Cyclopiazonic acid attenuates the divalent cations and augments the mRNA level of iNOS in the liver and kidneys of chickens

Abstract

An investigation was carried out into the occurrence of cyclopiazonic acid (CPA) producing fungi, the level of CPA contamination in chickens' diet, CPA effects on serum levels of divalent cations, on nitric oxide (NO) content and mRNA level of inducible nitric oxide synthase (iNOS) in the liver and kidney of chickens, as well as the cellular and molecular pathways of CPA toxicity. Mycological and HPLC analyses were used to determine the mycobiota and CPA level, respectively. The mycological studies revealed that 34.46 and 23.07% of the isolated fungi were Aspergillus flavus and Penicillium cyclopium, respectively. HPLC analyses showed the highest (0.95±0.35 μg/g) and lowest (0.08±0.03 μg/g) levels of CPA in maize and mix diet, respectively. For toxicological studies, male chickens (Ross 308) were assigned to the control and test groups (n=8), which received normal saline and 10, 25 and/or 50 μg/kg CPA for 28 days. The effects of CPA on NO content of the liver and kidneys were determined using the Griess reaction, and the effects on the serum level of divalent cations were established using commercially available kits. The effects of CPA on the mRNA level of iNOS were investigated using RT-PCR. CPA lowered the serum level of divalent cations, while NO contents were enhanced significantly (P<0.05). The mRNA level of iNOS in birds of the CPA test groups showed a reverse relationship with NO increase. These data suggest that CPA producing fungi along with CPA contamination in chickens' diet result in hepatic and renal disorders. Moreover, CPA induced disorders might contribute to the biochemical alterations such as NO increase that is reversely associated with mRNA level of iNOS.