<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Priestley,C. M.</style></author><author><style face="normal" font="default" size="100%">Burgess,Ian F.</style></author><author><style face="normal" font="default" size="100%">Williamson,E. M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Lethality of essential oil constituents towards the human louse, Pediculus humanus, and its eggs</style></title><secondary-title><style face="normal" font="default" size="100%">Fitoterapia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Control</style></keyword><keyword><style  face="normal" font="default" size="100%">Essential oils</style></keyword><keyword><style  face="normal" font="default" size="100%">head lice</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Ovicidal</style></keyword><keyword><style  face="normal" font="default" size="100%">Pediculicidal</style></keyword><keyword><style  face="normal" font="default" size="100%">Pediculosis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">77</style></volume><pages><style face="normal" font="default" size="100%">303 - 309</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Essential oils have been widely used in traditional medicine for the  eradication of lice, including head lice, but due to the variability of  their constitution the effects may not be reproducible. In an attempt  to assess the contribution of their component monoterpenoids, a range  of common individual compounds were tested in in vitro toxicity model  against both human lice (Pediculus humanus, an accepted model of  head lice lethality) and their eggs, at different concentrations. No  detailed study into the relative potencies of their constituent  terpenoids has so far been published. Adult lice were observed for lack  of response to stimuli over 3 h and the LT50 calculated, and  the percentage of eggs failing to hatch was used to generate ovicidal  activity data. A ranking was compiled for adult lice and partially for  eggs, enabling structure–activity relationships to be assessed for  lethality to both, and showed that, for activity in both life-cycle  stages, different structural criteria were required. (+)-Terpinen-4-ol  was the most effective compound against adult lice, followed by other  mono-oxygenated monocyclic compounds, whereas nerolidol was  particularly lethal to eggs, but ineffective against adult lice.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue></record></records></xml>