Toxicity of aflatoxin B1 to Helicoverpa zea and bioactivation by cytochrome P450 monooxygenases.
Toxicity of aflatoxin B1 to Helicoverpa zea and bioactivation by cytochrome P450 monooxygenases.
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黄曲霉毒素 B1 对玉米夜蛾的毒性和细胞色素 P450 单加氧酶的生物活性。
DOI：
10.1007/s10886-006-9062-7
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发表时间：
2006
影响因子：
2.3
通讯作者：
Berenbaum,MayR
中科院分区：
文献类型：
--
作者：
Zeng,RenSen;Zeng,RenSenL;Niu,Guodong;Wen,Zhimou;Schuler,MaryA;Berenbaum,MayR
玉米耳虫（Helicoverpa Zea）侵染玉米（Zea mays）使植物容易受到曲霉真菌的感染，并伴随致癌真菌毒素黄曲霉毒素B1 （AFB1）的污染。虽然摄入AFB1对牲畜和人类的影响有充分的记录，但对自然遇到这种真菌毒素的昆虫的影响还没有很好的定义。AFB1对h不同阶段的毒性。玉米（1、3、5龄）用不同浓度的人工饲料进行评价。虽然AFB1在低浓度（1 ~ 20 ng/g）下没有急性毒性，但它有显著的慢性影响，包括发育延迟、死亡率增加、化蛹率降低和蛹重减轻。敏感性随发育阶段的不同而不同；中等浓度（200 ng/g）可导致1龄幼虫完全死亡，而相同浓度对5龄幼虫遇到AFB1没有可检测到的不良影响。当AFB1浓度较高（1 μg/g）时，5龄幼虫化蛹时出现形态畸形。细胞色素P450单加氧酶（P450）参与黄曲霉毒素在该物种中的生物活化，这是由已知的P450抑制剂胡椒酰丁醇（PBO）的毒性作用证明的；饲粮中添加1 μg/g AFB1时，4龄幼虫未化蛹，添加0.1% PBO可使化蛹率提高至71.7%。添加1 μg/g AFB1的4龄和5龄的化蛹率在PBO的存在下也显著提高。P450诱导剂苯巴比妥对AFB1毒性的影响不如PBO明显。总的来说，这些发现表明，与许多其他脊椎动物和无脊椎动物一样，AFB1对h的毒性。p450介导的代谢生物激活的结果。
Infestation of corn (Zea mays) by corn earworm (Helicoverpa zea) predisposes the plant to infection byAspergillusfungi and concomitant contamination with the carcinogenic mycotoxin aflatoxin B1 (AFB1). Although effects of ingesting AFB1 are well documented in livestock and humans, the effects on insects that naturally encounter this mycotoxin are not as well defined. Toxicity of AFB1 to different stages ofH. zea(first, third, and fifth instars) was evaluated with artificial diets containing varying concentrations. Although not acutely toxic at low concentrations (1−20 ng/g), AFB1 had significant chronic effects, including protracted development, increased mortality, decreased pupation rate, and reduced pupal weight. Sensitivity varied with developmental stage; whereas intermediate concentrations (200 ng/g) caused complete mortality in first instars, this same concentration had no detectable adverse effects on larvae encountering AFB1 in fifth instar. Fifth instars consuming AFB1 at higher concentrations (1 μg/g), however, displayed morphological deformities at pupation. That cytochrome P450 monooxygenases (P450s) are involved in the bioactivation of aflatoxin in this species is evidenced by the effects of piperonyl butoxide (PBO), a known P450 inhibitor, on toxicity; whereas no fourth instars pupated in the presence of 1 μg/g AFB1 in the diet, the presence of 0.1% PBO increased the pupation rate to 71.7%. Pupation rates of both fourth and fifth instars on diets containing 1 μg/g AFB1 also increased significantly in the presence of PBO. Effects of phenobarbital, a P450 inducer, on AFB1 toxicity were less dramatic than those of PBO. Collectively, these findings indicate that, as in many other vertebrates and invertebrates, toxicity of AFB1 toH. zearesults from P450-mediated metabolic bioactivation.