1,720,993 research outputs found
Alimentazione e agricoltura biologica: quali effetti sulla salute?
No full textLo studio analizza le tematiche trattate dal "Human health implication of organic food and organic agriculture” dello European Parliamentary Research Service che contiene un’ampia rassegna della recente letteratura scientifica sugli impatti dei diversi sistemi produttivi sulla qualità dei prodotti vegetali e animali, le implicazioni salutistiche dell’uso di pesticidi e antibiotici e le possibili azioni finalizzate ad aumentare la sostenibilità dei sistemi agroalimentari
Glucose-6-phosphate dehydrogenase in small intestine of rabbit: biochemical properties and subcellular localization
No full textBiochemical properties and cellular and subcellular distribution patterns of glucose-6-phosphate dehydrogenase (G6PD) were investigated in small intestine of rabbits. The specific activity of G6PD in fresh homogenates of small intestine was 19 ± 9 IU/g protein. This value did not change significantly after dialysis. The kinetic and electrophoretic properties of the partially purified enzyme were similar to those found in other rabbit tissues. Enzyme histochemical analysis of G6PD activity using the tetrazolium salt method showed high activity in epithelial cells of villi and crypts of Lieberkuïhn. The activity in acinar cells of Brunner's glands was lower than that in epithelium, whereas cells of the muscularis externa showed a very low activity. Immunohistochemical analysis showed that the amounts of G6PD protein were lower in the epithelium than in Brunner's glands and muscularis externa. The differences between distribution patterns of activity and protein of G6PD may reflect the presence of inactive enzyme molecules in Brunner's glands and muscularis externa or posttranslational activation of G6PD in epithelium. Electron microscopic immunocytochemical analysis performed with gold-labelled antibodies showed the presence of G6PD protein throughout the cytoplasm and at smooth endoplasmic reticulum in enterocytes. In Paneth cells and cells of Brunner's glands, G6PD was found in the cytoplasm, at rough endoplasmic reticulum and Golgi complex. Immunolabelling was not found in mitochondria or nuclei. Our findings show that G6PD is heterogeneously distributed in cells of the small intestine and that the enzyme is associated with rough and smooth endoplasmic reticulum to support synthetic functions in these compartments by NADPH production
Glucose-6-phosphate dehydrogenase in small intestine
No full textThe work describes the immunohistochemical detection of glucose-6-phosphate dehydrogenase in small intestin
Caecal absorption of vitexin-2-O-xyloside and its aglycone apigenin, in the rat
No full textThe in vivo bioavailability of the flavone-C-glycosides has been little studied compared to their O-glycoside analogues, which are both more common in nature and considered more easily hydrolyzed than C-glycosides, by both enterocytes and gut microbiota. In this study, we used vitexin-2-O-xyloside (VOX), an apigenin-8-C-glucoside-2-O-xyloside, purified from seeds of Swiss chard (Beta vulgaris cicla), to investigate VOX absorption into portal blood compared to its aglycone, apigenin. We used a rat model in which we ligated the ileo- and colo-caecal junctions, then administered apigenin or VOX directly into the caecum. Blood samples were drawn from the portal vein at timed intervals over 40 min. The kinetic profile of appearance in portal blood of the compounds and their metabolites was evaluated by HPLC-ESI-MS. Apigenin was found in portal blood both as the aglycone and as an apigenin-glucuronide derivative. The VOX was found unchanged and as a reduced monoglycoside, which underwent glucuronidation. By collecting the bile, we confirmed that the liver received unchanged VOX, which was returned to the gut by enterohepatic recirculation for reabsorption from the ileum. The amount of apigenin and VOX remaining in the caecum accounted for ∼15% and ∼26%, respectively. These data show for the first time that the C-glycoside VOX is absorbed unchanged and undergoes enterohepatic recirculation in addition to hydrolysis to the monoglycoside, reduction and conjugation to form a bioavailable glucuronide. © 2013 The Royal Society of Chemistry
The cellular antioxidant activity in red blood cells (CAA-RBC): A new approach to bioavailability and synergy of phytochemicals and botanical extracts
No full textIn the present work, human red blood cells (RBC) were used to determine cellular antioxidant activity
(CAA-RBC) of pure phytochemicals and botanical extracts, with the aim to predict their bioavailability.
