-Carotene 15,15 -monooxygenase (formerly termed , -carotene 15,15 -dioxygenase, EC 1.13.11.21) catalyzes the conversion of provitamin A carotenoids to retinal in vertebrate tissues. In the present study, we investigated whether preformed vitamin A or -carotene and its direct metabolites can regulate the enzyme activity in vivo. We found dose-dependent decreases in intestinal , -carotene monooxy...

BACKGROUND/AIM The aim of the present study was to investigate the protective effect of β-carotene on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three β-carotene-pretreated groups. To induce the I/R lesions, the celiac artery was clamped for 30 min. The clamp was then removed to allow repe...

Accumulation of beta-carotene during postharvest ripening of nine Thai mango cultivars was assessed after verifying extraction and high-performance liquid chromatographic quantification of the beta-carotene stereoisomers for this sample matrix. No relevant trans-cis isomerization was induced by the analytical procedure. The vitamin A potential of mangoes was evaluated at different ripening stag...

This study investigated whether a high dietary intake or serum concentration of antioxidant (pro-) vitamins could attenuate the acute respiratory effects of air pollution in panels of adults (n = 227) aged 50-70 yrs with chronic respiratory symptoms in two winters starting in 1993/1994. Subjects performed daily peak expiratory flow (PEF) measurements in the morning and evening and reported the ...

The aim of the present study was to investigate the anticancer and immunity activity of β-carotene in hepatocellular carcinoma (HCC) rats. Three days after transplantation, forty Wistar rats were randomly divided into four groups, each group consisting of 10 animals. These groups were control group (untreated), low-dose β-carotene-treated group (20 mg/kg), middle-dose group (40 mg/kg) and high-...

Serum concentrations of retinol, alpha-tocopherol, beta-carotene and lycopene were measured by reversed-phase high-performance liquid chromatography (r-P HPLC) in 260 randomly selected healthy adult Kuwaitis (159 men and 101 women) aged 18-63 years (mean 33.3 years) to established reference ranges of the micronutrient antioxidants. Total cholesterol concentrations were assayed by an enzymatic m...

BACKGROUND AND OBJECTIVES Kale is a rich source of provitamin A- β-carotene. This study used intrinsically labeled kale [2H9] β-carotene to determine the effect of peanut butter on the bioconversion of kale β-carotene to vitamin A in preschool children. METHODS AND STUDY DESIGN Preschool children (n=37; age 12-36 mo) were randomly assigned to 50 g cooked kale (1.5 mg β-carotene content) with ...

Human serum contains many different antioxidants which may be important in the maintenance of antioxidant status. β-carotene and lycopene are carotenoids with potent antioxidant activity. Carotenoids intake probably protects against cancers and may affect the risk of several chronic conditions. α-tocopherol is well known for its function as antioxidant and in reduction of heart disease and canc...

Diet quality indices can predict nutritional adequacy of usual intake, but validity should be determined. The aim was to assess the validity of total and sub-scale score within the Australian Recommended Food Score (ARFS), in relation to fasting plasma carotenoid concentrations. Diet quality and fasting plasma carotenoid concentrations were assessed in 99 overweight and obese adults (49.5% fema...

During an investigation into certain aspects of the carotene metabolism of ruminants, it was desired to obtain an indication of the effect of the composition of the feed on the availability of carotene to the animals. The most convenient method of measuring approximately the carotene absorption appeared to be by determining its apparent digestibility using the ordinary digestibility-trial techn...