Malarial parasites observations

Once the presence of malarial parasites has been confirmed, it is vital to identify the particular plas-modial strain involved, since appropriate use of chemotherapy depends on the particular species responsible for the acute attack. Unfortunately, mixed infections, that is, simultaneous infections with more than one species of plasmodia, are often observed. If more than a single species is involved, treatment appropriate for the elimination of all strains must be instituted to avoid delayed attacks or misinterpretations. 

Alphonse Laveran, a French Army physician working in North Africa in the 1880s, was the first to observe malarial parasites in human blood. Their mode of transmission was not understood, however, until Ronald Ross, a British medical officer in India, found the organisms within the bodies of Anopheles mosquitoes. Malaria is caused by four species of parasitic protozoa Plasmodium vivax, P. ovale, P. malariae, satid P. falciparum. These organisms have complex life cycles involving several different developmental stages in both human and mos-... 

Ball, E. G. (1945). Chemical and nutritional observations on malarial parasites grown in vitro. Fed. Proc. 5,397-399. 

Chalcones are one of the classes of flavonoids well known for their antiplasmodial properties. Licochalcone A (65), isolated from Chinese licorice roots, was shown to display strong in vitro activity against both chloroquine-susceptible (3D7) and chloroquine-resistant (Dd2) P. falciparum strains it also displayed a strong in vivo acitivity in mice infected with P. yoelii, when administered intraperitoneally or orally for 3 to 6 days. The compound appeared to inhibit the growth of the parasites at all stages (rings, trophozoites, and schizonts). Although licochalcone and some derivatives interred the clinical trials as anti-malarials, none of them have ever made it to the market due to severe toxicity observed in phase II clinical trials. 

Nothing of a nutritional nature is known regarding these parasitic protozoans with the single exception of the malarial organism, Plasmodium, The very nature of their habitat and their close association with their hosts preclude precise observations. Even in the malarial organisms our biochemical knowledge is meager indeed, as compared to other more amenable types. 

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