Amongst the pure flavonoids, isorhamnetin, tamarixetin, myricetin, and kaempferol showed the highest
activity in the CAA-RBC assay; whereas, with the ‘‘chemical” oxygen radical absorbance capacity
(ORAC) assay, the compounds that showed the highest activity were isorhamnetin, resveratrol, apigenin
and catechin. When the CAA-RBC assay was applied to herbal extracts, the Vitis vinifera showed the highest
value, a position that this extract maintained also when the ORAC assay was used. Other extracts
showed a different order of effectiveness with the two methods.
We also employed the CAA-RBC to assess synergistic or antagonistic effects of combinations of herbal
extracts and we again compared the results with the ORAC assay. Punica granatum + Malus domestica synergized
in the CAA-RBC assay, but not in the ORAC assay; Aspalathus linearis extract interacted positively
with Vaccinium myrtillus, both in the ORAC assay and in the CAA-RBC assay. We concluded that the CAARBC
assay, coupled with the ORAC assay, was useful for evaluating intracellular bioactivity and synergy
amongst phytochemicals or extracts
Nutritional and functional potential of Beta vulgaris cicla and rubra
No full textSwiss chard (Beta vulgaris cicla, BVc) and beetroot (Beta vulgaris rubra, BVr) are vegetables of the Chenopodiaceae family, widely consumed in traditional western cooking. These vegetables represent a highly renewable and cheap source of nutrients. They can be cultivated in soils with scarce organic material and little light and water. BVc and BVr have a long history of use in folk medicine. Modern pharmacology shows that BVc extracts possess antihypertensive and hypoglycaemic activity as well as excellent antioxidant activity. BVc contains apigenin flavonoids, namely vitexin, vitexin-2-O-rhamnoside and vitexin-2-O-xyloside, which show antiproliferative activity on cancer cell lines. BVr contains secondary metabolites, called betalains, which are used as natural dyes in food industry and show anticancer activity. In this light, BVc and BVr can be considered functional foods. Moreover, the promising results of their phytochemicals in health protection suggest the opportunity to take advantage of the large availability of this crop for purification of chemopreventive molecules to be used in functional foods and nutraceutical products
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Enhancement of flavonoid ability to cross the blood-brain barrier of rats by co-administration with α-tocopherol
No full textVitamin E and polyphenols could exhibit a therapeutic role in the treatment of oxidative stress-induced neurodegenerative diseases. Therefore, their ability to cross the blood-brain barrier (BBB) represents an important issue to be explored by different diet combinations. In this study, we have evaluated the ability of α-tocopherol to support epigallocatechin-3-gallate (EGCG), quercetin and rutin to cross the BBB, following oral administration. Eighteen rats were fed a standard diet (C), a diet supplemented with α-tocopherol (A), with a mixture of EGCG, quercetin and rutin (P); or with a mixture of α-tocopherol and the three flavonoids (AP). Flavonoids and their conjugated derivatives were assayed in brain and plasma by HPLC-MS, whereas α-tocopherol was detected by RP-HPLC. The oxidative damage, due to the potential pro-oxidant activity of flavonoids, was evaluated by the presence of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in hippocampal Cornus Ammonis, one of the most vulnerable sites in the brain. Our results indicate that α-tocopherol is able to promote quercetin transport across the BBB. The mixture of rutin and quercetin seems to favour the accumulation of quercetin and/or its conjugated derivatives in the brain. In contrast, α-tocopherol does not affect EGCG transport across the BBB. The densitometric analysis of 8-OHdG immunoreactivity does not reveal any difference of oxidative damage among the experimental groups. Our results suggest that α-tocopherol may promote quercetin transport across the BBB, leading to a significant increase of α-tocopherol and quercetin concentration in the brain. This journal i
The ORAC/kcal ratio qualifies nutritional and functional properties of fruit juices, nectars, and fruit drinks
No full textFruit beverages are source of antioxidants, but their sugar content plays an important role in the epidemic of obesity. In this study, we considered 32 fruit beverages consumed in Italy (13 fruit juices, 11 nectars, and 8 fruit drinks), which were analyzed for caloric intake, total phenols (TP), ascorbic acid, and antioxidant capacity (oxygen radical absorbance capacity (ORAC) method). Results showed that the caloric intake was almost completely provided by the sugar content, ranging from 5.5 to 19%. The ORAC/kcal ratio was taken as an indicator of the antioxidant performance of fruit beverages. Fruit juices containing berries, red orange, and goji showed the best performances, together with berries or pears nectars and fruit drinks made with rose hips or tea extracts. The 95% of antioxidant capacity was provided by TP, which showed a significant linear correlation with the net ORAC values. Overall, the results indicate that the ORAC/kcal ratio is a suitable parameter to rank the quality of fruit beverages
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