Phospholipid, Oleic Acid Micelles and Dietary Olive Oil Influence the Lutein Absorption and Activity of Antioxidant Enzymes in Rats

This study reports on the results of repeated gavages and dietary feeding of lutein dispersed either in phospholipids or fatty acid micelles or vegetable oils and the effects on lutein bioavailability and antioxidant enzymes in rats. For the gavage study, rats (n = 5/group) were intubated with lutein solubilized either in oleic acid (OLA, 18:1n-9) or linoleic acid (LNA, 18:2n-6) or phosphatidylcholine (PC) or lysophosphatidylcholine (LPC) or no phospholipid (NoPL) micelles for 10 days. For the dietary study, rats (n = 5/group) were fed a diet containing fenugreek leaf (lutein source), either with olive (OO) or sunflower (SFO) or groundnut (GNO, control) oil or l-α-lecithin (PL) for 4 weeks. The gavage study showed that the plasma, liver and eye lutein levels in OLA and LPC groups were higher by 23.9, 20.8 and 25.5% and 16.1, 28.5 and 14.0% than LNA and PC groups, respectively. The dietary study showed the plasma (35.0 and 43.5%) and eye (18.5 and 37.0%) lutein levels in OO were higher than SFO and GNO groups. The plasma and eye lutein levels in the PL group were higher by 20 and 31.3% than in the control. It is evident that OO and PL modulate lutein absorption, which in turn modulates antioxidant enzymes and fatty acids in plasma and tissues compared to SFO. Hence, selection of the fat source may be vital to enhancing the lutein bioavailability.