•Boiling increased phenolics of undigested blackjack (BP) but not spinach (SO).•Phenolics in raw BP and SO were more bioaccessible than the boiled counterparts.•Antioxidant activity of raw and boiled ...BP and SO decreased after in vitro digestion.•Cellular protective activity of BP and SO were retained after in vitro digestion.•Undigested BP and SO inhibited oxidative damage of LDL and DNA better than digests.
The effects of boiling and in vitro human simulated digestion on phenolic compounds and bioactivity of the African leafy green vegetable, Bidens pilosa, known as Blackjack in South Africa, was investigated and compared to the leafy green vegetable Spinacia oleracea (Spinach). Metabolites such as 3-caffeoylquinic acid, catechin, 4-caffeoylquinic acid, quercetin-3-O-robinobioside, rutin and quercetin-3-O-glucoside were dominant in the boiled methanolic compared with the raw methanolic extracts of the Blackjack. The total phenolic and flavonoid content generally decreased after in vitro complete digestion for both raw and boiled extracts, indicating that pH and environment associated with digestion alters the bioactivity of the extracted phenolics. Both leafy green vegetables had beneficial effects, but all Blackjack extracts were more effective in preventing the AAPH-mediated oxidation of Caco-2 cells, low-density lipoprotein and deoxyribonucleic acid than those of the spinach. This study identified the health benefits of eating Blackjack and therefore, the cultivation and consumption of this leafy green vegetable should be promoted.
Tea (Camellia sinensis) has been consumed for centuries as traditional medicine for various diseases, including diabetes. The mechanism of action of many traditional medicines, including tea, often ...requires elucidation. Purple tea is a natural mutant of Camellia sinensis, grown in China and Kenya, and is rich in anthocyanins and ellagitannins.
Here we aimed to determine whether commercial green and purple teas are a source of ellagitannins and whether green and purple teas, purple tea ellagitannins and their metabolites urolithins have antidiabetic activity.
Targeted UPLC-MS/MS was employed to quantify the ellagitannins corilagin, strictinin and tellimagrandin I, in commercial teas. The inhibitory effect of commercial green and purple teas and purple tea ellagitannins was evaluated on α-glucosidase and α-amylase. The bioavailable urolithins were then investigated for additional antidiabetic effects, by evaluating their effect on cellular glucose uptake and lipid accumulation.
Corilagin, strictinin and tellimagrandin I (ellagitannins) were identified as potent inhibitors of α-amylase and α-glucosidase, with Ki values significantly lower (p < 0.05) than acarbose. Commercial green-purple teas were identified as ellagitannin sources, with especially high concentrations of corilagin. These commercial purple teas, containing ellagitannins, were identified as potent α-glucosidase inhibitors with IC50 values significantly lower (p < 0.05) than green teas and acarbose. Urolithin A and urolithin B were as effective (p> 0.05) as metformin in increasing glucose uptake in adipocytes, muscle cells and hepatocytes. In addition, similar (p > 0.05) to metformin, both urolithin A and urolithin B reduced lipid accumulation in adipocytes and hepatocytes.
This study identified green-purple teas as an affordable widely available natural source with antidiabetic properties. Furthermore, additional antidiabetic effects of purple tea ellagitannins (corilagin, strictinin and tellimagrandin I) and urolithins were identified.
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•Purple teas are a source of ellagitannins; corilagin, strictinin and tellimagrandin I.•Purple tea ellagitannins are dual inhibitors of α-amylase and α-glucosidase.•Green-purple teas are potent α-glucosidase inhibitors.•Urolithin A and urolithin B increase cellular glucose uptake.•Urolithin A and urolithin B decrease cellular lipid accumulation.
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•Black nightshade and spinach phenolics and bioactivity were studied.•Total phenolics and flavonoids were either unchanged or reduced after boiling.•Phenolics and TEAC activity was ...reduced after the in vitro digestion of vegetables.•All vegetable extracts prevented the oxidative damage of Caco-2 and L929 cell lines.•Oxidative damage of DNA was prevented by all vegetable extracts.
Solanum nigrum complex (Black nightshade) is a wild leafy vegetable with phenolic antioxidant compounds related to the reduction of oxidative stress. Changes in phenolics and bioactivity due to cooking and gastrointestinal digestion of black nightshade were compared to spinach. Predominant compounds of black nightshade were myricetin, quercetin-3-O-robinoside, 3,4-dicaffeoylquinic acid, 3-caffeoylquinic acid, and rutin, which were improved after boiling but reduced after in vitro digestion. Phenolics were reduced after digestion of black nightshade and spinach; however, bioactivity was still retained, especially in preventing oxidative stress in Caco-2 cells. Hence, indicating their potential to reduce oxidative stress related diseases of the digestive tract.
