Muscle atrophy increases the production of reactive oxygen species and the expression of atrophy-related genes, which are involved in the ubiquitin-proteasome system. In the present study, we investigated the effects of β-carotene on oxidative stress (100 μM-H2O2)-induced muscle atrophy in murine C2C12 myotubes. β-Carotene (10 μM) restored the H2O2-induced decreased levels of myosin heavy chain...

Validation of an in vivo method we developed recently and its application to assess the role of dietary factors in carotene conversion were tested in rats. We compared the ratio of area under plasma vitamin A time-curves (AUC(0-12h)) obtained after a dose of beta-carotene to that after a dose of vitamin A, with the in vitro intestinal supernatant beta-carotene dioxygenase activity. In separate ...

ß-Carotene is present in extremely high concentrations in bovine corpus luteum. The aim of this study was to examine the extent of the seasonal variation in concentrations of luteal ß-carotene in cows. A total of 102 corpora lutea collected throughout all 12 months of the year were analysed by high performance liquid chromatography (HPLC). The mean ß-carotene concentration of the luteal tissues...

The circulating levels of β-carotene are modulated not only by sex, but also by autosomal gene variations and fruit intake. The aim of this study was to investigate the interactions between β-carotene metabolism-related gene single nucleotide polymorphisms (SNPs; genetic factors) and nutrient intake (environmental factors) relating to their effects on circulating β-carotene. The serum concentra...

p-Carotene (pro-vitamin A) is a lipid-soluble antioxidant capable of quenching singlet oxygen and scavenging free-radical species [ 1-31, Epidemiological studies have established a correlation between p-carotene dietary supplementation with a reduced risk of cancer and heart disease thus providing a basis for clinical investigation [4, 51. The antioxidant properties of pcarotene, perhaps in com...

Vitamin A and its derivatives have recently reported to be implicated in synaptic plasticity. The possible effect of vitamin A and its precursor, ?-carotene, on seizure acquisition was tested in PTZ kindling model of epilepsy. Vitamin A and ?-carotene were tested for their ability to 1) suppress seizures (clonic and tonic) and lethality induced by PTZ in PTZ-kindled mice (anticonvulsant effect)...

Use of isotopes as tracers has had an important role in elucidating key features of vitamin A and retinoid metabolism in animal models and humans. Their use has shown that beta-carotene absorption is variable, and that the appearance of beta-carotene and its metabolites in the blood by time since dosing follows characteristic patterns. Retinol formed from beta-carotene shows a different pattern...

The vitamin A values of plant foodstuffs, as found by biological tests with rats, are often lower than would have been expected from the results of chemical estimations of the carotene content. The causes of this discrepancy presumably lie mainly in a less complete absorption of carotene from vegetables than from the oily solution in which the international /3-carotene standard is administered,...

Background: Although interventional trials demonstrated that moderate-dose b-carotene supplementation increases lung cancer mortality in smokers and asbestos-exposedworkers, differences in serum concentrations in absence of supplementation have not been studied in asbestos-exposed workers. Methods: A mortality analysis was performed to assess the relationship of nonsupplemented serum b-carotene...

Experimental and epidemiological evidence supports the hypothesis that oxidation of low density lipoprotein (LDL) appears to be important in mediating the atherogenicity of LDL. To test this hypothesis in humans, it will be necessary to perform intervention studies in large populations. We performed two studies to assess the effectiveness of supplementation with /3-carotene and vitamin E, used ...