beta-carotene and Down-Syndrome

Down's syndrome (DS) has the highest incidence among chromosomal disorders and is a predisposing factor in acute leukemia pathogenesis. DS patients are sensitive to both physical and chemical inducers at the DNA level. Studies on beta-carotene, an antioxidant, suggested the there is a relationship between high beta-carotene diet and reduced tumor incidence in humans indicating that beta-carotene is a chemopreventive agent against cancer. Sister chromatid exchange (SCE) is known as a sensitive parameter among the genotoxicity tests. In this study, we aimed to investigate the in vitro effect of beta-carotene on SCE frequencies in 7 DS patients and 7 healthy controls aged between 0-16 years. A direct leukomogenic agent Mitomycin-C (MMC) was used as a powerful SCE inducer. Addition of MMC to the cultures alone resulted in a significant enhancement of SCE frequencies in both groups when compared to the spontaneous values. In the study, beta-carotene seemed to decrease MMC induced mean SCE/cell values, but did not have an effect on unstimulated cells. As this is a limited study, it is hard to conclude that beta-carotene is a chemopreventive agent in DS patients, although our results seem to support other investigators' reports.

Topics: Adolescent; Antioxidants; beta Carotene; Cells, Cultured; Child; Child, Preschool; Down Syndrome; Female; Humans; Infant; Lymphocytes; Male; Mitomycin; Sister Chromatid Exchange

In previous reports, deficiencies in serum vitamin A were considered a frequent finding in persons with Down's syndrome. Based on this assumption, the regular determination of both serum carotene and vitamin A has been recommended for the preventive care of this population. In the author's preventive medicine clinic for children with Down's syndrome, we have checked these items routinely in 44 fasting patients (aged 14 months to 19 years). The author was surprised to find no patient with either a deficiency of carotene or vitamin A, but 14 patients had hypercarotenemia. Any known aetiology of this finding, such as excessive ingestion, diabetes mellitus or hypothyroidism, could not be verified. It has to be mentioned that the previous reports on serum carotene levels were based on determinations by conventional spectrophotometric methods (normal range: 50-670 micrograms/dl), whereas the author applied an improved method of high-performance liquid chromatography with a much lower normal range (50-750 micrograms/l). Further investigations are to be performed to verify these findings and to evaluate probable mechanisms of hypercarotenemia in persons with Down's syndrome.

Topics: Adolescent; beta Carotene; Carotenoids; Child; Child, Preschool; Down Syndrome; Female; Humans; Hypervitaminosis A; Infant; Male; Reference Values; Vitamin A

The sensitivity of human erythrocytes to photohemolysis sensitized by addition of protoporphyrin IX can be selectively affected by their enrichment with substances carried by cationic liposomes. In particular the enrichment which superoxide dismutase is accompanied by a copper-related greater sensitivity toward photohemolysis, as observed in the Down's syndrome (mongolism). Instead it is possible to protect the erythrocytes against the phototoxic effect of protoporphyrin by enrichment with small amounts of beta-carotene.

Topics: Animals; beta Carotene; Carotenoids; Cattle; Down Syndrome; Erythrocytes; Hemolysis; Humans; Kinetics; Light; Liposomes; Protoporphyrins; Superoxide Dismutase