Main Ustilaginoidins and Their Distribution in Rice False Smut Balls

Rice false smut has become an increasingly serious fungal disease in rice (Oryza sativa L.) production worldwide. Ustilaginoidins are bis-naphtho-γ-pyrone mycotoxins previously isolated from the rice false smut balls (FSBs) infected by the pathogen Villosiclava virens in rice spikelets on panicles. To investigate the main ustilaginoidins and their distribution in rice FSBs, five main bis-naphtho-γ-pyrones, namely ustilaginoidins A (1), G (2), B (3), I (4) and C (5), were isolated and identified by NMR and high-resolution mass spectrometry as well as by comparison with the data in the literature. The rice FSBs at early, middle and late maturity stages were divided into their different parts and the contents of five main ustilaginoidins for each part were determined by HPLC analysis. The results revealed that the highest levels of ustilaginoidins were in late stage rice FSBs, followed by those at middle stage. Most ustilaginoidins, 96.4% of the total quantity, were distributed in the middle layer at early stage. However, ustilaginoidins were mainly distributed in the outer and middle layers at middle and late stages. Small amounts of ustilaginoidins A (1) and G (2) were found in the inner part of rice FSBs at each maturity stage. The contents of ustilaginoidins A (1) and G (2) without hydroxymethyl groups at C-2 and C-2’ of the γ-pyrone rings in rice FSBs were relatively high at early stage, while the contents of ustilaginoidins B (3), I (4), and C (5) with hydroxymethyl groups at C-2 or C-2’ were relatively high at late stage.     

Development of a Monoclonal Antibody-Based icELISA for the Detection of Ustiloxin B in Rice False Smut Balls and Rice Grains

Rice false smut is an emerging and economically-important rice disease caused by infection by the fungal pathogen Villosiclava virens. Ustiloxin B is an antimitotic cyclopeptide mycotoxin isolated from the rice false smut balls that formed in the pathogen-infected rice spikelets. A monoclonal antibody (mAb) designated as mAb 1B5A10 was generated with ustiloxin B—ovalbumin conjugate. A highly-sensitive and specific indirect competitive enzyme-linked immunosorbent assay (icELISA) was then developed. The median inhibitory concentration (IC₅₀) of the icELISA was 18.0 ng/mL for the detection of ustiloxin B; the limit of detection was 0.6 ng/mL, and the calibration range was from 2.5 to 107.4 ng/mL. The LOD/LOQ values of the developed ELISA used for the determination of ustiloxin B in rice false smut balls and rice grains were 12/50 μg/g and 30/125 ng/g, respectively. The mAb 1B5A10 cross-reacted with ustiloxin A at 13.9% relative to ustiloxin B. Average recoveries of ustiloxin B ranged from 91.3% to 105.1% for rice false smut balls at spiking levels of 0.2 to 3.2 mg/g and from 92.6% to 103.5% for rice grains at spiking levels of 100 to 5000 ng/g. Comparison of ustiloxin B content in rice false smut balls and rice grains detected by both icELISA and high performance liquid chromatography (HPLC) demonstrated that the developed icELISA can be employed as an effective and accurate method for the detection of ustiloxin B in rice false smut balls, as well as rice food and feed samples.     

Genetic Relationships,Carbendazim Sensitivity and Mycotoxin Production of the Fusarium Graminearum Populations from Maize,Wheat and Rice in Eastern China

Members of the Fusarium graminearum species complex (FGSC) are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV) and deoxynivalenol (DON) and the estrogenic mycotoxin zearalenone (ZEN), which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str.) was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON) chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture.     

Mycotoxigenic Fungi and Natural Co-Occurrence of Mycotoxins in Rainbow Trout (Oncorhynchus mykiss) Feeds

Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of <10 to 4.2 × 10⁴ CFU/g on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), <10 to 5.1 × 10⁴ CFU/g on Dichloran Chloramphenicol Peptone Agar (DCPA) and <10 to 3.6 × 10⁴ CFU/g on Dichloran 18% Glycerol Agar (DG18). The most frequent mycotoxigenic fungi were Eurotium (frequency (Fr) 25.0%), followed by Penicillium (Fr 21.4%) and Aspergillus (Fr 3.6%). The most prevalent mycotoxigenic species were E. repens (Fr 21.4%) and E. rubrum (Fr 14.3%). All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb), 50% samples with zearalenone (median 87.97 ppb) and aflatoxins (median 2.82 ppb), 25% with ochratoxin A (median 5.26 ppb) and 3.57% samples with deoxynivalenol (median 230 ppb). Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples.     

