Acute and subchronic toxicity of aflatoxin B1 to rohu, Labeo rohita (Hamilton).

Pathological alterations in various organs of rohu (L. rohita) fingerlings following acute (0, 7.50, 11.25 and 13.75 mg/kg body weight) and subchronic (0, 1.25 and 2.50 mg/kg body weight) single i.p. aflatoxin B1 exposure for 10 and 90 days, respectively, were investigated. Mortality (dose-dependent) was marked only during acute toxicosis. The changes observed in various organs were dose and time dependent. The acute dose groups revealed toxic changes viz., necrotic and vascular changes in liver and gill lamellae; meningitis, congestion in brain, degeneration and inflammatory reaction in heart along with degenerative to necrotic changes in kidney tubules and sloughing of the intestinal mucosa. During subchronic exposure to this toxin, preneoplastic lesions in liver along with changes in spleen, intestine, gill and pancreas were recorded. With low doses of aflatoxin, the fish did not reveal any mortality or external signs other than catchexia and increased pigmentation on scales. In composite culture practice of Indian major carps, this could be of economic significance.

Alterations of phosphatidylinositol signal transduction pathway in hepatic mitochondria following aflatoxin B1 administration.

A single dose of aflatoxin B1 (7 mg/kg body wt) to male rats significantly stimulated the turnover of mitochondrial phosphoinositides 1-7 hr following its administration. The elevation of phosphatidylinositol 3,4,5-trisphosphate was most pronounced whose level continued to be moderately high even at 17 hr period. The level of diacylglycerol showed a marked increase from 4 hr till 7 hr after carcinogen treatment, whereas that of inositol 1,4,5-trisphosphate recorded an increase with a maximum at 7 hr followed by a gradual decrease to near normal level at 24 hr period. The activation of phosphatidylinositol cycle together with an activation of PI 3-kinase, whose product PIP3 is known to be involved in apoptosis might contribute to the early step in the manifestation of toxicity and/or carcinogenicity.

Effects of single oral doses of scopoletin and aflatoxin B1 on the clotting time, serum cholesterol and phospholipid levels of chicks.

The plasma cholesterol and phospholipid levels as well as the bleeding time of chicks treated with single oral doses of scopoletin (60 micrograms/kg, body wt) and aflatoxin B1 (50 micrograms/kg, body wt) were measured at intervals for a period of one week (168 h). Both compounds generally increased the bleeding time (AFB1 0.8-28.7%, Scopoletin 0.5-38.2%), serum total and free cholesterol, and the serum phospholipid levels but decreased the levels of the serum esterified cholesterol fraction relative to control throughout the period of study. The extent of these changes elicited by the respective compounds and the variation in the differences between their respective effects varied with the measured parameters. The importance of the similarities in the effects elicited by aflatoxin B1 and Scopoletin was highlighted.

Effect of long term feeding and withdrawal of aflatoxin B1 and ochratoxin A on kidney cell transformation in albino rats.

Subacute doses (1/20 LD50) of aflatoxin B1 and ochratoxin A were fed to weanling albino rats individually and in combination for 36 weeks and then rats were maintained on toxin free normal diet for a period of 24 weeks. Livers of rats were fatty, wherever aflatoxin was administered but the enzyme activity did not show significant differences among various groups. However, in a few individuals whose livers were severely affected, higher concentrations of urine creatinine, liver RNA and DNA, and ALT enzyme activity were recorded. Histopathological examination showed various stages of hepatoma and hepatocarcinoma including nodular hyperplasia, hypertrophy, vacuolisation, degeneration, pseudolobulation, cellular infiltration and fibrosis of liver of rats fed with aflatoxin individually and in combination. Few anaplastic cells in the corticomedullary region and nuclear enlargement of proximal tubular epithelium of kidney were found wherever combined toxin and ochratoxin alone were administered. Liver tumor expression was time dependent.

Método rápiro y económico para detectar aflatoxinas y zearalenona en alimentos para animales / Rapid and economic metod to detect aflatoxins and zeralenone in animal feed

Resumo: Se ha dearrollado un método cuantitativo (A-Z) para determinas Aflatoxina B1 y Zearalenona en mezclas de alimntos destinados al consumo animal. También puede ser usado para cuantificar Aflatoxinas B2, G1 y G2, y puede ser aplicado a maíz. El método, rápido, acuosa de metanol, bipartición con cloroformo y cuantificación visual por cromotografía en capa delgada (TLC). No requiere complicadas etapas de perificación y permite eliminar interferencias empleando una TLC bidimensional, siendo apropriado para laboratorios pequenos, sin equipamento sofisticado. Detecta 1-2ug/Kg de Aflatoxina B1 y 25ug/Kg de Zearalenona. La validez de la técnica ha sido demonstrada por comparación con el método CB de 1a A.O.A.C. de determinación de Aflatoxinas en maíz y con el método oficial de la A.O.A.C. para Zearelenona en maíz (au)