Ameliorating the toxic effects of Acacia angustissima with polyethylene glycol in rats

Acacia angustissima is a tropical legume, which has potential as a fodder tree, but contains secondary compounds which have an anti-nutritional effect in ruminants. This study was designed to indicate whether condensed tannins alone are responsible for the anti-nutritional affect or whether non-protein amino acids or other unidentified plant components contribute to the anti-nutritional effect. Feeding rats diets containing ground plant material or purified A. angustissima polyphenolics at similar levels of polyethylene glycol (PEG) binding capacity (3.9 g/100 g dry matter (DM)) resulted in weight loss (-8.4 and -10.2 g per day) and reduced intake (3.4 and 2.9 g per day) in both groups compared to average daily gain (1.4 and 1.5 g per day) and intake (15.8 and 17.4 g per day) of control diets. The effect on intake and average daily gain was ameliorated by the addition of PEG, which complexes with phenolic compounds. These results verify that in rats the anti-nutritional effect is caused by polyphenolics in A. angustissima

Evaluation of toxicity of Acacia angustissima in a rat bioassay

Acacia angustissima has potential as a fodder tree, but was toxic to sheep when fed without adaptation at levels higher than 50 g per day in previous studies. In the present study it was determined that rats are sensitive to anti-nutritional factor(s) of A. angustissima and can therefore be used in bioassays to evaluate the toxicity of this legume. Weanling rats fed a diet supplemented with 7.5% A. angustissima had reduced intake and average daily gain (ADG) (4.5 and -0.8 g/d) when compared to rats fed a diet containing 7.5% Medicago sativa (6.8 and 2.4 g/d). When A. angustissima leaves were incubated in the rumen of steers for 24 h before feeding to the rats no toxicity symptoms were observed suggesting that the anti-nutritional factors were either transformed by rumen microbial activity, solubilized out of the plant leaves or reduced due to oven drying. Variable mild lymphocytic typhlitis was observed in cecal tissues in both groups fed 7.5% A. angustissima, either whole or after rumen incubation. No other significant histological or gross pathological changes were observed. In order to ascertain the nature of the anti nutritional factor(s) milled A. angustissima leaf material was extracted with a variety of solvents and extracts added to rat diets to determine their effect. Intake and ADG (6.0 and 0.5 g/d) were significantly reduced in rats fed a diet containing a 70% acetone extract compared to the rats fed the control diet (8.8 and 3.1 g/d). The rats fed the 70% acetone extract containing diet showed an increase in cecal wet weight and/or contents, salivary gland dry weight (% of live weight), fecal nitrogen excretion and increased concentrations of proline, glycine and glutamic acid in the feces. Further fractionation of a 70% acetone fraction was performed to yield ethyl acetate, acetone and watersoluble fractions. Again intake and ADG (6.7 and 0.2 g/d) were significantly reduced in rats fed a diet containing a 70% acetone extract compared to the rats fed the control diet (10.7 and 3.6 g/d). In vitro incubation of the 70% acetone fraction with rumen fluid did not result in significant microbial transformation of the anti-nutritional factors (7.4 and 0.1 g/d). Intake and ADG were significantly reduced when compared to the control diet in the diet containing the ethyl acetate soluble fraction (8.6 and 2.1 g/d), but no anti-nutritional effects were noted in the diets containing the acetone (11.3 and 3.8 g/d) or water-soluble fractions (11.1 and 3.8 g/d) of the 70% acetone extraction. The size increase in salivary glands, increased fecal nitrogen excretion and increased concentrations of proline, glycine and glutamic acid in the feces together with decreased intake and ADG when diets are fed containing phenolics indicate that phenolics were the major component involved in the antinutritional effects of A. angustissima used in these studies. Condensed tannins, but not gallotannins, were detected in phenolic-containing plant extracts. Inhibition of intake and weight gain of condensed tannin containing diets was reversed by polyethylene glycol, which complexes with tannins

Severe acute pancreatitis and reduced acinar cell apoptosis in the exocrine pancreas of mice deficient for the Cx32 gene.

BACKGROUND & AIMS: The early events leading to acinar cell injury during acute pancreatitis are poorly characterized. Signaling through gap junction channels contributes to the homeostasis of the exocrine pancreas by coordinating acinar cell activity within an acinus. To explore the role of gap junctional communication in acinar cell response to injury, we analyzed the course of acute pancreatitis induced by injection of cerulein in mice deficient for Cx32, the major gap junction protein expressed in the exocrine pancreas. METHODS: The severity of pancreatitis was evidenced by measuring serum amylase activity, pancreatic edema, acinar cell necrosis, pancreatic tumor necrosis factor alpha concentration, and myeloperoxidase activity. Acinar cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), caspase-3 activity, and Bax/Bcl-2 expression. Expression and function of connexin were evaluated by immunofluorescence and dye coupling. RESULTS: Cx32-deficient mice exhibited a deleterious course of acute pancreatitis with increased necrosis, edema, and inflammation of the exocrine pancreas. In addition, the exocrine pancreas of Cx32-deficient mice showed a decreased number of TUNEL-positive acinar cells and decreased caspase-3 activity but no change in Bax or Bcl-2 pancreatic expression. Interestingly, chemicals known to induce apoptosis in vivo had no effect on Cx32-deficient pancreatic acinar cells. CONCLUSIONS: Deficiency of a pancreatic connexin converts a mild reversible form of acute pancreatitis into a severe disease and decreases the sensitivity of acinar cells to apoptotic stimuli. The results show that acinar cell-to-cell communication plays a key role in the modulation of severity of acute pancreatitis

First Results from CUORE: A Search for Lepton Number Violation via 0νββ0\nu\beta\beta Decay of 130^{130}Te

International audienceThe CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-number-violating process: Te130 neutrinoless double-beta decay. Examining a total TeO2 exposure of 86.3 kg yr, characterized by an effective energy resolution of (7.7±0.5)  keV FWHM and a background in the region of interest of (0.014±0.002)  counts/(keV kg yr), we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of T1/20ν(Te130)>1.3×1025  yr (90% C.L.); the median statistical sensitivity of this search is 7.0×1024  yr. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find T1/20ν(Te130)>1.5×1025  yr (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find mββ<(110-520)  meV, where the range reflects the nuclear matrix element estimates employed