Rat lens aldose reductase inhibitory activities of Coptis japonica root-derived isoquinoline alkaloids

The inhibitory activity of Coptis japonica root-derived materials was evaluated against lens aldose reductase isolated from male Sprague-Dawley rats and compared to that of three commercially available isoquinoline alkaloids (berberine sulfate, berberine iodide, and palmatine chloride), as well as quercitrin as aldose reductase inhibitor. The biologically active constituents of C. japonica extract were characterized as the isoquinoline alkaloids, berberine chloride and palmatine iodide, by spectral analysis. The inhibitory effects varied with both chemical and concentration used. The IC(50) values of berberine chloride and palmatine iodide are 13.98 and 13.45 nM, respectively. Among three berberines and two palmatines, the inhibitory activity was much greater for the choridated and sulfated analogues than for those with iodide. Quercitrin was a much more potent inhibitor than berberines and palmatines. Nonetheless, berberines and palmatines may be useful as lead compounds and new agents for aldose reductase inhibition.     

Selective growth-inhibiting effects of compounds identified in Tabebuia impetiginosa inner bark on human intestinal bacteria

The growth-inhibiting activity of anthraquinone-2-carboxylic acid and lapachol identified in the inner bark of taheebo, Tabebuia impetiginosa, toward 10 human intestinal bacteria was evaluated by using a paper disk diffusion bioassay and compared to those of seven lapachol congeners (1,4-naphthoquinone, naphthazarin, menadione, lawsone, plumbagin, juglone, and dichlone) as well as two commercially available antibiotics, chloramphenicol and tetracycline. Anthraquinone-2-carboxylic acid exhibited very strong growth inhibition of Clostridium paraputrificum at 1 microg/disk while 100 microg/disk of lapachol was needed for moderate growth inhibition of the same organism. These two isolates exhibited weak inhibition of Clostridium perfringens and Escherichia coli at 100 microg/disk while no adverse effects were observed on the growth of Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium infantis, Lactobacillus acidophilus, and Lactobacillus casei at 1000 microg/disk. Structure-activity relationships indicate that a methyl group in the C-2 position of 1,4-naphthoquinone derivatives might play an important role in antibacterial activity.     

Degradation of neohesperidin dihydrochalcone by human intestinal bacteria

The degradation of neohesperidin dihydrochalcone by human intestinal microbiota was studied in vitro. Human fecal slurries converted neohesperidin dihydrochalcone anoxically to 3-(3-hydroxy-4-methoxyphenyl)propionic acid or 3-(3,4-dihydroxyphenyl)propionic acid. Two transient intermediates were identified as hesperetin dihydrochalcone 4'-beta-d-glucoside and hesperetin dihydrochalcone. These metabolites suggest that neohesperidin dihydrochalcone is first deglycosylated to hesperetin dihydrochalcone 4'-beta-d-glucoside and subsequently to the aglycon hesperetin dihydrochalcone. The latter is hydrolyzed to the corresponding 3-(3-hydroxy-4-methoxyphenyl)propionic acid and probably phloroglucinol. Eubacterium ramulus and Clostridium orbiscindens were not capable of converting neohesperidin dihydrochalcone. However, hesperetin dihydrochalcone 4'-beta-d-glucoside was converted by E. ramulus to hesperetin dihydrochalcone and further to 3-(3-hydroxy-4-methoxyphenyl)propionic acid, but not by C. orbiscindens. In contrast, hesperetin dihydrochalcone was cleaved to 3-(3-hydroxy-4-methoxyphenyl)propionic acid by both species. The latter reaction was shown to be catalyzed by the phloretin hydrolase from E. ramulus.     

Selective responses of three Ginkgo biloba leaf-derived constituents on human intestinal bacteria

The selective responses of Ginkgo biloba leaf-derived materials against six intestinal bacteria was examined using an impregnated paper disk method and compared with that of bilobalide, ginkgolides A and B, kaempferol, and quercetin. The components of G. biloba leaves were characterized as kaempferol 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside), kaempferol 3-O-(2' '-O-beta-D-glucopyranosyl)-alpha-L-rhamnopyranoside, and quercetin 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside) by spectroscopic analysis. The growth responses varied with each bacterial strain tested. At 2 mg/disk, kaempferol 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside) and quercetin 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside) revealed potent inhibition against Clostridium perfringens, and kaempferol 3-O-(2' '-O-beta-D-glucopyranosyl)-alpha-L-rhamnopyranoside showed a clear inhibitory effect on Escherichia coli. At 0.5 mg/disk, quercetin 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside) showed a strong activity against C. perfringens, but weak activity was exhibited by kaempferol 3-O-alpha-(6' "-p-coumaroylglucosyl-beta-1,4-rhamnoside) against C. perfringens and kaempferol 3-O-(2' '-O-beta-D-glucopyranosyl)-alpha-L-rhamnopyranoside against E. coli. No inhibition was observed from treatments conducted with bilobalide, ginkgolides A and B, kaempferol, or quercetin. Furthermore, these isolated compounds did not inhibit Bifidobacterium bifidum, B. longum, B. adolescentis, or Lactobacillus acidophilus.     

