Bagnall Neil H, Hines Barney M, Lucke Andrew J, Gupta Praveer K, Reid Robert C, Fairlie David P, Kotze Andrew C
CSIRO Agriculture and Food, St. Lucia, Queensland 4067, Australia.
Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
Int J Parasitol Drugs Drug Resist. 2017 Apr;7(1):51-60. doi: 10.1016/j.ijpddr.2017.01.001. Epub 2017 Jan 10.
Histone deacetylase inhibitors (HDACi) are being investigated for the control of various human parasites. Here we investigate their potential as insecticides for the control of a major ecto-parasite of sheep, the Australian sheep blowfly, Lucilia cuprina. We assessed the ability of HDACi from various chemical classes to inhibit the development of blowfly larvae in vitro, and to inhibit HDAC activity in nuclear protein extracts prepared from blowfly eggs. The HDACi prodrug romidepsin, a cyclic depsipeptide that forms a thiolate, was the most potent inhibitor of larval growth, with equivalent or greater potency than three commercial blowfly insecticides. Other HDACi with potent activity were hydroxamic acids (trichostatin, CUDC-907, AR-42), a thioester (KD5170), a disulphide (Psammaplin A), and a cyclic tetrapeptide bearing a ketone (apicidin). On the other hand, no insecticidal activity was observed for certain other hydroxamic acids, fatty acids, and the sesquiterpene lactone parthenolide. The structural diversity of the 31 hydroxamic acids examined here revealed some structural requirements for insecticidal activity; for example, among compounds with flexible linear zinc-binding extensions, greater potency was observed in the presence of branched capping groups that likely make multiple interactions with the blowfly HDAC enzymes. The insecticidal activity correlated with inhibition of HDAC activity in blowfly nuclear protein extracts, indicating that the toxicity was most likely due to inhibition of HDAC enzymes in the blowfly larvae. The inhibitor potencies against blowfly larvae are different from inhibition of human HDACs, suggesting some selectivity for human over blowfly HDACs, and a potential for developing compounds with the inverse selectivity. In summary, these novel findings support blowfly HDAC enzymes as new targets for blowfly control, and point to development of HDAC inhibitors as a promising new class of insecticides.
组蛋白去乙酰化酶抑制剂（HDACi）正在被研究用于控制各种人体寄生虫。在此，我们研究它们作为杀虫剂控制绵羊主要体外寄生虫——澳大利亚羊绿蝇（Lucilia cuprina）的潜力。我们评估了来自不同化学类别的HDACi抑制绿蝇幼虫体外发育以及抑制从绿蝇卵制备的核蛋白提取物中HDAC活性的能力。HDACi前药罗米地辛是一种形成硫醇盐的环缩肽，是幼虫生长最有效的抑制剂，其效力与三种商业绿蝇杀虫剂相当或更高。其他具有强效活性的HDACi包括异羟肟酸（曲古抑菌素、CUDC - 907、AR - 42）、硫酯（KD5170）、二硫化物（沙马泊林A）以及一种带有酮基的环四肽（阿皮西丁）。另一方面，某些其他异羟肟酸、脂肪酸和倍半萜内酯小白菊内酯未观察到杀虫活性。此处研究的31种异羟肟酸的结构多样性揭示了杀虫活性的一些结构要求；例如，在具有柔性线性锌结合延伸的化合物中，在存在可能与绿蝇HDAC酶发生多重相互作用的支链封端基团时观察到更强的效力。杀虫活性与绿蝇核蛋白提取物中HDAC活性的抑制相关，表明毒性很可能是由于抑制了绿蝇幼虫中的HDAC酶。对绿蝇幼虫的抑制剂效力不同于对人HDAC的抑制，表明对人HDAC的选择性高于绿蝇HDAC，以及开发具有相反选择性化合物的潜力。总之，这些新发现支持绿蝇HDAC酶作为控制绿蝇的新靶点，并指出开发HDAC抑制剂作为一类有前景的新型杀虫剂。
