Betanin inhibits the myeloperoxidase/nitrite-induced oxidation of human low-density lipoproteins

Production of nitrogen dioxide by the activity of myeloperoxidase (MPO) in the presence of nitrite is now considered a key step in the pathophysiology of low-density lipoprotein (LDL) oxidation. This study shows that betanin, a phytochemical of the betalain class, inhibits the production of lipid hydroperoxides in human LDL submitted to a MPO/nitrite-induced oxidation. Kinetic measurements including time-course of particle oxidation and betanin consumption, either in the presence or in the absence of nitrite, suggest that the antioxidant effect is possibly the result of various actions. Betanin scavenges the initiator radical nitrogen dioxide and can also act as a lipoperoxyl radical-scavenger. In addition, unidentified oxidation product(s) of betanin by MPO/nitrite inhibit(s) the MPO/nitrite-induced LDL oxidation as effectively as the parent compound. In the light of betanin bioavailability and post-absorbtion distribution in humans, present findings may suggest favourable in vivo activity of this phytochemical

A Review on Human Pedestrian Movement System using Agent-Based Simulation and Discrete Event Simulation

Human pedestrian is a complex behavior which involves various inputs and outputs and requires a lot of decision making process. By understanding fundamentals of Discrete Event Simulation (DES) and Agent-Based Simulation (ABS), it is found that both are suitable to simulate this complex movement. This paper proposed the idea of understanding how, in its basic knowledge, these two simulation models can be combined together to enhance human pedestrian movement in high density crowd areas. Its effectiveness might not be achieved without understanding factors that may affect pedestrian’s traffic flow

Absorption, excretion, and distribution of dietary antioxidant betalains in LDLs: potential health effects of betalains in humans

ABSTRACT Background: Betalains were recently identified as natural antioxidants. However, little is known about their bioavailability from dietary sources. Objective: The objective was to evaluate the bioavailability of betalains from dietary sources. Design: The plasma kinetics and urinary excretion of betalains were studied in healthy volunteers (n 8) after a single ingestion of 500 g cactus pear fruit pulp, which provided 28 and 16 mg indicaxanthin and betanin, respectively. The incorporation of betalains inLDLand the resistance of the particles to ex vivo–induced oxidation was also researched. Results: Betanin and indicaxanthin reached their maximum plasma concentrations 3 h after the fruit meal and declined according to first-order kinetics. The half-life of betanin (0.94 0.07 h) was shorter than that of indicaxanthin (2.36 0.17 h). Both compounds had disappeared from plasma by 12 h after intake. The urinary excretion of indicaxanthin and betanin over 12 h represented 76 3.0% and 3.7 0.2%, respectively, of the ingested compounds. LDL isolated 3 and 5 h after the fruit meal incorporated betalains at concentrations of 100.5 11and50 7.2pmol/mgLDLprotein, respectively. In addition, the particles appeared more resistant to ex vivo–induced oxidative injury than did the samples isolated before fruit ingestion (P 0.05)—the higher the amount of betalains incorporated, the higher the resistance. The concentrations of vitamin E and -carotene in LDL did not change significantly after fruit ingestion. Conclusion: Our results show that cactus pear fruit is a source of bioavailable betalains and suggest that indicaxanthin and betanin may be involved in the observed protection of LDL against ex vivo– induced oxidative modifications

Dietary indicaxanthin from cactus pear (Opuntia ficus-indica L. Mill) fruit prevents eryptosis induced by oxysterols in a hypercholesterolaemia relevant proportion and adhesion of human erythrocytes to endothelial cell layers

