Protease Inhibitor From the Crude Extract of Plant Seeds Affects the Digestive Proteases in Hyphantria Cunea (Lep.: Arctiidae)

Abstract

Proteases are one of the most important digestive enzymes in the midgut of Hyphantria cunea Drury. Proteases are responsible for protein digestion. In the present study, we evaluated the efficiency of some plant inhibitors on proteases in the gut of the H. cunea. Last instar larvae were collected from mulberry trees. The digestive system of the larvae was used as an enzyme source. The total proteolytic and trypsin activity were assessed by the hemoglobin and BApNA, respectively, as the substrate. The evaluation of the total proteolytic and trypsin activities in various pHs showed the highest relative activity at a pH of 11. Also, the inhibitory effect of inhibitors extracted from Alhagi maurorum Medik., Lathyrus sativus L., Vicia faba L., Prosopis farcta (Banks & Sol.) Eig., and Panicum miliaceum L. on the digestive protease of the fall webworm was measured. Protease inhibitors extracted from A. maurorum, P. farcta and P. miliaceum showed negligible inhibition but L. sativus was able to inhibit 34.72% and 100% of the total activity of proteolytic and trypsin, respectively. Also, the total proteolytic and trypsin activities were inhibited by the inhibitor from V. faba, at 22.27% and 100%, respectively. The zymogram pattern of trypsin with nitro-cellulose membranes showed 2 isoforms in the gut of H. cunea. The inhibitor from L. sativus completely inhibited both isoforms. Gel electrophoresis of proteolitytic activity revealed at least 6 isoforms the inhibitor extracted from L. sativus; completely inhibiting some of them. The inhibitor from L. sativus was purified by ammonium sulfate precipitation and gel-filtration. The molecular mass of the inhibitor was determined as 45 kDa. The highest inhibition of trypsin activity by the inhibitor from L. sativus occurred at a pH of 10. The stability of the inhibitor from L. sativus was evaluated at different pHs and temperatures. The results showed that the inhibitor from L. sativus was stable at a pH of 11.0, and showed 45% inhibition on trypsin activity at a pH of 11. Also, this inhibitor revealed stability up to 50°C.

Effects of natural protease inhibitors on high protease activity flours

“…Trypsin inhibitor activity was reported in seeds of grass pea (Roy, 1980;Wang et al, 1998). Aghaali et al (2013) indicated that protease inhibitor from the crude extract of grasspea seeds was able to inhibit 35% and 100% of the total proteolytic and tryptic activities in digestive systems of Hyphantria cunea pest, respectively. Wu and Whitaker (1990) purified four trypsin and (2)Katepwa þ CEE*; (3) Katepwa þ CEE þ Pefabloc-SC*; (4)Katepwa þ CEE þ EDTA-Na 2 *; (5) Katepwa þ CEE þ Chymostatin*; (6)Katepwa þ CEEþ3,4-dichloroisocoumarin*; (7) Katepwa þ CEE þ Trypsin inhibitor from soybean*; (8)Katepwa þ CEE þ Trypsin inhibitor from egg-white*; (9)Katepwa þ CEE þ Trypsin-chymotrypsin inhibitor*; (10) Katepwa þ CEEþa 2 -macroglobulin*; (11)Katepwa þ CEE þ TLCK-HCl*.…”

Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae)

“…The use of pesticides, though, has been challenged due to some factors including the rapid development of resistance in exposed pests, resurgence of pest populations, environmental pollutions, and unwanted effects on non-target organisms such as pollinators, natural enemies, and humans (Weisenburger 1993;Biondi et al 2012b;Lu et al 2012;El-Naggar and Zidan 2013). Plant-derived (botanical) insecticides have long been considered as environmentally friendly agents which are alternatives to synthetic chemical pesticides for pest management (Agbenin and Marley 2006;Isman 2006;Aghaali et al 2013). A large number of plant substances have been introduced for use as insect anti-feedants or repellents (Isman 2006;Ramos et al 2006;Bacci et al 2007;Mahdavi-Arab et al 2008).…”

Current status of the management of fall webworm, Hyphantria cunea: Towards the integrated pest management development

“…The effect of inhibitors extracted from Alhagi maurorum Medik., Lathyrus sativus L., Vicia faba L., Prosopis farcta Eig. and Panicum miliaceum L. on the digestive protease of the FWW was evaluated and able to inhibit 34.72% and 100% of the total activity of proteolytic and trypsin, respectively (Aghaali, Ghadamyari, Hosseininaveh, & Riseh, ). The bio insecticide efficacy of secondary metabolites from spinosad and azadyrachtines, a group of limonoids, obtained from the seeds of the neem tree ( Azadirachta indica ) was also performed and spinosad exhibited quick action, comparative to that of other bio‐pesticides (Brudea et al., ).…”