Effects of Periplocoside P from Periploca sepium on the Midgut Transmembrane Potential of Mythimna separata Larvae.
Periplocoside P (PSP) isolated from the root bark of Periploca sepium contains a pregnane glycoside skeleton and possesses high insecticidal properties. Preliminary studies indicated that PSP disrupts epithelial functions in the midgut of lepidopteran larvae. In the present study, we examined the effects of PSP on the apical and basolateral membrane voltages, Vaand Vbl, respectively, of cells from (1) midguts isolated from the larvae of the oriental armyworm Mythimna separata that were in vitro incubated with toxins and (2) midguts isolated from M. separata larvae force-fed with PSP. We compared the effects of PSP with the effects of the Bacillus thuringiensis toxin Cry1Ab and inactive periplocoside E (PSE) on the midgut epithelial cells. The results showed that Varapidly decreased in the presence of PSP in a time- and dose-dependent manner, similar to the effects of Cry1Ab. By contrast, PSE did not affect the Vaand Vbl. Additionally, PSP did not influence the Vbl. Given these results, we speculate that PSP may modulate transport mechanisms at the apical membrane of the midgut epithelial cells by inhibiting the V-type H+ATPase.
Institute of Pesticide Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
YingYing
Y
Wang
Institute of Pesticide Science, Northwest A&F University, Yangling, Shaanxi 712100, China.|Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Shaanxi 712100, China.
Zhijun
Z
Qi
Institute of Pesticide Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
Meng
M
Qi
Institute of Pesticide Science, Northwest A&F University, Yangling, Shaanxi 712100, China.|Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Shaanxi 712100, China.
Zhaonong
Z
Hu
Institute of Pesticide Science, Northwest A&F University, Yangling, Shaanxi 712100, China.|Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Shaanxi 712100, China.
Wenjun
W
Wu
D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D004731:Endotoxins / Q000494:pharmacology*; D006027:Glycosides / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D007422:Intestines / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D009036:Moths / Q000187:drug effects* / Q000254:growth & development; D031109:Periploca / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D011283:Pregnenes / Q000494:pharmacology*
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006027:Glycosides; D006460:Hemolysin Proteins; D007306:Insecticides; D010936:Plant Extracts; D011283:Pregnenes; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C000599497:periplocoside P