Effects of estivation on lutein and beta-carotene concentrations in Biomphalaria glabrata (NMRI strain) and Helisoma trivolvis (Colorado strain) snails as determined by quantitative high performance reversed phase thin layer chromatography

High performance thin layer chromatrography (HPTLC) on C-18 chemically bonded silica gel layers with petroleum ether-acetonitrile-methanol (1:2:2) mobile phase and visible mode slit-scanning densitometry was used to examine the effects of estivation on beta-carotene and lutein in the medically and economically important snails Biomphalaria glabrata (NMRI strain) and Helisoma trivolvis ( Colorado strain). Snails were estivated for 2 weeks in moist chambers at 24 degrees C and a relative humidity of 98%. Controls were maintained at 24 degrees C for the same period in aerated aquaria containing artificial spring water and fed Romaine lettuce leaves ad libitum. As determined by HPTLC analysis, estivation had no significant effect on the weight percentage of beta-carotene in the whole body or digestive gland-gonad complex (DGG) of both snail species. A significant reduction (Student's t-test, P < 0.5) was found in the percentage of lutein in the DGG of H. trivolvis. Whereas published and unpublished studies have demonstrated marked reductions of carbohydrates and lipids in estivated pulmonate snails, the effects of estivation on lipophilic pigments in these snails does not appear to be as pronounced.