Current Pharmaceutical Design - Volume 14, Issue 9, 2008

The high impact of diseases caused by parasitic protozoa shortens working capacity, causing premature disability, shortening of life quality and expectancy of individuals, leading to economical and social losses. In this issue of Current Pharmaceutical Design several articles, written by colleagues with a major contribution on the area, deal with drugs that interfere with specific structures/organelles of the most important Read More

As eukaryotic cells, protozoa present a classical structural organization where most of the structures and organelles typical of mammalian cells are found. However, even for usual organelles these organisms present structural diversity. In addition, some of the protozoa structures, such as the mitochondria, peroxisomes and even the Golgi complex, are not observed. On the other hand, new organelles such as the hydrogenoso Read More

Chemotherapy is the primary means of treating protozoan parasitic infections. A problem for chemotherapy is to find a novel and potential molecule in protozoa, which could be exploited as drug target. To reach this goal, mitochondrion of protozoa can be considered as the most valuable and potential organelle because of its unique structure and function compared to their natural host habitat. In fact, the respirat Read More

Many trypanosomatid protozoa, such as those belonging to the Trypanosoma and Leishmania genera cause serious diseases to man. Such parasites present an unusual feature, a mitochondrial DNA arranged in catenated circles, known as kinetoplast DNA (kDNA). The replication of kDNA network is a complex process, which involves many proteins. Some of them are classified as topoisomerases and play essential bi Read More

Apicomplexan parasites infectious to humans include Plasmodium spp., Babesia spp., Toxoplasma gondii, Cryptosporidium spp., Isospora belli and Cyclospora cayetanensis. With exception of Cryptosporidium spp., these parasites possess a non-photosynthetic plastid-like organelle called apicoplast. The apicoplast possesses a small circular genome and harbours prokaryotic-type biochemical pathways. As the most import Read More

Hydrogenosomes are spherical or slightly elongated organelles found in non-mitochondrial organisms. In Trichomonas hydrogenosomes measure between 200 to 500 nm, but under drug treatment they can reach 2 μm. Like mitochondria hydrogenosomes: (1) are surrounded by two closely apposed membranes and present a granular matrix: (2) divide in three different ways: segmentation, partition and the heart form; (3) th Read More

Acidocalcisomes are acidic organelles rich in calcium and phosphorus that have been conserved from bacteria to man. In parasitic protozoa acidocalcisomes possess enzymes that are absent or different from their mammalian counterparts and could be potential targets for chemotherapy, such as the vacuolar proton translocating pyrophosphatase, and the soluble inorganic pyrophosphatase, both of which a Read More

Lysosomes were first described as vacuolar structures containing various hydrolytic enzymes at acidic pH. Subsequent studies revealed that the lysosome/vacuolar system is complex and composed of distinct membrane-enclosed vesicles including endosomes, primary and mature lysosomes, autophagic vesicles, residual bodies, multivesicular bodies, and digestive lysosomes. Lysosomes express a battery of hydrolytic enzymes Read More

Fatty acid biosynthesis pathways in protozoan parasites are reviewed with a view to targeting this metabolism for drug therapy. The type II fatty acid biosynthesis pathways derived from bacteria in protozoan relict plastids and mitochondria are examined in different groups with emphasis on apicomplexa. The suitability of different enzymes from the type II fatty acid biosynthesis pathway for drug intervention, and the state-of- Read More

Protozoan parasites, such as those responsible for malaria and African Sleeping Sickness, represent a huge burden to the developing world. Current chemotherapy to combat these diseases is inadequate: antiquated, toxic and increasingly ineffective due to drug resistance. In this article, the potential usefulness of targeting key regulators of the parasite cell cycle will be discussed, paying particular attention to three families of Read More

Parasitic protozoa such as Leishmania, Trypanosoma, Plasmodium, Toxoplasma gondii, Giardia and Trichomonas are able to cause several diseases affecting millions of people around the world with dramatic consequences to the socio-economic life of the affected countries. Diseases like malaria, leishmaniasis and trypanosomiasis have been classified by the World Health Organization as neglected diseases, because they Read More