Lipoxin A4 inhibits UV radiation-induced skin inflammation and oxidative stress in mice.

BACKGROUND: Lipoxin A4 (LXA4) is a metabolic product of arachidonic acid. Despite potent anti-inflammatory and pro-resolution activities, it remains to be determined if LXA4 has effect on ultraviolet (UV) radiation-induced skin inflammation. OBJECTIVE: To investigate the effects of systemic administration with LXA4 on UV radiation-induced inflammation and oxidative damage in the skin of mice. METHODS: Varied parameters of inflammation and oxidative stress in the skin of mice were evaluated after UV radiation (4.14 J/cm2). RESULTS: Pretreatment with LXA4 significantly inhibited UV radiation-induced skin edema and myeloperoxidase activity. LXA4 efficacy was enhanced by increasing the time of pre-treatment to up to 72 h. LXA4 reduced UV radiation-induced skin edema, neutrophil recruitment (myeloperoxidase activity and LysM-eGFP+ cells), MMP-9 activity, deposition of collagen fibers, epidermal thickness, sunburn cell counts, and production of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6 and IL-33). Depending on the time point, LXA4 increased the levels of anti-inflammatory cytokines (TGF-ß and IL-10). LXA4 significantly attenuated UV radiation-induced oxidative damage returning the oxidative status to baseline levels in parameters such as ferric reducing ability, scavenging of free radicals, GSH levels, catalase activity and superoxide anion production. LXA4 also reduced UV radiation-induced gp91phox [nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) subunit] mRNA expression and enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target enzyme nicotinamide adenine dinucleotide (phosphate) quinone oxidoreductase (Nqo1) mRNA expression. CONCLUSION: LXA4 inhibited UV radiation-induced skin inflammation by diminishing pro-inflammatory cytokine production and oxidative stress as well as inducing anti-inflammatory cytokines and Nrf2.

Optimisation of soy flour fermentation parameters to produce ß-glucosidase for bioconversion into aglycones.

The solid state fermentation (SSF) parameters of defatted soybean flour (DSF) with Aspergillus oryzae IOC 3999/1998 or Monascus purpureus NRRL 1992 was evaluated using a rotational central composite experimental design to optimise the production of ß-glucosidase and convert glycosidic isoflavones in aglycones. Variables investigated were initial pH of DSF, volume of water added to 10 g of DSF and incubation temperature. ß-Glucosidase activity was measured using the synthetic substrate, p-nitrophenyl-ß-D-glucoside. The content of isoflavones was determinate by ultra performance liquid chromatography. The highest production of ß-glucosidase for both strains occurred when adding 10 mL of water to the DSF, incubating at 30 °C and using 6.0 as the initial DSF pH. A. oryzae IOC 3999/1998 expressed ß-glucosidase activity at 10.7 times higher than M. purpureus NRRL 1992. The DSF fermentation was more efficient in converting isoflavones with M. purpureus NRRL 1992.

Enhanced in vitro and in vivo antioxidant activity and mobilization of free phenolic compounds of soybean flour fermented with different beta-glucosidase-producing fungi.

AIMS: To evaluate the soybean polyphenol glucosides bioconversion to aglycone forms by different beta-glucosidases-producing filamentous fungi to enhance their antioxidant activity. METHODS AND RESULTS: Soybean defatted flour was submitted to solid-state fermentation with Aspergillus niger, Aspergillus niveus and Aspergillus awamori. The fungi studied produced approximately the same beta-glucosidase activity units amount when p-nitrophenyl-beta-d-glucopyranoside was used as substrate for the assay. However, electrophoretic analysis, using 4-methylumbellipheryl-beta-d-glucopyranoside as substrate, showed that beta-glucosidase produced by A. niveus was more active. Fermented methanolic extracts showed an increase in polyphenol and genistein contents and antioxidant activities. The highest genistein content was found in soybean fermented by A. niveus. Methanolic extracts of the soybean fermented by the different fungi showed a similar capacity of scavenging H(2)O(2) generated in vivo by the tumour promoter 12-O-tetradecanoyl phorbol-13-acetate. CONCLUSIONS: A. niveus synthesized a beta-glucosidase with higher specificity to hydrolyse genistin beta-glycosidic bond than those produced by A. awamori and A. niger. SIGNIFICANCE AND IMPACT OF THE STUDY: The utilization of these beta-glucosidases-producing fungi in soybean fermentation processes resulted in the obtaining of methanolic extracts with different antioxidant potentials that could be used either therapeutically or as an antioxidant in nonphysiological oxidative stress conditions, as the one induced in skin by UV radiation.