Introduction Il existe une forte relation entre obésité, insulino-résistance et carence en vitamines au niveau plasmatique. L’objectif de cette étude est d’évaluer l’impact de la teneur en vitamines ...alimentaires sur la prise de poids et la sensibilité à l’insuline chez la souris. Matériels et méthodes Des souris ont été soumises durant 12 semaines à un régime normo-lipidique et normo-vitaminique (lot contrôle) ou apportant seulement 50 % de la ration vitaminique recommandée (lot 50 %). La prise alimentaire, et la prise de poids ont été suivies quotidiennement. À la fin de l’expérience, l’index HOMA a été déterminé, les animaux ont été sacrifiés afin de déterminer le poids des organes et les profils d’expression génique au niveau du tissu adipeux et du foie. Résultats La prise alimentaire, la prise de masse totale des animaux et la masse du foie était identique dans les 2 lots. En revanche, nous avons observé un doublement de l’index d’adiposité (somme des masses des tissus adipeux épididymaux, périrénaux et inguinaux rapporté à la masse totale des animaux) des animaux du lot 50 %. De même l’index HOMA des animaux du lot 50 % était significativement augmenté. Au niveau du tissu adipeux, l’expression des ARNm codant l’adiponectine était significativement plus faible chez les animaux du lot 50 %, tandis qu’au niveau du foie, les taux d’ARNm de PPARγ; étaient augmentés et ceux de PPARα; diminués. Conclusion Ces résultats préliminaires semblent montrer qu’un régime hypovitaminé favorise la prise de masse grasse, modifie la sensibilité à l’insuline, en agissant probablement au niveau du métabolisme lipidique hépatique, via une diminution des capacités oxydatives.
The ability of rosemary to modulate cytochrome P450 (CYP) and detoxication enzymes in rat liver was evaluated by comparing the effects of dried leaves and leaf extracts with different chemical ...compositions: essential oil (EO) containing monoterpenes, a dichloromethane extract (DCME) containing phenolic diterpenes and a water-soluble extract (WSE) containing phenolic compounds such as rosmarinic acid and flavonoids. Chemical analyses were done in order to characterize the composition of extracts. Male Wistar rats received the leaves or extracts of rosemary in their diet at 0.5% (w/w) for 2 weeks. The effects of such treatments were evaluated for CYP (1A, 2B, 2E1), glutathione
S-transferase (GST), NAD(P)H: quinone reductase (QR) and UDP-glucuronosyltransferase (UGT) activities and on protein levels (immunoblot analyses). Expression of specific UGT isoforms (mRNA semi-quantification by RT-PCR) was measured. Our study reports that EO selectively induced CYP, particularly CYP2B. WSE enhanced both CYP and detoxication enzymes. DCME acted as a monofunctional inducer, inducing GST, QR and UGT, in particular UGT1A6. Considering the specific pattern of induction obtained with DCME and WSE treatment, it should be relevant to evaluate the chemopreventive potency of these extracts on carcinogenesis in animal models.
The effects of a water-soluble extract (WSE) of rosemary and its purified antioxidant rosmarinic acid (RA) on xenobiotic metabolizing enzymes (XME) were studied in rat liver after dietary ...administration. The modulation of phase I enzymes such as cytochrome P450 (CYP) 1A, 2B, 2E1, 3A, and phase II enzymes such as glutathione
S-transferase (GST), quinone reductase (QR) and UDP-glucuronosyltransferase (UGT) was evaluated by measuring enzyme activities with specific substrates. Protein levels of CYPs and rGST A1/A2, A3/A5, M1, M2 and P1 were measured using antibodies in Western blots. Caffeic acid was also studied because it results from RA biotransformation in rat after oral administration. Male SPF Wistar rats received the different compounds at 0.5% (w/w) incorporated into their diet for 2 weeks. WSE, containing RA, flavones and monoterpenes enhanced CYP 1A1, 2B1/2, 2E1 and GST (especially rGST A3/A5, M1 and M2), QR and UGT. On the contrary, no modification of XME was observed in response to RA or CA (except for a slight increase of UGT activity after CA treatment). The induction of XME by WSE could be attributed to flavones, monoterpenes or an additive effect of all components.
