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.

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.

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.