Potential of laticifer fluids for inhibiting Aedes aegypti larval development: evidence for the involvement of proteolytic activity

Memórias do Instituto Oswaldo Cruz

Márcio V Ramos¹  Danielle A Pereira¹  Diego P Souza¹  Eliane S Araújo¹  Cléverson Dt Freitas¹  Mariana G Cavalheiro¹  Mayara Patricia V Matos¹  Ana Fu Carvalho² 

[1] ,Universidade Federal do Ceará Departamento de Biologia Fortaleza CE ,Brasil

关键词: Aedes aegypti;    biological control;    cysteine proteinases;    latex;    larvae;    papain;   

DOI  :  10.1590/S0074-02762009000600001

来源: SciELO

【 摘 要 】

It has been shown previously that the laticifer fluid of Calotropis procera (Ait.) R.Br. is highly toxic to the egg hatching and larval development of Aedes aegypti L. In the present study, the larvicidal potential of other laticifer fluids obtained from Cryptostegia grandiflora R.Br., Plumeria rubra L. and Euphorbia tirucalli L. was evaluated. We attempted to correlate larvicidal activity with the presence of endogenous proteolytic activity in the protein fraction of the fluids. After collection, the fluids were processed by centrifugation and dialysis to obtain the soluble laticifer protein (LP) fractions and eliminate water insoluble and low molecular mass molecules. LP did not visibly affect egg hatching at the doses assayed. LP from Cr. grandiflora exhibited the highest larval toxicity, while P. rubra was almost inactive. E. tirucalli was slightly active, but its activity could not be correlated to proteins since no protein was detected in the fluid. The larvicidal effects of LP from C. procera and Cr. grandiflora showed a significant relationship with the proteolytic activity of cysteine proteinases, which are present in both materials. A purified cysteine proteinase (papain) from the latex of Carica papaya (obtained from Sigma) was similarly effective, whereas trypsin and chymotrypsin (both serine proteinases) were ineffective. The results provide evidence for the involvement of cysteine proteinase activity in the larvicidal action of some laticifer fluids. C. procera is an invasive species found in areas infested with Ae. aegypti and thus could prove useful for combating mosquito proliferation. This is the first report to present evidence for the use of proteolytic enzymes as chemical agents to destroy Ae. aegypti larvae.

【 授权许可】

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