Trichinellosis is a foodborne zoonotic disease caused by T. spiralis affecting human and animals. Treatment with commercially available drugs has not been satisfactory due to rapid development of drug-resistant particularly against encapsulated larvae. There is an increasing
need to discover alternative anthelminthics agents from medicinal plants. The present study
evaluated the in vitro antiparasitic activities of myrrh crude extract and myrrh volatile oil on T.
spiralis larvae compared to albendazole to estimate their sublethal concentrations on the infectivity of T. spiralis larvae in mice. The in vitro effect of these agents was evaluated by assessing mortality rate and by a scanning electron microscopic analysis of ultrastructural changes in
the cuticle of the larvae. The surface changes induced by crude myrrh extract and albendazole
were more severe than those observed after exposure to myrrh volatile oil. All responses to the
substances were time dose-dependent and highly significantly different from the control group
(p<0.001). 100% mortality rate of larvae occurred on the 4
th
day at 3, 5, &7mg/ml of myrrh crude extract, on the 7
th
day with volatile oil while total larval death occurred on the 1
st
day of exposure in to 5, 10, 15 & 20µg/ml of albendazole. In vitro exposure to sublethal dose of albendazole, crude myrrh extract and volatile oil extract resulted in infectivity reduction by 100%, 98%
& 88% respectively in intestinal phase and 100%, 98% &59% respectively in muscular phase.