Aflatoxin M1 (AFM1) is a milk hygiene quality indicator established in Mexico. Aflatoxin M1 is a metabolite of aflatoxin B1 (AFB1), becoming from contaminated feed. The thermal treatments usually applied to raw milk did not reduce the concentrations on AFM1 in milk. The aim of the present work was to conduct a screening of AFM1 I raw (n=50) collected from raw milk collecting facilities and 7 pasteurized milk brand (n=84) samples. All the samples tested were both produced in Jalisco State and commercialized in Guadalajara, Mexico. The analyses were performed using the competitive direct ELISA kit Agraquant® Aflatoxin M1 (Romer Labs). Statistical analysis was performed using a one-way ANOVA by Sigma Stat 3.0 program. AFM1 was found in 100% of the tested samples, ranging from < 0.005 to 0.100 µg/L in raw milk, and from < 0.005 to 0.637 µg in pasteurized milk. A total 18.6% (25/134) samples showed levels above Maximum Residue Limit (MRL) established by the European Community (0.05 µg/kg), 0.7% (1/134) for raw and 17.9% (24/134) for pasteurized milk. Only 0.7% (1/134) of the tested samples exceeded this MRL established in Mexico by NOM-243-SSA1-2010 which is 0.5 µg/L AFM1. Statistical differences were found (p<0.05) between sampling months; the highest level was detected in December, while no differences were detected among milk collecting facilities and either among pasteurized milk brands.

Entre los indicadores de calidad higiénico sanitaria de la leche en México, se encuentra el nivel de contaminación con aflatoxina M1 (AFM1), proveniente de animales que han consumido alimento contaminado con aflatoxina B1 (AFB1). Los tratamientos térmicos como la pasteurización, generalmente no disminuyen la concentración de AFM1, por lo que en el presente trabajo se estudió la presencia de AFM1 en leche cruda de vaca de 10 centros de acopio (n=50) y 7 marcas de leche pasteurizada (n=84) comercializadas en la zona metropolitana de Guadalajara, Jalisco, México. La determinación de AFM1 se realizó mediante un juego de reactivos tipo ELISA competitivo- directo (Agraquant® Aflatoxina M1, Romer Labs). El análisis estadístico se llevó a cabo mediante una prueba de ANOVA de una sola vía con el programa Sigma Stat 3.0. Se detectó AFM1 en el 100% de las muestras estudiadas, con niveles en el rango de < 0.005 a 0.100 µg/L y de < 0.005 a 0.637 µg/L en leche cruda y pasteurizada respectivamente. El 18.6 % (25/134) de las muestras superaron el LMR establecido por la Unión Europea (0.05 µg/kg), presentándose porcentajes en leches cruda y pasteurizada de 0.7% (1/134) y 17.9% (24/134) respectivamente, pero sólo el 0.7 % (1/134) excedió el límite de AFM1 establecido para México en la NOM-243-SSA1-2010, que es de 0.5 µg/kg. Se observaron diferencias estadísticamente significativas (p<0.05) entre los meses analizados, con los niveles mayores en el mes de diciembre, pero no se encontraron diferencias entre centros de acopio (leche cruda) y tampoco entre marcas de leche pasteurizada.

The objective of this work was to determine the frequency of detection of some of the most frequently antimicrobials in raw and pasteurized milk in Jalisco, Mexico in one year. To this aim, a combination of the yogurt inhibition test as screening method was conducted simultaneously with the confirmation of the positive samples using Twin Sensor for b-lactam and tetracycline antibiotics and High Pressure Liquid Chromatography for sulfonamides, nitrofurans and chloramphenicol. From 264 tested samples, 26 (9.8%) gave positive results to the presence of antimicrobials. The largest percentage corresponded to pasteurized milk, with 20 (13.8 %) positive samples. In raw milk, the positive rate was lower (5%). August showed the overall highest percentage of contamination (27.3 %). From the 20 pasteurized milk samples analyzed, 6 contained b- lactam antibiotics, while only 2 of them were positive to tetracycline. Three raw milk samples were positive to b-lactam and other 3 to tetracycline residues. The 77 % of the positive samples to yogurt test contained at least 1 sulfonamide, identifying sulfamerazine as the most frequent. Both raw and pasteurized milk showed samples above the MRLs for sulfonamides. There were no positive samples to nitrofurans or chloramphenicol. It can be concluded that there is a problem with antimicrobial residues in milk for human consumption in the state of Jalisco, which violates the established Regulations concerning raw milk destined to human consumption.

