scholarly journals Apocarotenoids: Emerging Roles in Mammals

2018 ◽  
Vol 38 (1) ◽  
pp. 153-172 ◽  
Author(s):  
Earl H. Harrison ◽  
Loredana Quadro

Apocarotenoids are cleavage products of C40 isoprenoid pigments, named carotenoids, synthesized exclusively by plants and microorganisms. The colors of flowers and fruits and the photosynthetic process are examples of the biological properties conferred by carotenoids to these organisms. Mammals do not synthesize carotenoids but obtain them from foods of plant origin. Apocarotenoids are generated upon enzymatic and nonenzymatic cleavage of the parent compounds both in plants and in the tissues of mammals that have ingested carotenoid-containing foods. The best-characterized apocarotenoids are retinoids (vitamin A and its derivatives), generated upon central oxidative cleavage of provitamin A carotenoids, mainly β-carotene. In addition to the well-known biological actions of vitamin A, it is becoming apparent that nonretinoid apocarotenoids also have the potential to regulate a broad spectrum of critical cellular functions, thus influencing mammalian health. This review discusses the current knowledge about the generation and biological activities of nonretinoid apocarotenoids in mammals.

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.


2010 ◽  
Vol 13 (11) ◽  
pp. 1863-1869 ◽  
Author(s):  
Nguyen Cong Khan ◽  
Phan Van Huan ◽  
Nguyen Van Nhien ◽  
Le Danh Tuyen ◽  
Saskia de Pee ◽  
...  

AbstractObjectiveTo characterize the relationship between serum carotenoids, retinol and anaemia among pre-school children.DesignA cross-sectional study was conducted in two groups: anaemic and non-anaemic. Serum levels of retinol, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin were measured in the study subjects.SettingSix rural communes of Dinh Hoa, a rural and mountainous district in Thai Nguyen Province, in the northern mountainous region of Vietnam.SubjectsA total of 682 pre-school children, aged 12–72 months, were recruited.ResultsGeometric mean serum concentrations of carotenoids (μmol/l) were 0·056 for α-carotene, 0·161 for β-carotene, 0·145 for β-cryptoxanthin, 0·078 for lycopene, 0·388 for lutein and 0·075 for zeaxanthin. The mean levels of Hb and serum retinol were 108·8 g/l and 1·02 μmol/l, respectively. The prevalence of anaemia and vitamin A deficiency was 53·7 % and 7·8 %, respectively. After adjusting for sex and stunting, serum retinol concentrations (μmol/l; OR = 2·06, 95 % CI 1·10, 3·86, P = 0·024) and total provitamin A carotenoids (μmol/l; OR = 1·52, 95 % CI 1·01, 2·28, P = 0·046) were independently associated with anaemia, but non-provitamin A carotenoids (μmol/l; OR = 0·93, 95 % CI 0·63, 1·37, P = 0·710) were not associated with anaemia.ConclusionsAmong pre-school children in the northern mountainous region of Vietnam, the prevalences of vitamin A deficiency and anaemia are high, and serum retinol and provitamin A carotenoids are independently associated with anaemia. Further studies are needed to determine if increased consumption of provitamin A carotenoids will reduce anaemia among pre-school children.


2017 ◽  
Vol 87 (5-6) ◽  
pp. 279-286
Author(s):  
Tawanda Muzhingi ◽  
Kyung-Jin Yeum ◽  
Andrew H. Siwela ◽  
Odilia Bermudez ◽  
Guangwen Tang

Abstract. Provitamin A carotenoids in plant foods provide more than 80% of vitamin A intake for people in developing countries. Therefore, the conversion efficiency of β-carotene to vitamin A is important, as it determines the effectiveness of plant foods as sources of vitamin A in humans. The objective of this study was to determine the effect of plant food antioxidants such as α-tocopherol, γ-tocopherol, α-tocotrienol, γ-tocotrienol and total γ-oryzanol on the cleavage of β-carotene in vitro. Rat intestinal mucosa post mitochondrial fractions were incubated with β-carotene-rich extracts of kale and biofortified maize for an hour at 37°C. Rat intestinal mucosa post mitochondrial fractions were also incubated with β-carotene in the presence of either α-tocopherol, γ-tocopherol, α-tocotrienol, γ-tocotrienol or γ-oryzanol for 60 min at 37°C. The β-carotene cleavage products were extracted and analyzed by an HPLC equipped with a C18 column at 340nm and 450nm. When β-carotene alone was incubated without intestinal mucosa homogenate (control), no cleavage products were detected. When β-carotene alone was incubated with intestinal mucosa homogenate, β-apo-13-carotenone, β-apo-14-carotenal, retinal, retinol and retinoic acid were formed. However, incubation of β-carotene with either α-tocopherol, γ-tocopherol or α-tocotrienol resulted in a 10 fold inhibition of β-apo-14-carotenal and β-apo-13-carotenone formation. Antioxidant rich biofortified maize extract incubated with postmitochondrial fraction produced less β-apo-13-carotenone compared to the kale extract. These results suggest that antioxidants inhibit the cleavage of β-carotene and the formation of excentric cleavage products (β-apo-13-carotenone, β-apo-14-carotenal).


