Saponins as Insecticides: a Review
Chaieb, I. 2010. Saponins as insecticides: a review Tunisian Journal of Plant Protection 5: 3950. Saponins are heterosides (substances containing in their structure one or more sugar molecule) of plan t origin. This type of molecules has an interesting p esticide potential and this review constitutes an inventory of principal researches realized in this direction. In the first part of this review, saponi ns are defined and their different structural families are presented. The biological significance and princip al sources of saponins were also outlined. The second part of this review focused on insecticidal activit ies of saponins. In fact, these substances are known by their toxicity to harmful insects (anti feeding, disturbance of the moult, growth regulation, mortal ity. the insecticidal activity of saponins is d ue to their interaction with cholesterol, causing a distu rbance of the synthesis of ecdysteroids. These substances are also protease inhibitors or cytotoxi c to certain insects. The third part of the review gave an idea on the limits which can slow down the use o f saponins as insecticides: saponins have a strong toxicity to mammals because of their cytotoxic and haemolytic activities. The second constraint is the loss of molecule activity due to degradation of sug ars associated with the aglycone. The hydrophilic nature of saponins limits their penetration through the lipophilic insect cuticle. The structural complexity of saponins limits the exact identificat ion and synthesis of active molecules.