Investigations of dose, age, and duration of administration on the hepatorenal damage induced in mice by cultural products of Penicillium viridicatum

Isolation of a compound from Eupatorium adenophorum (Spreng.) [Ageratina adenophora (Spreng.)] causing hepatotoxicity in mice

Regular ingestion of Eupatorium adenophorum [Ageratina adenophora (Spreng.)] or Crofton weed causes chronic pulmonary disease in horses mainly in Australia, New Zealand, and the Himalayas. The disease is characterized by pulmonary interstitial fibrosis, emphysema, alveolar epithelisation and reduced tolerance to exercise. Horses apparently are the only animals affected and there are numerous reports of farms losing all their horses. The disorder was produced experimentally in horse feeding trials, and it was shown that characteristic lesions occurred in the lungs. In studies with laboratory animals, mice were shown to be suitable test animals, but in this species lesions occur in the liver rather than the lungs. The hepatic injury in these animals is characterized by multiple areas of focal necrosis of the parenchyma associated with degeneration and loss of the epithelium lining the small bile ducts. The active principle 9-oxo-10,11 dehydroagerophorone responsible for these lesions in mice has been isolated from E. adenophorum. Although the compound has been shown to exhibit toxicity to larvae of invertebrate species, no mammalian toxicity studies have been previously reported involving the isolated toxin. The mechanism of the toxic effect of the compound as well as its possible relevance to the respiratory disease in the horse remain to be investigated.

Histopathology of Mycotoxicosis produced in Swiss albino mice by metabolites of some fungal isolates

Of 199 fungal cultures isolated from some of the common cereals collected from different parts of Uttar Pradesh and Madhya Pradesh, 70 produced toxic metabolites. Of the 70 fungi isolated, 59 produced toxins which caused visible lesions in livers, kidneys, and spleens but did not cause mortality. Toxicity, graded in terms of the mortality rate and the extent of lesions in livers, kidneys, and spleens, was found to be highest in various species of Aspergillus (40%), followed by Chaetomium spp. (31%).

Production of xanthomegnin and viomellein by species of Aspergillus correlated with mycotoxicosis produced in mice

By using thin-layer chromatography and infrared spectroscopy, xanthomegnin and viomellein have been isolated and identified from species of the Aspergillus ochraceus group. A correlation was established between the occurrence of these fungal quinones in the fungal cultural products and the ability of these products to induce mycotoxicosis in mice. In addition, a method was employed to estimate the amount of xanthomegnin and viomellein produced by the fungi.

Mycotoxicosis produced in rats by cultural products of an isolate of Aspergillus ochraceus

The toxicity of an isolate of Aspergillus ochraceus was examined in weanling male Sprague-Dawley rats fed diets containing a rice culture or fungal mat of the organism for 5 wk. The ground rice culture was mixed with a commercial purified diet at concentrations of 5, 7·5 and 10% and the fungal mat at concentrations of 1, 2 and 3%. In groups fed the rice-culture diets, weight gains were reduced and all the rats in the group fed the 10% diet died. Rats fed fungal-mat diets showed a marked reduction in weight gain, and the death rate was high (about 83%) in groups fed the 2 or 3% diet. Gross lesions found in groups fed either type of diet included focal necrosis in the liver, greenish discoloration of the kidneys, gastric ulceration, ulceration of the scrotal epidermis and corneal opacity. Histological changes in the liver included necrosis of the epithelium of biliary ducts, periductal oedema, pericholangitis, periductal fibrosis and disseminated focal hepatocellular necrosis. Necrosis of epithelium occurred also in the extraheptic ducts and was accompanied by an interstitial pancreatitis in certain rats. Foci of leucocytes and macrophages were found in the dermis of the scrotum and in the epididymal adipose connective tissue. Ulceration of the epidermis occurred late in the sequence of scrotal changes. Ocular lesions comprised corneal oedema, interstitital keratitis, iridocyclitis and hypopyon. Renal lesions consisted of tubular necrosis and hyaline and biliary casts within convoluted tubules.