Preliminary isolation and in vitro antiyeast activity of active fraction from crude extract of Gracilaria changii

Objective:

To isolate the active fraction from crude extract of Gracilaria changii and to determine its in vitro antifungal activity.

Materials and Methods:

The active fraction was isolated from the crude extract of G. changii by various purification procedures such as column chromatography, thin layer chromatography, bioauthograph etc. The in vitro antifungal activity (Candida albicans) of the active fraction (1.00, 0.50, and 0.25 mg/ml) was studied by disc diffusion method and the effect of the active fraction on the morphology of yeast was done by scanning electron microscope (SEM) studies.

Results:

An active fraction with remarkable antifungal activity was separated from the crude extract. The active fraction was effective as a fungicide against C. albicans and showed a dose-dependent antifungal activity. A Scanning Electron Microscope (SEM) study confirmed the fungicidal effect of G. changii active fraction on C. albicans, by changing the normal morphology of C. albicans.

Conclusion:

From G. changii crude extract, an active fraction with remarkable in vitro antifungal activity has been isolated.     

In vitro and in vivo antioxidant activities of the aqueous extract of Celosia argentea leaves

Objective:

The aqueous extract of Celosia argentea var. cristata L. leaves at 100, 200, and 400 mg/kg body weight (b.w.) was investigated against cadmium (Cd)-induced oxidative stress in Wistar rats. The in vitro antioxidant of the extract was evaluated using ammonium thiocyanate, reducing power, and membrane stabilizing models.

Materials and Methods:

For the in vivo study, 30 male rats (Rattus norvegicus) weighing 138.02 ± 7.02 g were completely randomized into 6 groups (A–F) of 5 animals each. Animals in groups A and B received 0.5 ml of distilled water and the same volume containing 8 mg/kg b.w. of Cd, respectively, for 7 days orally. Animals in groups C, D, E, and F were treated like those in group B except that they received 100 mg/kg b.w. of ascorbic acid, and 100, 200, and 400 mg/kg b.w. of the extract, respectively, in addition to Cd.

Results:

Phytochemical screening revealed the presence of alkaloids (0.61%), saponins (2.93%), cardiac glycosides (0.21%), cardenolides (0.20%), phenolics (3.26%), and flavonoids (2.38%). A total of 10 mg/ml of the extract inhibited linoleic acid oxidation by 67.57%. The highest reducing power was 100 mg/ml as against 10 mg/ml for ascorbic acid. In addition, 2 mg/ml of the extract produced a membrane stabilizing activity of 63.49% as against 77.46% for indomethacin. Compared with the distilled water control group, the administration of Cd alone significantly (P < 0.05) decreased the alkaline phosphatase activity of the rat liver and brain. This decrease was accompanied by a corresponding increase in the serum enzyme. The simultaneous administration of the extract and Cd produced an enzyme activity that compared favorably (P > 0.05) with the animals that received Cd and ascorbic acid. In addition, the reduction in the superoxide dismutase and catalase activity of the liver and brain of the animals, serum uric acid, albumin and bilirubin, and also the increase in the serum malondialdehyde content in animals treated with Cd alone was attenuated by the extract; the values compared well (P > 0.05) with those simultaneously administered with Cd and ascorbic acid.

Conclusion:

Overall, the results indicated that the aqueous extract of C. argentea leaves attenuated Cd-induced oxidative stress in the animals, with the best result at 400 mg/kg b.w. The antioxidant activity of the extract may be attributed to the phenolic and flavonoid components of the extract. The induction of antioxidant enzymes and scavenging of free radicals may account for the mechanism of action of the extract as an antioxidant.     