Antiphotooxidative activity of protoberberines derived from Coptis japonica makino in the chlorophyll-sensitized photooxidation of oil

Antiphotooxidative components were isolated from the methanolic extract of Coptis japonica Makino by liquid-liquid partitioning fractionation, subsequent column chromatography on Sephadex LH-20 and silica gel, and preparative silica gel TLC. The isolated compounds were identified as coptisine, jatrorrizhine, berberine, and magnoflorine by a combination of spectroscopic studies using UV-visible, IR, mass-spectrometry, and NMR. Coptisine, jatrorrizhine, and berberine isolated from Coptis japonica Makino showed strong antiphotooxidative activity in the chlorophyll-sensitized photooxidation of linoleic acid. However, these compounds did not show either inhibitory activity against lipid peroxidation in rat liver microsomes nor DPPH radical scavenging activity, indicating that their antiphotooxidative activity was not due to the radical chain reaction breaking ability but due to singlet oxygen quenching activity. Commercially available authentic protoberberines (berberine chloride and palmatine chloride) also showed strong antioxidative activity in the chlorophyll-sensitized photooxidation of linoleic acid. The antiphotooxidative activities of the berberine chloride and palmatine chloride were significantly higher than that of ascorbyl palmitate in the chlorophyll-sensitized photooxidation of linoleic acid. These results clearly showed for the first time the antiphotooxidative properties of protoberberines in chlorophyll-sensitized photooxidation of oil.     

Selective growth inhibitor toward human intestinal bacteria derived from Pulsatilla cernua root

Among 21 medicinal plants, the growth-inhibiting activity of Pulsatilla cernua root-derived materials toward human intestinal bacteria was examined by using an impregnated paper disk method. The biologically active components of P. cernua roots were characterized as 4-hydroxy-3-methoxycinnamic acid and 3,4-dihydroxycinnamic acid by spectroscopic analysis. The activity was compared with that of six commercially available cinnamic acid derivatives trans-cinnamaldehyde, trans-cinnamic acid, cinnamyl alcohol, 2-methoxycinnamic acid, 3-methoxycinnamic acid, and 4-methoxycinnamic acid. The growth responses varied with each bacterial strain tested. Two isolated compounds revealed a potent inhibition against Clostridium perfringens, and moderate to weak activity against Escherichia coli was exhibited by 4-hydroxy-3-methoxycinnamic acid. Weak or no inhibitory activity was obtained against the bifidobacteria or Lactobacillus acidophilus. The inhibitory effect was much more pronounced in C. perfringens and E. coli as compared to B. adolescentis, B. bifidum, B. fragilis, B. longum, or L. acidophilus. Cinnamaldehyde exhibited a strong growth-inhibiting activity, but no inhibition was observed from treatments with trans-cinnamic acid, cinnamyl alcohol, 2-methoxycinnamic acid, 3-methoxycinnamic acid, and 4-methoxycinnamic acid. These results may be an indication of at least one of the pharmacological actions of P. cernua root.     

Differential effects of flavonoids on barrier integrity in human intestinal Caco-2 cells

Flavonoids, present in fruits, vegetables, and teas, provide beneficial effects for our health. We investigated the effect of a number of flavonoids on tight junction (TJ) barrier integrity in human intestinal Caco-2 cells. Transepithelial electrical resistance (TER; a TJ integrity marker) across cell monolayers was measured in cells incubated with flavonoids for 24 h. Chrysin decreased the TER, indicating a decrease in TJ integrity. Daidzein, hesperetin, naringenin, and morin increased the TER, indicating increased TJ integrity. Luteolin and genistein increased or normalized the TER after a transient decrease. Immunoblot analysis revealed that these changes in TER were caused by modification of the cytoskeletal association and expression of TJ proteins, zonula occludens (ZO)-1, ZO-2, occludin, junctional adhesion molecule-1, and/or claudins. Our results suggest that various flavonoids participate in the regulation of intestinal TJ barrier integrity and that this regulation may partially contribute to the flavonoid-mediated biological effects on our health.     

