细辛精油对2种农业害虫保护酶和解毒酶活性的影响

Effects of Asarum Essential Oils on Protection/Detoxification Enzyme Activities of Two Agricultural Pest Insects

为评价细辛精油的杀虫潜力和作用机制,研究了不同方法提取的细辛精油对2种农业害虫保护酶和解毒酶活性的影响。3种细辛精油分别为:水蒸气蒸馏提取的精油X1、超临界CO2萃取的精油X3、超临界CO2萃取后经硅胶柱层析得到的馏分X5。将X1以1 000mg/L的剂量喷洒在玉米嫩苗上,将X3和X5以0.5mg/g的剂量分别加入玉米螟人工饲料中,检验黏虫幼虫取食含X1的玉米嫩苗以及亚洲玉米螟幼虫取食含X3或X5的人工饲料的反应,以不添加细辛精油的处理为对照。结果表明:在设置剂量下,细辛精油X1和X3对试虫超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)3种保护酶总体表现为抑制作用;精油X5对试虫POD活性表现出一定的抑制作用,但对试虫SOD、CAT有诱导激活作用。细辛精油对试虫羧酸酯酶(CarE)、酸性磷酸酯酶(ApE)、谷胱甘肽-S-转移酶(GST)均表现出一定的诱导激活作用,但诱导作用随着处理时间的延长而降低,碱性磷酸酯酶(ALP)的活性在前期显著升高,后期显著降低,表明细辛精油处理下,试虫可增加解毒代谢能力,但较长时间处理表现为毒害作用的积累,导致试虫解毒酶活性和解毒能力随时间不断下降。综合分析,细辛精油的杀虫作用可能是通过抑制昆虫的保护酶系而实现的。

To evaluate the insecticidal potential and mechanism of asarum essential oils, the effects of three kinds of asarum essential oils extracted by different methods on protection/detoxification enzyme activities of Asian corn borer[Ostrinia furnacalis （Guenee）] and army worm[Mythirnna seperata （Walker）] were studied. The three asarum essential oils were as follows：essential oil X1 was extracted by steam distillation method,essential oil X3 was extracted by supercritical COs ex- traction method,and essential oil X5 was a product obtained by refining X3 through a silica gelcolumn chromatography. X1 was sprayed on the corn sprout,according to a dose of I 000 mg/L. X3 and X5 were separately added to the corn borer artificial feed, according to a dose of 0.5 mg/g. The experiment tested the response of Asian corn borer larvae fed on artificial diet containing X3 or XS, and response of army worm larvae fed on tender corn shoots containing X1. In control group,asarum essential oil was not added. The results showed that, under the set experimental concentrations,essential oils X1 and X3 inhibited the activities of three protective enzymes （su- peroxide dismutase,SOD; catalase, CAT ; peroxidase, POD） of the test insects; X5 showed cer- tain inhibitory effect on POD activity of the test insects,but exhibited an activation effect on SOD and CAT. Asarum essential oils showed some activation effect on carboxylesterase （CarE）, acid phosphatase （APE） and glutathione S-transferase （GST）,but the degree of activation effect re- duced over time,meanwhile alkaline phosphatase（ALP） activity significantly increased early,then significantly reduced,which demonstrated that insects firstly increased their detoxification ability under excessive exogenous compound, and then the detoxification capacity would decrease with the accumulation of toxic substances. The insecticidal effect of asarum essential oils may be achieved by inhibiting the insects＇ protective enzymes.