Current Therapies Focused on High-Density Lipoproteins Associated with Cardiovascular Disease.

High-density lipoproteins (HDL) comprise a heterogeneous family of lipoprotein particles divided into subclasses that are determined by density, size and surface charge as well as protein composition. Epidemiological studies have suggested an inverse correlation between High-density lipoprotein-cholesterol (HDL-C) levels and the risk of cardiovascular diseases and atherosclerosis. HDLs promote reverse cholesterol transport (RCT) and have several atheroprotective functions such as anti-inflammation, anti-thrombosis, and anti-oxidation. HDLs are considered to be atheroprotective because they are associated in serum with paraoxonases (PONs) which protect HDL from oxidation. Polyphenol consumption reduces the risk of chronic diseases in humans. Polyphenols increase the binding of HDL to PON1, increasing the catalytic activity of PON1. This review summarizes the evidence currently available regarding pharmacological and alternative treatments aimed at improving the functionality of HDL-C. Information on the effectiveness of the treatments has contributed to the understanding of the molecular mechanisms that regulate plasma levels of HDL-C, thereby promoting the development of more effective treatment of cardiovascular diseases. For that purpose, Scopus and Medline databases were searched to identify the publications investigating the impact of current therapies focused on high-density lipoproteins.

Activated and Micronized Zeolite in the Modulation of Cellular Oxidative Stress in Mexican Smokers: A Randomized Clinical Trial.

BACKGROUND: Activated and micronized zeolites are used as detoxifying agents in humans. Detoxification is attributed to their ability to reduce lipid peroxidation by scavenging free radicals. OBJECTIVE: To evaluate activated and micronized zeolites as modulators of cellular oxidative stress in Mexican smokers without lung diseases. METHODS: Randomized clinical trial. Subjects were randomly divided into three groups: activated and micronized zeolites, n = 29; vitamin E, an accepted antioxidant, n = 29; and maltodextrin as control, n = 27. Each group received the corresponding supplementation, dissolved in water, once a day for 30 days as follows: activated and micronized zeolites, 5.4 g activated and micronized zeolite; vitamin E, 400 mg D-alpha tocopheryl acetate; and maltodextrin, 250 mg of maltodextrin. The thiobarbituric acid reactive substances assay was used to screen for lipid peroxidation. Catalase activity, plasma antioxidant capacity, and hydrogen peroxide levels were also measured. Results were analyzed by a one-way ANOVA and post hoc test of Bonferroni. RESULTS: Subjects administered activated and micronized zeolites had equivalent antioxidant activities as subjects administered vitamin E. CONCLUSIONS: Activated and micronized zeolites may be useful as a modulator of oxidative stress in smokers. However, inclusion of a comparison group of non-smokers would be useful in future studies to assess the degree to which zeolites reverse the oxidant stress.

Carotenoid metabolism is induced in rice bran during very high temperature stress.

BACKGROUND: Postharvest yellowing (PhY) causes yellowing in rice endosperm during conditions of high temperature and moisture. Rice bran was investigated as a model tissue for studying PhY and for determining the possibility of carotenoids as the source of the yellow color. RESULTS: A survey of different colored rice and wild (non-sativa) rice lines resulted in the identification of several purple bran lines having very low or no bran carotenoids. Transcription levels of phytoene synthase, the first committed step in carotenoid biosynthesis, were higher in carotenoid-containing bran, indicating that carotogenesis is an ongoing process in mature bran. Bran and endosperm subjected to PhY conditions had a similar temperature optimum and color responses, so bran was utilized to investigate carotenoid levels and transcription levels of genes for carotogenesis during PhY. During PhY, total carotenoid levels in bran increased while levels of the predominant xanthophyll carotenoid, lutein, decreased. This difference could be explained by carotenoids being metabolized into apocarotenoids, which have high antioxidant activities and can be highly colored. This mechanism is further supported by the long-term transcription during PhY of CCD1, which encodes an enzyme in apocarotenoid production. CONCLUSION: We propose that PhY is an active, metabolic response to a very high temperature stress and that the increase in total carotenoids in bran during PhY is a result of the production of colored apocarotenoids.

The effect of induced yellowing on the physicochemical properties of specialty rice.

BACKGROUND: Postharvest yellowing (PHY) of rice kernels can be a major problem in the rice industry. This is especially true with high-valued specialty rice, because profit loss will be greater. The objective of this work was to determine whether a significant change occurs in the physicochemical properties (apparent amylose and protein concentrations, viscosity profile and gelatinisation temperature) as a result of induced PHY. RESULTS: In this study, four specialty rices (Basmati, Jasmine, Arborio and Sushi) were yellowed using a laboratory method. PHY increased apparent amylose concentration. It also significantly increased onset and peak gelatinisation temperatures. However, peak, breakdown and setback Rapid ViscoAnalyzer viscosities were decreased by PHY. Trough viscosity for Basmati and Jasmine decreased, whereas it increased for Arborio. Moisture and protein concentrations were unchanged by the yellowing process. Attempts to rehydrate the kernels after induced PHY caused them to fracture, thus making them unsuitable for their intended purpose. CONCLUSION: This study indicates that rice that has been subjected to PHY shows a reduction not only in appearance but also in cooking and processing quality, decreasing its value. However, the changes differed for each rice type, with Jasmine being affected the least.

