Xiaoyaosan ameliorates depressive-like behavior and susceptibility to glucose intolerance in rat: involvement of LepR-STAT3/PI3K pathway in hypothalamic arcuate nucleus.

BACKGROUND: Accumulating evidence has demonstrated that arcuate nucleus (ARC) of the hypothalamus is likely responsible for the close association between chronic stress, depression, and diabetes. Xiaoyaosan (XYS), a Chinese herbal formula, remarkably improves depressive-like behavior and glucose intolerance, but the mechanism remains unclear. Leptin receptor (LepR) regulates energy expenditure and depression by mediating the action of leptin on the ARC. Therefore, we hypothesized that XYS may regulate depressive-like behavior and glucose intolerance via the leptin and its cascade LepR-STAT3/PI3K pathway in the ARC. METHODS: A rat model of depressive-like behavior and susceptibility to glucose intolerance was induced by exposure to chronic unpredictable mild stress (CUMS) for six weeks. XYS (2.224 g/kg) was orally gavaged for six weeks, and fluoxetine (2.0 mg/kg) was administrated to the positive control group. Depressive-like behaviors were assessed using the open field test (OFT), sucrose preference test (SPT) and forced swim test (FST). Fasting blood glucose (FBG) and oral glucose tolerance test (OGTT) were performed to evaluate the effects of XYS on blood glucose. Peripheral leptin and blood lipids were detected using enzyme-linked immunosorbent assay and an automatic biochemical analyzer, respectively. The effects of XYS on the LepR-STAT3/PI3K pathway were detected by quantitative real-time PCR and western blotting. RESULTS: XYS ameliorated CUMS-induced depressive-like behaviors and elevated blood glucose. XYS improved the food intake but have no significant effects on the body weight. Peripheral leptin and its central receptor were also suppressed by XYS, accompanied by the downregulation of JAK2/STAT3 and PI3K/AKT pathway in the ARC. Additionally, XYS increased AGRP and NPY expression but inhibited POMC in the ARC. CONCLUSIONS: XYS improves depressive-like behaviors and susceptibility to glucose intolerance induced by CUMS, which may be achieved by the downregulation of the LepR-STAT3/PI3K signaling pathway in the ARC.

Xiaoyaosan inhibits neuronal apoptosis by regulating the miR-200/NR3C1 signaling in the prefrontal cortex of chronically stressed rats.

BACKGROUND: Depression is a prevalent emotion disorder which is thought to be due to neuronal structural alterations and/or functional impairment within specific brain regions. Several studies have shown that microRNAs are involved in the pathogenesis of depression. As a Chinese herbal formula, Xiaoyaosan (XYS) could have antidepressive effects, although the mechanisms associated with microRNAs are poorly understood. PURPOSE: In this study, we investigated whether inhibition of the miR-200a/b-3p/NR3C1 pathway in the prefrontal cortex is involved in the anti-neuronal apoptosis and anti-stress effects of XYS and then further delineated the underlying mechanism. METHODS: To evaluate the efficacy of XYS in relieving stress behaviors and altering the expression of miRNAs involved in the regulation of these behaviors in vivo, a chronic unpredictable mild stress (CUMS) rodent model and RNA-seq were performed. Primary cortical neurons were used to evaluate the molecular function of miR-200a/b-3p and detect the in vitro neuroprotective function of paeoniflorin, which is one of the main components of XYS. To investigate the function of miR-200a/b-3p in stress behaviors, stereotactic microinjection of AAV2/9-Syn-miR-200a/b-3p was performed to deliver the treatment to the rat mPFC. RESULTS: XYS reduced the anxiety and depression-like behaviors associated with chronic stress and reduced the expression of miR-200a/b-3p and neuronal apoptosis in the prefrontal cortex (PFC). The overexpression of miR-200a/b-3p in primary cortical neurons reduced the expression of the target gene NR3C1, increased the protein expression of cleaved caspase-3 and Bax, and decreased the anti-apoptotic protein Bcl-2. One of the active ingredients of XYS, paeoniflorin, can inhibit miR-200a/b-3p-mediated apoptosis of primary neurons and abnormal expression of apoptosis-related proteins. After overexpressing miR-200a/b-3p in vivo (vmPFC), the rats eventually showed significant anxiety-like behaviors similar to those caused by chronic stress. CONCLUSION: Our findings indicate that XYS can inhibit the CUMS-induced expression of miR-200a/b-3p, regulate miR-200a/b-3p/NR3C1 signaling in the PFC caused by chronic stress, and reduce neuronal apoptosis and stress-related behaviors.