Screening of intestinal microflora for effective probiotic bacteria

Increasing consumer awareness of health-promoting intestinal bacteria has fueled the addition of viable probiotic bacteria as functional ingredients in certain foods. However, to effectively market the enhanced attributes of these foods, the added probiotic bacteria need to have scientific credibility. The scientific rationale for using many of the strains of probiotic bacteria currently on the market is weak. Furthering the current understanding of what features a bacterium needs to have for effective probiotic functionality will enable the selection of strains with a more credible scientific rationale. To screen for effective strains, one must understand the microbial diversity in the intestines of healthy individuals. The advent of molecular tools has greatly enhanced our ability to accomplish this. These tools comprise genetic fingerprinting, specific probes, molecular speciation, and techniques for the in situ analysis of specific microbial groups in the intestine. This review will detail these scientific approaches and how their impact will improve criteria for selection of probiotic bacteria.     

Combination effects of heavy metals and fluoranthene on soil bacteria

The effects of (1) Cd, Cu, Zn, and fluoranthene (FLA), separately applied, and (2) combinations of one of these heavy metals with FLA on the growth of bacteria were studied in agar plate experiments. The bacteria were extracted from A horizons of a Eutric Regosol and a Calcic Chernozem. Significant reductions of bacterial counts were observed for both soils at concentrations > 1.0 mg Cd l^–1, 0.5 mg Cu l^–1, and 0.5 mg Zn l^–1, respectively. Additions of FLA up to 100 mg l^–1 did not result in increasing reductions of bacterial growth in the Regosol. Only 0.5, 2, and 100 mg FLA l^–1 caused significant reductions of 22–27%. Bacterial counts were not affected by 0.2 mg FLA l^–1. Low concentrations of heavy metals which were not affective when added separately were found to reduce bacterial growth when applied in combination with 0.2 mg FLA l^–1. At higher levels of heavy metals up to 2.5 mg l^–1, addition of FLA also increased the toxicity of the metals. It is assumed that the enhancement of toxicity by FLA is due to an alteration of the permeability of bacterial cell membranes. Received: 19 July 1996     

Laboratory tests can predict beneficial effects of phosphate-solubilising bacteria on plants

Phosphorus is important in plant growth but in the soil it reacts readily to form insoluble compounds, which are not readily available for plant utilisation. Although the presence of soil microorganisms capable of solubilising phosphate has been known for many years, their isolation and use as crop inoculants have met with only limited success. This project aimed to develop a more robust method of selecting strains, which would give a more reliable indication of their usefulness for Australian crops, with a particular focus on wheat. Bacteria were isolated from a typical black wheat growing soil from the North-Western wheat belt of New South Wales using a differential medium containing insoluble phosphate. In all, 48 isolates were tested in the laboratory for their ability to colonise the roots of wheat seedlings in sterile perlite and to solubilise phosphate in the rhizosphere of plants grown on agar plates. To establish whether strains selected for their laboratory performance could benefit wheat grown in unsterilised field soil, a pot trial was carried out in a high-illumination growth chamber. Seven strains of varying capabilities were used to determine the effects of inoculation on releasing unavailable phosphorus and improving growth and yield, in comparison with conventional phosphorus fertiliser. Strains that were good phosphorus solubilisers in laboratory tests resulted in increased grain yield and grain phosphorus content in the presence or absence of applied dicalcium phosphate. It was also seen that the ability to colonise plant roots in high numbers was not always necessary for a positive effect. Strains that were predicted in the laboratory to be either poor or highly variable phosphorus solubilisers performed worst in the pot trial. The laboratory tests were found to be useful tools for quickly ranking isolates in terms of their ability to supply the phosphorus requirements of wheat grown in pots of non-sterile soil.     

Spectrophotometric analysis of alkaloids with picrolonic acid.

The spectroscopic characteristics of the interaction of alkaloids with picrolonic acid were studied. In solvents of low and intermediate polarity, the presence of alkaloids caused a red shift of the 322 nm band of nonionized picrolonic acid to 355 nm, corresponding to the anionic resonance band. There was also a considerable increase in absorptivity, which was dependent on both the basicity (pKa) and molar concentration of the alkaloid present. Arylamines, aromatic N-heterocycles, and alkaloids lacking an aliphatic amine moiety did not show observable shifts. The interaction was developed into a spectrophotometric assay for the following alkaloids in pharmaceutical preparations: atropine, ephedrine, codeine, emetine, quinine, and strychnine. The method is sensitive to 2 mug alkaloid/ml, with an accuracy of not equal to 1.5% and a standard deviation of not equal to 1.05 - 1.31%.     

