Effects of diet and larval trematode parasitism on lutein and beta-carotene concentrations in planorbid snails as determined by quantitative high performance reversed phase thin layer chromatography.

High performance thin layer chromatography (HPTLC) was used to quantify the concentrations of beta-carotene and lutein in Biomphalaria glabrata and Helisoma trivolvis (Colorado and Pennsylvania strains) snails under various conditions. These conditions were: snails fed a lettuce (L) vs. a yolk (Y) diet; B. glabrata infected with Echinostoma caproni vs. uninfected snails; and H. trivolvis (PA) infected with Echinostoma trivolvis vs. uninfected snails. The pigments were extracted from the snail whole bodies and digestive gland-gonad complexes, separated by reversed phase HPTLC, and quantified by densitometric scanning with standard calibration curves. Snails on the L-diet showed significant increases (Student's t-test, P<0.05) in the concentrations of beta-carotene and lutein compared to snails on the Y-diet. Snails infected with echinostomes showed no significant differences (Student's t-test, P>0.05) in the concentrations of lutein and beta-carotene compared to the uninfected cohorts. Our results were compared with previous studies that analyzed beta-carotene and lutein in snails infected with larval trematodes. Variations in the results of our study compared with others reflect intrinsic differences in the larval trematode-snail systems used.