Effects of bile salt-stimulated lipase-treated triglycerides and free fatty acids on extracellular stages of Eimeria tenella.

Normal human milk (NHM) has antiprotozoal activity unrelated to immunological components; this activity extends to sporozoites of Eimeria tenella. This activity may be due to free fatty acids (FFA) enzymatically hydrolyzed from triacyl glycerols by a bile salt-stimulated lipase (BSSL) found in NHM. Sporozoites were therefore incubated in the presence of several saturated and unsaturated FFA. Anticoccidial activity was observed for many unsaturated fatty acids and for some saturated fatty acids. In addition, sporozoites were added to solutions of triglycerides (trilinolein, triolein and trilinolenin) preincubated with BSSL and sodium cholate, which resulted in killing of the parasites. Triglycerides alone showed no anticoccidial activity. These results were duplicated with first generation merozoites. Intracellular stages of E. tenella were affected by FFA only at concentrations that inhibited host cells.