Abstract Toxic oxysterols in a hypercholesterolaemia-relevant proportion cause suicidal death of human erythrocytes or eryptosis. This process proceeds through early production of reactive oxygen species (ROS), release of prostaglandin (PGE2) and opening of PGE2-dependent Ca channels, membrane phosphatidylserine (PS) externalisation, and cell shrinkage. The present study was the first to reveal that a bioavailable phytochemical, indicaxanthin (Ind) from cactus pear fruit, in a concentration range (1·0–5·0microM) consistent with its plasma level after a fruit meal, prevents PS externalisation and cell shrinkage in a dose-dependent manner when incubated with isolated healthy human erythrocytes exposed to an oxysterol mixture for 48 h. Dietary Ind inhibited ROS production, glutathione (GSH) depletion, PGE2 release and Ca2+ entry. Ind alone did not modify the erythrocyte redox environment or affect other parameters. Ex vivo spiking of normal human blood with the oxysterol mixture for 48 h induced eryptosis, resulting in the production of ROS and decreased levels of GSH, which was prevented by concurrent exposure to 5 microM-Ind. The adherence of eryptotic erythrocytes to the endothelium causes vascular tissue injury. Erythrocytes isolated from blood incubated with the oxysterol mixture plus 5mM-Ind did not adhere to endothelial cell monolayers. Eryptotic erythrocytes may contribute to thrombotic complications in hypercholesterolaemia. Our findings suggest the positive effects of diets containing Ind on erythrocytes in hypercholesterolaemic subjects

Biothiols, taurine, and lipid-soluble antioxidants in the edible pulp of Sicilian cactus pear (Opuntia ficus-indica) fruits and changes of bioactive juice components upon industrial processing

Biothiols, taurine, and flavonols, as well as tocopherols and carotenoids have been assessed in the edible pulp of Sicilian red (Sanguigna), yellow (Surfarina), and white (Muscaredda) cultivars of cactus pear. The yellow cultivar has the highest level of reduced glutathione (GSH, 8.1 ( 0.78 mg/100 g pulp), whereas the white cultivar showed the highest amount of cysteine (1.21 ( 0.12 mg/100 g pulp). Taurine accounted for 11.7 ( 1.0 mg/100 g in the yellow pulp, while lower levels were measured in the others. With the exception of kaempferol in the yellow cultivar (2.7 ( 0.2 íg/100 g pulp), the edible pulp of cactus pear was not a source of flavonols. Very low amounts of lipid-soluble antioxidant vitamins such as vitamin E and carotenoids were measured in all cultivars. As a consequence of industrial processing, a total loss of GSH and â-carotene and a net decrease of vitamin C and cysteine were revealed in the fruit juice, whereas betalains, taurine, and vitamin E appeared to be less susceptible to degradation

Phytochemical indicaxanthin suppresses 7-ketocholesterol-induced THP-1 cell apoptosis by preventing cytosolic Ca++ increase and oxidative stress

7-Ketocholesterol (7-KC)-induced apoptosis of macrophages is considered a key event in the development of human atheromas. In the present study, the effect of indicaxanthin (Ind), a bioactive pigment from cactus pear fruit, on 7-KC-induced apoptosis of human monocyte/macrophage THP-1 cells was investigated. A pathophysiological condition was simulated by using amounts of 7-KC that can be reached in human atheromatous plaque. Ind was assayed within a micromolar concentration range, consistent with its plasma level after dietary supplementation with cactus pear fruit. Pro-apoptotic effects of 7-KC were assessed by cell cycle arrest, exposure of phosphatidylserine at the plasma membrane, variation of nuclear morphology, decrease of mitochondrial trans-membrane potential, activation of Bcl-2 antagonist of cell death and poly(ADP-ribose) polymerase-1 cleavage. Kinetic measurements within 24 h showed early formation of intracellular reactive oxygen species over basal levels, preceding NADPH oxidase-4 (NOX-4) over-expression and elevation of cytosolic Ca2þ, with progressive depletion of total thiols. 7-KC-dependent activation of the redox-sensitive NF-kB was observed. Co-incubation of 2·5mM of Ind completely prevented 7-KC-induced pro-apoptotic events. The effects of Ind may be ascribed to inhibition of NOX-4 basal activity and over-expression, inhibition of NF-kB activation, maintaining cell redox balance and Ca homeostasis, with prevention of mitochondrial damage and consequently apoptosis. The findings suggest that Ind, a highly bioavailable dietary phytochemical, may exert protective effects against atherogenetic toxicity of 7-KC at a concentration of nutritional interest