Phosphorylated modification and in vitro antioxidant activity of Radix Hedysari polysaccharide

Phosphorylated modification of a polysaccharide obtained from Radix Hedysari (RHP) was studied. Three phosphorylated polysaccharides (RHPP) with variable degrees of substitution (DS(p)) were obtained with 4-dimethylaminopyridine (DMAP) and N, N' Dicyclocarbodiimide (DCC) as catalyst. The structures of RHPP were characterized by FT-IR spectra and (13)C NMR spectra. Depending on different reaction time, RHPP showed different DS(p) ranging from 0.30 to 0.66, and different Mw ranging from 86.6 to 89.7?KDa. Compared with RHP, RHPP exhibited superior antioxidant activities in vitro, which indicated that phosphorylated modification could enhance antioxidant activities of RHP. Furthermore, it was obvious that the DS(p) had a significant effect on the antioxidant activity.     

Postharvest senescence of fresh lotus pods and seeds is delayed by treatment with 1‐methylcyclopropene

Fresh lotus pods were treated with 1‐methylcyclopropene (1‐MCP) at a concentration of 0.5 μL L^?1 for 24 h at 25°C and then stored at 25°C for 8 days. First, their quality and physiological changes during storage were measured in terms of visual appearance, respiration rate, firmness, and the contents of sugars, protein, total phenolics and malondialdehyde (MDA). The results showed that the 1‐MCP treatment reduced the browning of fresh lotus pods, and inhibited the respiration rate during storage. In addition, the 1‐MCP treatment alleviated changes in firmness, delayed starch and protein degradation, and the accumulation of reducing sugars and total sugars in lotus seeds, preserving the good taste of lotus seeds. Moreover, the 1‐MCP treatment alleviated the increase of MDA and effectively inhibited the decrease in total phenolics in lotus seeds during days 6 to 8 of storage. Meanwhile, the results of antioxidant capacity in lotus seeds indicated that 1‐MCP not only sustained a higher level of 1,1‐diphenyl‐2‐picrylhydrazyl free radical scavenging activity, but also increased the activities of superoxide dismutase, catalase and peroxidase throughout the storage period. However, the 1‐MCP treatment reduced polyphenol oxidase activity in seeds relative to the control. Moreover, we found that the adenosine triphosphate content and energy charge during the last 4 days of storage were higher in 1‐MCP‐treated seeds than in the control. These results indicated that the use of 0.5 μL L^?1 1‐MCP provided an effective method, via multiple lines of evidence, to delay the postharvest senescence of fresh lotus pods and seeds.     

The combined effect of 1‐methylcyclopropene and citral suppressed postharvest grey mould of tomato fruit by inhibiting the growth of Botrytis cinerea

1‐Methylcyclopropene (1‐MCP, 1 μl/L) and 1 × minimum fungicidal concentration (MFC) citral alone and in combination were used to treat on postharvest tomato fruits to investigate their influence on disease incidence and postharvest quality during fruit storage, which were stored at 90%–95% relative humidity and 25 ± 2°C. Weight loss, pH, hue angle (Hue^°), total soluble solid (TSS), ascorbic acid content, firmness and antioxidant enzyme activities were evaluated after each storage period. 1 μl/L 1‐MCP or 1 × MFC citral reduced weight loss, retarded peel colour changes and retained postharvest fruit quality. 1 μl/L 1‐MCP + 1 × MFC citral could better maintain firmness and ascorbic acid content and increase antioxidant enzyme activities, compared to other treatments. Disease incidence of tomato fruit was significantly decreased, and spore germination and mycelia growth of Botrytis cinerea were suppressed by the combined treatment with 1 μl/L 1‐MCP and 1 × MFC citral. These results indicate that the combined treatment could effectively delay postharvest tomato fruits senescence and inhibit postharvest pathogens in vitro.     

