ALCOHOLIC PRECIPITATE OF Oreochromis niloticus SKIN GLYCOSAMINOGLYCANS REVEALS ANTIOXIDANT POTENTIAL
DOI:
https://doi.org/10.18817/repesca.v16i3.3608Resumo
Oreochromis niloticus skin contains anticoagulant glycosaminoglycans-OnGAGs, but their obtaining as antioxidants at lower cost require studies. This research examined OnGAGs, by eco-friendly method, on yield, physical-chemical features and in vitro antioxidant effects. Tritured skin was digested with papain, in 100 mM sodium acetate buffer (pH 5)+5 mM cysteine/EDTA, to obtain OnGAGs. Then, OnGAGs precipitated and washed with alcohol were verified by agarose/polyacrylamide gels electrophoreses stained with toluidine blue or Stains-All. Infrared characterized OnGAGs extract. Antioxidant potentials were tested by DPPH, total antioxidant capacity and ferrous ion chelanging-FIC assays using BHT, ascorbic acid and EDTA as respective standards. Alcoholic precipitate yielded 2.32 ± 0.19% and revealed dermatan-unrelated OnGAGs, with relatively reduced charge and size ~40kDa from the molecular analyses. OnGAGs had concentration-dependent antioxidation in all assays evaluated, but there was a preponderant response as powerful as EDTA by FIC method (~100% inhibition, 4 mg mL-1) with contaminants. OnGAGs from skin recovered with alcohol had antioxidant effects, but toxicity studies are need due to low purity.







