title: Gossypol-induced suicidal erythrocyte death.
abstract: Side effects of gossypol, a polyphenolic component of Gossypium, with male contraceptive, anticancer, antimicrobial and antiviral activities include anemia due to accelerated demise of erythrocytes. Erythrocytes may be cleared from circulating blood following apoptosis-like suicidal death or eryptosis. Hallmarks of eryptosis are cell shrinkage and cell membrane scrambling with subsequent phosphatidylserine-exposure at the cell surface. Stimulators of eryptosis include increase of cytosolic Ca(2+)-activity ([Ca(2+)](i)). The present study explored, whether gossypol stimulates eryptosis of human erythrocytes. Utilizing flow cytometry, [Ca(2+)](i) was estimated from Fluo-3 fluorescence, cell volume from forward scatter, phosphatidylserine-exposure from annexin-V-binding, and hemolysis from hemoglobin release. A 48 h exposure to gossypol (0.75 μM) significantly increased [Ca(2+)](i), decreased forward scatter and increased annexin-V-binding. Gossypol exposure was followed by a slight but significant increase of hemolysis. Removal of extracellular Ca(2+) significantly blunted the effect of gossypol (1 μM) on annexin-V-binding. The present observations reveal a novel effect of gossypol on human erythrocytes, which contributes to or even accounts for the triggering of anemia by this substance.
authors.affiliation: Department of Physiology, University of Tuebingen, Gmelinstrasse 5, 72076 Tuebingen, Germany.
authors.forename: Mohanad
authors.initials: M
authors.lastname: Zbidah
authors.forename: Adrian
authors.initials: A
authors.lastname: Lupescu
authors.forename: Nazneen
authors.initials: N
authors.lastname: Shaik
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
mesh_terms: D000814:Aniline Compounds / Q000032:analysis; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D016923:Cell Death; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D003600:Cytosol / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects*; D005434:Flow Cytometry; D006072:Gossypol / Q000633:toxicity*; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D010718:Phosphatidylserines / Q000378:metabolism; D014966:Xanthenes / Q000032:analysis
chemical_list: D000814:Aniline Compounds; D017304:Annexin A5; D010718:Phosphatidylserines; D014966:Xanthenes; C059715:Fluo-3; D006072:Gossypol; D002118:Calcium