Dimerization of piceatannol by Momordica charantia peroxidase and α-glucosidase inhibitory activity of the biotransformation products

Stilbenes, especially those oligomers, have great potential to be antihyperglycemic agents. In this study, eight stilbene dimers, including five new ones, were obtained by biotransformation of piceatannol using Momordica charantia peroxidase (MCP) for the first time. Their structures were established on the basis of spectroscopic evidences. These piceatannol dimers displayed potential α-glucosidase inhibitory activities, and trans double bond, tetrahydrofuran ring, and free adjacent phenolic dihydroxyls were found to be important for their activities. Enzymatic biotransformation of stilbenes by M.charantia peroxidase (MCP) was showed to be a prominent way to produce oligomeric stilbenes for antihyperglycemic development.     

Anti-hyperglycemic and anti-oxidative effect of aqueous extract of Momordica charantia pulp and Trigonella foenum graecum seed in alloxan-induced diabetic rats

Diabetes is an oxidative stress disorder and oxidative damage to tissues such as heart, kidney, liver and other organs may be a contributory factor to several diabetic complications. Momordica charantia (family: Cucurbitaceae) and Trigonella foenum graecum (family: Fabaceae) are used traditionally in Indian folk medicine to manage diabetes mellitus. In the present study, the anti-hyperglycemic and anti-oxidative potential of aqueous extracts of M. charantia pulp and seed powder of T. foenum graecum were assessed in alloxan (150 mg/kg body weight) induced diabetic rats. Alloxan treatment to the rats could induce diabetes as the fasting blood glucose (FBG) levels were > 280 mg/dl. Treatment of diabetic rats for 30 days with M. charantia and T. foenum graecum could significantly (p < 0.001) improve the FBG levels to near normal glucose levels. Antioxidant activities (superoxide dismutase, catalase, reduced glutathione content and glutathione-s-transferase) and lipid peroxidation levels were measured in heart, kidney and liver tissues of normal, diabetic and experimental animals (diabetics + treatment). TBARS levels were significantly (p < 0.001) higher and anti-oxidative activities were found low in diabetic group, as compared to the control group. Significant (p < 0.001) improvement in both the TBARS levels and antioxidant activities were observed when M. charantia and T. foenum graecum were given to diabetic rats. Our results clearly demonstrate that M. charantia and T. foenum graecum are not only useful in controlling the blood glucose levels, but also have antioxidant potential to protect vital organs such as heart and kidney against damage caused due to diabetes induced oxidative stress.     

Sulfated modification and cytotoxicity of <Emphasis Type="Italic">Portulaca oleracea</Emphasis> L. polysaccharides

A water-soluble polysaccharide (POP1) was isolated from Portulaca oleracea L. Four sulfated derivatives of POP1 (POP1-s1, POP1-s2, POP1-s3 and POP1-s4) were prepared by chlorosulfonic acid method with N,N-Dicyclohexylcarbodiimide (DCC) as a dehydration-condensation agent. FT-IR spectra and ¹³C NMR spectra indicated the sulfated groups had been introduced at the C-6 and C-2 positions of POP1. Sulfated derivatives had different degree of substitution (DS) ranging from 1.01 to 1.81, and different weight-average molecular mass (Mw) ranging from 41.4 to 48.5 KDa. Sulfated derivatives except POP1-s5 inhibited the growth of HepG2 cells and Hela cells in vitro significantly, which indicated that sulfated modification could enhance cytotoxicity of POP1 on tumor cells. Flow cytometric studies revealed that sulfated derivatives could mediate the cell-cycle arrest of Hela cells in the S phase.     