2010 ◽  
Vol 103 (11) ◽  
pp. 1594-1601 ◽  
Author(s):  
Richard A. Ejoh ◽  
Joseph T. Dever ◽  
Jordan P. Mills ◽  
Sherry A. Tanumihardjo

Leafy vegetables are important sources of provitamin A carotenoids. Information on their ability to provide vitamin A is often misleading because of the methodology used to assess bioefficacy. Mongolian gerbils were used to evaluate the bioefficacy of provitamin A carotenoids in tropical leafy vegetables (i.e. Solanum nigrum, Moringa oleifera, Vernonia calvoana and Hibiscus cannabinus) that are indigenous to Africa. Gerbils (n 67) were vitamin A-depleted for 5 weeks. After a baseline kill (n 7), the gerbils were weight-matched and assigned to six treatment groups (n 10; four vegetable groups; negative and positive controls). For 4 weeks, the treatments included 35 nmol vitamin A (theoretical concentrations based on 100 % bioefficacy) in the form of vegetables or retinyl acetate. In addition to their diets, the control and vegetable groups received daily doses of oil, while the vitamin A group received retinyl acetate in oil matched to prior day intake. Serum and livers were analysed for vitamin A using HPLC. Serum retinol concentrations did not differ among groups, but total liver vitamin A of the vitamin A and vegetable groups were higher than that of the negative control group (P < 0·0001). Liver β-carotene 15,15′-monooxygenase-1 expression levels were determined for two vegetable groups and were similar to the positive and negative controls. Conversion factors for the different leafy vegetables were between 1·9 and 2·3 μg β-carotene equivalents to 1 μg retinol. Small quantities of these vegetables maintained vitamin A status in gerbils through efficient bioconversion of β-carotene to retinol.


2017 ◽  
Vol 242 (15) ◽  
pp. 1508-1514 ◽  
Author(s):  
Jesse Sheftel ◽  
Bryan M Gannon ◽  
Christopher R Davis ◽  
Sherry A Tanumihardjo

Plants that undergo C4 photosynthesis, such as maize, are enriched in the stable isotope of carbon (13C) compared with other dietary plants and foods. Consumption of maize that has been biofortified to contain elevated levels of provitamin A carotenoids (orange maize) increased the abundance of 13C in serum retinol of Mongolian gerbils. We evaluated this method in humans to determine if it has potential for further use in intervention effectiveness studies. A random subset of samples from a two-month randomized controlled feeding trial of rural three- to five-year old Zambian children were used to determine the impact of orange maize intake on serum carotenoid concentrations ( n = 88) and 13C-natural abundance in serum retinol ( n = 77). Concentrations of β-cryptoxanthin (a xanthophyll provitamin A carotenoid) and the dihydroxy xanthophylls lutein and zeaxanthin, which do not have vitamin A activity, were elevated in children consuming orange maize compared with those consuming a white maize control ( P < 0.001), while β-carotene was not different ( P > 0.3). Furthermore, 13C natural abundance was higher after two months’ intervention in the orange maize group compared with the white maize group ( P = 0.049). Predictions made from equations developed in the aforementioned gerbil study estimated that maize provided 11% (2–21%, 95% confidence interval) of the recent dietary vitamin A to these children. These results demonstrate that orange maize is efficacious at providing retinol to the vitamin A pool in children through provitamin A carotenoids, as monitored by the change in 13C enrichment, which was not reflected in serum β-carotene concentrations. Further effectiveness studies in countries who have adopted orange maize should consider determining differences in retinol 13C-enrichment among target groups in addition to profiling serum xanthophyll carotenoids with specific emphasis on zeaxanthin. Impact statement Maize biofortified with provitamin A carotenoids (orange) has been released in some African markets. Responsive and sensitive methods to evaluate dissemination effectiveness are needed. This study investigated methods to evaluate effectiveness of orange maize consumption using serum from Zambian children fed orange maize for two months. Many varieties of orange maize contain higher amounts of the xanthophyll carotenoids in addition to β-carotene compared with typical varieties. This study uniquely showed higher concentrations of the maize xanthophylls lutein, zeaxanthin, and β-cryptoxanthin in children who consumed orange maize compared with white. Furthermore, maize is a C4 plant and is therefore naturally enriched with 13C. Higher 13C was detected in the serum retinol of the orange maize consumers with no change in serum β-carotene concentration suggesting preferential bioconversion to retinol. The combined analyses of serum zeaxanthin specifically and 13C-natural abundance of retinol could prove useful in effectiveness studies between orange maize adopters and non-adopters.