Se determinó la frecuencia de aparición de antimicrobianos en leche cruda y pasteurizada del estado de Jalisco durante un año, combinando la prueba del Yogurt como método de selección, seguido del método grupo específico Twin Sensor® para b- lactámicos y tetraciclinas, simultáneamente con la detección de sulfonamidas, nitrofuranos y cloranfenicol por HPLC de fase reversa. Se analizaron mensualmente 10 centros de acopio y el total (12 marcas) de leche pasteurizada comercializada en el estado de Jalisco. De 264 muestras analizadas mediante la prueba del yogurt, 26 resultaron positivas a la presencia de antimicrobianos, equivalente a 9.8 % de contaminación total. En leche pasteurizada se hallaron 20 muestras positivas (13.8%), mientras que en leche cruda el porcentaje fue inferior (5%). La mayor frecuencia de contaminación se presentó en el mes de agosto con 27.3%. De las 20 muestras de leche pasteurizada analizadas, seis contenían b-lactámicos y dos tetraciclinas, mientras que en leche cruda se detectaron 3 muestras positivas a b-lactámicos y 3 a tetraciclinas. El 77% de las muestras detectadas positivas contenía al menos una sulfonamida, siendo la sulfamerazina la más frecuente. Se detectaron niveles de sulfonamidas por encima del LMR en leche cruda como en pasteurizada. No se encontraron muestras positivas a nitrofuranos ni cloranfenicol. Se puede concluir que existe un problema de contaminación con antimicrobianos en la leche consumida en el estado de Jalisco, que viola la Norma vigente.

Policosanol is a mixture of higher aliphatic alcohols purified from sugar cane wax, with cholesterol-lowering effects demonstrable in experimental models and in patients with type II hypercholesterolemia. The protective effects of policosanol on atherosclerotic lesions experimentally induced by lipofundin in rabbits and rats and spontaneously developed in stumptail monkeys have been described. The present study was conducted to determine whether policosanol administered orally to rabbits with exogenous hypercholesterolemia also protects against the development of atherosclerotic lesions. Male New Zealand rabbits weighing 1.5 to 2 kg were randomly divided into three experimental groups which received 25 or 200 mg/kg policosanol (N = 7) orally for 60 days with acacia gum as vehicle or acacia gum alone (control group, N = 9). All animals received a cholesterol-rich diet (0.5%) during the entire period. Control animals developed marked hypercholesterolemia, macroscopic lesions and arterial intimal thickening. Intima thickness was significantly less (32.5 ± 7 and 25.4 ± 4 µm) in hypercholesterolemic rabbits treated with policosanol than in controls (57.6 ± 9 µm). In most policosanol-treated animals, atherosclerotic lesions were not present, and in others, thickness of fatty streaks had less foam cell layers than in controls. We conclude that policosanol has a protective effect on the atherosclerotic lesions occurring in this experimental model.

Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. An inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. Thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in Mongolian gerbils. Policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. Control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. In the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. In another experimental model, comparison between groups showed that the brain water content of control gerbils (N = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (N = 13), whereas policosanol (200 mg/kg) (N = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. cAMP levels in the brain of control-ligated Mongolian gerbils (N = 8) were significantly lower than those of sham-operated animals (N = 10). The policosanol-treated group (N = 10) showed significantly higher cAMP levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). In conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models in Mongolian gerbils, suggesting a possible therapeutic effect in cerebral vascular disorders.