?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Effects+of+four+tanniferous+plant+extracts+on+the+in+vitro+exsheathment+of+third-stage+larvae+of+parasitic+nematodes&rft.creator=D.%2C+BAHUAUD&rft.creator=C.%2C+MARTINEZ-ORTIZ+DE+MONTELLANO&rft.creator=S.%2C+CHAUVEAU&rft.creator=F%2C+PREVOT&rft.creator=F.%2C+TORRES-ACOSTA&rft.creator=I.%2C+FOURASTE&rft.creator=H.%2C+HOSTE&rft.subject=+Sheep+and+goats&rft.subject=+Health+and+welfare&rft.description=The+anthelmintic+properties+of+tanniferous+plants+and+of+their+secondary+metabolites+represent+one+possible+alternative+to%0D%0Achemotherapy+that+is+currently+being+explored+as+a+means+of+achieving+sustainable+control+of+gastrointestinal+nematodes+in%0D%0Aruminants.+Previous+in+vivo+and+in+vitro+results+suggest+that+tanniferous+plants+can+have+direct+anti-parasitic+effect+against%0D%0Adifferent+stages+of+nematodes.+However%2C+the+mode+of+action+of+the+bioactive+plant+compounds+remains+obscure.+The%0D%0Aobjectives+of+the+current+study+were+(1)+to+examine+the+hypothesis+that+extracts+of+tanniferous+plants+might+interfere+with%0D%0Athe+exsheathment+of+third-stage+infective+larvae+(L3)%3B+(2)+to+assess+the+role+of+tannins+in+the+process+by+examining+the%0D%0Aconsequence+of+adding+an+inhibitor+of+tannins+(polyethylene+glycol%3A+PEG)+to+extracts.+The+effects+of+4+tanniferous+plant%0D%0Aextracts+on+exsheathment+have+been+examined+on+L3+of+Haemonchus+contortus+and+Trichostrongylus+colubriformis.+Artificial%0D%0Aexsheathment+was+induced+in+vitro+by+adding+hypochlorite+solution+to+larval+suspension.+The+evolution+of+exsheathment%0D%0Awith+time+was+measured+by+repeated+observations+at+10-min+interval+for+60+min.+The+selected+plants+were%3A+genista%0D%0A(Sarothamnus+scoparius)%2C+heather+(Erica+erigena)%2C+pine+tree+(Pinus+sylvestris)%2C+and+chestnut+tree+(Castanea+sativa)%2C+with+tannin%0D%0Acontents+ranging+from+1.5+to+24.7%25+of+DM.+Extracts+of+a+non-tanniferous+plant+(rye+grass%2C+tannin+content%3A+0.3%25+of+DM)%0D%0Awere+included+in+the+assay+as+negative+controls.+The+extracts+were+tested+at+the+concentration+of+600+mg%2Fml+and+the+effects%0D%0Awere+compared+to+the+rate+of+exsheathment+of+control+larvae+in+PBS.+No+statistical+differences+in+the+pattern+of%0D%0Aexsheathment+was+observed+after+addition+of+rye+grass+or+genista+extracts+for+both+nematode+species+and+with+heather%0D%0Aextracts+for+T.+colubriformis.+In+contrast%2C+pine+tree+extracts+on+larvae+of+both+species+and+heather+extracts+with+H.+contortus%0D%0Ainduced+a+significant+delay+in+exsheathment.+Last%2C+contact+with+chest+nut+extracts+led+to+a+total+inhibition+of+the+process+for%0D%0Aboth+nematodes.+These+results+suggest+that+extracts+of+tanniferous+plants+might+affect+a+key+process+in+the+very+early+stages%0D%0Aof+larval+invasion+of+the+host.+In+most+cases%2C+the+addition+of+PEG+led+to+a+total+or+partial+restoration+towards+control+values.%0D%0AThis+suggests+that+tannins+are+largely+involved+in+the+inhibitory+process.+However%2C+other+secondary+metabolites+may+also%0D%0Ainterfere+with+the+process+that+would+help+to+explain+some+of+the+differences+in+response+observed+between+the+two%0D%0Anematode+species.&rft.date=2005&rft.type=Journal+paper&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Forgprints.org%2F6980%2F1%2Fdianeparasitology.pdf&rft.identifier=D.%2C+BAHUAUD%3B+C.%2C+MARTINEZ-ORTIZ+DE+MONTELLANO%3B+S.%2C+CHAUVEAU%3B+F%2C+PREVOT%3B+F.%2C+TORRES-ACOSTA%3B+I.%2C+FOURASTE+and+H.%2C+HOSTE+(2005)+Effects+of+four+tanniferous+plant+extracts+on+the+in+vitro+exsheathment+of+third-stage+larvae+of+parasitic+nematodes.+Parasitology.&rft.relation=http%3A%2F%2Forgprints.org%2F6980%2F