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Trypsin inhibitor from Leucaena leucocephala seeds delays and disrupts the development of Aedes aegypti, a multiple‐disease vector
Author(s) -
Almeida Filho Luiz CP,
de Souza Terezinha M,
Tabosa Pedro MS,
Soares Nayana G,
RochaBezerra Lady CB,
Vasconcelos Ilka M,
Carvalho Ana FU
Publication year - 2017
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.4284
Subject(s) - aedes aegypti , midgut , biology , trypsin , chikungunya , biochemistry , kunitz sti protease inhibitor , enzyme , microbiology and biotechnology , larva , botany , outbreak , virology
Abstract BACKGROUND Nowadays, the Aedes aegypti mosquito represents a serious public health issue in view of the large outbreaks of the arboviral diseases zika, dengue, chikungunya and yellow fever. This holometabolous insect has midgut digestive enzymes that are trypsin‐ and chymotrypsin‐like proteins. Protease inhibitors are able to bind to proteolytic enzymes and promote a blockage in digestion and nutrition, leading to death. Thus, we investigated the effect of trypsin inhibitor of Leucaena leucocephala ( LTI ) seeds on egg hatching, larval development and digestive midgut proteases. RESULTS LTI was obtained by trichloroacetic acid precipitation followed by a single chromatography step on anhydrous trypsin sepharose. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate showed a single protein band with a molecular mass close to 20 kDa . After exposure of Ae. aegypti eggs to LTI (0.3 mg mL −1 ), egg hatching was reduced (50%). LTI did not show acute toxicity on newly hatched larvae incubated under the same conditions, but after 10 days of exposure a high mortality rate (86%) was observed and the surviving larvae had a 25% delay in development. LTI was able to inhibit in vitro the midgut enzymatic activity (70%), and when larvae were incubated with LTI solution we observed an inhibition of 56%. CONCLUSIONS LTI is a promising new tool to control critical points of Ae. aegypti development. © 2016 Society of Chemical Industry