Rumen bacteria are involved in the onset of onion-induced hemolytic anemia in sheep

Anaemia in Ruminants Caused by Plant Consumption

Plant toxicology has affected animals throughout evolution. Plants have adapted themselves to the environment. This adaptation has led to the development of defensive strategies to avoid being consumed. Plants have several chemical compounds, which can cause deleterious effects on people or animals that consume them, causing a wide variety of clinical signs. Plants from various latitudes, both cultivated for human and animal feeding or decorative purpose and even wild growth plants are able to generate anaemia in ruminants. Coumarins or ptaquiloside predispose bleeding and haemorrhages, causing a haemorrhagic disease in affected animals. In this group, some important fodder plants, such sweet clover (Genus Melilotus spp.), or other weeds distributed worldwide, such as bracken fern (Pteridium aquilinum) of giant fennel (Ferula communis), are included. On the other hand, sulfur-containing chemicals (e.g., n-propyl disulfate and S-propyl cysteine sulfoxides (SMCOs)) may cause severe direct damage to the erythrocyte and their membrane, leading to their destruction and causing haemolytic anaemia in the animal. This review presents the most frequent intoxication by plants causing anaemia in ruminants. Toxic compounds, clinical signs, diagnosis and possible treatments are also presented.

Systematic study on active compounds as antibacterial and antibiofilm agent in aging onions

Quantitative investigation and systematic studies of quercetin, total phenolics, flavonoids, antioxidants, antibacterial and antibiofilm or antibiofouling properties of methanolic extracts of onions obtained from six different varieties have been carried out to explore their relative merits in terms of biological activities of fresh and aging onions. Total phenolic content in the extracts was examined spectrophotometrically using Folin–Ciocalteau’s phenol reagent and total antioxidant activity was studied by FRAP and DPPH methods. In vitro antibacterial activity of the extracts was investigated on Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus cereus) respectively, by using a modified Kirby–Bauer disc diffusion method. Antibiofilm activity was tested by crystal violet assay. The best results against biofilm formation were observed for the extracts obtained from onions stored for three months. The total phenolic and antioxidant content found to be increased upon aging in all the six varieties; red skinned onion (Happyhong) showed the highest level of total phenolics (5110.07 ± 196.56 μg GAEg⁻¹ FW) and total flavonoids (2254.00 ± 154.82 μg QEg⁻¹ FW) after three months. The results showed that in all the varieties, quercetin content as well as biological activity increases with aging in the stored onions compared with the fresh ones.

Fatal Onion (Allium Cepa) Toxicosis in Water Buffalo (Bubalus Bubalis)

Toxicosis caused by the ingestion of onion ( Allium cepa) by 5 water buffalo ( Bubalus bubalis) occurred in the district of Caçador, Santa Catarina, Brazil. The water buffalo died after ingestion of a large quantity of onion that had been left in the pasture. Clinical signs started 8 days postingestion and were characterized by pale mucous membranes, lethargy, and dark urine. At necropsy, pieces of onions were found in the rumen of 1 animal. The carcass smelled strongly of onion, and the kidneys and urine were dark brown. Microscopic renal lesions included tubular degeneration and necrosis with deposits of eosinophilic material in the cytoplasm of renal tubular epithelial cells and tubular lumina. These changes were consistent with hemoglobinuric nephrosis. Centrilobular coagulation necrosis was observed in the liver accompanied by hemorrhage and macrophages containing brown cytoplasmic pigment. A diagnosis of hemolytic anemia caused by onion toxicosis was based on the epidemiological data, clinical signs, macroscopic changes, and histological lesions.

Oxidants and regulation of K(+)-Cl(-) cotransport in equine red blood cells

The effect of oxidants on K(+)-Cl(-) cotransport (KCC) was investigated in equine red blood cells. Carbon monoxide mimicked O(2). The substituted benzaldehyde, 12C79 (5 mM), markedly increased O(2) affinity. In N(2), however, O(2) saturation was low (<10%) but KCC remained active. Nitrite (NO(2)(-)) oxidized heme to methemoglobin (metHb). High concentrations of NO(2)(-) (1 and 5 mM vs. 0.5 mM) increased KCC activity above control levels; it became O(2) independent but remained sensitive to other stimuli. 1-Chloro-2, 4-dinitrobenzene (1-3 mM) depleted reduced glutathione (GSH). Prolonged exposure (60-120 min, 1 mM) or high concentrations (3 mM) stimulated an O(2)-independent KCC activity; short exposures and low concentrations (30 min, 0.5 or 1 mM) did not. The effect of these manipulations was correlated with changes in GSH and metHb concentrations. An oxy conformation of Hb was necessary for KCC activation. An increase in its activity over the level found in oxygenated control cells required both accumulation of metHb and depletion of GSH. Findings are relevant to understanding the physiology and pathology of regulation of KCC.