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Several Bauhinia species are widely used in Southern South America in the treatment of infections, pain and several diseases including diabetes. Flavonoid compounds based on quercetin and kaempferol glycoside derivatives are believed to be responsible for their therapeutic properties. To investigate this, we have studied two native species from Argentina: B. uruguayensis (BU) and B. forficata subsp. pruinosa (BF). We have analyzed the major polyphenol components in hydro-methanolic extracts of leaves, by high performance liquid chromatography tandem mass spectrometry. Chromatographic analysis yielded five main compounds in BF, corresponding to rutinosides and rhamnosides derivatives of kaempferol and quercetin, which are considered chemotaxonomic markers and responsible for antioxidant activity. The presence of kaempferitrin, an antidiabetic agent, has been confirmed. In extracts of BU, four major compounds were identified as rhamnosides and galloyl derivates from quercetin and kaempferol. One of these compounds, quercitrin-3-rhamnoside may confer anti-inflammatory and analgesic properties to BU extracts.

In this work we have studied the isolation and culture of mature bovine hepatocytes on plastic dishes without exogenous matrix. The liver has been disaggregated in a collagenase solution instead of undergoing a perfusion step. After a few days in culture, the plates showed several clusters of different cell types. Although the average yield was 1.60-0.57·10 8 viable liver cells per gram of tissue, these cultures were formed by non-parenchymal cells and only very few or none by parenchymal cells. In these cultures, actin structures used as a marker for Stellate (Ito) cells have been visualized by immunocytochemical techniques. In order to increase the proportion of parenchymal cells a centrifugation on Percoll, which separates cell sub-populations, has been introduced. Though the yield was lower than in the previous method, these prepurified cultures were only composed of hepatocytes. It has been shown that these cells exhibited albumin synthesis, which is a specific hepatocytes function. In addition, these cultures were capable of producing metabolites of 7-ethoxycoumarin at a higher rate than non purified cell cultures. Therefore this simplified procedure for the isolation and culture of functional and viable hepatocytes may be applied for in vitro studies in bovine.

This study reports an accurate and sensitive strategy for zeranol (ZER) determination in bovine urine samples. ZER is a mycotoxin widely used as a synthetic growth promoter in the livestock production whose residues could present a potential risk for human health. Therefore, its use as an animal feed additive has been banned in most countries. ZER determination was accomplished using an electrochemical system in which bimetallic Au-Pt nanoparticles (Au-PtNPs) were electro-synthesized on a screen-printed carbon electrode (SPCE). The obtained Au-PtNP platform was immunofunctionalized using specific anti-ZER antibodies as a strategy to avoid potential interference. After biorecognition, ZER was directly oxidized and detected by square-wave voltammetry (SWV). The Au-PtNP surface was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV). The limit of detection calculated was 0.01 ng mL(-1) with a wide linear range from 0.03 to 30 ng mL(-1). This method promises to be suitable for ZER quantification in bovine urine samples ensuring food quality and safety, as well as consumer's health.

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In Argentina, Fusarium verticillioides causes 'ear rot', a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.