scholarly journals Studies on the bioavailability of the provitamin A carotenoid, β-carotene, using human exfoliated colonic epithelial cells

2004 ◽  
Vol 92 (2) ◽  
pp. 241-245 ◽  
Author(s):  
T. Gireesh ◽  
P. P. Nair ◽  
P. R. Sudhakaran

The possibility of using exfoliated colonic epithelial cells for assessing the bioavailability of β-carotene was examined. Analysis of exfoliated colonic epithelial cells showed the presence of β-carotene and vitamin A. The β-carotene content was significantly lower in cells from stool samples of subjects on a β-carotene-poor diet than those receiving a single dose of a β-carotene supplement. Colonic epithelial cells isolated from stool samples collected daily during a wash-out period while the subjects were on a β-carotene-poor diet showed a steady decrease in β-carotene content, reaching the lowest value on day 7. Kinetic analysis showed that a single dose of a β-carotene supplement in the form of spirulina (Spirulina platensis) or agathi (Sesbania grandiflora) after the wash-out period caused an increase in the β-carotene content after a lag period of 5–7 d, but the vitamin A levels during these periods were not significantly affected. Analysis of plasma β-carotene concentration also showed similar changes, which correlated with those of exfoliated colonic cells. A relationship between the β-carotene content of the diet and that of the colonic epithelial cells suggests that analysis of the β-carotene content in exfoliated human colonic epithelial cells is a useful non-invasive method to assess the bioavailability of provitamin A β-carotene.

2009 ◽  
Vol 45 (3) ◽  
pp. 527-537 ◽  
Author(s):  
Pollyanna Costa Cardoso ◽  
Ceres Mattos Della Lucia ◽  
Paulo César Stringheta ◽  
José Benício Paes Chaves ◽  
Helena Maria Pinheiro-Sant'Ana

This study investigated the α- and β-carotene content and provitamin A value of four leafy vegetables sold at local and street markets in Viçosa, MG, Brazil, in the spring and winter of 2002. Carotenoids were analyzed by high-performance liquid chromatography. α-Carotene was detected in all samples sold during spring, but was only present in a few samples of smooth and curly lettuce and kale in winter. β-Carotene was found in marked quantities in all leafy vegetables analyzed. Duncan's test (α = 5%) showed significantly higher α-carotene content in curly lettuce and vitamin A value in large-leaved watercress in the spring. Mean β-carotene content and vitamin A value were 7544, 8751, 2584, 2792, 8193, and 5338 μg/100 g and 666, 760, 227, 238, 698, and 460 μg RAE/100 g in large-leaved and hydroponic watercress, smooth and curly lettuce, kale and spinach, respectively. All leafy vegetables analyzed represent important sources of provitamin A and supply an important part of the daily requirements of children and adults.


2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang

Humans need vitamin A and obtain essential vitamin A by conversion of plant foods rich in provitamin A and/or absorption of preformed vitamin A from foods of animal origin. The determination of the vitamin A value of plant foods rich in provitamin A is important but has challenges. The aim of this paper is to review the progress over last 80 years following the discovery on the conversion of β-carotene to vitamin A and the various techniques including stable isotope technologies that have been developed to determine vitamin A values of plant provitamin A (mainly β-carotene). These include applications from using radioactive β-carotene and vitamin A, depletion-repletion with vitamin A and β-carotene, and measuring postprandial chylomicron fractions after feeding a β-carotene rich diet, to using stable isotopes as tracers to follow the absorption and conversion of plant food provitamin A carotenoids (mainly β-carotene) in humans. These approaches have greatly promoted our understanding of the absorption and conversion of β-carotene to vitamin A. Stable isotope labeled plant foods are useful for determining the overall bioavailability of provitamin A carotenoids from specific foods. Locally obtained plant foods can provide vitamin A and prevent deficiency of vitamin A, a remaining worldwide concern.


1946 ◽  
Vol 36 (2) ◽  
pp. 95-99 ◽  
Author(s):  
B. C. Ray Sarkar ◽  
K. C. Sen

1. With the object of determining the vitamin A value of carotene in different green fodders, an investigation has been undertaken to study (i) the relation between the chemically determined carotene and its biological activity as compared with that of standard carotene, (ii) the purity of apparent carotene from different sources, (iii) absorption of carotene in rats, and (iv) the relative efficiency of the standard carotene and preformed vitamin A.2. Biological tests have shown that the chemical method of assay is a fair index of the true carotene content in green fodders, and carotene in the form of an extract is quite as effective in the system as that present in the plant tissues. β-Carotene appears to be predominant in these materials.


