Oxytetracycline, tetracycline, chlortetracycline and doxycycline in pasteurised cow's milk commercialised in Brazil.

The aim of this study was to investigate the presence of tetracycline residues in pasteurised cow's milk using high-performance liquid chromatography coupled with UV/VIS detection to determine the exposure of Brazilian's population to antibiotic residues. One hundred samples collected from the State of Paraná, Brazil, were analysed. Three of these samples were contaminated at the following concentrations: 121.8 µg·kg(-1) for oxytetracycline, 93.5 µg·kg(-1) for tetracycline and 134.6 µg·kg(-1) for chlortetracycline (61.6 µg·kg(-1)) and doxycycline (73.0 µg·kg(-1)). The median tetracycline residue concentration found in the samples was 42.3 µg·kg(-1), and the estimated daily intake (EDI) was 0.05 µg Kg(-1) bw day(-1) in Brazil. These results demonstrate that the occurrence of tetracycline in Brazilian milk was low (3%) and only for 2% above the maximum residue limit, so the risk to the population from the presence of these residues in milk was low (<1% of the acceptable daily intake).

Evaluation of Agaricus blazei in vivo for antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities.

The development of various types of cancer results from the interaction among endogenous, environmental and hormonal factors, where the most notable of these factors is diet. The aim of the present study was to determine the antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities of Agaricus blazei. The test antigenotoxicity (Comet Assay) and anticarcinogenic (Test of Aberrant Crypt Foci) assess changes in DNA and/or intestinal mucosa that correlate to cancer development. Tests of phagocytosis in the spleen and differential count in blood cells allow the inference of modulation of the immune system as well as to propose a way of eliminating cells with DNA damage. Supplementation with the mushroom was carried out under pre-treatment, simultaneous treatment, post-treatment and pre-treatment+continuous conditions. Statistical analysis demonstrated that the mushroom did not have genotoxic activity but showed antigenotoxic activity. Supplementation caused an increase in the number of monocytes and in phagocytic activity, suggesting that supplementation increases a proliferation of monocytes, consequently increasing phagocytic capacity especially in the groups pre-treatment, simultaneous and pre-treatment+continuous. The data suggest that A. blazei could act as a functional food capable of promoting immunomodulation which can account for the destruction of cells with DNA alterations that correlate with the development of cancer, since this mushroom was demonstrated to have a preventive effect against pre-neoplastic colorectal lesions evaluated by the aberrant crypt foci assay. According to these results and the literature, it is believed that supplementation with A. blazei can be an efficient method for the prevention of cancer as well as possibly being an important coadjuvant treatment in chemotherapy.