title: Mancozeb-induced genotoxicity and apoptosis in cultured human lymphocytes.
abstract: OBJECTIVE
  Mancozeb is a dithiocarbamate fungicide known to be genotoxic and induces tumors in rodents at various sites. There is no report in the literature about its genotoxicity in humans. Here, we investigated the association between mancozeb exposure and induction of genotoxic and proapoptotic changes in cultured human lymphocytes (CHLs).
  
  
  METHODS
  Lymphocytes were isolated from peripheral blood of healthy non-smoking donors. Induction of micronuclei and chromosomal aberrations was recorded both by conventional and flow cytometric methods. Annexin-V FITC was used for the differentiation of apoptotic and necrotic cells by flow cytometry.
  
  
  RESULTS
  Mancozeb exposure (0.5, 2 and 5 μg/ml) to CHLs leads to significant induction in the frequency of chromosomal aberrations (CAs) and micronuclei (MN), in a dose-dependent manner. Concomitantly, pro-oxidant potential of mancozeb was also recorded, by increase in the levels of reactive oxygen species (ROS) generation. Our results demonstrated that ROS plays a critical role in the initiation of mancozeb induced apoptosis in CHLs through two ways, primarily through mitochondria-mediated pathway including induction of ROS, decrease in mitochondrial membrane potential (ΔΨm), along with cytochrome c release from mitochondria, and activation of the caspase cascade. The other pathway includes increase in ROS, which resulted in activation of NF-κB, expression of FasL and triggered FasL-dependent pathway, which also involves caspase-8. Therefore, exposure to mancozeb can lead to induction of apoptosis in CHLs through both mechanisms.
  
  
  CONCLUSIONS
  The results of study confirm that mancozeb exposure can induce genotoxicity and apoptosis in CHLs, thus pose a potential risk to exposed human population.
authors.affiliation: Proteomics Laboratory, Indian Institute of Toxicology Research (CSIR), P.O. Box 80, M.G. Marg, Lucknow, UP 226001, India.
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Srivastava
authors.forename: Wahid
authors.initials: W
authors.lastname: Ali
authors.forename: Richa
authors.initials: R
authors.lastname: Singh
authors.forename: Kulpreet
authors.initials: K
authors.lastname: Bhui
authors.forename: Shilpa
authors.initials: S
authors.lastname: Tyagi
authors.forename: Abdulaziz A
authors.initials: AA
authors.lastname: Al-Khedhairy
authors.forename: Pramod Kumar
authors.initials: PK
authors.lastname: Srivastava
authors.forename: Javed
authors.initials: J
authors.lastname: Musarrat
authors.forename: Yogeshwer
authors.initials: Y
authors.lastname: Shukla
mesh_terms: D017304:Annexin A5 / Q000737:chemistry; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D002869:Chromosome Aberrations / Q000139:chemically induced; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005659:Fungicides, Industrial / Q000008:administration & dosage / Q000633:toxicity*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000473:pathology; D008344:Maneb / Q000008:administration & dosage / Q000633:toxicity*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism; D009152:Mutagenicity Tests; D017382:Reactive Oxygen Species / Q000378:metabolism; D015038:Zineb / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D017304:Annexin A5; D005659:Fungicides, Industrial; D017382:Reactive Oxygen Species; D008344:Maneb; D045304:Cytochromes c; D016650:Fluorescein-5-isothiocyanate; C013099:mancozeb; D015038:Zineb