Antioxidative effects of lactic acid bacteria on the colonic mucosa of iron-overloaded mice

The antioxidative effects of lactic acid bacteria on lipid peroxidation in the colonic mucosa were investigated. Among 49 strains of lactic acid bacteria, Streptococcus thermophilus YIT 2001 showed the highest inhibitory activity against lipid peroxidation in liposomes induced by ferrous iron. Feeding a diet containing 0.4% St. thermophilus YIT 2001 (2 x 10(8) colony-forming units per mouse per day) for 2 weeks caused a significant decrease of lipid peroxide (thiobarbituric acid reactive substance) in the colonic mucosa of iron-overloaded mice (0.07% Fe in the diet). The mucosal lipid peroxide level did not correlate with the soluble iron concentration of the cecal contents. Therefore, it is suggested that the antioxidative effect of St. thermophilus YIT 2001 in the colonic mucosa was not due to the removal of ferrous iron from the reaction system of lipid peroxidation.     

Resistance of autochthonous soil bacteria to shock biocide effects

It was determined that bacteria in soils are characterized by a high resistance to short (1 day) treatments with saturated solutions of mineral salts, 96% ethanol, 1 N HCl, and 1 N NaOH. The soil treatment with acid and alkali did not cause any significant decrease of the bacteria number (staining with acridine orange) in the studied samples of alluvial meadow soil and ordinary chernozem; a significant amount of cells (10 to 30%) preserved the undisturbed structure of their DNA. The shock effects of the saturated salt solutions and ethanol on the bacteria were much weaker as compared with the acid and alkali treatments: 60 to 90% of the cells preserved an undisturbed structure of their DNA. The biocide treatments had significant effects on the number of saprotrophic bacteria grown on a glucose-peptone-yeast medium and manifested themselves in a decrease of the amount and taxonomic diversity, as well as in the essential rearrangement of the structure, of the saprotrophic bacterial complex: the absolute domination of bacilli and almost complete inhibiting of Gram-negative bacteria were observed. The proteobacteria and cytophagous bacteria appeared to be most sensitive to the biocide soil treatments; the bacteria of the actinomycetic line and bacilli were less sensitive. The cells resistant to the applied treatments were almost always found among the representatives of the Arthrobacter, Rhodococcus, Micrococcus, Myxococcus, and Polyangium genera.     

Fermentation of plant cell wall derived polysaccharides and their corresponding oligosaccharides by intestinal bacteria

New types of nondigestible oligosaccharides were produced from plant cell wall polysaccharides, and the fermentation of these oligosaccharides and their parental polysaccharides by relevant individual intestinal species of bacteria was studied. Oligosaccharides were produced from soy arabinogalactan, sugar beet arabinan, wheat flour arabinoxylan, polygalacturonan, and rhamnogalacturonan fraction from apple. All of the tested substrates were fermented to some extent by one or more of the individual species of bacteria tested. Bacteroides spp. are able to utilize plant cell wall derived oligosaccharides besides their reported activity toward plant polysaccharides. Bifidobacterium spp. are also able to utilize the rather complex plant cell wall derived oligosaccharides in addition to the bifidogenic fructooligosaccharides. Clostridium spp., Klebsiella spp., and Escherichia coli fermented some of the selected substrates in vitro. These studies do not allow prediction of the fermentation in vivo but give valuable information on the fermentative capability of the tested intestinal strains.     

Effect of dextransucrase cellobiose acceptor products on the growth of human gut bacteria

The selective fermentation by human gut bacteria of gluco-oligosaccharides obtained from the reaction between the glucosyl group of sucrose and cellobiose, catalyzed by dextransucrases (DSR) from Leuconostoc mesenteroides , has been evaluated. Oligosaccharides were fractionated according to their molecular weight, and their effect on the growth of different bacterial groups was studied. To determine the structure (position and configuration of glycosidic linkages)-function relationship, their properties were compared to those of DSR maltose acceptor products (DSRMal) and of recognized prebiotic carbohydrates (fructo-oligosaccharides, FOS). Cellobiose acceptor products (DSRCel) showed bifidogenic properties similar to those of FOS. However, no significant differences related to molecular weight or isomeric configurations were found for DSRCel and DSRMal products.     

