Microencapsulation of fish oil by casein-pectin complexes and gum arabic microparticles: oxidative stabilisation.

This study was aimed to microencapsulate fish oil (FO) in two biocompatible polymeric blends: gum arabic (GA)-maltodextrin (MD) and casein-pectin (CP)-MD. GA-MD microparticles and CP-MD microparticles were produced by spray-drying and complex coacervation and spray-drying, respectively. Encapsulation efficiency, particle size, moisture content, oxidative stability, and morphological properties were analysed. Encapsulation efficiencies of 51.2-56.8% (w/v) for GA and 64.7-67.9% (w/v) for CP preparations were found. GA particle sizes varied from 2 to 100 µm and from 2 to 120 µm for CP microparticles. Spherical forms with depressions in the topography of both systems were evidenced by scanning electron microscopy. Confocal microscopy evidenced surface oil on GA microparticles, corroborating encapsulation efficiency. CP was more efficient than GA to reduce oxidation, with maximum peroxide values (PVs) of 17.40 mmol/kg oil after 28 d at 40 °C/75% relative humidity (RH). Thus, CP is a promising biopolymeric blend for encapsulation of FO that provides protection against lipid oxidation.

Fish oil attenuates persistent inflammatory pain in rats through modulation of TNF-α and resolvins.

UNLABELLED: Fish oil (FO), source of omega-3 fatty acids (FA), has been widely studied in the treatment of inflammatory diseases and inflammatory pain (IP). Omega-3 FA give rise to eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, metabolized to eicosanoids and converted to resolvins with important anti-inflammatory action. AIMS: This study investigates the effects of oral doses of omega-3 FA from FO and concentrated fish oil (CFO) in a model of sub-chronic IP, induced by Complete Freund's Adjuvant (CFA). MAIN METHODS: IP was induced by intraplantar injection of CFA into the right hind paw of Wistar rats. Three groups were pre-treated with omega-3 FA: two groups received CFO (460mg of EPA/360mg of DHA and 690mg of EPA/540mg of DHA) and one group received natural FO (460mg EPA/300mg DHA), for 7days before IP induction (pre-treatment) and 5days after induction (treatment). KEY FINDINGS: TNF-α levels were reduced by CFO 690 (67.9%; p<0.01), CFO 460 (57.7%; p<0.01), FO 460 (26.2%), compared to the augment promoted by CFA (549.7%; p<0.001). Resolvin levels were increased in treated groups with respect to the CFA control group (CFO 690=3196.3%, p<0.01; CFO 460=3347.1%, p<0.01; FO=1653.5%). SIGNIFICANCE: The results indicate that the tested doses reduced inflammatory pain effectively in a short pre-treatment period, through modulation of TNF-α and resolvins and that CFO presented better results than FO. Therefore, Ω-3 FA from FO can be proposed for use as complementary medicine in the treatment of painful and inflammatory diseases.

Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp) consumed in Brazil.

BACKGROUND: The cowpea (Vigna unguiculata L. Wap.) is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. OBJECTIVES: The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. METHODS: Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. RESULTS: When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. CONCLUSIONS: Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

Effects of cooking methods on the iron and zinc contents in cowpea (Vigna unguiculata) to combat nutritional deficiencies in Brazil.

BACKGROUND: Because iron deficiency anemia is prevalent in developing countries, determining the levels of iron and zinc in beans, the second most consumed staple food in Brazil, is essential, especially for the low-income people who experience a deficiency of these minerals in their diet. OBJECTIVES: This study aimed to evaluate the effect of cooking methods by measuring the iron and zinc contents in cowpea cultivars before and after soaking to determine the retention of these minerals. METHODS: The samples were cooked in both regular pans and pressure cookers with and without previous soaking. Mineral analyses were carried out by Spectrometry of Inductively Coupled Plasma (ICP). RESULTS: The results showed high contents of iron and zinc in raw samples as well as in cooked ones, with the use of regular pan resulting in greater percentage of iron retention and the use of pressure cooker ensuring higher retention of zinc. CONCLUSIONS: The best retention of iron was found in the BRS Aracê cultivar prepared in a regular pan with previous soaking. This cultivar may be indicated for cultivation and human consumption. The best retention of zinc was found for the BRS Tumucumaque cultivar prepared in a pressure cooker without previous soaking.

In vivo and in vitro evaluation of octyl methoxycinnamate liposomes.

