title: Cytotoxic effects of aflatoxin B1 on human brain microvascular endothelial cells of the blood-brain barrier.
abstract: Aflatoxins are mycotoxins produced by Aspergillus spp. Although AFB1 is implicated as a carcinogen in hepatocellular carcinoma, brain autopsies in affected areas have revealed its presence in 81% of cases. Given its haematogenous spread, here we determined the cytotoxic effects of AFB1 on primary human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, human umbilical vein endothelial cells (HUVEC) as well as immortalized epithelial cells of human hepatocellular carcinoma (Huh7). The cell types were exposed to AFB1 (3-32 nM) for 24 h and release of lactate dehydrogenase was measured as cell cytotoxicity marker. Furthermore, DNA was collected from both cell types and DNA adduct formation was determined by immunoblot using anti-AFB1-DNA adduct antibody. At 32 nM, AFB1 killed >85% HBMEC, while controls showed minimal effects (P < .05). Similar concentrations of AFB1 showed 22% cell death of HUVEC, while the same concentration did not kill Huh7. At low concentrations, in other words, 3.2 nM, AFB1 produced DNA adduct formation in HBMEC, while high concentration (32 nM) did not form DNA adducts. For HUVEC, 16 nM and 32 nM exhibited DNA adduct formation. For Huh7, 3.2 nM did not form DNA adducts, while 32 nM exhibited DNA adduct formation. For the first time, we report that AFB1 affected the viability of primary endothelial cells but not immortalized Huh7 cells. Cytotoxicity of brain endothelial cells suggests extra-hepatic complications post-AFB1 exposure.
authors: Department of Biological and Biomedical Sciences Department of Medicine, Aga Khan University, Karachi, Pakistan.
authors: Humaira
authors: H
authors: Qureshi
authors: Department of Medicine, Aga Khan University, Karachi, Pakistan.
authors: Saeed S
authors: SS
authors: Hamid
authors: Department of Biological and Biomedical Sciences Department of Medicine, Aga Khan University, Karachi, Pakistan.
authors: Syed Shayan
authors: SS
authors: Ali
authors: Department of Biological and Biomedical Sciences Department of Medicine, Aga Khan University, Karachi, Pakistan.
authors: Javeria
authors: J
authors: Anwar
authors: Department of Biological and Biomedical Sciences.
authors: Anwar Ali
authors: AA
authors: Siddiqui
authors: Department of Biological and Biomedical Sciences naveed5438@gmail.com.
authors: Naveed Ahmed
authors: NA
authors: Khan
mesh_terms: D016604:Aflatoxin B1 / Q000633:toxicity*; D001230:Aspergillus; D001812:Blood-Brain Barrier / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018736:DNA Adducts / Q000032:analysis; D042783:Endothelial Cells / Q000187:drug effects*; D022781:Hepatocytes / Q000187:drug effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis
chemical_list: D018736:DNA Adducts; D016604:Aflatoxin B1; D007770:L-Lactate Dehydrogenase
keywords: Aflatoxin B1 (AFB1); Aspergillus flavus; Huh7; blood-brain barrier; endothelial cells