Safety assessment of consumption of glabrous canary seed (Phalaris canariensis L.) in rats.

Canary seed is a nutrient-rich cereal grain; however, it has not been used in human food in part due to concerns regarding safety of consumption. Glabrous or hairless canary seed has potential human food use as trichomes are absent. The objective of the oral feeding studies reported here was to assess the safety of yellow and brown glabrous canary seed cultivars as human cereal foods. The first study was a 90-day rat oral toxicity study, which compared the effects of diets containing 50% of either brown dehulled glabrous, brown hulled glabrous, or brown hulled pubescent (hairy) hulled canary seed to a diet containing 50% wheat. No significant adverse effects were observed. In a 28-day and a 90-day study rats were fed yellow or brown glabrous canary seed groats in the AIN-76 diet at concentrations levels of 2.5%, 5% and 10%. The NOAELs in 90-day study were 5.15 g/kg/d and 5.23 g/kg/d for yellow and brown canary seed groats. Consumption of canary seed was associated with reduced incidence and severity of liver lipidosis as compared to controls. The combined results of these studies clearly demonstrate the safety of consumption of glabrous canary seed, and support its use as a human cereal grain.

A study of nutrient digestibility and growth performance of broiler chicks fed hairy and hairless canary seed (Phalaris canariensis L.) products.

A nutrient retention study and a growth study were conducted with broiler chickens to evaluate the nutritive value and potential toxicity of 2 hairless canary seed products-hulled seed and groats (cultivar CDC Maria), and one hairy hulled canary seed (cultivar Keet). Each treatment was replicated 6 times (6 groups of 4 birds each). The hairless canary seed groat, hairless hulled canary seed, and the hairy hulled canary seed contained 24.5, 21.8, and 16.3% CP; 7.1, 5.8, and 6.6% ether extract; 1.5, 14.2, and 12.3% acid detergent fiber, and 3,867, 3,205 and 3,292 kcal/kg of AME(n), on a DM basis, respectively. The hairless canary seed groat, hairless hulled canary seed, and the hairy hulled canary seed protein comprised, respectively, 0.49, 0.33, and 0.33% lysine (DM basis), which was 79, 78, and 67% digestible (apparent ileal); 0.65, 0.53, and 0.60% cysteine (DM basis), which was 86, 87, and 85% apparent ileal digestible; and 0.40, 0.30, and 0.25% methionine (DM basis), which was 89, 90, and 86% apparent ileal digestible. In the second study, a 35-d feeding study with male broiler chickens was conducted. The canary seed products were compared with a Canadian Western Red Spring wheat control. Each treatment was replicated 6 times (6 groups of 4 birds each). The test ingredients comprised 50% of the corn/soybean diets. The birds fed the hulled canary seed (hairy or hairless) had similar weight gain, feed intake, and G:F to those fed wheat. There were no statistically significant (P = 0.05) differences in the weights of the bursa, heart, kidneys, liver, spleen, or the pancreas, nor was there any effect on serum lactate dehydrogenase or creatine kinase. The data indicated that feeding hulled canary seed increased the number of gizzard ulcers (P < 0.01). It was concluded that canary seed does not contain anti-nutritional components that negatively affect broiler performance or bird health. However, the canary seed hulls may damage the gizzard lining.

Vitamin E protects porcine but not bovine cultured aortic endothelial cells from oxygen-derived free radical injury due to hydrogen peroxide.

