title: Dihydroartemisinin (DHA) treatment causes an arrest of cell division and apoptosis in rat embryonic erythroblasts in whole embryo culture.
abstract: Within 24 hr after oral administration of the antimalarial artesunate to rats on Day 10 or 11 postcoitum (pc), there is depletion of embryonic erythroblasts (EEbs), leading to embryo malformation and death. The proximate agent is dihydroartemisinin (DHA), the primary metabolite. We investigated the causes of EEb depletion by evaluating effects of DHA on EEbs in whole embryo culture (WEC). Rat embryos cultured starting on Day 9 pc were treated with 1 or 7 μM DHA for 24 hr starting after 19 hr of culture (∼Day 10 pc) and for 2 to 12 hr starting after 43 hr of culture (∼Day 11 pc). DHA effects indicating the depletion of EEbs were paling of the visceral yolk sac and reductions in visible blood cells, H&E-stained normal (Type II or III) EEbs, and dividing (BrdU-stained) EEbs. DHA-induced abnormal cell division was indicated by increases in symmetric and asymmetric binuclear cells. DHA-induced apoptosis was indicated by increases in TUNEL- and Caspase-3-positive cells and EEbs with fragmented nuclei. In addition, although the overall number of EEbs was decreasing, DHA caused increases in the numbers of circulating early-stage (Type I or earlier) EEbs that could not be accounted for by cell division, suggesting the release of new, less sensitive erythroblasts from the yolk sac. In summary, treatment of Day 10 or 11 pc rat embryos with DHA in WEC resulted in defective and arrested cell division in EEbs followed by apoptosis, suggesting a mechanism for their depletion after artesunate treatment in vivo.
authors.affiliation: Safety Assessment, GlaxoSmithKline, King of Prussia, Pennsylvania.
authors.forename: Lorraine M
authors.initials: LM
authors.lastname: Posobiec
authors.forename: Robert L
authors.initials: RL
authors.lastname: Clark
authors.forename: Paul B
authors.initials: PB
authors.lastname: Bushdid
authors.forename: Susan B
authors.initials: SB
authors.lastname: Laffan
authors.forename: Kai-Fen
authors.initials: KF
authors.lastname: Wang
authors.forename: Tacey E K
authors.initials: TE
authors.lastname: White
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000009:adverse effects / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D037621:Artemisinins / Q000009:adverse effects* / Q000494:pharmacology*; D053148:Caspase 3; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000002:abnormalities; D047108:Embryonic Development / Q000187:drug effects; D004900:Erythroblasts / Q000166:cytology / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000962:Antimalarials; D037621:Artemisinins; C039060:artenimol; D053148:Caspase 3
keywords: artesunate; dihydroartemisinin; embryogenesis; erythroblast; erythrocyte; rat; teratogen; whole embryo culture