Larvicidal activity of a toxin from the seeds of Jatropha curcas Linn. against Aedes aegypti Linn. and Culex quinquefasciatus Say.
The larvicidal effects of the crude protein extract and purified toxin, Jc-SCRIP,   from the seed coat of Jatropha curcas Linn. against the third instar larvae of mosquitoes,   Aedes aegypti Linn. and Culex quinquefasciatus Say, were investigated. This test compared   the effects of the purified toxin with crude protein extracts from seed kernels of J. curcas and   Ricinus communis. At various concentrations of purified toxin and crude protein extract, the   larval mortality of both Ae. aegypti and Cx. quinquefasciatus were positively correlated with   increased exposure time. The larvae of Cx. quinquefasciatus were more susceptible to the   toxin and both extracts than the larvae of Ae. aegypti. After 24 hours of exposure, the extract   showed larvicidal activity against Ae. aegypti and Cx. quinquefasciatus with (LC50) values of   3.89 mg/ml and 0.0575 mg/ml, respectively. The toxin, Jc-SCRIP, showed larvicidal activity   against Ae. aegypti and Cx. quinquefasciatus with (LC50) values of 1.44 mg/ml and 0.0303 mg/   ml, respectively. These results indicated that the crude protein extract and Jc-SCRIP were   more toxic to the third instar larvae of Cx. quinquefasciatus than that of Ae. aegypti. The   potent larvicidal activities of the seed coat extract and the Jc-SCRIP toxin from J. curcas   suggest that they may be used as bioactive agents to control the mosquito population.
Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand.
Nuchsuk
N
Chanthakan
Wetprasit
W
Nuanchawee
Roytrakul
R
Sittiruk
Ratanapo
R
Sunanta
D000330:Aedes / Q000187:drug effects*; D000818:Animals; D003465:Culex / Q000187:drug effects*; D057075:Enzyme Assays; D031286:Jatropha / Q000737:chemistry*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D009032:Mosquito Control / Q000379:methods; D010572:Pest Control, Biological / Q000379:methods*; D010936:Plant Extracts / Q000494:pharmacology; D010947:Plants, Toxic / Q000737:chemistry; D012278:Ricinus / Q000737:chemistry; D012639:Seeds / Q000737:chemistry*; D013997:Time Factors; D014118:Toxins, Biological / Q000302:isolation & purification / Q000494:pharmacology*
D010936:Plant Extracts; D014118:Toxins, Biological