2012 ◽  
Vol 2 (2) ◽  
pp. 60 ◽  
Author(s):  
Beatrice Nakhauka Ekesa ◽  
Judith Kimiywe ◽  
Inge Van den Bergh ◽  
Guy Blomme ◽  
Claudie Dhuique-Mayer ◽  
...  

<p>Changes in the concentrations and retention levels of total and individual provitamin A carotenoids (pVACs) during ripening and local processing of the four most popular <em>Musa</em> cultivars of Eastern Democratic Republic of Congo were established through HPLC analysis. The predominant pVACs were all <em>trans</em> ?- and ?-carotene, together constituting about 90% of total pVACs content in raw and processed <em>Musa</em> fruit pulp. The proportion of ?- and ?-carotene was not significantly different in the tested East African Highland Bananas (AAA-EAHB) (‘Nshikazi’ and ‘Vulambya’); in the plantains (‘Musilongo’ and ‘Musheba’), proportion of ?-carotene was almost twice that of ?-carotene. An increase in total pVACs was observed during ripening, with highest levels at ripening stage 3 in all four cultivars. Total pVACs values were as high as 1081µg/100gfw in ‘Vulambya’ and 1819µg/100gfw in ‘Musilongo’. Boiling of the AAA-EAHB and AAB-Plantains resulted to retention of between 40-90% and &gt;95% respectively. Plantains deep-fried in fully-refined palm oil and crude red palm oil for 2 minutes did not seem to lose any pVACs, the levels of total pVACs observed after frying were 100% of what was observed when the fruit was raw. Retinol Activity Equivalents (RAE), in boiled products varied between 22.3 and 173 RAEµg/100gfw, whereas deep fried products had &gt;190 RAEµg/100g edible portion. These results show that the tested AAA-EAHBs and the plantains could meet at least 14% and 30 % of Vitamin A recommended dietary intakes respectively. The findings can therefore guide consumer consumption patterns to maximize vitamin A intake for improved health in these regions and also direct researchers in the selection of <em>Musa</em> cultivars to be incorporated within existing farming systems in the fight against vitamin A deficiency (VAD).</p>


2021 ◽  
Vol 11 (23) ◽  
pp. 11097
Author(s):  
Ana Lima ◽  
Filipe Arruda ◽  
Jorge Medeiros ◽  
José Baptista ◽  
João Madruga ◽  
...  

The scientific community is paying increasing attention to plant waste valorization, and also to “greener” practices in the agriculture, food and cosmetic sectors. In this context, unused forest biomass (e.g., leaves, seed cones, branches/twigs, bark and sapwood) of Cryptomeria japonica, a commercially important tree throughout Asia and the Azores Archipelago (Portugal), is currently waste/by-products of wood processing that can be converted into eco-friendly and high added-value products, such as essential oils (EOs), with social, environmental and economic impacts. Plant-derived EOs are complex mixtures of metabolites, mostly terpenes and terpenoids, with valuable bioactivities (e.g., antioxidant, anti-inflammatory, anticancer, neuroprotective, antidepressant, antimicrobial, antiviral and pesticide), which can find applications in several industries, such as pharmaceutical, medical, aromatherapy, food, cosmetic, perfumery, household and agrochemical (e.g., biopesticides), with manifold approaches. The EOs components are also of value for taxonomic investigations. It is known that the variation in EOs chemical composition and, consequently, in their biological activities and commercial use, is due to different exogenous and endogenous factors that can lead to ecotypes or chemotypes in the same plant species. The present paper aims to provide an overview of the chemical composition, biological properties and proposals of valorization of C. japonica EO from several countries, and also to indicate gaps in the current knowledge.


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.


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