缓释复合肥对黄连营养效应的研究

田间试验研究了4种黄连缓释专用复合肥（SRF）对3～5年生黄连产量与药用品质的影响。结果表明,缓释复合肥料较普通复合肥料（CK）显著或极显著提高各年份黄连的生物量与根茎产量，以SRF4与SRF-的增加幅度最大（6．3％～18．7％）。各缓释复合肥处理对不同年份黄连植株地上部和地下部养分含量的影响表现为氮、磷养分含量变化特点相同。钾含量则相反。缓释复合肥的养分比例明显影响不同年份黄连的药用品质，SRF3对3年生和5年生黄连小檗碱、生物碱含量增加明显，4年生黄连则以SRF-的提高作用最大。无论地上部还是地下部，较高的N／P比、N／K比，较低的K／P比均有利于提高不同年份黄连的产量，提出的高产（量）优质处理对应的养分比例可作为高产优质黄连植株营养诊断的重要依据。     

Orosensory stimulation effects on human saliva proteome

Saliva flow induced by 6-gingerol (pungent), hydroxy-α/β-sanshools (tingling), and citric acid (sour) was measured, and the time-dependent changes in the whole saliva proteome were analyzed by means of 2D-PAGE, followed by tryptic in-gel digestion and MALDI-TOF-MS peptide mass fingerprint analysis. The proteins showing significantly decreased abundance after oral 6-gingerol stimulation were identified as glutathione S-transferase P, the heat shock protein β-1, the heat shock 70 kDa protein 1, annexin A1, and cytoplasmic β-actin, whereas prolactin inducible proteins (PIP), short palate, lung and nasal epithelium carcinoma-associated protein 2 (SPLUNC2), zinc-α-2-glycoproteins (Zn-α-GP), and carbonic anhydrase VI (CAVI) were found with increased abundance. As the effects of this study were observed instantaneously upon stimulation, any proteome modulation is very likely to result from the release of proteins from preformed vesicles and not from de novo synthesis. The elevated levels of SPLUNC2, Zn-α-GP, and CAVI might be interpreted to trigger innate protective mechanisms in mucosal immunity and in nonimmune mucosal defense and might play an important role during the initial stage of inflammation.     

PGPR菌剂对辣椒的促生效应及根际土壤细菌的响应研究

研究田间条件下PGPR菌剂灌根对辣椒根际土壤细菌数量及群落结构的影响,为深入探究PGPR菌剂的田间促生机制提供理论依据。以4株PGPR菌株制成PGPR菌剂,对辣椒进行灌根,并采用Illumina-MiSeq平台对辣椒根际土壤细菌V3-V4区进行Paired-end测序,结合细菌及功能菌群数量、辣椒产量指标,比较分析菌剂灌根配施全量化肥(PGPR-CF1)、菌剂灌根配施80%化肥(PGPR-CF2)和全量化肥(CK)处理后对辣椒根际土壤细菌数量及群落结构特征的影响。结果表明:PGPR菌剂灌根后辣椒根际土壤细菌及包含固氮、解磷及解钾等功能菌群的数量显著提高,且物种丰度和多样性均高于对照,细菌优势度则表现为PGPR-CF1和CK组高于PGPR-CF2。所有土样共得到有效序列573 896条,在相似水平为97%下聚类分析得到OTUs数分别为2 153个(CK)、2 337个(PGPR-CF1)、2 358个(PGPR-CF2);各处理辣椒根际土壤中的优势门为酸杆菌门、放线菌门、拟杆菌门、绿弯菌门、浮霉菌门和变形菌门,相对丰度总占比分别为83.7%(PGPR-CF1)、79.55%(PGPR-CF2)和79.77%(CK)。PGPR菌剂灌根后增加了伯克霍尔德氏菌目、芽孢杆菌目、鞘脂单胞菌目等的相对丰度,降低了芽单胞菌目、酸杆菌目的相对丰度。Pearson指数表明,辣椒产量和单果重与根际土壤细菌多样性和丰度正相关。研究显示,PGPR菌剂处理,可以提高根际土壤细菌和功能菌群的数量,同时影响了物种多样性和群落结构,并促进了辣椒增产。     

产脂肽菌株发酵生物有机肥的生物防治与促生作用研究

选取对番茄青枯菌有明显抑制作用的产脂肽菌株XZ-173,与有机肥混合发酵制成生物有机肥。通过温室盆栽试验,评价了该生物有机肥对番茄青枯病的防治效果及对番茄的促生效用。结果表明,生物有机肥能够显著降低青枯病发病率,相对防效达56.8%。与施用化肥和未添加XZ-173的有机肥处理相比,施用该生物有机肥能显著提高番茄植株叶绿素含量、番茄地上部和地下部生物量、根际土壤细菌和放线菌数量,显著降低根际土壤中真菌数量。生物有机肥的有益效果使其在作物种植中具有广阔的应用前景。