the present study, we set up an Abeta induced PC12 cell damage modle and studied the protective effect and related mechanisms of T(10), monomer extracted from Chinese herb Tripterygium wilfordii Hook F. PC12 cells were treated with different concentrations of Abeta (5x10(-4), 5x10(-3), 5x10(-2), 5x10(-1), 5, 50 micromol/L) for 48 h, cell viability was detected by MTT conversion. The apoptotic rate of PC12 cells was quantitatively determined using FACS assay. After PC12 cells were treated with 1x10(-11) mol/L T(10) for 48 h and then co-treated with 50 micromol/LAbetafor 48 h, the apoptotic rate and the change in intracellular Ca(2+) concentration of PC12 cells were analyzed by FACS assay and confocal, respectively. It was found that 5 micromol/L Abeta decreased the cell viability to 66.3% and 50 micromol/L Abeta decreased it to 55.1%, significantly different from that of the control group. After treatment with 50 micromol/L Abeta for 48 h, the apoptotic rate of PC12 cells increased obviously. The apoptotic rate was 5.37% in the control group, while after treatment with 0.5, 5 and 50 micromol/L Abeta for 48 h, the apoptotic rate of PC12 cells went up to 10.19%, 8.02% and 16.63%, respectively. At the same time, the concentration of intracellular Ca(2+) increased greatly after treatment with 50 micromol/L Abeta for 48 h. At the concentration of 1x10(-11) mol/L T(10) remarkably inhibited the apoptosis induced by 50 micromol/L Abeta. In the naive group, the apoptotic rate was 4.83%. The apoptotic rate went up to 17.24% after treatment with 50 micromol/L Abeta for 48 h. After co-treatment with 1x10(-11) mol/L T(10) and 50 micromol/L Abeta, the apoptotic rate decreased to 8.91%, significantly different from that of the control group. At the same time, at the concentration of 1x10(-11 )mol/L T(10) remarkably inhibited the increase of intracellular Ca(2+) concentration induced by Abeta. The results indicate that T(10) has obvious protective effect on PC12 cells, which may be related to the inhibition of the cell apoptosis and increment of intracellular Ca(2+) concentration induced by Abeta.

Neurotrophic and neuroprotective effects of tripchlorolide, an extract of Chinese herb Tripterygium wilfordii Hook F, on dopaminergic neurons.

It has been reported recently that the immunosuppressant FK506 produced neurotrophic and neuroprotective effects on dopaminergic neurons in vitro and in vivo. We investigated whether tripchlorolide, an immunosuppressive extract of Chinese herb Tripterygium wilfordii Hook F, could exert similar neurotrophic and neuroprotective effects similar to those of FK506. It was found that tripchlorolide promoted axonal elongation and protected dopaminergic neurons from a neurotoxic lesion induced by 1-methyl-4-phenylpyridinium ion (MPP+) at concentrations of as low as 10(-12) to 10(-8) M. In situ hybridization study revealed that tripchlorolide stimulated brain-derived neurotrophic factor (BDNF) mRNA expression. In vivo administration of tripchlorolide (1 microg/kg, ip) for 28 days effectively attenuated the rotational behavior challenged by D-amphetamine in the model rats by transection of the medial forebrain bundle. In addition, tripchlorolide treatment (0.5 or 1 microg/kg/day for 28 days) increased the survival of dopaminergic neurons in substantia nigra pars compacta by 50 and 67%, respectively. Moreover, tripchlorolide markedly prevented the decrease in amount of dopamine in the striatum of model rats. Taken together, our data provide the first evidence that tripchlorolide acts as a neuroprotective molecule that rescues MPP+ or axotomy-induced degeneration of dopaminergic neurons, which may imply its therapeutic potential for Parkinson's disease. The underlying mechanism may be relevant to its neurotrophic effect and its efficacy in stimulating the expression of BDNF.