Plasmodium falciparum: differing effects of non-esterified fatty acids and phospholipids on intraerythrocytic growth in serum-free medium.

ABSTRACT

Different combinations of non-esterified fatty acids (NEFA) had variable effects on intraerythrocytic growth of Plasmodium falciparum. All stages of the parasite cultured in medium supplemented with cis-9-octadecenoic acid (C181-cis-9), hexadecanoic acid (C160), phospholipids (Pld) and bovine albumin free of NEFA were similar to those grown in complete growth medium. Three typical growth patterns indicating suppressed schizogony (SS), suppressed formation of merozoites (SMF), and inhibited invasion of merozoites (IMI) resulted from culture in other combinations of lipids. Unsaturated or saturated NEFA with longer or shorter carbon chains than C181-cis-9 or C160, higher degree of unsaturation, and trans-forms mainly resulted in SS and SMF effects. However, IMI or partial IMI was observed with tetradecanoic acid or octadecanoic acid enriched with C181-cis-9, and cis-9-hexadecenoic acid plus C160. Isoforms of C181-cis-9 also mainly resulted in partial IMI. SMF also occurred with C181-cis-9 plus C160 in the absence of Pld. Thus different NEFA exerted distinct roles in erythrocytic growth of the parasite by sustaining development at different stages.