The effect of fibrates on high density lipoprotein (HDL)-cholesterol levels is suggested to be mediated by its binding to peroxisome proliferator-activated receptor-g (PPARg). Upon ligand binding, PPARg heterodimerizes with the 9-cis retinoic acid receptor (RXR), and the heterodimer regulates gene expression. We assessed the hypothesis that a dual treatment with fibrate plus 9-cis b-carotene-rich powder of the alga Dunaliella bardawil, as a source of 9-cis retinoic acid, would improve the drug's effect on HDL-cholesterol levels.

patients with plasma HDL-cholesterol levels below 40 mg/dl and triglyceride (TG) levels above 200 mg/dl after fibrate treatment (for at least 6 weeks). are given four capsules of Dunaliella, providing 60 mg b-carotene/day. The all-trans to 9-cis b-carotene ratio in the capsules is about 1:1.