Malaria cytotoxic effect

Experiments performed in vitro revealed that in contrast to DFO, which has a major cytotoxic effect only on trophozoites and early schizonts of P. falciparum, reversed siderophores have a cytotoxic effect on ring-stage and cytostatic effects on trophozoites and schizonts . These observations provided the basis for studying combinations of iron chelators for antimalarial therapy. When DFO is added to malaria parasites cultured in erythrocytes in combination with the more lipophilic and more permeate reversed siderophore 66, a strong synergistic inhibitory effect on parasite growth is observed. This effect may result from the different speeds of permeation of the two chelators... 

Of the sesquiterpene lactones identified so far, the one with the best described biosynthesis is the dmg artemisinin, which is used in the treatment of malaria. A second well-studied sesquiterpene lactone is the germacranolide costunolide, which exhibits various cytotoxic effects. Both artemisinin and costunolide were identified in Asteraceae, and although these are not guaianolides, many of the reaction sequences generating these molecules are believed to be similar to those generating guaianolides. 

The volatile oil and extracts have a cytotoxic effect on the larvae of Culex pipiens mosquito and a repellent effect against Aedes aegypti malaria mosquito. Moderate repellent activity was exhibited by fenchone and E-9-octadecenoic acid of the oil. ° ... 

Manzamines have shown a variety of bioactivities ineluding cytotoxicity, antimicrobial, pesticidal, and anti-inflammatory properties [2] some of them demonstrated effects on HTV and AIDS opportunistic infections [2], To date, the greatest potential for the manzamine alkaloids appears to be against malaria with manzamine A showing improved aetivity over the elinieally used drugs chloroquine and artemisinin both in vitro and in vivo [2]. 

Documented effects Compounds isolated from the roots exhibited leishmanicidal activity in vitro and inhibited growth of cultured malaria parasites, human lymphocytes, and human carcinoma cell lines (Sairafianpour et al. 2001). Compounds isolated from the aboveground parts exhibited cytotoxic activity against leukemia cells (Aoyagi et al. 2006). 

Five isoquinoline alkaloid dimers with pavine and tetrahydrobenzylisoquinoline moieties, known as hervelines A-D (VIII.1-VIII.4) and HB (VIII.5), have been isolated from the stem bark of Hernandia voyronii Jum. (8,9,48), used as an adjuvant to chloroquine in Malagasy herbal practice and against chronic malaria (8,9). Two of them, harvelines B (VIII.2) and C (VIII.3) reversed in vitro chloroquine resistance to the resistant strain of P. falciparum (9) and exhibited moderate antimalarial activity (8,9,48). Harveline HB (VIII.5), an alkaloid whose structure has not been determined, also potentiated the effect of chloroquine and showed weak in vitro cytotoxicity against HeLa cells (48). 

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