Kostyukovsky Moshe, Rafaeli Ada, Gileadi Carina, Demchenko Nataly, Shaaya Eli
ARO, Volcani Center, Institute for Technology and Storage of Agricultural Products, Department of Stored Products, PO Box 6, Bet Dagan 50250, Israel.
Pest Manag Sci. 2002 Nov;58(11):1101-6. doi: 10.1002/ps.548.
As a result of screening a large number of essential oils from Israeli aromatic plants and their biologically active constituents, we isolated two oils with high activity against several stored-product insects. In this study the effect of these compounds on the acetylcholinesterase and the octopamine systems in insects was studied in order to elucidate their mode of action. Inhibition of acetylcholinesterase activity in vitro was evident only at high concentrations (10(-3) M) and could not account effectively for the low-dose mortality for some stored-product insects observed in vivo. However, the essential oil constituents were found to cause a significant increase in the levels of the intracellular messenger, cyclic AMP of abdominal epidermal tissue in the model insect, Helicoverpa armigera Hübn. The effect was significant even at low, physiological concentrations (10(-8) M) when tested directly on abdominal epidermal tissue preparations in vitro. This intracellular response was found to resemble closely the significant increases in the levels of the cyclic AMP of abdominal epidermal tissue due to treatment with the neurotransmitter/neuromodulator, octopamine. Subsequent treatment with the octopaminergic antagonist, phentolamine, effectively inhibited the cyclic AMP levels induced by essential oil treatment, indicating possible competitive activation of octopaminergic receptors by essential oil constituents.
通过对大量以色列芳香植物精油及其生物活性成分进行筛选，我们分离出了两种对几种仓储害虫具有高活性的精油。在本研究中，对这些化合物在昆虫体内对乙酰胆碱酯酶和章鱼胺系统的影响进行了研究，以阐明其作用模式。体外乙酰胆碱酯酶活性的抑制仅在高浓度（10⁻³ M）时才明显，并且不能有效解释在体内观察到的某些仓储害虫低剂量死亡率的原因。然而，发现精油成分可导致模型昆虫棉铃虫腹部表皮组织细胞内信使环磷酸腺苷（cAMP）水平显著升高。在体外直接对腹部表皮组织制剂进行测试时，即使在低的生理浓度（10⁻⁸ M）下，这种影响也很显著。发现这种细胞内反应与用神经递质/神经调节剂章鱼胺处理后腹部表皮组织cAMP水平的显著升高非常相似。随后用章鱼胺能拮抗剂酚妥拉明进行处理，有效抑制了精油处理诱导的cAMP水平，表明精油成分可能竞争性激活了章鱼胺能受体。