UNLABELLED: Solar radiation causes damage to human skin, and photoprotection is the main way to prevent these harmful effects. The development of sunscreen formulations containing nanosystems is of great interest in the pharmaceutical and cosmetic industries because of the many potential benefits. This study aimed to develop and evaluate an octyl methoxycinnamate (OMC) liposomal nanosystem (liposome/OMC) to obtain a sunscreen formulation with improved safety and efficacy by retaining OMC for longer on the stratum corneum. METHODS: The liposome/OMC nanostructure obtained was tested for enzymatic hydrolysis with lipase from Rhizomucor miehei and biodistribution with liposomes labeled with technetium-99m. The liposome/OMC formulation was then incorporated in a gel formulation and tested for ocular irritation using the hen's egg test-chorio-allantoic membrane (HET-CAM) assay, in vitro and in vivo sun protection factor, in vitro release profile, skin biometrics, and in vivo tape stripping. RESULTS: The liposome/OMC nanosystem was not hydrolyzed from R. miehei by lipase. In the biodistribution assay, the liposome/OMC formulation labeled with technetium-99m had mainly deposited in the skin, while for OMC the main organ was the liver, showing that the liposome had higher affinity for the skin than OMC. The liposome/OMC formulation was classified as nonirritating in the HET-CAM test, indicating good histocompatibility. The formulation containing liposome/OMC had a higher in vivo solar photoprotection factor, but did not show increased water resistance. Inclusion in liposomes was able to slow down the release of OMC from the formulation, with a lower steady-state flux (3.9 ± 0.33 µg/cm(2)/hour) compared with the conventional formulation (6.3 ± 1.21 µg/cm(2)/hour). The stripping method showed increased uptake of OMC in the stratum corneum, giving an amount of 22.64 ± 7.55 µg/cm(2) of OMC, which was higher than the amount found for the conventional formulation (14.57 ± 2.30 µg/cm(2)). CONCLUSION: These results indicate that liposomes are superior carriers for OMC, and confer greater safety and efficacy to sunscreen formulations.

DNA methylation: a promising target for the twenty-first century.

BACKGROUND: Over the last few years DNA methylation and its involvement in diseases such as cancer has become of great interest for applied research. Since reversal of aberrant DNA methylation may influence the behavior of tumors, the methylation of DNA CpG sites is a potential target for the development of inhibitors for use in cancer treatment. OBJECTIVE/METHODS: We briefly review the structural and mechanistic features of DNA methylation, including a structural analysis of the three main human DNA methyltransferases and some (pre)clinical results. RESULTS/CONCLUSION: Despite side effects, data obtained to date still support the vision that DNA-methylation, possibly associated with the use of histone deacetylases (HDACs) and/or artificial transcription factors (ATFs), is a promising target for improving anticancer therapy in the 21st century.

Preparation of a very stable immobilized biocatalyst of glucose oxidase from Aspergillus niger.

Glucose oxidase (GOX) has been immobilized on different activated supports, including glyoxyl agarose, epoxy sepabeads and glutaraldehyde-activated supports. Immobilization onto supports pre-activated with glutaraldehyde rendered the most thermo-stable preparation of GOX. Therefore, as the glutaraldehyde chemistry gave a high stabilization of the enzyme, we proposed another technique for improving the multipoint attachment through glutaraldehyde: the enzyme was ionically adsorbed on cationic supports with primary amino groups and then the immobilized preparation was treated with a glutaraldehyde solution. The decrease on enzyme activity was <20%. Following this methodology, we achieved the highest stability of all the immobilization systems analyzed, showing a half-life 100 times higher than the soluble enzyme. Moreover, this derivative showed a higher stability in the presence of organic solvents (for instance methanol) or hydrogen epoxide than the ionically adsorbed enzyme or the soluble one. Therefore, the adsorption of GOX on aminated cationic support and subsequent treatment with glutaraldehyde was presented as a very successful methodology for achieving a very stable biocatalyst.

Enzyme stabilization by glutaraldehyde crosslinking of adsorbed proteins on aminated supports.

The stabilization achieved by different immobilization protocols have been compared using three different enzymes (glutaryl acylase (GAC), D-aminoacid oxidase (DAAO), and glucose oxidase (GOX)): adsorption on aminated supports, treatment of this adsorbed enzymes with glutaraldehyde, and immobilization on glutaraldehyde pre-activated supports. In all cases, the treatment of adsorbed enzymes on amino-supports with glutaraldehyde yielded the higher stabilizations: in the case of GOX, a stabilization over 400-fold was achieved. After this treatment, the enzymes could no longer be desorbed from the supports using high ionic strength (suggesting the support-protein reaction). Modification of the enzymes immobilized on supports that did not offer the possibility of react with glutaraldehyde showed the same stability that the non modified preparations demonstrating that the mere chemical modification did not have effect on the enzyme stability. This simple strategy seems to permit very good results in terms of immobilization rate and stability, offering some advantages when compared to the immobilization on glutaraldehyde pre-activated supports.

A new sunscreen of the cinnamate class: synthesis and enzymatic hydrolysis evaluation of glyceryl esters of p-methoxycinnamic acid.

Glyceryl esters of p-methoxycinnamic acid, 1,3-dipalmitoyl-2-p-methoxycinnamoyl-1,2,3-propanetriol and 1,3-dioctanoyl-2-p-methoxycinnamoyl-1,2,3-propanetriol were synthesised in an attempt to increase substantivity and decrease eventual undesirable effects of sunscreens of this class. To assess if the glyceryl esters could present a higher stability towards hydrolysis by lipases in the stratum corneum, hydrolysis rates were determined in vitro using a commercial fungal lipase from Rhizomucor miehei. Results presented herein show that the glyceryl esters have similar lambda(max) and epsilon values to sunscreens of the cinnamate class. The ester 1,3-dipalmitoyl-2-p-methoxycinnamoyl-1,2,3-propanetriol presented a 2.8 times lower hydrolysis rate by lipase, in vitro, than the commercial sunscreen 2-ethylhexyl-p-methoxycinnamate (alkyl ester). This finding suggests that this triacylglycerol can possibly have a longer retention time in the skin and consequently promote a more intense and effective antisolar action than the commercial sunscreen.