Simotang Alleviates the Gastrointestinal Side Effects of Chemotherapy by Altering Gut Microbiota.

Simotang oral liquid (SMT) is a traditional Chinese medicine (TCM) consisting of four natural plants and is used to alleviate gastrointestinal side effects after chemotherapy and functional dyspepsia (FD). However, the mechanism by which SMT helps cure these gastrointestinal diseases is still unknown. Here, we discovered that SMT could alleviate gastrointestinal side effects after chemotherapy by altering gut microbiota. C57BL/6J mice were treated with cisplatin (DDP) and SMT, and biological samples were collected. Pathological changes in the small intestine were observed, and the intestinal injury score was assessed. The expression levels of the inflammatory factors IL-1ß and IL-6 and the adhesive factors Occludin and ZO-1 in mouse blood or small intestine tissue were also detected. Moreover, the gut microbiota was analyzed by high-throughput sequencing of 16S rRNA amplicons. SMT was found to effectively reduce gastrointestinal mucositis after DDP injection, which lowered inflammation and tightened the intestinal epithelial cells. Gut microbiota analysis showed that the abundance of the anti-inflammatory microbiota was downregulated and that the inflammatory microbiota was upregulated in DDP-treated mice. SMT upregulated anti-inflammatory and anticancer microbiota abundance, while the inflammatory microbiota was downregulated. An antibiotic cocktail (ABX) was also used to delete mice gut microbiota to test the importance of gut microbiota, and we found that SMT could not alleviate gastrointestinal mucositis after DDP injection, showing that gut microbiota might be an important mediator of SMT treatment. Our study provides evidence that SMT might moderate gastrointestinal mucositis after chemotherapy by altering gut microbiota.

Feruloylated oligosaccharides and ferulic acid alter gut microbiome to alleviate diabetic syndrome.

Gut microbiome has been proven to be involved in the development of type 2 diabetes (T2D). Additionally, increasing evidence showed that the composition of gut microbiome is highly associated with the outcome of T2D therapy. Previously we demonstrated that feruloylated oligosaccharides (FOs) and ferulic acid (FA) alleviated diabetic syndrome in rats, but the detailed mechanism has not been explored yet. In this study we strived to characterize how FOs and FA altered the gut microbiome and related metabolome in diabetic rats by using high-throughput sequencing of 16S rRNA and gas chromatography (GC). Our results showed that FOs reduced the abundance of Lactobacillus, Ruminococcus, Oscillibacter, and Desulfovibrio, but increased the abundance of Akkermansia, Phascolarctobacterium and Turicibacter. The structure of gut microbiome in FOs treated rats was similar with healthy rats rather than diabetic rats. Likewise, FA decreased the portion of Lactobacillus, Ruminococcus, but promoted the growth of Bacteroides, Blautia, Faecalibacterium, Parabacteroides and Phascolarctobacterium. Additionally, the short-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs), the main bacterial lipid metabolites in gut mediating host glucose metabolism, was dramatically elevated along with FOs and FA treatment. Our findings indicated that FOs and FA attenuated diabetic syndrome in rats most likely by modulating the composition and metabolism of gut microbiome. The study gives new insight into the mechanism underlying the anti-diabetes effect of functional foods as well as facilitates the development of dietary supplements for diabetic patients.

Xiaoyaosan improves depressive-like behavior in rats with chronic immobilization stress through modulation of the gut microbiota.

Depression has become the leading cause of disability worldwide and a growing public health problem in China. In addition, intestinal flora may be associated with depression. This study investigated the effect of the decoction Xiaoyaosan (XYS) against depressive behavior through the regulation of intestinal flora. Fifty-two healthy male Sprague-Dawley rats were randomly divided into four groups (i.e., control, model, XYS, and fluoxetine). The latter three groups were subjected to 21 days of chronic restraint stress to produce the stress depression model. Rats in the XYS and fluoxetine groups received intragastric administration of XYS and fluoxetine, respectively. The behavioral changes of the rats were observed after 21 days. Stool specimens were sequenced using the 16S rDNA high-throughput method to detect the structure and changes in intestinal flora. There was no difference observed in alpha diversity among the groups. At the phylum level, XYS regulated the abundance of Bacteroidetes, Proteobacteria, Firmicutes, Chloroflexi, and Planctomycetes. At the genus level, XYS reduced the abundance of the Prevotellaceae_Ga6A1_group, Prevotellaceae_UCG-001, and Desulfovibrio. On the contrary, it increased the abundance of the Ruminococcaceae family to improve depression-like behavior. The mechanism involved in this process may be related to short-chain fatty acids, lipopolysaccharides, and intestinal inflammation.