title: The cytotoxicity of aflatoxin b1 in human lymphocytes.
abstract: OBJECTIVE
  Aflatoxin B1 (AFB1) is a naturally occurring carcinogenic and immunosuppressive compound. This study was designed to measure its toxic effects on human peripheral blood mononuclear cells (PBMC).
  
  
  METHODS
  The study recruited 7 healthy volunteers. PBMC were isolated and cellular respiration was monitored using a phosphorescence oxygen analyser. The intracellular caspase activity was measured by the caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin. Phosphatidylserine exposure and membrane permeability to propidium iodide (PI) were measured by flow cytometry.
  
  
  RESULTS
  Cellular oxygen consumption was inhibited by 2.5 μM and 25 μM of AFB1. Intracellular caspase activity was noted after two hours of incubation with 100 μM of AFB1. The number of Annexin V-positive cells increased as a function of AFB1 concentration and incubation time. At 50 μM, a significant number of cells became necrotic after 24 hours (Annexin V-positive and PI-positive).
  
  
  CONCLUSIONS
  The results show AFB1 is toxic to human lymphocytes and that its cytotoxicity is mediated by apoptosis and necrosis.
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Suleiman
authors: S
authors: Al-Hammadi
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Farida
authors: F
authors: Marzouqi
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Aysha
authors: A
authors: Al-Mansouri
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Allen
authors: A
authors: Shahin
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Mariam
authors: M
authors: Al-Shamsi
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Eric
authors: E
authors: Mensah-Brown
authors: College of Medicine & Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors: Abdul-Kader
authors: AK
authors: Souid
keywords: Aflatoxin B1; Caspases; Cellular Respiration; Leukocytes, Mononuclear; Mitochondria; Oxygen Analyzer