Ross C. Beier

Natural Toxicants in Foods

The purpose of exploring the potential naturally occurring toxic hazards of food plants is not to suggest an irrational avoidance of these common foods. However, it is important to identify, define, and investigate the natural toxicants in our foods and to provide some perspective on these chemicals and to show clearly that their toxicology is unknown in most cases. Many natural toxicants have functions in a manner similar to synthetic pesticides or other biohazardous chemicals. Humans apply synthetic pesticides to food and ornamental plants to prevent insect, fungal, and other pest damage. However, plants produce natural toxicants to protect themselves from pathogens and pests. The natural pesticide concentration in our foods may be as much as 10,000 times higher than that of synthetic pesticide residues (Ames, 1983). Because of the protection they provide to plants, these natural chemicals are prime candidates to be bred into plants by plant producers and plant breeders (Barz et al., 1990).

Development of an improved monoclonal antibody‐based Elisa for fumonisin b1–3 and the use of molecular modeling to explain observed detection limits

Monoclonal antibodies were prepared against the fumonisins, a group of mycotoxins produced by the plant pathogen, Fusarium moniliforme. Splenic lymphocytes, from Balb/c mice immunized with fumonisin B1‐ovalbumin conjugate, were fused with SP2/O myeloma cells, and 14 hybridomas were selected. In a competitive enzyme‐linked immunosorbent assay, fumonisin B1‐bovine serum albumin and free fumonisin B1 (FB1) competed for the monoclonal antibody. The concentrations of FB1 required to inhibit 50% antibody binding (IC50) ranged from 300 to 670 ppb. Antibodies also cross‐reacted with fumonisins B2 and B3 (FB2, FB3), and the hydrolyzed backbone of fumonisin B1 (HB‐FB1). None of the 14 monoclonal antibodies recognized the sphingolipids, sphingosine and sphinganine, that are structurally similar to the backbone of the fumonisins. Three‐dimensional computer models of FB1, FB2 and FB3 show the amine backbone folding with the two esterified trimethyl‐propane‐1,2,3‐tricarboxylic acid side‐chains to form a cage into which...

Evaluation of linalool, a natural antimicrobial and insecticidal essential oil from basil: Effects on poultry

Linalool is a natural plant-product used in perfumes, cosmetics, and flavoring agents. Linalool has proven antimicrobial and insect-repellent properties, which indicate it might be useful for control of enteropathogens or insect pests in poultry production. However, there are no published reports that linalool may be safely administered to or tolerated by chickens. Linalool was added to the diets of day-of-hatch chicks, and they were fed linalool-supplemented diets for 3 wk. We studied the effects of linalool on serum chemistry, gross pathology, feed conversion, and relative liver weights. Linalool had a dramatic negative dose-dependent effect on feed conversion at concentrations in the feed exceeding 2% linalool, but not on gross pathology. Liver weights were significantly increased in the 5% linalool-treated birds. There was a statistical effect on blood glucose, but this parameter remained below the cut-offs for elevated serum glucose, and the result is likely of no biological significance. Linalool caused serum aspartate aminotransferase (AST) levels to increase, but it did not increase serum gamma-glutamyl transferase levels. The linalool effect on AST was dose-dependent, but in linalool doses between 0.1 and 2% of the feed, AST was not elevated beyond normal parameters. Linalool at 2% or less may be safely added to chicken feed. We suggest future studies to evaluate the addition of linalool to the litter, where it may be used as an antimicrobial or an insect repellent or to produce a calming effect.

Simultaneous determination of cyromazine and dicyclanil in animal edible tissues using UPLC-MS/MS

Cyromazine and dicyclanil are both used as insect growth regulators. This paper describes an easy and innovative simultaneous extraction method for residues of cyromazine and dicyclanil in food of animal origin, and a confirmation procedure using UHPLC-MS/MS. The sample was extracted, deproteinised by 1% trichloracetic acid in water-acetonitrile, followed by selective defatting using hexane based on the degree of matrix complexity; cleaned-up on an mixed-mode cation exchange (MCX) cartridge; and quantified by using matrix-matched calibration. The mean recoveries were all between 62.0% and 99.2%, and the RSDs were all below 9.94%. The present method was rapid, sensitive and reliable, which was applied to the quantitative analysis of these residues in animal tissues.

