Lipids in Health and Disease

The requirement of cholesterol for internalization of eukaryotic pathogens like protozoa (Leishmaniasis, Malaria and Toxoplasmosis) and the exchange of cholesterol along with other metabolites during reproduction in Schistosomes (helminths) under variable circumstances are poorly understood. In patients infected with some other helminthes, alterations in the lipid profile have been observed. Also, the mechanisms involved in lipid changes especially in membrane proteins related to parasite infections remain uncertain. Present review of literature shows that parasites induce significant changes in lipid parameters, as has been shown in the in vitro study where substitution of serum by lipid/cholesterol in medium and in experimental models (in vivo). Thus changes in lipid profile occur in patients having active infections with most of the parasites. Membrane proteins are probably involved in such reactions. All parasites may be metabolising cholesterol, but the exact relationship with pathogenic mechanism is not clear. So far, studies suggest that there may be some factors or enzymes, which allow the parasite to breakup and consume lipid/cholesterol. Further studies are needed for better understanding of the mechanisms involved in vivo. The present review analysis the various studies till date and the role of cholesterol in pathogenesis of different parasitic infections. Introduction Parasitic protozoa and helminthes are responsible for some of the most devastating and prevalent diseases of humans, threatening the lives of nearly one-third of the worldwide human population leading to more than 2 million deaths annually. Habitats of parasites are extremely varied and common parasites of man (protozoa, helminthes and arthropods) normally inhabit the intestine, blood, liver, lungs brain, muscles and lymphatic tissues [1]. Many species of parasites have complex life cycles involving developmental stages that live in soil or water, or use various kinds of intermediate hosts, including vertebrates and invertebrates and cold and warmblooded animals. In such varied environments, parasites have become adapted to using/tolerating widely differing oxygen, carbon dioxide, hydrogen ion concentrations and temperatures [1]. Their nutritional requirements and their means of obtaining and utilizing the nutrients required for growth, motility and reproduction are also varied. The requirement of cholesterol for internalization of eukaryotic pathogens under such variable circumstances is poorly understood. Published: 09 May 2005 Lipids in Health and Disease 2005, 4:10 doi:10.1186/1476-511X-4-10 Received: 16 March 2005 Accepted: 09 May 2005 This article is available from: http://www.lipidworld.com/content/4/1/10 © 2005 Bansal et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.