title: The antimitotic effect of the neem terpenoid azadirachtin on cultured insect cells.
abstract: When cultured insect cells (Sf9) were grown in the presence of 5 x 10(-6) M azadirachtin, there was a rapid increase in the mitotic index, with the appearance of many aberrant mitotic figures. Flow cytometry established that cells accumulated in the G2/M phase of the cell cycle, and that the effect was concentration-dependent. At 10(-8) M a period of 20 h was necessary to raise the proportion in G2/M to 42% above the control values, but at 5 x 10(-6) M more than 90% of the cells were in this phase. Azadirachtin had the same effect on C6/36 mosquito cells, but failed to affect L929 murine fibroblast cells even at a concentration of 10(-4) M over 72 h. Experiments with colchcine and taxol showed similarities of action between azadirachtin and colchicine, and azadirachtin was apparently able to displace colchicine-fluorescein from binding-sites in living insect cells. Another similarity between azdirachtin and colchicine was that both phytochemicals prevented the polymerisatrion in vitro of mammalian tubulin, although the azadirachtin was much less effective.
authors.affiliation: Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G12 8QQ Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Salehzadeh
authors.forename: A
authors.initials: A
authors.lastname: Akhkha
authors.forename: W
authors.initials: W
authors.lastname: Cushley
authors.forename: R L P
authors.initials: RL
authors.lastname: Adams
authors.forename: J R
authors.initials: JR
authors.lastname: Kusel
authors.forename: R H C
authors.initials: RH
authors.lastname: Strang
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D003078:Colchicine / Q000494:pharmacology; D005347:Fibroblasts; D005434:Flow Cytometry; D006074:Gout Suppressants / Q000494:pharmacology; D007313:Insecta / Q000166:cytology*; D007306:Insecticides / Q000494:pharmacology*; D036701:Limonins / Q000494:pharmacology*; D051379:Mice; D008938:Mitosis / Q000187:drug effects*; D014404:Tubulin / Q000378:metabolism
chemical_list: D006074:Gout Suppressants; D007306:Insecticides; D036701:Limonins; D014404:Tubulin; C010329:azadirachtin; D003078:Colchicine