Isolation and partial characterization of 3 nontoxic d‐galactose–specific isolectins from seeds of Momordica balsamina

Three isolectins denoted hereforth MBaL‐30, MBaL‐60, and MBaL‐80 were isolated from seeds extract of Momordica balsamina by 30%, 60%, and 80% ammonium sulfate saturations, respectively. The native molecular weights of these lectins, as judged by gel filtration, were 108, 56, and 160 kDa, respectively. On SDS‐PAGE, under reduced condition, 27 kDa band was obtained for all isolectins. The lectins hemagglutinating activities were variably inhibited by d ‐galactose (minimum inhibitory concentrations = 12.5mM, 50mM, and 0.391mM, respectively). MBaL‐30 and ‐60 could agglutinate all human blood types with slight preference for the A and O blood groups, whereas MBaL‐80 did not agglutinate B and AB blood types. The 3 isolectins were purified from crude seeds extract, collectively, in a single step on the affinity matrix Lactamyl‐Seralose 4B; this purified lectin fraction, which contains all isolectins, is termed MBaL. The N‐terminal of MBaL till the 25th amino acid was NLSLSELDFSADTYKSFIKNLRKQL, which shares 88% sequence identity with Momordica charantia lectin type‐2 ribosomal inactivating protein from Momordica charantia and 50% with momordin II from Momordica balsamina . MBaL retained 100% activity at up to 50°C for 30 minutes. MBaL‐30 and MBaL‐60 exhibited maximum activities in the pH range between 4 and 8, while MBaL‐80 was showing maximum activity in the pH range between 3 and 5. Treatment of MBaL‐30 and MBaL‐60 with EDTA completely abolished their hemagglutinating activities. Addition of Zn and Fe ions to the ethylenediaminetetraacetic acid–treated MBaL‐30 and MBaL‐60 lectins did not only regained the loss of activity but also resulted in 200% to 300% increase in activity, respectively. MBaL‐30 and ‐60 agglutinated gram positive Listeria monocytogenes and Staphylococcus aureus, whereas MBaL‐30 could merely agglutinate Escherichia coli . None of these lectins could arrest bacterial growth. Addition of MBaL to cancer cell lines (Gastric cancer cell line (AGS) and Gastric cencer cell line (MKN45), Glioblastoma (ECV‐304), and Human urinary bladder cancer cell line (U87‐MG)) at varying concentrations did not cause statistically significant changes on cell growth and viability.     

苦瓜多糖的提取、分离纯化及组成性质

正交实验确定提取工艺后,用热水提取法得到苦瓜多糖(MCP).对MCP进行DEAE-32离子交换层析分离,得到3个多糖组分MCP1、MCP2和MCP3. 进一步采用Sephacryl S-400凝胶层析进行分离,经凝胶层析和高效液相色谱检测表明,MCP1、MCP2为均一性多糖组分.通过高效液相凝胶色谱法测定了两者的相对分子质量分别为1.16×106和7.45×105.用PMP衍生化法测定其单糖,结果表明: MCP1系由Man、Rham、GlcUA、GalUA、Glu、Gal、Xyl、Ara等单糖组成的杂多糖,摩尔比为1.03:2.93:1.00:14.95:2.16:30.70:2.85:4.50.MCP2系由Rham、GalUA、Gal、Xyl、Ara等单糖组成的杂多糖,对应的摩尔比为1.63:21.88:4.66:1.00:1.29.紫外光谱表明该多糖不含蛋白质和核酸.     

苦瓜的营养价值、化学成分以及药理作用研究进展

本文总结了半个多世纪来国内外学者对苦瓜的研究,为苦瓜进一步开发提供了借鉴。     

Protection of Momordica charantia polysaccharide against intracerebral hemorrhage-induced brain injury through JNK3 signaling pathway

Abstract

It has been well documented that Momordica charantia polysaccharide (MCP) has multiple biological effects such as immune enhancement, anti-oxidation and anti-cancer. However, the potential protective effects of MCP on stroke damage and its relative mechanisms remain unclear. Our present study demonstrated that MCP could scavenge reactive oxygen species (ROS) in intra-cerebral hemorrhage damage, significantly attenuating the neuronal death induced by thrombin in primary hippocampal neurons. Furthermore, we found that MCP prevented the activation of the c-Jun N-terminal protein kinase (JNK3), c-Jun and caspase-3, which was caused by the intra-cerebral hemorrhage injury. Taken together, our study demonstrated that MCP had a neuroprotective effect in response to intra-cerebral hemorrhage and its mechanisms involved the inhibition of JNK3 signaling pathway.     

