SITOPHILUS GRANARIUS (L.) ACETYLCHOLINESTERASE INHIBITION BY SCROPHULARIA CANINA L. EXTRACTS Most insecticides act on the nervous system at synaptic and axonal sites by affecting acetylcholinesterase (AChE), the enzyme responsible for the cleavage of neurotransmitter acetylcholine. In order to obtain new pesticides from natural products we checked the effect of 4 different extracts from Scrophularia canina L. on the activity of the AChE of the product-stored pest Sitophilus granarius (L.). The dried and powdered aerial parts (10 g) were extracted by maceration (24 h) at room temperature in 90 ml of solvent: water, methanol, petroleum ether and hexane, with the resulting 4 extracts filtered and evaporated (water extract was liophilized). AChE activity was detected spectrophotometrically in a crude extract of Sitophilus granarius (L.) (50 adults) by using DTNB (Ellman’s reagent) either in the absence or in the presence of different concentration of the 4 extracts. No inhibition for both petroleum ether and hexane extracts was found. On the contrary, both water and methanolic extracts showed a significant inhibition of AChE (IC50 = 1.9±0.2 and 0.5±0.05 mg/ml, respectively). Thus, S. canina appears as a possible source of natural product for pest control.
L’acetilcolinesterasi (AChE) è un enzima responsabile della rimozione del neurotrasmettitore acetilcolina e, quindi, di importanza vitale per gli insetti e per i vertebrati. Diversi principi attivi ad attività insetticida hanno come meccanismo di azione l’inibizione di questo enzima. Al fine di individuare nuovi biocidi di origine naturale, la parte epigea di Scrophularia canina L. è stata raccolta, essiccata (45° C, 5 gg) triturata e lasciata macerare (10 g in 90 ml per 24 h) in 4 diversi solventi a crescente polarità: esano, etere di petrolio, metanolo, acqua distillata. Gli estratti ottenuti, portati a secco e risospesi in tampone fosfato, sono stati saggiati, a differenti concentrazioni, sull’attività di AChE di Sitophilus granarius (L.) (estratto grezzo di insetto), mediante analisi spettrofotometrica. Gli estratti con solventi apolari non hanno mostrato attività anticolinesterasica. Al contrario, gli estratti in acqua e alcol hanno determinato notevole inibizione dell’enzima con IC50 pari a 1,9±0,2 e 0,5±0,05 mg/ml, rispettivamente. Alla luce di questi risultati la S. canina si candida come possibile fonte di composti naturali ad azione insetticida.
INIBIZIONE DELL’ACETILCOLINESTERASI DI SITOPHILUS GRANARIUS (L.) DA ESTRATTI DI SCROPHULARIA CANINA L
PAVENTI G;GERMINARA GS;
2013-01-01
Abstract
SITOPHILUS GRANARIUS (L.) ACETYLCHOLINESTERASE INHIBITION BY SCROPHULARIA CANINA L. EXTRACTS Most insecticides act on the nervous system at synaptic and axonal sites by affecting acetylcholinesterase (AChE), the enzyme responsible for the cleavage of neurotransmitter acetylcholine. In order to obtain new pesticides from natural products we checked the effect of 4 different extracts from Scrophularia canina L. on the activity of the AChE of the product-stored pest Sitophilus granarius (L.). The dried and powdered aerial parts (10 g) were extracted by maceration (24 h) at room temperature in 90 ml of solvent: water, methanol, petroleum ether and hexane, with the resulting 4 extracts filtered and evaporated (water extract was liophilized). AChE activity was detected spectrophotometrically in a crude extract of Sitophilus granarius (L.) (50 adults) by using DTNB (Ellman’s reagent) either in the absence or in the presence of different concentration of the 4 extracts. No inhibition for both petroleum ether and hexane extracts was found. On the contrary, both water and methanolic extracts showed a significant inhibition of AChE (IC50 = 1.9±0.2 and 0.5±0.05 mg/ml, respectively). Thus, S. canina appears as a possible source of natural product for pest control.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