Biochemical Evaluation of the Hypoglycemic Effects of Extract and Fraction of Cassia fistula Linn. in Alloxan-induced Diabetic Rats

Various extracts of flowers of Cassia fistula Linn (Leguminosae) such as petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous, and crude aqueous extracts and two fractions of ethanol extract were tested for antihyperglycemic activity in glucose-overloaded hyperglycemic rats. The effective antihyperglycemic extracts and fraction were tested for their hypoglycemic activity at two dose levels, 200 and 400 mg/kg, respectively. To confirm their utility in higher models, the effective extracts and fraction of C. fistula were subjected to antidiabetic study in an alloxan-induced diabetic model at two dose levels, 200 and 400 mg/kg, respectively. Biochemical parameters like glucose, urea, creatinine, serum cholesterol, serum triglyceride, high-density lipoprotein, low-density lipoprotein, hemoglobin, and glycosylated hemoglobin were also assessed in experimental animals. The petroleum ether and ethanol extracts of C. fistula and the water-soluble fraction of ethanol extract were found to exhibit significant antihyperglycemic activity. The extracts, at the given doses, did not produce hypoglycemia in fasted normal rats, and the fraction exhibited weak hypoglycemic effect after 2 h of the treatment. Treatment of diabetic rats with ethanol extract and water-soluble fraction of this plant restored the elevated biochemical parameters significantly (P<0.05) to the normal level. No activity was found in the petroleum ether extract of the plant. Comparatively, the water-soluble fraction of ethanol extract was found to be more effective than the ethanol extract, and the activity was comparable with that of the standard, glibenclamide (5 mg/kg).     

In vitro and in vivo hepatoprotective effects of the total alkaloid fraction of Hygrophila auriculata leaves

Objective:

To investigate the total alkaloid fraction of the methanol extract of leaves of Hygrophila auriculata for its hepatoprotective activity against CCl4-induced toxicity in freshly isolated rat hepatocytes, HepG2 cells, and animal models.

Materials and Methods:

Mature leaves of H. auriculata were collected, authenticated, and subjected to methanolic extraction followed by isolation of total alkaloid fraction. Freshly isolated rat hepatocytes were exposed to CCl4 (1%) along with/without various concentrations of the total alkaloid fraction (80–40 µg/ml). Protection of human liver-derived HepG2 cells against CCl4-induced damage was determined by the MTT assay. Twenty-four healthy Wistar albino rats (150–200 g) of either sex were used for the in vivo investigations. Liver damage was induced by administration of 30% CCl4 suspended in olive oil (1 ml/kg body weight, i.p).

Results:

The antihepatotoxic effect of the total alkaloid fraction was observed in freshly isolated rat hepatocytes at very low concentrations (80–40 µg/ml). A dose-dependent increase in the percentage viability was observed when CCl4-exposed HepG2 cells were treated with different concentrations of the total alkaloid fraction. Its in vivo hepatoprotective effect at 80 mg/kg body weight was comparable with that of the standard Silymarin at 250 mg/kg body weight.

Conclusion:

The total alkaloid fraction was able to normalize the biochemical levels which were altered due to CCl4 intoxication.     

Multi-Toxic Endpoints of the Foodborne Mycotoxins in Nematode Caenorhabditis elegans

Aflatoxins B₁ (AFB₁), deoxynivalenol (DON), fumonisin B₁ (FB₁), T-2 toxin (T-2), and zearalenone (ZEA) are the major foodborne mycotoxins of public health concerns. In the present study, the multiple toxic endpoints of these naturally-occurring mycotoxins were evaluated in Caenorhabditis elegans model for their lethality, toxic effects on growth and reproduction, as well as influence on lifespan. We found that the lethality endpoint was more sensitive for T-2 toxicity with the EC₅₀ at 1.38 mg/L, the growth endpoint was relatively sensitive for AFB₁ toxic effects, and the reproduction endpoint was more sensitive for toxicities of AFB₁, FB₁, and ZEA. Moreover, the lifespan endpoint was sensitive to toxic effects of all five tested mycotoxins. Data obtained from this study may serve as an important contribution to knowledge on assessment of mycotoxin toxic effects, especially for assessing developmental and reproductive toxic effects, using the C. elegans model.     

