Nitrogen fertilization rates mediate rhizosphere soil carbon emissions of continuous peanut monoculture by altering cellulose-specific microbess.

Introduction: Crops influence both soil microbial communities and soil organic carbon (SOC) cycling through rhizosphere processes, yet their responses to nitrogen (N) fertilization have not been well investigated under continuous monoculture. Methods: In this study, rhizosphere soil microbial communities from a 5-year continuous mono-cropped peanut land were examined using Illumina HighSeq sequencing, with an N fertilization gradient that included 0 (N0), 60 (N60), 120 (N120) and 180 (N180) kg hm-2. Soil respiration rate (R s) and its temperature sensitivity (Q 10) were determined, with soil carbon-acquiring enzyme activities assayed. Results and discussion: The obtained results showed that with N fertilization, soil mineral N (Nmin) was highly increased and the soil C/N ratio was decreased; yields were unchanged, but root biomass was stimulated only at N120. The activities of ß-1,4-glucosidase and polyphenol oxidase were reduced across application rates, but that of ß-1,4-cellobiohydrolase was increased only at N120. Bacterial alpha diversity was unchanged, but fungal richness and diversity were increased at N60 and N120. For bacterial groups, the relative abundance of Acidobacteria was reduced, while those of Alphaproteobacteria and Gammaproteobacteria were increased at N60 and N120. For fungal members, the pathogenic Sordariomycetes was inhibited, but the saprotrophic Agaricomycetes was promoted, regardless of N fertilization rates. RDA identified different factors driving the variations in bacterial (root biomass) and fungal (Nmin) community composition. N fertilization increased R s slightly at N60 and significantly at N120, mainly through the promotion of cellulose-related microbes, and decreased R s slightly at N180, likely due to carbon limitation. N fertilization reduced microbial biomass carbon (MBC) at N60, N120 and N180, decreased SOC at N120 and N180, and suppressed dissolved organic carbon (DOC) at N180. In addition, the unchanged Q 10 may be a joint result of several mechanisms that counteracted each other. These results are of critical importance for assessing the sustainability of continuously monocultured ecosystems, especially when confronting global climate change.

Cyclic-di-AMP Phosphodiesterase Elicits Protective Immune Responses Against Mycobacterium tuberculosis H37Ra Infection in Mice.

Many antigens from Mycobacterium tuberculosis (M. tuberculosis) have been demonstrated as strong immunogens and proved to have application potential as vaccine candidate antigens. Cyclic di-AMP (c-di-AMP) as a bacterial second messenger regulates various bacterial processes as well as the host immune responses. Rv2837c, the c-di-AMP phosphodiesterase (CnpB), was found to be relative to virulence of M. tuberculosis and interference with host innate immune response. In this study, recombinant CnpB was administered subcutaneously to mice. We found that CnpB had strong immunogenicity and induced high levels of humoral response and lung mucosal immunity after M. tuberculosis intranasally infection. CnpB immunization stimulated splenocyte proliferation and the increasing number of activated NK cells but had little effects on Th1/Th2 cellular immune responses in spleens. However, CnpB induced significant Th1/Th2 cellular immune responses with a decreased number of T and B cells in the lungs, and significantly recruits of CD4+ and CD8+ T cells after M. tuberculosis attenuated strain H37Ra infection. Besides, we first reported that CnpB could stimulate IFN-ß expression transitorily and inhibit the autophagy of macrophages in vitro. In mice intranasally infection model, CnpB immunization alleviated pathological changes and reduced M. tuberculosis H37Ra loads in the lungs. Thus, our results suggested that CnpB interferes with host innate and adaptive immune responses and confers protection against M. tuberculosis respiratory infection, which should be considered in vaccine development as well as a drug target.

Coptidis rhizoma and its main bioactive components: recent advances in chemical investigation, quality evaluation and pharmacological activity.

BACKGROUND: Coptidis rhizoma (CR) is the dried rhizome of Coptis chinensis Franch., C. deltoidea C. Y. Cheng et Hsiao or C. teeta Wall. (Ranunculaceae) and is commonly used in Traditional Chinese Medicine for the treatment of various diseases including bacillary dysentery, typhoid, tuberculosis, epidemic cerebrospinal meningitis, empyrosis, pertussis, and other illnesses. METHODS: A literature survey was conducted via SciFinder, ScieneDirect, PubMed, Springer, and Wiley databases. A total of 139 selected references were classified on the basis of their research scopes, including chemical investigation, quality evaluation and pharmacological studies. RESULTS: Many types of secondary metabolites including alkaloids, lignans, phenylpropanoids, flavonoids, phenolic compounds, saccharides, and steroids have been isolated from CR. Among them, protoberberine-type alkaloids, such as berberine, palmatine, coptisine, epiberberine, jatrorrhizine, columamine, are the main components of CR. Quantitative determination of these alkaloids is a very important aspect in the quality evaluation of CR. In recent years, with the advances in isolation and detection technologies, many new instruments and methods have been developed for the quantitative and qualitative analysis of the main alkaloids from CR. The quality control of CR has provided safety for pharmacological applications. These quality evaluation methods are also frequently employed to screen the active components from CR. Various investigations have shown that CR and its main alkaloids exhibited many powerful pharmacological effects including anti-inflammatory, anti-cancer, anti-diabetic, neuroprotective, cardioprotective, hypoglycemic, anti-Alzheimer and hepatoprotective activities. CONCLUSION: This review summarizes the recent phytochemical investigations, quality evaluation methods, the biological studies focusing on CR as well as its main alkaloids.

Cytotoxic and apoptosis-inducing activity of C21 steroids from the roots of Cynanchum atratum.

