Toxoplasmosis is caused by an obligate intracellular parasite, Toxoplasma gondii (T. gondii) that infects nearly one-third of the world’s population. Infection can be acquired by ingestion of tissue cysts in raw or undercooked infected meat, ingesting of food or water contaminated with sporulated oocysts shed in the feces of an infected cat, blood transfusion, organ transplantation and congenitally, across the placenta from the mother to the fetus. Toxoplasmosis is the most frequent opportunistic infection in pregnant women and in immunocompromised individuals causing serious complications in the form of encephalitis, myocarditis, and pneumonitis with higher mortality rates. There are still few effective treatments for this disease, their main goal being the reduction of the parasite replication rate to avoid more extensive damage to the organs involved as well as to prevent the severe complications. The combination of pyrimethamine and sulfadiazine is the mainstay for treatment and prophylaxis of most clinical presentations of toxoplasmosis. However, this combination has shown efficacy against acute toxoplasmosis but failed against toxoplasmic encephalitis, chorioretinitis, and congenital toxoplasmosis. Anti-Toxoplasmic drugs need to be effective against the different parasitic stages and strains, be capable of killing tachyzoites, have a high ocular, placental and cerebral penetration and have a total lack of fetal toxicity and teratogenic effects. No available drug fulfills all these criteria. The side effects, the potential appearance of resistant strains and the lack of efficacy against Toxoplasma tissue cyst are the particular drawback of the available treatments. The discovery of viable low-toxicity compounds capable of preventing and treating T. gondii would represent a great advance in the treatment of infections, especially in immunocompromised patients. Therefore, the research studies involving the parasite’s proteomics and functional genomics are necessary for the development of new and safer drugs. Nowadays, there is an increasing awareness of the therapeutic potential of natural products and medicinal plants that are frequently considered to be less toxic and free from side effects than synthetic drugs in treating various diseases. The importance of these plants as sources of natural product bioactive molecules to medicine lies not only in their pharmacological or chemotherapeutic effect but also in their role as template molecules for the production of new drug substances. This book aims at giving an update on recent advances in the search for new drugs for the treatment of toxoplasmosis.
ا.د. نجوى مصطفى السيد | Nagwa Mostafa El-Sayed | 3421