کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2204111 | 1100554 | 2006 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effects of a neem extract on blood feeding, oviposition and oocyte ultrastructure in Anopheles stephensi Liston (Diptera: Culicidae) Effects of a neem extract on blood feeding, oviposition and oocyte ultrastructure in Anopheles stephensi Liston (Diptera: Culicidae)](/preview/png/2204111.png)
Secondary metabolites of the neem tree (Azadirachta indica A. Juss., Meliaceae) exhibit a wide range of biological activities in insects. However, few studies have addressed the effects of neem extracts or compounds in arthropods of medical importance. In this study, a laboratory strain of Anopheles stephensi was used to assess the effects of a commercial formulation (Neem Azal® (NA)), containing azadirachtin A at 34%, on blood feeding, oviposition and oocyte ultrastructure. Oral administration of Neem Azal® to A. stephensi females through artificial blood meals did impair blood intake and oviposition in a concentration dependent manner. Similar results were obtained on females, which had consumed Neem Azal® in sucrose solution before taking a blood meal of plain blood. Neem treated females displayed a delay in oocyte development in both the phase of vitellogenesis and the phase of choriogenesis. The ultrastructural studies on ovaries from Neem Azal® treated females revealed distinct structural modifications indicative of: (i) a complete block of oogenesis, (ii) impairment of vitellogenesis and vitelline envelope formation, (iii) a severe degeneration of follicle cells. In agreement with results obtained in other insects, this study indicates that Neem Azal® impairs hormone control of oogenesis and exerts a cytotoxic effect on both follicular cells and oocytes of the Asian malaria vector A. stephensi.
Journal: Tissue and Cell - Volume 38, Issue 6, December 2006, Pages 361–371