Two new (1-2) and two known C21 steroids (3-4) were isolated from the roots of Cynanchum atratum. Their structures were elucidated by detailed 1D and 2D spectroscopic. The MTT assay showed that compounds 1-4 displayed obvious cytotoxic activities against HepG2 cells with IC50 values ranging from 10.19µM to 76.12µM. Compounds 1-3 also exhibited cytotoxic effects in A549 cells with IC50 values of 30.87-95.39µM. Compound 3 showed the antiproliferative activity via G0/G1 cell cycle arrest and proapoptosis in HepG2 cells by Flowcytometry analysis. Western blotting analysis revealed that compound 3 could induce HepG2 cell apoptosis via the mitochondrial pathway by downregulating Bcl-2 expression, upregulating Bax protein expression, and activating caspase-9 and caspase-3.

Antihyperlipidaemic effect of triterpenic acid-enriched fraction from Cyclocarya paliurus leaves in hyperlipidaemic rats.

CONTEXT: Cyclocarya paliurus (Batal) Iljinskaja (Juglandaceae) is an edible and medicinal plant; the leaves are used in Chinese folkloric medicine to treat dyslipidaemia and diabetes. OBJECTIVE: This study evaluates the antihyperlipidaemic potential of the triterpenic acid-enriched fraction (TAE) from C. paliurus and the underlying mechanism. MATERIALS AND METHODS: The hyperlipidaemic rats were induced by high fat diet for 6 weeks. After oral administration of TAE (200 and 400 mg/kg), the neutral fraction (150 and 300 mg/kg) and statin (4 mg/kg) to the hyperlipidaemic rats for 4 weeks, lipid profile and apolipoprotein (apoB48) level in plasma, and the expression levels of apoB48, microsomal triglyceride transfer protein (MTP), phosphorylation of mitogen-activated protein kinase (MAPK) and tumour necrosis factor α (TNF-α) in intestine were examined. The main constituents in the TAE were identified by HPLC-MS. RESULTS: TAE administration (400 mg/kg) decreased the levels of atherogenic lipids in serum and liver (p < 0.05) and increased serum high-density lipoprotein cholesterol by 19.7%. Furthermore, TAE treatment (200 and 400 mg/kg) decreased plasma apoB48 level by 15.3 and 19.5%, downregulated intestinal apoB48 and MTP expression levels (p < 0.05), and inhibited TNF-α expression by 36.2 and 56.2% and the phosphorylation level of MAPK by 8.8 and 13.2%, respectively. HPLC analysis revealed the presence of pentacyclic- and tetracyclic-triterpene acids in TAE. CONCLUSION AND DISCUSSION: These findings suggested that TAE possessed antihyperlipidaemic activity partially involved in the inhibitory effect on apoB48 overproduction, which may provide evidence about its potential role in ameliorating dyslipidaemia.

The chloroform extract of Cyclocarya paliurus attenuates high-fat diet induced non-alcoholic hepatic steatosis in Sprague Dawley rats.

BACKGROUND: Hepatic steatosis (HS) is the early stage of nonalcoholic fatty liver disease which is caused by impaired hepatic lipid homeostasis. Cyclocarya paliurus, an herbal tea consumed in China, has been demonstrated to ameliorate abnormal lipid metabolism for the treatment of metabolic diseases. PURPOSE: We aimed to investigate the regulative effect of chloroform extract from Cyclocarya paliurus (ChE) on treatment of HS, as well as key factors involved in hepatic lipid metabolism. STUDY DESIGN: Sprague Dawley rats were fed with high-fat diet (HFD) for 6 weeks to induce HS and treated with or without ChE by gavage for 4 weeks. METHODS: The body weight, relative liver weight and liver fat content were measured. Serum and liver total cholesterol, triglyceride and non-esterified fatty acids, as well as hepatic malonaldehyde levels were accessed by biochemical methods. Serum and liver TNF-α levels were quantified by ELISA kit. Histologic analysis and 1H-MRS study were performed to evaluate HS level. RT-PCR and Western blot were also applied to observe the expression changes of key factors involved in hepatic lipid intake, synthesis, utilization and export. RESULTS: ChE significantly decreased the rats' body weight, serum lipid and TNF-α level. ChE also reduced their relative liver weight, liver fat content, hepatic oxidative products and TNF-α level. Hepatic steatosis in HFD-fed rats was effectively regressed after 2-weeks administration of ChE. Moreover, ChE treatment remarkably reduced HFD-induced high expression level of fatty acid synthesis genes (including sterol-regulatory element-binding protein 1, acetyl-CoA carboxylase 1 and fatty acid synthase). However, it had no effect on mRNA expression of some genes involved in lipid uptake, ß-oxidation and lipid outflow. CONCLUSION: ChE exerted a promising regression effect on HS due to a reduced level of serum non-esterified fatty acids which might lead to a decrease in the amount of lipid taken in by the liver, as well as owing to the inhibition of hepatic lipid de novo synthesis to reduce liver lipid production.

C21 steroidal glycosides from Cynanchum stauntonii induce apoptosis in HepG2 cells.

Two new (1-2) and three known (3-5) C21 steroidal glycosides were isolated from Cynanchum stauntonii. Their structures were elucidated on the basis of 1D and 2D-NMR spectroscopic data as well as HRTOFMS analysis. The cytotoxicity of the compounds against A549, HepG2, and 4T1 cell lines were evaluated by MTT assay. Compound 4 exhibited good inhibitory activities with the IC50 values 26.82, 12.24, and 44.12 µM, respectively. Furthermore, compound 4 could induce G1 phase arrest, upregulate the expression levels of caspases-3, -9, and Bax, and downregulate the expression level of Bcl-2. These results indicated that compound 4 might be valuable to anticancer drug candidates.