The influence of γ-irradiation on the content of phenolic compounds was evaluated on Moroccan Citrus fruits (Citrus clementina Hort. ex. Tanaka) treated at a mean dose of 0.3 kGy and stored for 49 ...days at 3 °C. The results show that irradiation has enhanced the synthesis of total phenolic compounds and is correlated with phenylalanine ammonia-lyase activity (PAL) during storage. Accumulation of phenolic compounds in cells is demonstrated and may be explained by the enhancement of PAL activity. HPLC/UV (diode array detector) analysis demonstrated that hesperidin was the major flavanone and nobiletin and heptamethoxyflavone were the major polymethoxylated flavones. Hesperidin is also the major phenolic compound in clementines. Irradiation stimulates the biosynthesis of hesperidin after 14 days of storage, corresponding to the maximum of PAL activity. p-Coumaric acid was also identified, and its content was particularly high in irradiated fruits after 49 days of storage. Accumulation of flavonoids and p-coumaric acid could be related to a better resistance. The percentage of losses due to peel injury “pitting” during storage was between 1 and 5% after 49 days of storage. The connections between irradiation, enzyme activity, phenolic content, and peel injury are briefly discussed. Keywords: γ-Radiation; Citrus clementina fruit; PAL activity; total phenolic compounds; hesperidin; p-coumaric acid
The phenolic composition and the degree of browning of pears were determined for nine cultivars at different stages of maturity. 5'-Caffeoylquinic acid and (-)-epicatechin were the two major ...phenolics found. Phenolic content and susceptibility of pears to browning were high in peel. Differences in phenolic composition and in the degree of browning were more influenced by the cultivar than by the maturity stage of the fruit. At harvest, the degree of browning was closely correlated with the initial amount of hydroxycinnamic esters and flavanols. After 4 days of storage at room temperature, the variation in enzymatic browning depended on the cultivar and the phenolic content decreased for all cultivars. Williams cultivar pears stored in air accumulated phenolics more than fruits stored under 1% CO2/1% O2 and 3% CO2/3% O2
Fruits and vegetables or their natural constituents which increase detoxication enzymes and/or reduce activating enzymes are considered as good candidates to prevent chemically-induced ...carcinogenesis. In this study, rats were fed a diet supplemented with 20% onion powder for 9 days. Several cytochrome P450 (CYP)s enzymes (CYP 1A, 2B, 2E1, 3A), which are involved in carcinogen activation, were determined by measuring their enzyme activities using specific substrates. In addition, phase II enzymes activities such as UDP-glucuronosyltransferase (UGT) and glutathione
S-transferase (GST), involved in detoxication of carcinogens, were measured. Protein levels of CYPs and GST A1/A2, A3/A5, Ml, M2 and P1 were measured using antibodies in Western blots. Consumption of onion induced CYP 1A and CYP 2B activities while it decreased CYP 2E1 activity. This later modification was accompanied by a decrease of CYP 2E1 levels. The same dietary treatment caused a slight increase of the total GST activity. The relative proportions of GST subunits were modified. GST Al/A2 subunits were increased while GST A3/A5 and GST M2 subunits were decreased and GST M1 and P1 were not modified. Onion consumption also increased
p-nitrophenol UGT activity. Taken together, these results suggest that the decrease of CYP 2E1 and the increase of phase II enzymes by onion can afford protection against some carcinogens, while the decrease of some GST subunits could increase the genotoxic effects of other chemicals. The modulating effect of onion could be ascribed to alk(en)yl polysulphides and/or glycosides of flavonols, which were identified in the onion powder.
Abstract
Background
Given the public health urgency facing the increasing rates of obesity and chronic diseases in the Caribbean, characterization of the nutrition transition and population groups at ...higher nutritional risk is needed. We identified dietary patterns in the French West Indies (FWI) and their association with individual characteristics.
Methods
This cross-sectional analysis included 1,144 Guadeloupeans and Martinicans from a representative survey. To identify dietary patterns, principal component analysis was performed using 25 food groups, followed by a clustering procedure classifying subjects in independent clusters. Their associations with health status, Diet Quality Index-International (DQI-I), food supply behaviors, sociodemographic and economic characteristics were studied using multivariable models.
