Differential cytotoxic effects of azadirachtin on Spodoptera frugiperda and mouse cultured cells

Azadirachtin is a natural biopesticide extracted from the neem tree (Azadir achta indica); however, its safety to mammals is not well documented. This study examined the influence of azadirachtin on the proliferation and morph ology of Spodotera frugiperda insect cells (SF-9), and mouse erythroleukemi a cells (MEL-Gh? 86). Cell kinetic studies conducted at 24 h intervals for 144 h showed that azadirachtin treatments (0.05, 0.20 and 0.50 mu g/ml) inh ibited cell multiplication of the SF-9 cells. This inhibitory effect was do se dependent. Conversely, azadirachtin at 30 mu g/ml did not reduce MEL-GM 86 cell proliferation. SF-9 cells displayed an increase in cell swelling an d cell abnormalities after 48 h of treatment with azadirachtin, whereas no such changes were detected in MEL-GM 86 cells. A scanning electron microsco pe study revealed that treatment with an azadirachtin concentration as low as 0.10 mu g/ml induced cell swelling and caused distortions on the cell su rface ultrastructure of SF-9 cells characterized by blebbing and ho les aft er 48 h of treatment. However, these effects were not seen in the azadirach tin-treated MEL-GM 86 cells.