Cytotoxic effect of beta-carotene in vitro is dependent on serum concentration and source.
In a previous study we reported that beta-carotene solubilized in tetrahydrofuran (THF) is toxic for human colonic tumor cells in vitro using media containing 10% fetal calf serum (FCS). Cytotoxicity was evident using beta-carotene concentrations that are achieved in human serum as a result of supplementation with 30 mg beta-carotene/day. In an attempt to determine the mechanism for this toxicity we investigated the effect of beta-carotene when present in human serum as a result of dietary supplementation. This effect was compared to that observed for cells incubated in THF-solubilized beta-carotene. The results indicate that human serum from subjects with a high concentration of beta-carotene is not cytotoxic. Subsequent analysis revealed that in contrast to the results using FCS, THF-solubilized beta-carotene is not cytotoxic in the presence of human serum. In addition, the effect observed with FCS is blunted with increasing FCS concentration from > or = 90% cytotoxicity using 10% FCS to 36% using 100% FCS. The difference in results obtained using FCS and human serum may be due to a serum component that is relatively lacking in FCS as compared to human serum.
Peram
V
V
Department of Medicine, Loyola University Medical Center, Maywood, IL 60153, USA.
Iftikhar
S
S
Lietz
H
H
Mobarhan
S
S
Frommel
T O
TO
D000970:Antineoplastic Agents / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms; D003470:Culture Media; D005527:Food, Fortified; D005663:Furans; D006801:Humans; D013997:Time Factors; D014407:Tumor Cells, Cultured; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood* / Q000633:toxicity*
D000970:Antineoplastic Agents; D003470:Culture Media; D005663:Furans; D019207:beta Carotene; C018674:tetrahydrofuran