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Abstract: Patulin (PAT) is a fungal secondary metabolite that exhibits potential cellular and animal toxicities. In this study, human promyelocytic leukemia (HL-60) cells were used to elucidate the mechanism and death mode associated with PAT. Morphological evidence of apoptosis, including membrane blebbing, nuclei fragmentation and DNA laddering formation was clearly observed 6h after exposure to PAT. The results of Western blotting indicated that PAT activated various processed caspases, and cleaved DFF45 and poly (ADP-ribose) polymerase (PARP) in a dose-dependent manner; it also induced a time-dependent increase in caspase 3 and 9 catalytic activities. The apoptosis mediated by PAT in HL-60 was accompanied with cytochrome c release from mitochondria and Bcl-2 expression decrease. The presence of thiol-containing compounds with PAT dramatically reduced the caspase 3 activity that was triggered by PAT; the addition of antioxidants, including mannitol and Tiron, had a similar effect. However, the suppression of p53 protein expression by RNA interference (RNAi) in human embryonic kidney (HEK293) cells did not significantly modify PAT-elicited caspase 3 activity. These findings suggest that PAT-induced apoptosis is mediated through the mitochondrial pathway without the involvement of p53; the interaction with sulfhydryl groups of macromolecules by PAT and the subsequent generation of reactive oxygen species (ROS) plays a primary role in the apoptotic process. [Copyright &y& Elsevier]

Aflatoxin B 1 (AFB 1 ) is the major mycotoxin that contaminates aquafeeds and regarded as a causative agent in illnesses and the mortality of aquacultural species. However, the effects of AFB 1 on developing fish and associated toxic mechanism are still unknown. This study examines the behavioral changes, neuronal morphology and gene expression in zebrafish embryos and larvae upon exposure to aflatoxin solutions. Treatment of 6 h post fertilization (hpf) embryos with AFB 1 at 15-75 ng/mL significantly changed the swimming patterns of seven days post-fertilization (dpf) zebrafish larvae. Larvae in the 15 ng/mL group demonstrated a hypolocomotor activity in free swimming, but hyperlocomotion was observed in the larvae exposed to 30-75 ng/mL AFB 1 . AFB 1 at 75 ng/mL also significantly reduced the startle response of 7 dpf larvae after tapping stimulus. Exposure to AFB 1 resulted in an aberrant morphology of trigeminal ganglion and hindbrain neurons in transgenic embryos (HuC:eGFP); this finding was supported by acetylated alpha-tubulin staining in wild-type fish. Additionally, AFB 1 altered the levels of neurotoxic markers, including gfap and huC. The transcriptomic profile of AFB 1 -treated embryos revealed several differentially expressed genes that are related to neuroactivity and neurogenesis. PCR analysis verified that AFB 1 significantly down-regulated the expression of ngfa and atp1b1b genes and increased that of prtga gene. The results herein indicate the toxicological impacts of AFB 1 on the behaviors and neurodevelopment of fish in the early embryonic stage. Disruption of neural formation and synapse dysfunction may be responsible for the behavioral alteration., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Monascus purpureus and its fermentation products have been used in food coloring and meat preservation in Asia for centuries and have also been recently used as dietary supplements because of their cholesterol-lowering ability. However, the presence of the mycotoxin citrinin (CTN), a secondary metabolite of Monascus species, in fermentation products is a potential threat to public health. In the present study, HPLC was used to analyze CTN levels in lipid and aqueous extracts of commercialized Monascus products. CTN was detected in lipid extracts of all examined samples at concentrations varying between 0.28 and 6.29 microg/g, but was not found in aqueous extracts. When human embryonic kidney cells (HEK293) were incubated for 72 h with Monascus extracts, the concentrations causing 50% cell death by all lipid extracts were in the range of 1.8-4.7 mg/mL, whereas aqueous extracts showed a lower cytotoxicity. Incubation of HEK293 cells with 60 microM pure CTN for 72 h caused cell viability to fall to 50% of control levels. In addition, coadministration of pure CTN and lipid extracts from Monascus samples significantly enhanced CTN cytotoxicity for HEK293 cells using the MTT assay. These results provide the first information about the cytotoxic effects of various Monascus samples and CTN-Monascus mixtures on a human cell line.