Preparation of an in-house reference material containing fumonisins in Thai rice and matrix extension of the analytical method for Japanese rice

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi is taxonomically near to F. verticillioides, and there are sporadic reports of fumonisin contamination in rice from Asia, Europe and the United States. Therefore, there exists the potential risk of fumonisin contamination in rice as well as the need for the validated analytical method for fumonisins in rice. Although both natural and spiked reference materials are available for some Fusarium mycotoxins in matrices of wheat and maize, there are no reference materials for Fusarium mycotoxins in rice. In this study, we have developed a method for the preparation of a reference material containing fumonisins in Thai rice. A ShakeMaster grinding machine was used for the preparation of a mixed material of blank Thai rice and F. verticillioides-infected Thai rice. The homogeneity of the mixed material was confirmed by one-way analysis of variance, which led this material to serve as an in-house reference material. Using this reference material, several procedures to extract fumonisins from Thai rice were compared. Accordingly, we proved the applicability of an effective extraction procedure for the determination of fumonisins in Japanese rice.     

In vitro antioxidant activity of pet ether extract of black pepper

Objective:

To investigate the in vitro antioxidant activity of different fractions (R1, R2 and R3) obtained from pet ether extract of black pepper fruits (Piper nigrum Linn.)

Materials and Methods:

The fractions R1, R2 and R3 were eluted from pet ether and ethyl acetate in the ratio of 6:4, 5:5 and 4:6, respectively.1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract.

Results:

The free radical scavenging activity of the different fractions of pet ether extract of P. nigrum (PEPN) increased in a concentration dependent manner. The R3 and R2 fraction of PEPN in 500 µg/ml inhibited the peroxidation of a linoleic acid emulsion by 60.48±3.33% and 58.89±2.51%, respectively. In DPPH free radical scavenging assay, the activity of R3 and R2 were found to be almost similar. The R3 (100µg/ml) fraction of PEPN inhibited 55.68±4.48% nitric oxide radicals generated from sodium nitroprusside, whereas curcumin in the same concentration inhibited 84.27±4.12%. Moreover, PEPN scavenged the superoxide radical generated by the Xanthine/Xanthine oxidase system. The fraction R2 and R3 in the doses of 1000µg/ml inhibited 61.04±5.11% and 63.56±4.17%, respectively. The hydroxyl radical was generated by Fenton''s reaction. The amounts of total phenolic compounds were determined and 56.98 µg pyrocatechol phenol equivalents were detected in one mg of R3.

Conclusions:

P. nigrum could be considered as a potential source of natural antioxidant.     

Hemostatic properties of Venezuelan Bothrops snake venoms with special reference to Bothrops isabelae venom

In Venezuela, Bothrops snakes are responsible for more than 80% of all recorded snakebites. This study focuses on the biological and hemostatic characteristics of Bothrops isabelae venom along with its comparative characteristics with two other closely related Bothrops venoms, Bothrops atrox and Bothrops colombiensis. Electrophoretic profiles of crude B. isabelae venom showed protein bands between 14 and 100 kDa with the majority in the range of 14-31 kDa. The molecular exclusion chromatographic profile of this venom contains five fractions (F1-F5). Amidolytic activity evaluation evidenced strong thrombin-like followed by kallikrein-like activities in crude venom and in fractions F1 and F2. The fibrinogenolytic activity of B. isabelae venom at a ratio of 100:1 (fibrinogen/venom) induced a degradation of Aα and Bβ chains at 15 min and 2 h, respectively. At a ratio of 100:10, a total degradation of Aα and Bβ chains at 5 min and of γ chains at 24 h was apparent. This current study evidences one of rarely reported for Bothrops venoms, which resembles the physiologic effect of plasmin. B. isabelae venom as well as F2 and F3 fractions, contain fibrinolytic activity on fibrin plate of 36, 23.5 and 9.45 mm²/μg, respectively using 25 μg of protein. Crude venom and F1 fraction showed gelatinolytic activity. Comparative analysis amongst Venezuelan bothropoid venoms, evidenced that the LD₅₀ of B. isabelae (5.9 mg/kg) was similar to B. atrox-Puerto Ayacucho 1 (6.1 mg/kg) and B. colombiensis-Caucagua (5.8 mg/kg). B. isabelae venom showed minor hemorrhagic activity, whereas B. atrox-Parguasa (Bolivar state) was the most hemorrhagic. In this study, a relative high thrombin-like activity was observed in B. colombiensis venoms (502-568 mUA/min/mg), and a relative high factor Xa-like activity was found in B. atrox venoms (126-294 mUA/min/mg). Fibrinolytic activity evaluated with 10 μg protein, showed that B. isabelae venom contained higher specific activity (50 mm²/μg) than B. colombiensis and B. atrox venoms, which should encourage the isolation of these fibrinolytic molecules to improve the quality of immunotherapy.     