The antioxidative effects of vitamin E (VE) are well known and have been demonstrated in in vitro studies. Since we previously observed that dextran sulfate was markedly more protective of porcine versus bovine aortic endothelial cells when damaged by hydrogen peroxide (H2O2), our objectives were to determine if a similar species difference could be observed with VE. The effects of VE or Trolox (a more water-soluble VE) against oxygen-derived free radical (OFR) injury produced by H2O2 was studied in porcine aortic endothelium (PAE) vs. bovine aortic endothelium (BAE) and bovine brain microvessel endothelium (BBME). VE or Trolox was added to culture medium for at least 24 h prior or immediately prior to H2O2 addition. In PAE, pretreatment with VE dissolved in either ethanol (VE-EtOH) or Tween 20 (VE-Tween 20), or Trolox dissolved in DMSO (Trolox-DMSO) was protective, shown by increased percent viable cells and reduced lactate dehydrogenase (LDH) release. EtOH, Tween 20 or DMSO alone was protective in PAE although DMSO or Tween 20 alone was less effective than when added with VE. VE-Tween 20 or Trolox-DMSO protected PAE when added just prior to H2O2 injury, but protection was significantly less than with pretreatment. DMSO immediately prior to H2O2 injury had no protective effect. Tween 20 immediately prior resulted in complete cell death. In BAE and BBME, pretreatment with VE-EtOH, EtOH, Trolox-DMSO, or DMSO alone had little or no protective effect. Pretreatment with VE-Tween 20 or Tween-20 alone was protective of BAE with Tween 20 being more effective than VE-Tween 20 suggesting that Tween 20 was the protective agent. These studies show that the protective effects of VE and Trolox as well as DMSO, EtOH, and Tween-20 are species dependent.

Marked variation in free radical injury between bovine and porcine endothelial cells cultured in different media.

Previous studies produced models of oxygen-derived free radical (OFR) injury, using H(2)O(2) or xanthine/xanthine oxidase (X/XO), in cultured porcine aortic endothelium (PAE) and rat coronary endothelium. H(2)O(2) at 0.1 mM resulted in 50% viability in both cell types. To determine if comparable H(2)O(2) or X/XO concentrations have the same injurious effect on endothelium from other sources, models of OFR injury were developed for bovine aortic endothelium (BAE) and bovine brain microvessel endothelium (BBME). Varying concentrations of H(2)O(2) (0.01 to 6 mM) or X/XO (10 microM/0.1 to 0.3 U/mL) were added to medium 24 h prior to evaluating cell damage. Injury was assessed using the Trypan blue exclusion test (% viability) and by measuring the release of lactate dehydrogenase into medium. H(2)O(2) concentrations required to produce 50% viability were >6 mM in BAE and BBME versus 1 mM in PAE when cells were grown in Dulbecco's modified Eagle's medium (DMEM). Similarly, BAE and BBME were less sensitive than PAE to damage by X/XO. Cells from both species were more sensitive to H(2)O(2) or X/XO injury when grown in Medium 199 (M199) versus DMEM. The most profound difference was observed with PAE where 50% viability was obtained with 0.12 versus 1.05 mM H(2)O(2) in M199 versus DMEM. These results indicate that bovine endothelial cells from aorta and brain are more resistant to free radical injury than PAE. The presence or absence of key media components (iron, pyruvate, cysteine, histidine) likely influences the extent of OFR injury.

Comparison of trophic effects of norepinephrine, insulin, and IGF-1 in mouse brown adipocytes.

The objective of this work was to evaluate whether insulin, like norepinephrine (NE), exerts direct growth effects in brown adipocytes, as assessed by changes in rates of protein labeling with [35S]methionine. Mouse brown adipocytes isolated by tissue collagenase digestion were incubated for up to 24 h with or without NE in Dulbecco's modified Eagle's medium with albumin, calf serum, and antibiotics. There was a 40% cell loss and a 50% decrease in cell content of succinate dehydrogenase (SDH) activity over 24 h. Both cell recovery and SDH content significantly improved in the presence of NE. In addition, NE increased [35S]methionine incorporation into proteins in both cytosolic and mitochondrial compartments. These effects of NE were inhibited by propranolol. Both insulin and insulin-like growth factor-1 (IGF-1) receptors were detected in brown adipocytes, with insulin receptors in much greater concentration. Increased protein labeling was observed when brown adipocytes were incubated for 4 h with 0.2-5 nM insulin in the absence of serum. This effect was small (30% stimulation) compared with the 200-350% increase observed with NE, and 5 nM IGF-1 had no effect. These results indicate direct trophic actions of both NE and insulin in mouse brown adipocytes, with the effects of NE an order of magnitude greater than those of insulin.