Gynostemma pentaphyllum polysaccharides ameliorate non-alcoholic steatohepatitis in mice associated with gut microbiota and the TLR2/NLRP3 pathway.

Recent studies have revealed the pivotal role of gut microbiota in the progress of liver diseases including non-alcoholic steatohepatitis (NASH). Many natural herbs, such as Gynostemma pentaphyllum (GP), have been extensively applied in the prevention of NASH, while the bioactive components and underlying mechanism remain unclear. The aim of this study was to investigate whether the polysaccharides of GP (GPP) have a protective effect on NASH and to explore the potential mechanism underlying these effects. C57BL/6 male mice were fed with a methionine-choline-deficient (MCD) diet for 4 weeks to induce NASH and administered daily oral gavage of sodium carboxymethylcellulose (CMC-Na), low dose of GPP (LGPP), high dose of GPP (HGPP), and polyene phosphatidylcholine capsules (PPC), compared with the methionine-choline-sufficient (MCS) group. Our results showed that the symptoms of hepatic steatosis, hepatocyte ballooning, liver fibrosis, and oxidative stress could be partially recovered through the intervention of GPP with a dose-dependent effect. Furthermore, gut microbiome sequencing revealed that HGPP altered the composition of gut microbiota, mainly characterized by the enrichment of genera including Akkermansia, Lactobacillus, and A2. Moreover, hepatic transcriptome analysis indicated that the anti-inflammatory effect of HGPP might be associated with toll-like receptor (TLR) and nod-like receptor (NLR) signaling pathways. HGPP could inhibit the expression of TLR2 and downregulate the expression of the NLRP3 inflammasome, as well as the pro-inflammatory cytokine tumor necrosis factor (TNF)-α and interleukin (IL)-1ß. In summary, GPP could ameliorate NASH possibly mediated via the modulation of gut microbiota and the TLR2/NLRP3 signaling pathway, indicating that GPP could be tested as a prebiotic agent in the prevention of NASH.

The improvement of nonalcoholic steatohepatitis by Poria cocos polysaccharides associated with gut microbiota and NF-κB/CCL3/CCR1 axis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) has been linked to inflammation induced by intestinal microbiota. Poria cocos polysaccharides (PCP) possesses anti-inflammation and immunomodulation functions; however, its preventive effects against NASH and potential mechanisms need to be explored. METHODS: The composition of PCP was determined using ion chromatography. C57BL/6 mice were administered the methionine and choline deficient (MCD) diet for 4 weeks to establish the NASH model or methionine-choline-sufficient (MCS) diet to serve as the control. Mice were assigned to the MCS group, MCD group, low-dose PCP (LP) group, and high-dose PCP (HP) group, and were administered the corresponding medications via gavage. Serum biochemical index analysis and liver histopathology examination were performed to verify the successful establishment of NASH model and to evaluate the efficacy of PCP. The composition of intestinal bacteria was profiled through 16S rRNA gene sequencing. Hepatic RNA sequencing (RNA-Seq) was performed to explore the potential mechanisms, which were further confirmed using qPCR, western blot, and immunohistochemistry. RESULTS: PCP consists of glucose, galactose, mannose, D-glucosamine hydrochloride, xylose, arabinose, and fucose. PCP could significantly alleviate symptoms of NASH, including histological liver damage, impaired hepatic function, and increased oxidative stress. Meanwhile, HP could reshape the composition of intestinal bacteria by significantly increasing the relative abundance of Faecalibaculum and decreasing the level of endotoxin load derived from gut bacteria. PCP could also downregulate the expression of pathways associated with immunity and inflammation, including the chemokine signaling pathway, Toll-like receptor signaling pathway, and NF-kappa B signaling pathway. The expression levels of CCL3 and CCR1 (involved in the chemokine signaling pathway), Tlr4, Cd11b, and NF-κb (involved in the NF-kappa B signaling pathway), and Tnf-α (involved in the TNF signaling pathway) were significantly reduced in the HP group compared to the MCD group. CONCLUSIONS: PCP could prevent the development of NASH, which may be associated with the modulation of intestinal microbiota and the downregulation of the NF-κB/CCL3/CCR1 axis.

[Type and subtype distribution of influenza virus and genetic evolution of hemagglutinin in Shanghai area in duration of 2004 - 2008].

OBJECTIVE: To analyze the type and subtype distribution of influenza virus and the genetic evolution of hemagglutinin (HA) in Shanghai area during 2004 to 2008. METHODS: All 962 throat swabs were collected from influenza-like patients in 5 influenza sentry hospitals and influenza outbreaks. Influenza viruses were isolated in MDCK cell lines, and then viral types and subtypes were identified. The HA of influenza A isolates selected by outbreak or sporadic patients in different areas and epidemic seasons were sequenced and analyzed by phylogenetic trees. RESULTS: A/H3N2, accounting for 54.9% (162/295), was the dominate subtype in recent years, but less popular in the end of 2005 to the middle of 2006 with 0% (0/16)and 23.5% (8/34) of positive specimen, respectively. There were more A/H1N1 isolates in 2005 - 2006 with 21.4% (12/56), 43.8% (7/16) and 76.5% (26/34) of positive specimen, respectively, but declined obviously in 2007 - 2008 accounting for only 0% (0/44) and 5.0% (7/139). Influenza B virus was more popular in 2004 to 2005 with 42.9% (24/56) and 56.2% (9/16), respectively, and not isolated from 2006 to 2007, then increased in 2008 accounting for 34.5% (48/139). Phylogenetic tree of HA showed that A/H1N1 isolates in the same year clustered from 2005 to 2008, and most A/H3N2 isolated were homologous in the same year during 2004 - 2008 while some were inserted to the clusters of near years and more distinguished sequences appeared. A/H1N1 and A/H3N2 isolates were all similar to the vaccine strains recommended by WHO. CONCLUSION: The distribution of influenza type and subtype kept on changing each year, but A/H3N2 dominated in most years. A/H1N1 and A/H3N2 in the same year clustered, but some A/H3N2 of near years were and evolved faster with more distinguished strains appeared in same interval. Generally, HA of influenza A isolates in Shanghai during 2004 to 2008 were similar to the WHO reference strains.

[Sequence analysis on measles viruses isolated in Shanghai in 2005].

OBJECTIVE: To ascertain the genetic characterization and genotype of measles viruses isolated in Shanghai region, in 2005. METHODS: Measles virus was isolated from throat swab specimens collected from suspected measles cases and 450 bp fragment of C terminus of nucleprotein (N) gene was amplified by RT-PCR. Sequence analysis was conducted to ascertain the genotype and to compare the difference of nucleotide with other measles virus strain published in GenBank. RESULTS: 4 measles viruses were isolated from 10 throat swab specimens, and the sequence analysis indicated that they belonged to H1 genotype. The homogeneity of 450 nucleotides in the C terminal of the N gene was at 98%-98.2% as compared to H1 genotype (China93-7). They differed from genotype H2 (China94-1) at 6.4%-6.9% and from genotype A (Edmonston) at 6.7%-6.9%, from measles vaccine (Shanghail91) at 7.6%-8.0%. They differed from the other measles viral strain isolated in China in 1993 - 2005 at 0.2%-3.7%. The variation within 4 isolated measles viruses was at 0.7%-1.3%. CONCLUSION: It was H1 genotype measles viruses,which are the native viruses in China that led to the outbreak of measles in Shanghai, in 2005.