Utilizing the genetic diversity within rice cultivars.

Plant breeding of rice emphasizes improvement in yield, disease resistance, and milling quality. Numerous other traits (e.g., bran carotenoids) that historically have not been selected for could provide added value in expanding niche markets, as well as be useful tools for understanding the genetic control of these traits. Residual heterozygosity is present in many rice cultivars; therefore, it is possible to select for different alleles within an existing cultivar. By identifying and using cultivars with high levels of variability for a trait, we were able to develop separate lines from single cultivars that showed high and low levels of that trait. The rice cultivar RU9101001 and the warm- and cold-sprouting lines that were derived from it were used to demonstrate that residual heterozygosity was present within a cultivar and that the original heterozygosity was separated in the derived lines. Rice simple sequence repeat markers were heterozygous in the parent RU9101001 cultivar, but the cold-sprouting lines were homozygous for one set of alleles and the warm-sprouting lines were homozygous for the other set. Through detailed phenotypic screening, we developed lines that exhibited low and high levels of the following traits in the specified cultivars: cold-sprouting from RU9101001 and Bonnet 73, postharvest yellowing from Tominishiki, early tillering from Hei Jaio and Tominishiki, and bran carotenoid levels from Spring. If variability exists in a cultivar, then utilization of residual heterozygosity may provide a quicker and more efficient means to develop lines with special characteristics using cultivars that are already agronomically valuable or to develop near isogenic lines for genetic and biochemical investigations.

Potential Mechanisms of the Improvement of Glucose Homeostasis in Type 2 Diabetes by Pomegranate Juice.

Pomegranate is a polyphenol-rich fruit. Studies have shown that extracts prepared from its juice or from different parts of the pomegranate plant have various biological activities including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, cardioprotective, and antidiabetic. The therapeutic potential has been attributed to various phytochemicals, including ellagic acid, punicic acid, flavonoids, anthocyanidins, anthocyanins, flavonols, and flavones. This review focuses on the scientific evidence of pomegranate juice as hypoglycemic, emphasizing the chemical composition and the possible mechanisms of action associated with this effect. Studies were identified using the PubMed, Scopus, and ISI Web of Science databases to identify relevant articles focused on the hypoglycemic effect of pomegranate juice. The physiological responses to pomegranate juice are reported here, including a decrease of oxidative stress damage, an increase of insulin-dependent glucose uptake, maintenance of ß-cell integrity, inhibition of nonenzymatic protein glycation, an increase of insulin sensitivity, modulation of peroxisome proliferator-activated receptor-gamma, inhibition of α-amylase, inhibition of α-glucosidase and dipeptidyl peptidase-4, and decreases in inflammation. Overall, we found a significant hypoglycemic effect of pomegranate in in vitro and in vivo studies and we summarize the potential mechanisms of action.

Subacute and subchronic toxicity of microencapsulated pomegranate juice in rats and mice.

Pomegranate (Punica granatum L.) is a fruit used extensively in traditional medicine by ancient and modern cultures. Different parts of the tree and fruit, such as leaf, peel, pericarp, aril, seed, and juice contain considerable amounts of phenolic compounds with high antioxidant activities. To improve its storability, pomegranate juice was microencapsulated by spray drying. The present study evaluated microencapsulated pomegranate juice (MPJ) for toxic effects in Wistar rats and CD-1 mice to determine if MPJ can be considered safe for human consumption and used as a nutraceutical. No deaths or deleterious effects occurred when high doses of 5000 mg/kg were orally administered in rats for 14 days, indicating an absence of subacute toxicity. Similarly, 3000 mg/kg MPJ administered to CD-1 mice for 90 days did not show subchronic toxicity. In fact, MPJ resulted in lowered weight gain in both rats and mice. Cytotoxic and microbiological analyses of MPJ were also performed. MPJ did not cause any cytotoxicity in epithelial cell culture as tested using the Alamar blue assay. Additionally, histopathological analysis of kidney and liver corroborated the absence of toxicity in CD-1 mice. The microbial load of the MPJ was low, and no pathogenic bacteria were present. In conclusion, the results reported here show that high doses of MPJ are apparently innocuous in rats and mice for the 14 and 90 days investigated, respectively. Although preliminary, our results suggest that MPJ may be safe to ingest and may even have beneficial effects in reducing weight gain.

Variations in bran carotenoid levels within and between rice subgroups.