Hepatoprotective and anti-inflammatory activities of Plantago major L

Objective:

The aim of this study was to investigate anti-inflammatory and hepatoprotective activities of Plantago major L. (PM).

Materials and Methods:

Anti-inflammatory activity: Control and reference groups were administered isotonic saline solution (ISS) and indomethacin, respectively. Plantago major groups were injected PM in doses of 5 mg/kg (PM-I), 10 mg/kg (PM-II), 20 mg/kg (PM-III) and 25 mg/kg (PM-IV). Before and three hours after the injections, the volume of right hind-paw of rats was measured using a plethysmometer.

Hepatoprotective Activity:

The hepatotoxicity was induced by carbon tetrachloride (CCl4) administration. Control, CCl4 and reference groups received isotonic saline solution, CCl4 and silibinin, respectively. Plantago major groups received CCl4 (0.8 ml/kg) and PM in doses of 10, 20 and 25 mg/kg, respectively for seven days. Blood samples and liver were collected on the 8th day after the animals were killed.

Results:

Plantago major had an anti-inflammatory effect matching to that of control group at doses of 20 and 25 mg/kg. It was found that reduction in the inflammation was 90.01% with indomethacin, 3.10% with PM-I, 41.56% with PM-II, 45.87% with PM-III and 49.76% with PM-IV. Median effective dose (ED50) value of PM was found to be 7.507 mg/kg. Plantago major (25 mg/kg) significantly reduced the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels when compared to the CCl4 group. The histopathological findings showed a significant difference between the PM (25 mg/kg) and CCl4 groups.

Conclusion:

The results showed that PM had a considerable anti-inflammatory and hepatoprotective activities.     

Screening of Alkaloidal Fraction of Conium maculatum L. Aerial Parts for Analgesic and Antiinflammatory Activity

Conium maculatum Linn. (Umbelliferae) has been traditionally used in the treatment of spasmodic disorders, and to relieve nervous excitation, rheumatic pains in the old and feeble, pain in stomach, pain of gastric ulcer, nervousness and restlessness. Alkaloids have long been considered as bioactive group of constituents present in C. maculatum. Despite a long tradition of use, C. maculatum has not been evaluated pharmacologically to validate its traditional claims for analgesic and antiinflammatory activities. Thus, the present investigations were undertaken with an objective to evaluate alkaloidal fraction of C. maculatum aerial parts for analgesic and antiinflammatory activities. Test doses (100 or 200 mg/kg, p.o.) of alkaloidal fraction were evaluated for analgesic activity using tail flick test and antiinflammatory activity using carrageenan-induced paw oedema test in rats. Morphine (5 mg/kg, p.o.) and indomethacin (5 mg/kg, p.o.) were used as standard analgesic and antiinflammatory drugs, respectively. Alkaloidal fraction of the plant exhibited significant analgesic activity at a dose of 200 mg/kg as it showed significant increase in tail flicking reaction time with respect to the control during 2 h intervals of observation. It also exhibited significant antiinflammatory activity at a dose of 200 mg/kg as it inhibited paw oedema in rats to 71% and reduced the paw volume one-fourth to the control during 1^st h of the study. The present investigations suggest that alkaloids are responsible for analgesic and antiinflammatory activities of C. maculatum.     

Evaluation of Immunomodulatory Activity of the Alkaloid Fraction of Trichopus zeylanicus Gaertn on Experimental Animals