Variability of responses to 1-methylcyclopropene by banana: influence of time of year at harvest and fruit position in the bunch

To examine the effect of early‐climacteric (postripening) 1‐methylcyclopropene (1‐MCP) exposure on the shelf‐life and quality of green Cavendish bananas (Musa acuminata cv. Williams) from the middle section of the bunch, bananas were harvested bimonthly and treated with 100 μL L^?1 ethylene for 2 consecutive days prior to exposure to 0, 100, 300, 1000, 3000 or 10 000 nL L^?1 1‐MCP for 24 h prior to storage at 22°C. 1‐MCP treatment at a concentration of 300 nL L^?1 or above increased banana shelf‐life significantly compared with the control, regardless of the month in which fruit were harvested except March where a higher concentration was needed (3000 nL L^?1). Fruit harvested in May were the most responsive with a greater than twofold increase in shelf‐life. To examine the effect of fruit position in the bunch on 1‐MCP efficacy, green fruit from the top or bottom of bunches were treated with 100 μL L^?1 ethylene for 2 consecutive days prior to early‐climacteric 1‐MCP (300 nL L^?1) exposure for 24 h at 22°C. In spring and autumn but not in summer, application of 1‐MCP to early‐climacteric fruit was more effective in fruit from the top than in those treated from the bottom of the bunch, increasing shelf‐life. Firmness of 1‐MCP‐treated fruit was up to 19% greater than that of the control across the year, except in fruit from the bottom of the bunch. Given that 1‐MCP is less effective in extending the shelf‐life of summer‐harvested fruit (particularly those from the bottom of the bunch), we conclude that preharvest conditions and fruit position in the bunch affect their responsiveness to ethylene and their behaviour during the ripening process.     

9种植物水浸提液对空心莲子草的化感作用

【背景】空心莲子草是难以防除的恶性入侵杂草,因此,探索高效无毒的化感防治方法具有重要意义。【方法】利用水浸提法研究了博落回、苦瓜、樟树、柳杉、凤尾蕨、柑橘、夹竹桃、洋葱及大蒜9种植物不同器官对空心莲子草的化感作用。【结果】与对照相比,博落回叶、苦瓜果肉与种子、凤尾蕨、樟树叶和柳杉叶的水浸提液对空心莲子草具有较强的化感作用,主要表现为空心莲子草叶片数和茎节数减少,株高与生物量的增长受到抑制。【结论与意义】不同植物水浸提液对空心莲子草的化感作用有所差异。本研究为利用植物的化感作用控制空心莲子草提供了依据。     

Carboxymethylation of a polysaccharide extracted from Ganoderma lucidum enhances its antioxidant activities in vitro

The chemical carboxylmethylated polysaccharide (C-GLP), which derived from water-insoluble crude Ganoderma lucidum polysaccharide (GLP), was prepared. Water solubility, chemical characterization, and antioxidant activities in vitro of C-GLP were determined. The solubility of C-GLP in distilled water reached 100 mg/ml, which was much higher than the solubility of GLP. Chemical analysis indicated that C-GLP was composed of Glc:Man:Gal = 33.0:1.0:3.4 with a molecular weight of 1.8 × 10⁶ Da and a carboxymethyl content of 11.07%. The signals of carboxymethyl were found in IR and ¹³C NMR spectra. Moreover, a high antioxidant activity of C-GLP was observed, especially in scavenging of hydroxyl radical (83.7% at 5 mg/ml) and hydrogen peroxide (51.6% at 10 mg/ml). This study indicates the effects of carboxymethylation on water-insoluble polysaccharide and explores a potential antioxidant in food industry and pharmaceuticals.     