Fate of [14C]xanthotoxin (8-methoxypsoralen) in laying hens and a lactating goat

The metabolism of xanthotoxin, a naturally occurring furanocoumarin photosensitizer, was studied in laying hens and a lactating goat treated with single oral doses equivalent to 10 mg xanthotoxin/kg of body weight. Within 48 h, essentially all of the administered radiocarbon was eliminated in the excreta of the laying hens, while in the goat 92% and 3% were excreted in the urine and feces, respectively. Radiocarbon residues in the milk, egg white, and egg yolk were low. Xanthotoxin, 8-hydroxypsoralen (xanthotoxol), 6-(7-hydroxy-8-methoxycoumaryl)-acetic acid (HCA) and 6-(7-hydroxy-8-methoxycoumaryl)-hydroxyacetic acid (HCHA) were identified in the excreta of laying hens. In the goat, xanthotoxin was metabolized to HCA, HCHA, xanthotoxol, 5,8-dihydroxypsoralen, psoralenquinone, 5-hydroxy-8-methoxy-psoralen and 3[5-(6-hydroxy-7-methoxybenzofuryl)]-propanoic acid. Thus, identified metabolites in one or both of these species arose throughO-demethylation, oxidative cleavage of the furan ring, hydroxylation, reduction, oxidation, and hydrolysis of the lactone ring.

Effect of sole or combined administration of nitrate and 3-nitro-1-propionic acid on fermentation and Salmonella survivability in alfalfa-fed rumen cultures in vitro

Ruminal methanogenesis is a digestive inefficiency resulting in the loss of dietary energy consumed by the host and contributing to environmental methane emission. Nitrate is being investigated as a feed supplement to reduce rumen methane emissions but safety and efficacy concerns persist. To assess potential synergies of co-administering sub-toxic amounts of nitrate and 3-nitro-1-propionate (NPA) on fermentation and Salmonella survivability with an alfalfa-based diet, ruminal microbes were cultured with additions of 8 or 16mM nitrate, 4 or 12mM NPA or their combinations. All treatments decreased methanogenesis compared to untreated controls but volatile fatty acid production and fermentation of hexose were also decreased. Nitrate was converted to nitrite, which accumulated to levels inhibitory to digestion. Salmonella populations were enriched in nitrate only-treated cultures but not in cultures co- or solely treated with NPA. These results reveal a need for dose optimization to safely reduce methane production with forage-based diets.

Detection of bacteria from a cecal anaerobic competitive exclusion culture with an immunoassay electrochemiluminescence sensor

A competitive exclusion (CE) culture of chicken cecal anaerobes has been developed and used in this laboratory for control of Salmonella typhimurium in chickens. The CE culture consists of 29 different species of micro-organisms, and is known as CF3. Detection of one of the CF3 bacteria, Eubacteria, and S. typhimurium were demonstrated using a commercial immunomagnetic (IM) electrochemiluminescence (ECL) sensor, the ORIGENR Analyzer. Analysis was achieved using a sandwich immunoassay. Bacteria were captured on antibody- conjugated 280 micron sized magnetic beads followed by binding of reporter antibodies labelled with ruthenium (II) tris(dipyridyl) chelate [Ru(bpy)32+]. The magnetic beads were then trapped on an electrode in the reaction cell of the ORIGENR Analyzer by a magnet, and the ECL was evoked from Ru(bpy)32+ on the tagged reporter antibodies by an electrical potential at the electrode. Preliminary IM-ECL assays with Eubacteria yielded a detection limit of 105 cfu/mL. Preliminary IM-ECL assays with S. typhimurium yielded a similar detection limit of 105 cfu/mL.

Computer pattern recognition of 13C NMR data for classification of glycosides

Abstract A pattern recognition technique is demonstrated for grouping data and assigning the carbohydrate structures of four carbohydrate moieties. Using existi

An Enzyme-Linked Immunosorbent Assay for Determination of Dicyclanil in Animal Tissue

Dicyclanil is a toxic, pyrimidine-derived insect growth regulator used in veterinary medicine for the prevention of myiasis. A competitive indirect enzyme-linked immunosorbent assay was developed firstly for the determination of dicyclanil in animal tissue. The antigen was prepared using the glutaraldehyde method and polyclonal antibodies were obtained by immunizing rabbits with a dicyclanil-bovine serum albumin conjugate. The antibody obtained was specific for dicyclanil with an IC50 of 9 ng/mL. Recoveries from sheep tissue and liquid milk were in the range of 52.5–72.4%, with coefficients of variation between 4.7% and 11.9%. The results were further confirmed by high performance liquid chromatography–tandem mass spectrometry.