Trichopus zeylanicus Gaertn, (Trichopodaceae) is also known as “Arogyappacha” meaning the greener of health by tribal inhabitants (Kani tribes). This plant used as health tonic and rejuvenator. The whole plant material of Trichopus zeylanicus is defatted and successively extracted with methanol. The alkaloid fraction of Trichopus zeylanicus was obtained from methanol extract. Up to the dose of 2000 mg/kg b.w. per orally alkaloid fraction of Trichopus zeylanicus did not show any mortality or toxicity. Immunomodulatory activity of alkaloid fraction of Trichopus zeylanicus Gaertn was evaluated using various in vivo models including neutrophil adhesion test, delayed type hypersensitivity reaction, and effect on hematological parameter like, total white blood cell''s, red blood cell''s and hemoglobin and cyclophosphamide induce immunosupression. Sheep red blood cells were used to immunized the animals. The percentage of neutrophils adhesion to the nylon fiber was dose dependently increased in alkaloid fraction of Trichopus zeylanicus75, 150 and 300 mg/kg, p.o treated groups (50.57, 52.99 and 54.21%), respectively compared to control group. A dose dependent potentiating of delayed type hypersensitivity reaction induced by sheep red blood cells was also observed from the alkaloid fraction of Trichopus zeylanicus. On chronic administration of alkaloid fraction of Trichopus zeylanicus (75, 150 and 300 mg/kg. p.o.) caused significant (P<0.001) increased in hematological parameter like, total white blood cell''s, red blood cell''s and hemoglobin. Alkaloid fraction of Trichopus zeylanicus also prevented the myelosupression in mice treated cyclophosphamide (30 mg/kg, p.o.). The result of present investigation suggested that alkaloid fraction of Trichopus zeylanicus stimulate defense system by modulating several immunological parameters.     

Effect of fruit extract of Fragaria vesca L. on experimentally induced inflammatory bowel disease in albino rats

Aim:

Ulcerative colitis and Crohn’s disease are chronic recurrent inflammatory bowel disease (IBD) of unknown origin. Oxidative stress is believed to be a key factor in the pathogenesis and perpetuation of the mucosal damage in IBD.

Materials and Methods:

Ethanolic extract of Fragaria vesca (EFFV) fruits was prepared by percolation method and subjected to oral toxicity testing using OECD guidelines. Albino rats were pretreated orally for 5 days with 3% gum acacia in control, EFFV 500 mg/kg in test and 5-aminosalisylic acid (5-ASA) 100 mg/kg in standard groups. Colitis was induced by transrectal administration of 4% acetic acid on 5^th day. All the animals were sacrificed with ether overdose 48 hours after colitis induction, and 10 cm colon segment was resected from proximal end. Colon was weighed (for disease activity index) and scored macroscopically and microscopically after histological staining. Biochemical assessments included myeloperoxidase (MPO) and tissue catalase (CAT), glutathione (GSH) and superoxide dismutase (SOD) measurements. Statistical analysis was done using one-way analysis of variance (ANOVA) followed by Dunnett’s “t” test.

Results:

EFFV showed significant (P < 0.05) prevention of increase in colon weight and disease activity index along with decrease in macroscopic and microscopic lesion score as compared to control group. Significant improvement was observed in the levels of MPO, CAT and SOD, except GSH (P < 0.05). However, the effect of EFFV was significantly less than 5-ASA (P < 0.05).

Conclusions:

EFFV at 500 mg/kg showed significant amelioration of experimentally induced IBD, which may be attributed to its antioxidant and anti-inflammatory properties.     

Quantitative Analysis of Cereulide Toxin from Bacillus cereus in Rice and Pasta Using Synthetic Cereulide Standard and 13C6-Cereulide Standard—A Short Validation Study

A single laboratory validation study of a rapid and sensitive quantitative method for the analysis of cereulide toxin produced by Bacillus cereus using ultra high performance liquid chromatography-electrospray-tandem mass spectrometry is presented. The analysis of this cyclic peptide toxin was validated for pasta and rice samples using a newly presented synthetic cereulide peptide standard, together with ¹³C₆-cereulide that previously have not been commercially available. The use of cereulide standard was also compared to the most frequently used surrogate standard, the antibiotic valinomycin. The performance of the method was evaluated by analyzing spiked sample pools from different types of rice and pasta, as well as 21 individual rice and pasta samples from differently prepared meals. Inoculation of samples with three cereulide toxin-producing strains of Bacillus cereus was finally used to mimic naturally contaminated foods. The quantification range of the method was 1–500 ng/g (R² = 0.999) and the limits of detection and quantification were 0.1 and 1 ng/g, respectively. The precision varied from 3% to 7% relative standard deviation and the trueness from −2% to +6% relative bias at different concentration levels in cooked rice and pasta.     