Water contamination with metals due to anthropogenic activity is increasing and subsequent exposure increases the risk of associated toxicity. Exposure is not limited to a single metal but usually ...involves mixtures of different metals at different concentrations. Little is known about the contribution of this type of exposure, in humans, to the development of non-communicable diseases such as cardiovascular disease, and an increased risk to thrombosis. The World Health Organization has established limits for metal levels in drinking water and this includes levels for copper (Cu), manganese (Mn) and mercury (Hg). In this study, at 100X these limits, the ability of the metals’ oxidative effects as catalysts of the Fenton reaction and/or ability to bind glutathione (GSH) were determined. The haemostatic effects of these metals, alone and in combination, at the World Health Organization limit were then evaluated. The ultrastructural and viscoelastic alterations of exposed ex vivo whole blood were also evaluated using scanning electron microscopy and thromboelastography® (TEG), respectively. Cu, alone and in combination with Mn and/or Hg, induced hydroxyl radical formation and reduced GSH levels. Ex vivo exposure caused deformation of erythrocytes and accelerated platelet activation especially for Cu, alone and in combination, with Mn. Reduction in the lysis potential of the clot was also observed for all combinations, especially Cu in combination with Hg as well as Mn alone. Although the TEG findings were not statistically significant, the trends indicate that the exposure to these metals, alone and in combination, adversely affects thrombus formation in ex vivo blood, thereby potentially increasing the risk in exposed individuals for thrombosis.
African green leafy vegetables (ALVs) are rich sources of nutrients and health-promoting bioactive metabolites that possess antioxidant, anti-inflammatory and anticancer properties that will assist ...in reducing the development of noncommunicable diseases. Irrespective of their reported health-promoting properties, ALVs face challenges of their use in food systems particularly the mainstream markets/urban consumers due to poor insights and lack of knowledge on their health benefits. Therefore, the review aims at providing information that promotes increased utilization and consumption of ALVs as not only a source of nutrients but antioxidants and other beneficial bioactive components using cellular models.
Heavy metals are natural elements characterized by their relatively large atomic mass as well as high density. It can be introduced into the ecosystem by the mining of heavy metals from deep within ...the earth's crust, thereby exposing the metals into air and water systems. Cigarette smoke is another source of heavy metal exposure and has been shown to have carcinogenic, toxic and genotoxic properties. Cadmium, lead, and chromium are the most abundant metals found in cigarette smoke. In response to tobacco smoke exposure, endothelial cells release inflammatory and pro-atherogenic cytokines that are linked to endothelial dysfunction. Endothelial dysfunction is directly related to the production of reactive oxygen species, leading to endothelial cell loss through necrosis and/or apoptosis. The current study aimed to investigate the effect of cadmium, lead, and chromium, alone and as part of metal mixtures, on endothelial cells. The EA.hy926 endothelial cell line was exposed to different concentrations of each of these metals and their combinations and analyzed using flow cytometric analyses with Annexin V. A clear trend was seen with the Pb + Cr as well as the triple combination group with the significant increase of early apoptotic cells. Scanning electron microscopy was used to study possible ultrastructural effects. Morphological changes observed with scanning electron microscopy included cell membrane damage and membrane blebbing at certain metal concentrations. In conclusion, the exposure of endothelial cells to cadmium, lead, and chromium, caused a disruption in cellular processes and morphology, possibly diminishing the protective ability of endothelial cells.
The distribution of metals across the environment is increasingly becoming a major concern as they not only pollute the environment but also pose a danger to humans and animals. Human exposure to ...heavy metals often occurs as a combination of metals the synergistic effects of which can be more toxic than a single metal. The aim of this study was to investigate the effects that the metals mercury (Hg), nickel (Ni) and manganese (Mn) alone and in combination have on erythrocyte morphology and other components of the coagulation system using the haemolysis assay, scanning electron microscopy (SEM), and confocal laser scanning microscopy. Human blood was exposed to the heavy metals ex vivo, and percentage haemolysis was determined. Ultrastructural analysis of erythrocytes, platelets and fibrin networks was performed using SEM. Analysis of phosphatidylserine (PS) flip-flop was determined using confocal laser scanning microscopy. At the highest concentration of 10,000× the World Health Organization safety limit, all the metals caused haemolysis. The results showed that the exposure of erythrocytes to Hg alone and in combination with other metals displayed more haemolysis compared to Ni and Mn alone and in combination. Components of the coagulation system showed ultrastructural changes, including the formation of echinocytes and the activation of platelets with all single metals as well as the combinations. Confocal laser scanning microscopy analysis showed the presence of PS on the outer surface of the echinocytes that were exposed to metals alone and in combination. It can, therefore, be concluded that these heavy metals have a negative impact on erythrocytes and the coagulation system.
Developments in image reconstruction techniques for planar imaging, also known as enhanced planar processing (EPP), enable the possibility to reconstruct planar scintigraphic images with low count ...statistics, providing the opportunity to reduce image acquisition time. In this study, the performance of EPP for oncologic half-time bone scintigraphy images was evaluated.
The EPP software was evaluated for different imaging conditions using standardized phantom experiments. Additionally, 51 patients with prostate and breast cancer were prospectively included and underwent bone scintigraphy using a standard and half-time protocol. Independent reading was performed on three image types (standard, half-time non-processed, and half-time EPP) by three observers, scoring the number and anatomical location of lesions, image quality, and diagnostic confidence by which the definitive diagnosis was made.
EPP images had improved contrast and lower noise levels compared to the non-processed half-time images. It was determined that EPP images acquired at double scan speed had similar image quality to the standard non-processed images. There was substantial agreement with respect to diagnosis and diagnostic confidence based on all three image types between the observers. Image quality in the EPP images was higher with respect to the non-processed half-time images, and was comparable to the standard images.
Diagnostic confidence was not affected by reduction in image acquisition time. There was substantial agreement between all three observers with respect to the diagnosis provided in all three image types. Subjective and objective image quality improved when half-time images were processed with EPP software.
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