Results
Four dietary patterns were identified, representing 25%, 24%, 31% and 20% of the sample: (1) a “healthy” cluster characterised by a high DQI-I, composed of high educated individuals; (2) a “traditional” cluster with a high DQI-I and high intakes of traditional dishes, formed mostly by women and older persons, with a high obesity prevalence (26%); (3) a “western” cluster with a low DQI-I, high intakes of sweetened beverages, snacks and fast foods, composed mainly of young subjects, buying their fruits, vegetables and tubers only or mainly in supermarkets; and (4) a “transitional” cluster with high intakes of bread, processed meat, sauces, alcoholic and sweetened beverages but conversely high intakes of tubers, legumes, fish and low intakes of biscuits and cakes, formed mainly by middle age men, self-employed or manual workers, and 35% had metabolic syndrome.
Conclusions
The dietary patterns identified reflect different steps of dietary change as described by Popkin, suggesting an ongoing nutrition transition in the FWI. This characterization provides useful information for public health actions regarding population groups at higher nutritional risk.
Key messages
Four diversified dietary patterns were identified suggesting an ongoing nutrition transition in the French West Indies.
Demographic and socioeconomic characteristics associated with dietary patterns, especially age, reflecting a generational contrast, provided needed information to guide future public health measures.
Poultry by-products are not often processed into high-value products. Rather than being transformed into meal for animal feed, a large quantity of chicken skin could be used to produce collagen, ...which is valued for its unique functional properties. The purpose of this research project was to extract and characterize collagen from chicken skin. Skins were first ground and then were heated to 40 or 60 degrees C to extract the fat. After mechanical separation, the collagen contained in the resulting solid phase was extracted with pepsin or ethylene diamine. Types I and III collagen were then isolated and characterized by SDS PAGE, antigen labeling, determination of tyrosine residues, and transmission electron microscopy. The total collagen content of the skin was recovered from the solid phase following heat treatment at 40 degrees C. Extraction yields varied with the solubilization process: 38.9% of the collagen content in the solid phase was extracted with pepsin and 25.1% with ethylene diamine. Ratios of type I to type III collagen fractionated using NaCl were 74.4:19.8% with pepsin and 62.4:31.7% with ethylene diamine. Characterization tests further revealed the presence of telopeptides solely on ethylene diamine-solubilized collagen. Chicken skin thus appears to be a good alternative source of high-quality collagen.
Abstract
Background
Obesity and metabolic diseases represent a major health burden in the Caribbean, particularly since a large part of the population is disadvantaged. However, socioeconomic ...inequalities in chronic diseases are poorly explored in this region, and the contribution of diet to explain these inequalities has not yet been studied. We investigated the association between socioeconomic position and the prevalence of metabolic syndrome (MetS), and explored whether this association was mediated by diet quality in the French West Indies.
Methods
This cross-sectional analysis included 1,144 adults (≥16 y) from a multistage sampling survey, representative of the Guadeloupean and Martinican population. The prevalence of MetS was assessed using the Joint Interim Statement. Dietary intakes were estimated using 24hours dietary recalls, and diet quality was assessed through the Diet Quality Index-International (DQI-I). Associations between socioeconomic indicators (education, employment, social assistance benefits) and prevalence of MetS, and the potential mediating effect of diet quality in this association were assessed using multivariable logistic regression models adjusted for sociodemographic factors.
Results
MetS prevalence adjusted for age and sex was 21% and 30% among Guadeloupean and Martinican, respectively. Compared to those with a high education level, low- and middle-educated subjects were more likely to be at risk of MetS (OR = 1.9; 95%CI = 1.0-3.6 and OR = 2.7; 95%CI = 1.4-5.1, respectively), as were recipients of social assistance benefits compared to non-recipients (OR = 2.2; 95%CI = 1.1-4.2). The DQI-I explained 11% of the overall variation in MetS due to education.
Conclusions
Socioeconomic inequalities in MetS prevalence were found in a Caribbean population but diet quality contributed only to socioeconomic inequalities due to education. Future public health measures need to target specifically populations with limited financial resources and low education.
Key messages
Our work identified subgroups with higher risk of MetS, which is needed when implementing public health measures, particularly in this Caribbean population with of high poverty rates.
Diet quality contributed only to socioeconomic inequalities due to education underlining that education may impact health through the ability to generate overall dietary behavior, long-term beneficial.
Purpose
Many epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in ...the general population. However, it is not clear whether these relationships occur in obese population.
Methods
We conducted a cross-sectional study in 108 obese non-diabetic patients.
Results
There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (α-carotene, β-carotene and β-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of β-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients.
Conclusion
These results suggest the existence of a favourable effect of β-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of β-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome.
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