Effects of some lignans and neolignans on the development and excretion of Rhodnius prolixus.
The effects of six lignans and neolignans as inhibitors of ecdysis and on the water balance in fourth-instar larvae of Rhodnius prolixus were studied by oral, topical and continuous contact treatments. The main results may be summarised as follows: (i) burchellin, pinoresinol, sesamin, licarin A and nordihydroguaiaretic acid (NDGA) did not cause feeding inhibition at doses of 100 micrograms/ml blood; podophyllotoxin had no antifeedant effect but caused a high moulting inhibition and significant toxicity when applied either orally or topically; (ii) the highest ecdysis inhibitory effects were observed with pinoresinol and NDGA when applied orally at a dose of 100 micrograms/ml (58% and 50% of moulting inhibition, respectively); burchellin inhibited 30% of the moulting at this concentration; (iii) by topical treatment none of the compounds presented any influence on the moulting cycle; and (iv) podophyllotoxin and burchellin significantly reduced the excretion of the insect in 24 h; the other compounds had no effect on excretion. The implications of these findings in relation to the pertinent biological events in R. prolixus are discussed.
Cabral
M M
MM
Departamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av. Brasil 5365, Rio de Janeiro, RJ, Brazil.
Azambuja
P
P
Gottlieb
O R
OR
Garcia
E S
ES
D000818:Animals; D001572:Benzofurans / Q000494:pharmacology; D004149:Dioxoles / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects; D005663:Furans / Q000494:pharmacology; D007814:Larva / Q000187:drug effects; D019770:Lauraceae; D017705:Lignans / Q000494:pharmacology*; D009637:Masoprocol / Q000494:pharmacology; D010946:Plants, Medicinal; D011034:Podophyllotoxin / Q000494:pharmacology; D012239:Rhodnius / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism
D001572:Benzofurans; D004149:Dioxoles; D005663:Furans; D017705:Lignans; C432503:licarin A; C053585:burchellin; D009637:Masoprocol; D011034:Podophyllotoxin; C054125:sesamin; C103298:pinoresinol