Immunomodulation of house flies exposed to azadirachtin

In this study the lethal and sub-lethal effects of azadirachtin on adult house flies, and the main variations in their immune-related gene expression levels were detected. Flies acquiring azadirachtin by ingestion showed different degrees of susceptibility depending on concentration and time of exposure to this compound, with LC50 value corresponding to 101.14 µg/ml, after five days of exposure to a dose of 7.5 µl/fly/day. Flies surviving ingestion of sublethal concentrations showed significant decrease in their lifespan and reproductive performance, including fecundity and percentage of egg hatching. A significant immune-stimulation effect of lower azadirachtin concentrations (25 µg/ml), and a general immunosuppression of most AMPs (i.e. attacin, cecropin, defensin, diptericin and muscin) at higher concentration levels (100 µg/ml) were observed. This study highlights the immunodeficiency potential of azadirachtin, providing new insights into understanding the physiological response of Musca domestica to this botanical compound at the molecular level.