An overview on extraction, composition, bioactivity and food applications of peanut phenolics.

Peanuts contain a diverse and vast array of phenolic compounds having important biological properties. They are allocated mostly in the seed coat (skin), an industrial waste with minor and undervalued applications. In the last few years, a considerable amount of scientific knowledge about extraction, composition, bioactivities and health benefits of peanut skin phenolics has been generated. The present review was focused on four main aspects: a) extraction methods and technologies for obtaining peanut skin phenolics with an emphasis on green-solvent extraction processes; b) variations in chemical profiles including those due to genetic variability, extraction methodologies and process-related issues; c) bioactive properties, especially antioxidant activities in food and biological systems; d) update of promising food applications. The revision was also aimed at identifying areas where knowledge is insufficient and to set priorities for further research.

Effects of oral phytoextract intake on phenolic concentration and redox homeostasis in murine encephalic regions.

Vegetable infusions (VI) are one of the main phenolic sources for humans. They may act as antioxidants in the central nervous system, but data about their effect are insufficient. The main objective of the study was to determinate the effects of oral VI of Argentinean plants on phenolic concentration and redox homeostasis in different murine encephalic regions. Redox changes (peroxides -HP-, anion superoxide -SO- and γ-glutamyltranspeptidase activity) and tissue phenolics were assessed in Balb/c mice of both sexes treated with the following VI extracts: Lantana grisebachii Seckt. var. grisebachii (Verbenaceae) (LG), Aspidosperma quebracho-blanco Schltdl. (Apocynaceae) (AQB), and Ilex paraguariensis A. St.-Hil. (Aquifoliaceae) (IP). Brain (telencephalon and diencephalon), midbrain, brainstem, and cerebellum were studied (analysis of variance, P < 0.05). A redox homeostasis depending on an appropriate phenolic balance was detected after marker analysis. Under situations without exogenous challenges, the excessive or deficient levels were deleterious on each region. This finding was confirmed independently of the utilized phytoextracts. LG and AQB caused such phenolic imbalance and triggered oxidative stress. IP group showed region-specific differential redox effects. Overall, the last extract exhibited the best redox profile when the complete encephalon was analyzed. Since this plant has sanitary impact due to its high human intake, new studies about it are warranted.

In vivo redox effects of Aspidosperma quebracho-blanco Schltdl., Lantana grisebachii Stuck and Ilex paraguariensis A. St.-Hil. on blood, thymus and spleen of mice.

Argentinian native plants Aspidosperma quebracho-blanco, Lantana grisebachii and Ilex paraguariensis are known to have antiinflammatory and antioxidant properties. We demonstrated it in vivo by the redox changes in murine hemolymphatic tissues after infusive extract intake of these plants as revealed in organic trophism, tissue phenolics, hydroperoxides, superoxide, nitrites and gamma-glutamyltranspeptidase in thymus, blood and spleen. A. quebracho-blanco reduced hydroperoxidation in blood and spleen of both sexes, with gamma-glutamyltranspeptidase negativization in lymphatic organs and thymic nitrosative up-regulation. Males have shown increased phenolic content in blood after treatment. L. grisebachii and I. paraguariensis treatment exhibited incomplete antioxidation and oxidative induction in the studied tissues. Different results according to sex were found in redox response to phenolics and their kinetics, with males showing antioxidant effects, whereas females showed oxidative susceptibility. A. quebracho-blanco exhibited protection of murine tissues against oxidation in both sexes and modulation of their trophism, supporting its therapeutic uses in inflammatory diseases. Also, gender had significant influence in phenolic biodistribution and redox response.

Short and long range surface plasmon polariton waveguides for xylene sensing.

Nanostructured plasmonic sensors are fabricated as sinusoidal surface plasmon metallic gratings (SPGs) embedded in a functional and porous hybrid sol-gel material, phenyl-bridged polysilsesquioxane (ph-PSQ). The metal layer is in contact with the environment through the sol-gel film, which works as sensitive element, changing its dielectric properties upon interaction with aromatic hydrocarbons. The combination of sensitivity, transparency and patternability offered by ph-PSQs gives the exceptional possibility to fabricate innovative optical sensors with straightforward processes. An embedded SPG is a thin metal slab waveguide, in which the surface plasmon polaritons (SPPs) at the two metal-dielectric interfaces superpose, resulting in two physical coupled modes: the long range SPPs (LRSPPs) and the short range SPPs (SRSPPs). An extended experimental and theoretical characterization of the optical properties of the plasmonic device was performed. The sensor performance was tested against the detection of 30 ppm xylene, monitoring the influence of the target gas on the SPPs modes. A reversible red-shift of the reflectance dips of both LRSPP and SRSPP resonances in the 1.9-2.9 nm range was observed and correlated to the interaction with the analyte. An enhancement in sensitivity associated with the rotation of the grating grooves with respect to the scattering plane (azimuthal rotation) was verified within the experimental errors. Collected data are compatible with theoretical predictions assuming a variation of the film refractive index of 0.011 ± 0.005.

Topical treatment of refractory distal ulcerative colitis with 5-ASA and sodium butyrate.

Nine patients with distal ulcerative colitis refractory to standard therapy were treated with intrarectal instillation of a sodium butyrate solution and 5-ASA. A marked clinical, endoscopical and, to a smaller extent, histological improvement was observed in seven of nine patients. The clinical improvement usually occurred within the second week of therapy, and thus earlier than in previous cases treated with butyrate alone. This preliminary experience suggests that the combined butyrate-5-ASA treatment may prove a useful therapeutic tool in refractory distal ulcerative colitis and possibly increase the effectiveness of the individual therapeutic regimens.

Fecal lactate and ulcerative colitis.

Impaired metabolism of short-chain fatty acids, as well as a modified fecal ionogram, have been reported in ulcerative colitis. Fecal water samples from 62 patients with ulcerative colitis were analyzed in the present investigation to evaluate changes in SCFAs and lactic acid in relation to activity and severity of disease. Short-chain fatty acid levels were high in quiescent and mild disease (162.6 +/- 63.6 and 147.8 +/- 63.2 mM/L, respectively), but significantly decreased in the severe form (64.7 +/- 46.9 mM/L). Lactate showed a progressive increase from mild colitis (3.0 +/- 1.8 mM/L) to severe colitis (21.4 +/- 18.6 mM/L). It thus appears that mild colitis displayed a fecal pattern characterized by normal pH and bicarbonate, slightly impaired electrolyte handling, high short-chain fatty acid values, and only moderately increased lactate. Severe colitis, on the other hand, was characterized by low fecal pH, bicarbonate, and potassium, high sodium and chloride, low short-chain fatty acid levels, and very high lactate levels. A critical lowering of intraluminal pH, which shifts bacterial metabolism from short-chain fatty acid to lactate production, may be responsible for the intraluminal pooling of lactate.