Carboxymethylation of polysaccharides from Auricularia auricula and their antioxidant activities in vitro

The chemical carboxymethylated polysaccharide (CMAAP), which is derived from the poorly water-soluble, crude polysaccharide from Auricularia auricula (AAP), was prepared. The degree of substitution of CMAAP was 0.857, and its solubility in water reached 0.6 mg/mL, much higher than that of AAP (0.1 mg/mL). One fraction, CMAAP22, was purified. Chemical analysis indicated that CMAAP22 was composed of mannose and glucose in a ratio of 1.06:1 with a molecular weight of 3.4 × 10⁶ Da. IR spectra and ¹³C NMR spectra indicated that the C2, C4 and C6 positions were partially substituted by -CH₂COOH. AFM revealed that CMAAP22 was spherical particle structure with a diameter of 80-300 nm. Moreover, the antioxidant activity of CMAAP22 was improved, nearly twice as much as that of the AAP, especially in the scavenging of DPPH and ABTS+.     

Salivary immunity in elderly individuals presented with Candida-related denture stomatitis

doi: 10.1111/j.1741‐2358.2011.00476.x
Salivary immunity in elderly individuals presented with Candida‐related denture stomatitis Objectives: Elderly individuals with Candida‐related denture stomatitis (DS) present with a reduced defence against Candida albicans. This study evaluated levels of antimicrobial mediators in the elderly DS saliva and salivary neutrophils’ activation characteristics compared with elderly and young without DS. Methods: Salivary peroxidases (SPO) and elastase activities (ELA), nitric oxide (NO), transforming growth factor beta (TGF‐β), IL‐6 and CCL3 production were determined in saliva from elderly with or without DS, and young control individuals. TLR4, CXCR1, CD11b, CD16 and CD32 expression on salivary neutrophils were evaluated. Correlations between number and apoptosis rate of salivary neutrophils, enzymatic activities and cytokine levels were determined. Results: Elderly DS individuals exhibited the lowest SPO and ELA activities. Also, the activity of both enzymes was low in elderly without DS. Although both elderly groups showed higher salivary NO and TGF‐β levels compared to young control groups, elderly DS presented the highest salivary NO, TGF‐β, IL‐6 and CCL3 levels. Decreased percentages of salivary TLR4⁺ and CD16⁺ neutrophils were detected in both elderly groups. Although these damages could influence the establishment and persistence of DS, the highest levels of salivary IL‐6 and CCL3 in elderly DS could be preventing more serious complications.     

Development and characterization of polymorphic microsatellite markers in Momordica charantia (Cucurbitaceae)

? Premise of the study: Polymorphic microsatellite markers were developed for Momordica charantia L. to investigate the genetic diversity and population structure within and between M. charantia and its four related species (Cucurbita pepo L., Luffa cylindrical L., Lagenaria siceraria L., and Cucumis sativus L.). ? Methods and Results: Using the Fast Isolation by AFLP of Sequence COntaining Repeats (FIASCO) method, 16 polymorphic microsatellite loci were identified in 36 individuals of M. charantia. Across all the M. charantia samples, the number of alleles per locus ranged from three to eight. Seven primers successfully amplified in the four related species. ? Conclusions: These markers will be useful to study population ecology and population differentiation among M. charantia species and its related species.     

Plant extracts as an alternative to control Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)

We evaluated the effects of crude extracts from the plantain Plantago lanceolata and the bitter gourd Momordica charantia on the oviposition preference and development of the coffee leaf miner Leucoptera coffeella Guérin-Mèneville & Perrottet under laboratory and/or greenhouse conditions. The ovicidal effects of these extracts were also studied in a greenhouse. Plantago lanceolata and M. charantia extracts also underwent fractionation directed by oviposition tests with the coffee leaf miner. The extracts of both plants reduced L. coffeella oviposition and egg hatching, apparently as a result of action of plant metabolites on the embryo. Adults originating from eggs treated with the extracts exhibited similar survival rates, but a higher female/male ratio. Fecundity was reduced for females obtained from eggs treated with the M. charantia extract. Partial chemical analysis indicated that both extracts produced polar fractions that reduced the oviposition of L. coffeella on coffee leaves under laboratory conditions. The extracts of P. lanceolata and M. charantia have potential for use in the development of new products to control the coffee leaf miner.     

