الفهرس 
EPIDEMIOLOGYOnly 14 pages are availabe for public view
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Abstract
Schistosomiasis still represents a major health problem in many developing countries in the tropics and subtropics. It is estimated that about 779 million people are exposed to the risk of infection. The actually infected people are estimated to amount to 207 million, of whom 120 million are symptomatic and 20 million have serious complica¬tions. Chemotherapy is the current mainstay in the strategy of morbidity control of schistosomiasis with praziquantel being the drug recommended by the WHO for this purpose. However, it is quite alarming to be dependent on a single drug in the control of a disease that still poses a great risk to a wide geographical area of the world. There are also many justifications for developing reasonable alternatives to praziquantel, including concerns about praziquantel resistance, its weak activity against juvenile stages of the parasite as well as the claimed toxicity of the drug in experimental animals. Moreover, the only alternative for praziquantel against S. mansoni, oxamniquine, suffers from many disadvantages and is being itself replaced by praziquantel in South America where it is essentially used. There are increasing interests to develop antischistosomal drugs from plant derivatives. Many botanical and herbal drugs have been tested for their possible activity against schistosomes, but only two of them have gained the most interest in scientific literature, i.e., artemether and myrrh.
Artemether is an artemisinin derivative obtained from the leaves of the Chinese worm-wood shrub (A. annua) that is essentially used for the treatment of chloroquine-resistant malaria, either singly or in combination. Moreover, it has antischistosomal properties with the main activity against juveniles, and is used as a prophylactic drug against S. japonicum infection in high transmission areas in China. On the other hand, myrrh extract is derived from the oleo-gum resin obtained after making cuts in the stems of C. molmol bushes that spread in north-east Africa and Arabia. In Egypt, it has been investigated for its antiparasitic activity where it is pharmaceutically produced and clinically used for the treatment of schistosomiasis and fascioliasis. Although no contradiction is found among studies on its activity against Fasciola species, there is a great discrepancy in the results of experimental studies and clinical trials regarding its antischistosomal activity.
The present study was conducted to provide preclinical data on whether artemether-myrrh combination would have a reasonable efficacy on the Egyptian strain of S. mansoni in mice. However, drug efficacy in experimental models does not often translate effectively to the human condition, and the issue of their possible effectiveness and dosing schemes should be answered by conducting the appropriate clinical trials. The present study aimed to assess and compare the efficacies of different dosing protocols of artemether, myrrh and their combination in experimentally infected mice harboring adult S. mansoni (Egyptian CD strain).
A total of 120 female Swiss albino mice, age-matched and weighing 20±2 g, were included in this study. Mice were infected subcutaneously with (60±10) cercariae of S. mansoni (Egyptian CD strain). Then, they were randomly allocated just prior to drug adminstration among nine treatment groups and three control groups, ten mice each. The treatment groups were assigned randomly among three experiments as follows: