Effect of mycotoxins isolated from Penicillium nigricans on glucose-6-phosphate dehydrogenase.

A new mycotoxin product (NMP) was isolated from the culture of mutated wild strain of P. nigricans which is less toxic and has sterol derivative. NMP (LD50 > 1 g/kg) showed antimicrobial and antineoplastic activities and does not affect the hematological parameters like RBC count and hemoglobin. It maintained normal blood glucose level by increasing the enzyme activity of glucose-6-phosphate dehydrogenase (EC-1.1.1.49; G-6-PDH) by 30%. It also maintained the normal ion balance in the blood of mice. NMP decreased Km value of glucose-6-phosphate dehydrogenase and thus increased substrate affinity of the enzyme. Reduction of toxicity of NMP has been well explained by higher activity of G-6-PDH which is highly specific for production of NADPH.

Effect of the mycotoxin citrinin on some hormones and on enzymes and substrates of the Embden-Meyerhof pathway in mice.

The effects of six weeks treatment with multiple i.p. doses of citrinin (15, 25 and 35 mg/kg) on some hormonal activities and on enzymes and substrates of the Embden--Meyerhof pathway in mice were studied. Adenosine triphosphatase, hexokinase, lactate dehydrogenase, lactic acid and pyruvic acid decreased in blood, liver, kidney and brain of citrinin-treated mice. Glucose levels in blood, kidney and brain increased and glycogen content of liver decreased. Cortisol, triiodothyronine and thyroxine levels of serum increased, but insulin levels decreased.