2009 ◽  
Vol 102 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Julie A. Howe ◽  
Bussie Maziya-Dixon ◽  
Sherry A. Tanumihardjo

Efforts to increase β-carotene in cassava have been successful, but the ability of high-β-carotene cassava to prevent vitamin A deficiency has not been determined. Two studies investigated the bioefficacy of provitamin A in cassava and compared the effects of carotenoid content and variety on vitamin A status in vitamin A-depleted Mongolian gerbils (Meriones unguiculatus). Gerbils were fed a vitamin A-free diet 4 weeks prior to treatment. In Expt 1, treatments (ten gerbils per group) included 45 % high-β-carotene cassava, β-carotene and vitamin A supplements (intake matched to high-β-carotene cassava group), and oil control. In Expt 2, gerbils were fed cassava feeds with 1·8 or 4·3 nmol provitamin A/g prepared with two varieties. Gerbils were killed after 4 weeks. For Expt 1, liver vitamin A was higher (P < 0·05) in the vitamin A (1·45 (sd 0·23) μmol/liver), lower in the control (0·43 (sd 0·10) μmol/liver), but did not differ from the β-carotene group (0·77 (sd 0·12) μmol/liver) when compared with the high-β-carotene cassava group (0·69 (sd 0·20) μmol/liver). The bioconversion factor was 3·7 μg β-carotene to 1 μg retinol (2 mol:1 mol), despite 48 % cis-β-carotene [(Z)-β-carotene] composition in cassava. In Expt 2, cassava feed with 4·3 nmol provitamin A/g maintained vitamin A status. No effect of cassava variety was observed. Serum retinol concentrations did not differ. β-Carotene was detected in livers of gerbils receiving cassava and supplements, but the cis-to-trans ratio in liver differed from intake. Biofortified cassava adequately maintained vitamin A status and was as efficacious as β-carotene supplementation in the gerbil model.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 541 ◽  
Author(s):  
Beloved Mensah Dzomeku ◽  
Julian P. Wald ◽  
Jens Norbert Wünsche ◽  
Donatus Nohr ◽  
Hans K. Biesalski

Diet diversification and the exploitation of traditional, micronutrient-rich germplasm of staple crops are generally regarded as sustainable and low-cost approaches to increase the micronutrient intake of resource-poor people. Sun’s UV index was collected daily throughout the year. The study assessed the seasonality of provitamin A carotenoids in three plantain cultivars in response to climatic condition. Fruits were harvested at three maturities and freeze-dried before analysis. The results showed that there were high levels of the sun’s UV-B radiations throughout the year with the highest occurring from November to May when the area experienced clear skies with minimal cloud cover. These high levels of the sun’s UV-B index occurred between 9.00 h GMT and 17.00 h GMT. The study also showed that α-carotene content increased with maturity in “Apantu” during the rainy seasons ranging from 95 to 172 μg/100 g of dry pulp. Similar trends were observed during the dry season with a range of 28 to 489 μg/100 g. The α-carotene contents were very high in the periods of high sun’s UV-B radiations compared to the periods of low sun’s UV-B radiations. The α-carotene levels in the giant French plantains showed similar trends. Intermediate French “Oniaba” and False Horn “Apantu” plantain cultivar showed the highest content of β-carotene during the dry season. The high provitamin A carotenoid levels in the cultivars coincided with the high levels of the sun’s UV index.


2005 ◽  
Vol 46 (10) ◽  
pp. 3562 ◽  
Author(s):  
Gurunadh Reddy Chichili ◽  
Donatus Nohr ◽  
Michael Scha¨ffer ◽  
Johannes von Lintig ◽  
Hans K. Biesalski

2021 ◽  
Vol 8 ◽  
Author(s):  
Junrui Cheng ◽  
Emilio Balbuena ◽  
Baxter Miller ◽  
Abdulkerim Eroglu

Background: Carotenoids are naturally occurring pigments accounting for the brilliant colors of fruits and vegetables. They may display antioxidant and anti-inflammatory properties in humans besides being precursors to vitamin A. There is a gap of knowledge in examining their role within colonic epithelial cells. We proposed to address this research gap by examining the effects of a major dietary carotenoid, β-carotene, in the in vitro epithelial cell model.Methods: We examined the function of β-carotene in the lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) signaling pathway. We conducted western blotting assays to evaluate expressions of TLR4 and its co-receptor, CD14. We also examined NF-κB p65 subunit protein levels in the model system. Furthermore, we studied the impact of β-carotene on the tight junction proteins, claudin-1, and occludin. We further carried out immunocytochemistry experiments to detect and visualize claudin-1 expression.Results: β-Carotene reduced LPS-induced intestinal inflammation in colonic epithelial cells. β-Carotene also promoted the levels of tight junction proteins, which might lead to enhanced barrier function.Conclusions: β-Carotene could play a role in modulating the LPS-induced TLR4 signaling pathway and in enhancing tight junction proteins. The findings will shed light on the role of β-carotene in colonic inflammation and also potentially in metabolic disorders since higher levels of LPS might induce features of metabolic diseases.


1947 ◽  
Vol 109 (2) ◽  
pp. 219-225 ◽  
Author(s):  
George W. Kohler ◽  
Ralph E. Lincoln ◽  
J. W. Porter ◽  
F. P. Zscheile ◽  
Ralph M. Caldwell ◽  
...  

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