The Insecticidal Activity of Rhinella schneideri (Werner, 1894) Paratoid Secretion in Nauphoeta cinerea Cocroaches.

摘要: Rhinella schneideri is a common toad found in South America, whose paratoid toxic secretion has never been explored as an insecticide. In order to evaluate its insecticidal potential, Nauphoeta cinerea cockroaches were used experimental model biochemical, physiological and behavioral procedures. Lethality assays with (RSPS) determined the LD50 value after 24 h (58.07µg/g) 48 exposure (44.07 µg/g) (R2 = 0.882 0.954, respectively). Acetylcholinesterase activity (AChE) RSPS at highest dose promoted enzyme inhibition of 40%, similar effect observed neostigmine administration (p < 0.001, n= 5). Insect locomotion recordings revealed that decreased distance traveled by up 37% concomitant 85% increase immobile episodes n 36). added vivo cockroach semi-isolated heart preparation irreversible dependent decrease rate, showing complete failure 30 min recording ≥ 6). addition, into nerve-muscle preparations induced dose-dependent neuromuscular blockade, reaching total blockage 70 applied The on spontaneous sensorial action potentials was characterized number spikes 61% 0.01). Meanwhile, there 42% mean area those 0.05, results obtained here highlight potential relevance biotechnological application.