Acute effects of aflatoxin on northern bobwhites (Colinus virginianus).

Aflatoxin is a widely occurring and harmful mycotoxin produced by strains of Aspergillus spp. growing on vegetable matter. We investigated the concentration of aflatoxin needed to impair normal physiologic responses and induce acute morbidity and mortality in Northern Bobwhites (Colinus virginianus). Ten wild-caught adult bobwhites (five males and five females) from southern Texas were randomly assigned to each treatment group (0, 100, 500, 1,000, and 2,000 parts per billion (ppb) aflatoxin; n=50). We orally administered 100 µL of aflatoxin, derived from Aspergillus flavus, once per week for 4 wk and monitored bird mass, daily feed consumption, liver histology, and blood chemistries. An in vitro white blood cell proliferation test was conducted using spleen tissue to determine the effect of aflatoxin on the immune system. There was no mortality in the control groups, whereas mortalities occurred in all treatment groups except in the 100 ppb aflatoxin treatment. Immunosuppression, reduction in gamma-globulin, glucose, and gamma-glutamyltransferase blood levels, and abnormal liver histology were observed in aflatoxin-exposed quail. Blood chemistry indicated cellular damage to the liver and kidneys. We concluded that short-term, acute doses of aflatoxin as low as 100 ppb can be detrimental to the health of Northern Bobwhites.

Hypoglycaemic effect of Opuntia lindheimeri Englem in a diabetic pig model.

The hypoglycaemic activity of Opuntia lindheimeri Englem. was investigated in non-diabetic (control pigs) and streptozotocin-induced diabetic pigs using an enteral (oral) route of administration. Following the administration of O. lindheimeri extract (0, 250 or 500 mg/kg body weight), blood glucose concentrations in control pigs fluctuated around initial baseline concentrations, but were not consistently affected by either the dose of O. lindheimeri or by the time following administration. In contrast, administration of O. lindheimeri extract to STZ-treated pigs resulted in both a dose- (p < 0.001) and time-dependent (p < 0.001) decrease in blood glucose concentrations. The hypoglycaemic effect of the extract was apparent within 1 h of administration, with maximal effects occurring at 4 h after administration. These results confirm the hypoglycaemic effect of O. lindheimeri extract in a diabetic pig model. In addition, given the physiological similarities of the pig to humans, this model will be of tremendous use in assessing the long-term effects of Opuntia administration on the secondary problems associated with diabetes.