Changes in beta-carotene levels by long-term administration of natural beta-carotene derived from Dunaliella bardawil in humans.

Abstract

Long-term administration of a beta-carotene preparation derived from Dunaliella bardawil, a beta-carotene-rich algae, was studied in healthy young male volunteers. The daily administration of 60 mg of the beta-carotene preparation (30 mg of all-trans beta-carotene and 30 mg of 9-cis beta-carotene) was performed and beta-carotene concentrations were determined in the plasma, red blood cells (RBC), platelets (PLT), and mononuclear cells (MN). The all-trans beta-carotene level increased four-, two-, and threefold the baseline in plasma, PLT, and MN, respectively. Basal levels of 9-cis beta-carotene in plasma, PLT, and MN were low and found as one-tenth, one-fifth, and one-fifth of all-trans beta-carotene, which increased three-, two-, and 1.5-fold the baseline, respectively. Plasma and RBC alpha-tocopherol levels were not changed by the intake of beta-carotene. No side effects or toxicities were documented in any of the subjects during the administration period. In conclusion, the bioavailability of beta-carotene derived from Dunaliella bardawil was preferential for all-trans beta-carotene, although a small amount of the 9-cis form was detected in the plasma and blood cells.