Kamyar MR, Kouri K, Rawnduzi P,
Studenik C, Lemmens-Gruber R.
Effects of moniliformin in presence of cyclohexadepsipeptides on
isolated mammalian tissue and cells.
Toxicol In Vitro. 2006 Dec;20(8):1284-91
Department of Pharmacology and Toxicology, University of
Vienna, Pharmacy Centre, Althanstrasse 14, A-1090 Vienna,
Austria.
Secondary metabolites produced by Fusarium spp. including
beauvericin, enniatin and moniliformin are mycotoxins identified
in cereal samples. The two cyclohexadepsipeptide mycotoxins
beauvericin and enniatin have cytotoxic, antibiotic,
insecticidal and ionophoric properties, while moniliformin
primarily acts as a cardiotoxic mycotoxin. In this study, we
examined the electromechanical and electrophysiological effects
of moniliformin and moniliformin with ionophoric mycotoxins on
cells (ventricular myocytes, Caco-2 cells) and in multicellular
preparations (papillary muscles and terminal ilea of the guinea
pig). Additionally, we investigated the influence of
moniliformin on cell homeostasis in absence and presence of the
cyclodepsipeptide mycotoxins (ventricular myocytes, Caco-2
cells). Experiments were performed using isometric measurements
of contractility, intracellular microelectrode and patch-clamp
techniques, and fluorescence imaging. While ionophoric
cyclohexadepsipeptides affect action potential parameters and
cell homeostasis, moniliformin did not change spontaneous rates
of activity or cardiac action potentials. Furthermore,
moniliformin had no effect on intracellular concentrations of
ions and ATP, and did not affect pH. Moniliformin reduced
contractility in papillary muscle, terminal ileum, the aorta and
the pulmonary artery. However, moniliformin did not alter
beauvericin and enniatin induced effects. From our studies, we
conclude that moniliformin is not solely a cardiotoxic secondary
metabolite, but also exerts its effects on smooth muscle.
Moreover, there is no synergistic relationship between
moniliformin and the concurrently produced cyclohexadepsipeptide
mycotoxins beauvericin and enniatin.
PMID: 16621435
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