Rice (Oryza sativa L.) is a major grain in the human diet and carotenoids are valuable antioxidants. However, little is known about varietal differences in the carotenoid contents of the rice bran. The objective of this study is to determine the relative differences in bran carotenoid levels among all the five subgroups of rice. Measurements were made by a recently described, rapid non-destructive fluorescence quenching method. Confirmation by high performance liquid chromatography (HPLC) after solvent extraction of the bran indicated that the major carotenoid was lutein. Our data showed that carotenoid levels were stable over 10 years of storage. Tropical japonica rice, the most consumed subgroup in the United States, tended to have the lowest levels of carotenoids in the bran while temperate japonicas had the highest. These differences in carotenoid content may open up new opportunities for identifying or breeding rice varieties with higher nutritional value.

Antibacterial activity of fresh pomegranate juice against clinical strains of Staphylococcus epidermidis.

BACKGROUND: Polyphenols have received a great deal of attention due to their biological functions. Pomegranate (Punica granatum L.) is a polyphenol-rich fruit. In the past decade, studies testing the antimicrobial activity of pomegranates almost exclusively used solvent extracts instead of fresh pomegranate juice (FPJ). The use of FPJ instead of solvent extracts would reduce toxicity issues while increasing patient acceptance. We established a model to test FPJ as a natural antimicrobial agent. OBJECTIVE: To evaluate the antimicrobial activity of FPJ on clinical isolates of multidrug-resistant Staphylococcus epidermidis strains. DESIGN: Sixty strains of S. epidermidis isolated from ocular infections were grown in the presence of FPJ, and minimum inhibitory concentration (MIC) was determined by broth and agar dilution methods. RESULTS: FPJ at 20% had a MIC equal to 100% (MIC100%) on all 60 strains tested. This inhibition of FPJ was confirmed by the growth kinetics of a multidrug-resistant strain exposed to different concentrations of FPJ. Additionally, the antimicrobial activity of FPJ was compared against commercial beverages containing pomegranate: Ocean Spray(®) had a MIC100% at 20%, followed by Del Valle(®) with a MIC15% at 20% concentration only. The beverages Jumex(®) and Sonrisa(®) did not have any antimicrobial activity. FPJ had the highest polyphenol content and antioxidant capacity. CONCLUSIONS: Overall, FPJ had antimicrobial activity, which might be attributed to its high polyphenol content and antioxidant capacity.

Ontogenetic changes in vitamin C in selected rice varieties.

Vitamin C (L-ascorbic acid) is a key antioxidant for both plants and animals. In plants, ascorbate is involved in several key physiological processes including photosynthesis, cell expansion and division, growth, flowering, and senescence. In addition, ascorbate is an enzyme cofactor and a regulator of gene expression. During exposure to abiotic stresses, ascorbate counteracts excessive reactive oxygen species within the cell and protects key molecules, including lipids, proteins, and nucleic acids, from irreversible damage. In this study we focus on understanding how ascorbate levels are controlled in rice (Oryza sativa) during plant development and in response to light intensity and photoperiod. Our results indicate that in rice ascorbate metabolism follows a different pattern compared to other species. In the rice accessions we analyzed, total foliar ascorbate content increases during development and peaks at the vegetative 2-4 and the reproductive 4 stages, whereas other research has shown that in Arabidopsis thaliana and other dicots, ascorbate content declines with plant age. The pattern in rice does not seem to change when plants were grown under increasing light intensity: 150, 400 or 1200-1500 µmol m(-2) s(-1). We observed little diurnal variation in AsA content in rice and did not see a steady decline during the dark period as has been reported in other species such as Arabidopsis and tomato. The total foliar ascorbate content of twenty-three rice accessions from four major rice subgroups was compared. These genotypes differed as much as eight-fold in ascorbate content at the V2 stage indicating the potential to enhance vitamin C levels in genotypes of global interest via breeding approaches.

Using a commercial DNA extraction kit to obtain RNA for RT-PCR from starchy rice endosperm.

The extraction of RNA from a starchy plant material, such as many common food grains, is difficult, and especially so from the mature endosperm of rice. Most commercial RNA kits are not suitable for starchy materials. Traditional RNA extraction procedures, in addition to being laborious and time consuming, leave hazardous organic wastes that result in expensive disposal costs. Interestingly, the numerous commercial DNA isolation kits now available often include directions for eliminating co-isolated RNA. This indicated an approach to obtain the generally unwanted RNA by-product by treating the total extraction product to intentionally retain RNA. A method was developed by which a two-step DNase procedure was applied to the product of the Cartagen Food DNA extraction kit that eliminated the DNA but left the co-extracted RNA. This modified procedure was compared with several other commercial and standard methods that are promoted as being able to work under high polysaccharide conditions. Successful extraction was determined by the production and amplification of cDNA by RT-PCR of actin. Extraction was successful from milled rice, as well as from cornmeal and wheat flour. The modification provides an RNA extraction method that is quick, easy, and inexpensive, and also eliminates the production of hazardous wastes.