Single oral dose of micellar b-carotene containing phospholipids improves b-carotene metabolism and plasma lipids in vitamin A-deficient rats.

Background Vitamin A (VA) deficiency is still a major
health problem in the developing world. It affects various
cellular functions and causes hypolipidemic effects in the
body. b-Carotene (BC)-rich foods are promising sources of
VA. Phospholipids are reported to improve BC bioefficacy
in normal rats, but whether they show similar effects during
VA deficiency is unknown.
Aim To compare the BC metabolism and plasma lipid
responses in VA-sufficient (?VA) and VA-deficient
(-VA) rats after a single oral dose of micellar BC containing
phospholipids.
Methods Groups of rats were fed with a VA-free diet and
when they attained the weight-plateau stage of deficiency,
both ?VA and -VA rats were divided into 2 groups
(phosphatidylcholine, PC and lysophosphatidylcholine,
LPC). Each group was further divided into 4 subgroups
(1, 2, 3, and 6 h; n = 5 rats/time point) and determined the
BC metabolism and plasma lipid responses to a post-dose
of micellar BC with phospholipids.
Results Maximal plasma BC (pmol/mL) levels were
observed at 2 h in PC (1330 ± 124) and at 1 h in LPC
(1576 ± 144) groups of ?VA rats, and at 3 h in the PC
(1621 ± 158) and LPC (2248 ± 675) groups of -VA rats.
Liver BC (pmol/g) was maximum at 1 h in the PC
(218 ± 32) and LPC (249 ± 24) groups of ?VA rats, and
at 2 h in PC (228 ± 23) and at 3 h in LPC (277 ± 18)
groups of -VA rats. Plasma and liver BC levels were
significantly (P\0.05) higher in -VA rats than ?VA rats.
Plasma retinyl palmitate (pmol/mL) was maximum at 3 h
in PC (97 ± 18) and at 2 h in LPC (126 ± 14) groups of
?VA rats, and at 2 h in the PC (92 ± 13) and LPC
(134 ± 27) groups of -VA rats. The higher (P\0.05) BC
monoxygenase activity in -VA rats compared to ?VA rats
supports the BC bioefficacy. Plasma retinol level was
improved in the PC and LPC groups, but the effect of LPC
was higher (P\0.05) than PC. Micellar phospholipids
mitigate the VA deficiency–induced hypolipidemic effects.
Conclusions Micellar phospholipids improved BC
metabolism and reinstated the hypolipidemic effects, perhaps
by modifying the fat-metabolizing enzymes and
repairing the altered intestinal membrane structure.