Comparison of the short-chain fatty acids in normal rat faeces after the treatment of Euphorbia kansui, a traditional Chinese medicine for edoema

Simvastatin improves learning and memory impairment via gut-brain axis regulation in an ovariectomized/D-galactose Alzheimer's rat model

AIM

Alzheimer's disease (AD) is the most prevalent form of dementia with multiple etiology and no effective remedy. Statins are a group of medicines that are basically used to lower cholesterol. However, several studies have recently done to assess the potential relationship between statins use and dementia but presented controversial results.

METHODS

In this study, using ovariectomy and D-galactose injection, a model of AD was induced in female rats, and then the protective effects of oral administration of simvastatin were investigated. shuttle box and Y-maze tests were done to assess the animals' learning and memory performance. Using GC-MC, ELISA, Immunohistochemistry and tissue staining techniques, changes in the amount of short-chain fatty acids (SCFAs), plasma and hippocampus neuroinflammatory markers and histological changes in the intestine and hippocampus were assessed in sham, disease and treatment groups.

KEY FINDINGS

Oral administration of simvastatin improved the gut microbiome activity (increased the amount of SCFAs in fecal samples) and strengthened the tight junctions of intestinal cells. Moreover, simvastatin reduced the amount of TNF-α and IL-1β in plasma and hippocampus. Also, cell death and Amyloid plaques notably decreased in the simvastatin-treated hippocampal tissue. All these physiological changes led to better performance in behavioral tasks in the treatment group in comparison to the disease group.

SIGNIFICANCE

These findings provide evidence that simvastatin may improve gut-brain axis followed by improvement in learning and memory via an anti-inflammatory effect.

Review on Processing Methods of Toxic Chinese Materia Medica and the Related Mechanisms of Action

Toxic Chinese materia medica (CMM) has both pharmacological activities and toxic effects. Based on thousands of years of experience in the application of CMMs, people have explored many practical processing methods of CMMs, also known as "Pao Zhi", to reduce/control toxicity and preserve/enhance efficacy. Toxic CMMs have been used throughout China's hospitals. Yet, the production and use of toxic CMM should be carried out in accordance with the Chinese pharmacopoeia (ChP) and the processing regulations formulated by the health administrative departments of provinces, autonomous regions, and municipalities directly under the Central Government. This paper summarizes the current understanding and awareness of toxicity and 45 toxic CMMs, the commonly used processing methods of toxic CMMs recorded in the 2020 edition of ChP, and the changes in the chemical component, toxicity, or efficacy profiles after processing. This review may provide useful information for the processing methods of toxic CMMs worldwide. We believe that with an in-depth study and understanding of toxic CMMs combined with a standardized application, the toxicity of CMMs will be predictable and controllable in the future.

Chronic acetyl-L-carnitine treatment alleviates behavioral deficits and neuroinflammation through enhancing microbiota derived-SCFA in valproate model of autism

Autism spectrum disorder is characterized by a variety of cellular and molecular abnormalities which leads to autism-associated behaviors. Besides behavioral defects, these individuals also suffer from various associated disorders such as gastrointestinal deficit, altered gut microbiota composition and their metabolite. This study examined the effect of ALC on microbiota SCFA production and its effects on brain inflammation in VPA autism model. After prenatal exposure to valproate (600 mg/kg, i.p.) on embryonic day 12.5, followed by ALC treatment (100 mg/kg during postnatal days 23-51, p.o.), ASD-like behaviors, SCFAs amount in feces, intestine integrity (Occludin and ZO-1 tight junction proteins), systemic and brain inflammation (TNF-α and IL-1β) were assessed. Then, Golgi-Cox staining and Western blot for Iba1 protein were utilized to identify the changes in microglia profile in cerebral cortex. In the VPA model, we found that induction of autism was associated with demoted levels of SCFAs in feces and disintegration of intestine tissue which led to elevated level of TNF-α in the plasma. Further, we characterized an increased number of microglia in our histology evaluation and Iba1 protein in cerebral cortex. We also observed elevated level of TNF-α and IL-1β in the cerebral cortex of VPA rat. All these abnormalities were significantly alleviated by ALC treatment. Overall, our findings suggest that alleviation of behavioral abnormalities by ALC therapy in the VPA model of autism is associated with an improvement in the gut microbiota SCFAs, intestinal barrier and recovery of microglia and inflammation in the brain.

Wei-Tong-Xin ameliorates functional dyspepsia via inactivating TLR4/MyD88 by regulating gut microbial structure and metabolites

BACKGROUND

Wei-Tong-Xin (WTX) is a traditional Chinese medicine (TCM) that has been screened and improved in accordance with the famous ancient Chinese formula "Wan Ying Yuan". It has been shown to be clinically effective in treating gastric dysmotility, but its underlying molecular mechanism remains unclear.

PURPOSE

This study primarily dealt with the effects and mechanisms of WTX on functional dyspepsia (FD) induced by chemotherapeutic drug cisplatin (CIS).

METHODS

Firstly, the UPLC fingerprint and multi-component determination of WTX were established. In vivo, gastrointestinal motility of mice was detected by charcoal propulsion test. Besides, H&E, western blot and qRT-PCR were performed to evaluate the occurrence of gastric antral inflammation. ROS-DHE staining was used to detect ROS levels. Further, the gut microbiota were subjected to sequencing by 16S rRNA, and the levels of bacterial metabolites short-chain fatty acids (SCFAs) and lipopolysaccharide (LPS) were detected by GC-MS and Limulus kits, respectively. The levels of GLP-1 in gastric antrum were assessed by ELISA kits. Finally, siRNA-FFAR2 experiment was performed in Raw 264.7 cells.

RESULTS

23 common peaks were obtained from the UPLC fingerprint, and the content of 10 target components was determined. WTX increased the relative abundance of Firmicutes and decreased the number of Verrucomicrobia, accompanied by changes in the levels of SCFAs and LPS. By mediating the expression changes of free fatty acid receptor 2 (FFAR2) and toll-like receptor 4 (TLR4), WTX inhibited the phosphorylation of nuclear factor-κB (NF-κB), JNK and P38, decreased the levels of IL-1β, inducible nitric oxide synthase (iNOS) and ROS, increased the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), IL-4 and arginase-1 (Arg-1). Decreased expressions of glucagon-like peptide 1 (GLP-1) induced by WTX promoted gastric motility in FD mice. In vitro, siRNA-FFAR2 of Raw 264.7 cells eliminated the effects of WTX on TLR4 signaling pathway.

CONCLUSIONS

In this study, the chemical profile of WTX was first reported. Based on remodeling the gut microbiota structure and adjusting the levels of metabolites (SCFAs and LPS), WTX inactivated the TLR4/MyD88 signaling pathway to inhibit the occurrence of gastric antral inflammation, which reversed the inhibitory effect of GLP-1 on gastric motility, and improved CIS-induced FD symptoms.