Biochemical Characterization of a Recombinant UDP-glucosyltransferase from Rice and Enzymatic Production of Deoxynivalenol-3-O-β-d-glucoside

Glycosylation is an important plant defense mechanism and conjugates of Fusarium mycotoxins often co-occur with their parent compounds in cereal-based food and feed. In case of deoxynivalenol (DON), deoxynivalenol-3-O-β-d-glucoside (D3G) is the most important masked mycotoxin. The toxicological significance of D3G is not yet fully understood so that it is crucial to obtain this compound in pure and sufficient quantities for toxicological risk assessment and for use as an analytical standard. The aim of this study was the biochemical characterization of a DON-inactivating UDP-glucosyltransferase from rice (OsUGT79) and to investigate its suitability for preparative D3G synthesis. Apparent Michaelis constants (K_m) of recombinant OsUGT79 were 0.23 mM DON and 2.2 mM UDP-glucose. Substrate inhibition occurred at DON concentrations above 2 mM (K_i = 24 mM DON), and UDP strongly inhibited the enzyme. Cu²⁺ and Zn²⁺ (1 mM) inhibited the enzyme completely. Sucrose synthase AtSUS1 was employed to regenerate UDP-glucose during the glucosylation reaction. With this approach, optimal conversion rates can be obtained at limited concentrations of the costly co-factor UDP-glucose. D3G can now be synthesized in sufficient quantity and purity. Similar strategies may be of interest to produce β-glucosides of other toxins.     

Evaluation of anti-ulcer activity of Samanea saman (Jacq) merr bark on ethanol and stress induced gastric lesions in albino rats

Objective:

To evaluate the antiulcer activity of Samanea saman (Jacq) Merr bark on ethanol and stress induced gastric lesions in albino rats.

Materials and Methods:

Gastric lesions were induced in rats by oral administration of absolute ethanol (5 ml/kg) and stress induced by water immersion. The antiulcer activity of methanolic extract of Samanea saman (Jacq) Merr bark (100 mg/kg, 200 mg/kg, 400 mg/kg) was compared with standard drugs. The parameters studied were ulcer index, gastric juice volume, pH, free acidity and total acidity.

Result:

Samanea saman (Jacq) Merr showed a dose dependent curative ratio compared to ulcer control groups. The extract at 400 mg/kg showed significant anti ulcer activity which is almost equal to that of the standard drug in both models. The volume of acid secretion, total and free acidity was decreased and pH of the gastric juice was increased compared to ulcer control group.

Conclusions:

The present study indicates that Samanea saman (Jacq) Merr bark extracts have potential anti ulcer activity.     

Aflatoxin,Fumonisin and Shiga Toxin-Producing Escherichia coli Infections in Calves and the Effectiveness of Celmanax?/Dairyman’s Choice? Applications to Eliminate Morbidity and Mortality Losses

Mycotoxin mixtures are associated with Shiga toxin-producing Escherichia coli (STEC) infections in mature cattle. STEC are considered commensal bacteria in mature cattle suggesting that mycotoxins provide a mechanism that converts this bacterium to an opportunistic pathogen. In this study, we assessed the mycotoxin content of hemorrhaged mucosa in dairy calves during natural disease outbreaks, compared the virulence genes of the STECs, evaluated the effect of the mucosal mycotoxins on STEC toxin expression and evaluated a Celmanax^®/Dairyman’s Choice™ application to alleviate disease. As for human infections, the OI-122 encoded nleB gene was common to STEC genotypes eliciting serious disease. Low levels of aflatoxin (1–3 ppb) and fumonisin (50–350 ppb) were detected in the hemorrhaged mucosa. Growth of the STECs with the mycotoxins altered the secreted protein concentration with a corresponding increase in cytotoxicity. Changes in intracellular calcium indicated that the mycotoxins increased enterotoxin and pore-forming toxin activity. A prebiotic/probiotic application eliminated the morbidity and mortality losses associated with the STEC infections. Our study demonstrates: the same STEC disease complex exists for immature and mature cattle; the significance of the OI-122 pathogenicity island to virulence; the significance of mycotoxins to STEC toxin activity; and, finally, provides further evidence that prebiotic/probiotic applications alleviate STEC shedding and mycotoxin/STEC interactions that lead to disease.