Nitrogen fixation characteristics of root nodules in different peanut varieties and their relationship with yield.

Root nodules in peanut (Arachis hypogaea L.) could directly utilize nitrogen (N) in the atmosphere as N source, which plays an important role in the N supply in peanut. However, little is known about the mechanism of efficient N fixation by root nodule. In this study, 15N tracer technology was used to investigate the characteristics of N fixation by root nodule and its relationship with peanut yields of 19 varieties in a pot culture experiment. Results showed that there were significant differences in nodule number, fresh quality, internal material, N fixation amount and other related indices among different varieties. The range of number and fresh mass of root nodule was 170.59-696.15 per pot and 0.83-3.74 g per pot, with coefficients of variation (CV) of 36.1% and 41.1%, respectively. The range of leghaemoglobin content and nitrogenase activity was 15.51-23.23 mg per pot and 2.75-20.46 µmol C2H4·h-1 per pot, with CV of 13.1% and 57.2%, respectively. The CV of nitrogenase activity was significantly higher than that of leghaemoglobin content, indicating that nitrogenase activity was not only affected by leghaemoglobin content but also other factors. The range of N fixation by root nodule and total N accumulation was 0.71-1.82 and 2.16-3.72 g per pot, with CV of 21.6% and 12.9%, respectively. The CV of the former was significantly higher than that of the latter, indicating that other N sources could automatically compensate the deficit when N fixation of root nodule was insufficient. Nitrogen fixation by root nodule was one of the main N sources for peanut, while the average N supply percentage was more than 40% of the total N, with a maximum of 50%. Cultivating the variety with high N supply capacity is an effective way for N-saving cultivation in the peanut production. Except for nodule number, there were significantly positive correlations between the other indices and peanut yield, indicating that the physiological indicators of N fixation were closely related to N fixation capacity by root nodule and the final yield. Therefore, enhancing these characters would help achieve high yield of peanut and simultaneously reduce fertilizer application.

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.

Triterpenoids from Cyclocarya paliurus and their inhibitory effect on the secretion of apoliprotein B48 in Caco-2 cells.

Five previously undescribed compounds including two triterpenoid aglycones, 3ß,23-dihydroxy-1,12-dioxo-olean-28-oic acid and 3ß,23,27-trihydroxy-1-oxo-olean-12-ene-28-oic acid, and three triterpenoid glucosides cyclocarioside L-N, along with 17 known compounds were isolated from a CH3Cl-soluble extract of the leaves of Cyclocarya paliurus. Two 27-nor-triterpenoid glycosides were isolated from the genus for the first time. Furthermore, the characterized compounds were tested for the inhibitory effects on apoliprotein B48 secretion in Caco-2 cells. Seven triterpenoid aglycones together with four triterpenoid saponins significantly decreased the apoliprotein B48 oversecretion induced by oleic acid in Caco-2 cells.

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.

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.

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A total of twenty genotypes of peanut (Arachis hypogaea) were used to investigate the differences in nitrogen (N) utilization characteristics in a pot experiment with 15N isotope tracing analysis. Results showed the main N sources for peanut in high fertility soils following as soil N source > N fixed by root nodule source > fertilizer N source. The N uptake and accumulation in peanut from total N and the three N supplied sources (fertilizer N, soil N and N fixation) varied among the different genotypes. N fixation source had the largest genetic variation among the twenty genotypes while genetic variation for fertilizer N source and soil N source were lower and similar. Significant differences showed among the twenty genotypes in pod producing efficiency of N and N use efficiency, and the highest values were respectively 3.6 and 2.1 times of the lowest values. There were also significant differences among the twenty genotypes in the harvest indexes of total N, fertilizer N source, soil N source and N fixation source, and the largest variation showed in the harvest index of N fixation source. The pod yields significantly or extremely significantly corrected with N accumulation amounts from different N sources, N harvest index, pod producing efficiency of N, and N use efficiency. According to N uptake and accumulation and pod yield, four major types of peanut were classified, namely high total N accumulation high yield type, high fertilizer N source high yield type, high soil N source high yield type, and high N fixation source high yield type. Four of the twenty genotypes had all characteristics of the four major types.