大孔吸附树脂对苦瓜皂甙的吸附研究

试验通过静态吸附对几种树脂进行筛选,结果表明D-101对苦瓜皂甙有较大的吸附率和解吸率,适合用来提取纯化苦瓜皂甙.进一步对D-101进行动态吸附研究,结果表明,浓度为95%的乙醇,3个柱体积可以洗脱几乎所有的苦瓜皂甙.苦瓜皂甙粗提物的上样浓度为2.8～5.6 ms/mL之间.     

High‐fat diet‐induced dysbiosis mediates MCP‐1/CCR2 axis‐dependent M2 macrophage polarization and promotes intestinal adenoma‐adenocarcinoma sequence

High‐fat diet (HFD) is a well‐known risk factor for gut microbiota dysbiosis and colorectal cancer (CRC). However, evidence relating HFD, gut microbiota and carcinogenesis is limited. Our study aimed to demonstrate that HFD‐induced gut dysbiosis promoted intestinal adenoma‐adenocarcinoma sequence. In clinical study, we found that HFD increased the incidence of advanced colorectal neoplasia (AN). The expression of monocyte chemoattractant protein 1 (MCP‐1), CC chemokine receptor 2 (CCR2) and CD163 in CRC patients with HFD was significantly higher than that in CRC patients with normal diet. When it comes to the Apc^min/+ mice, HFD consumption could induce gut dysbiosis and promote intestinal carcinogenesis, accompanying with activation of MCP‐1/CCR2 axis that recruited and polarized M2 tumour‐associated macrophages. Interestingly, transfer of faecal microbiota from HFD‐fed mice to another batch of Apc^min/+ mice in the absence of HFD could also enhance carcinogenesis without significant body weight gain and induced MCP‐1/CCR2 axis activation. HFD‐induced dysbiosis could also be transmitted. Meanwhile, antibiotics cocktail treatment was sufficient to inhibit HFD‐induced carcinogenesis, indicating the vital role of dysbiosis in cancer development. Conclusively, these data indicated that HFD‐induced dysbiosis accelerated intestinal adenoma‐adenocarcinoma sequence through activation of MCP‐1/CCR2 axis, which would provide new insight into better understanding of the mechanisms and prevention for HFD‐related CRC.     

Antioxidant property and production of exopolysaccharide from Armillaria mellea in submerged cultures: Effect of culture aeration rate

Effects of culture aeration rate on production and antioxidant property of exopolysaccharide (EPS) by Armillaria mellea were investigated in a 5‐L stirred‐tank bioreactor where an optimal biomass aeration rate of 1.2 vvm with 0.22 g/g cell yield and 0.6 vvm EPS formation rate with 7.66 mg/g product yield were achieved. A two‐stage aeration process to maximize the biomass and EPS productions proceeded with a 1.55‐fold enhancement (from 4.28 to 6.65 g/L) in biomass formation and a 2.68‐fold enhancement (from 86.9 to 233.2 mg/L) in the EPS production, as compared with those from the aeration rate of 0.3 vvm. The molecular weights of EPS in cultures of different aeration rates are closely correlated with their protein/polysaccharide ratios (R²=0.830) and EC₅₀ (EC₅₀, the effective concentration where the antioxidant property is 50%) values in antioxidant activity (R²=0.960), reducing power (R²=0.894) and chelating ability (R²=0.954). EPS from the two‐stage aeration rate culture shows a strong antioxidant property by the conjugated diene method, reducing power and chelating ability on ions. Therefore, we present results to regulate and to optimize A. mellea cultures to efficiently produce biomass and EPS. The fermented EPS has the potential to be used as for antioxidant‐related functional foods and pharmaceutical industries.