Abts radical

Fresh cup plant was harvested in Jilin Agricultural University (Changchun, China). The plants were in bloom stage. The entire crop was cut into 5 cm segments before drying at 50°C, then the dried cup plant segments were ground into powders, and passed through a 1 mm sieve prior to extraction of the polysaccharide. The reagents including DPPH radical, ABTS radical and vitamin C were obtained from Sigma-Aldrich (St. Louis, USA). All other chemicals used were analytical grade and bought from local suppliers.

Auricularia auricula waste residue powder was obtained by drying the powder of fruiting body after the polysaccharide was extracted. Human L02 hepatocyte cells were purchased from Fuheng Biological Technology Co.. ABTS radical and DPPH radical were purchased from Sigma‐Aldrich. Chemical reagents such as sodium hydroxide, hydrochloric acid, ethyl acetate, chloroform, ethanol, salicylic acid, ferrous sulfate, and hydrogen peroxide were purchased from Sinopharm Co..

Frozen Argentine red shrimp (Pleoticus muelleri) was purchased from a local business. Cephalothoraxes were separated, freeze-dried and subsequently ground. Partially purified phospholipids and bioactive co-extracts were obtained from the resulting powder with successive extraction steps for methanol, hexane and acetone, as described in a previous work [4 (link)]. Protein removal from the acetone-insoluble extract was carried out after alkaline solubilization. The resulting fractions were named PL, partially purified phospholipids; Hx, hexane-soluble extract; and Ac, acetone-soluble extract. The detailed chemical composition (neutral lipids, free fatty acids, phospholipids, fatty acid compositions, phospholipid species, astaxanthin, α-tocopherol, sterols, cholesterol) of PL, Hx and Ac was reported in previous work [4 (link)].
Di-sodium hydrogen phosphate dihydrate, sodium hydrogen phosphate anhydrous, hexane and acetone were purchased from Labkem S.A. (Barcelona, Spain). Sodium carbonate anhydrous, sodium hydrogen carbonate and methanol were purchased from Panreac Química S.A. (Madrid, Spain). ABTS radical was purchased from Sigma (St. Louis, MO, USA). Deionized water was obtained through the Milli-Q purification system (Merck KGaA, Darmstadt, Germany).

8-Hydroxy-7-methoxyflavone, (+)-catechin, (−)-epicatechin, quercetin (control), ascorbic acid, trolox, ABTS+ radical, potassium persulphate, xanthine, xanthine oxidase, anhydrous potassium carbonate, anhydrous sodium sulphate, acetic anhydride, pyridine, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were purchased from Sigma-Aldrich (Singapore). 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ, 99%), iron (III) chloride hexahydrate, and sodium acetate were purchased from Sigma-Aldrich (St. Louis, MO, USA). Allopurinol was purchased from Nacalai Tesque (Japan). Dipeptidyl peptidase-4 (DPP-4) inhibitor assay kit was purchased from Cayman (Michigan, USA). α-Glucosidase from Saccharomyces cerevisiae was purchased from Megazyme (Ireland). Methanol, chloroform, ethyl acetate, acetone, ethanol, dimethyl sulphoxide (DMSO), dimethyl sulphate, and thin layer chromatography (TLC) plates were purchased from Merck (Germany).

The antioxidant capacity was determined by the reduction method of the ABTS^•+ radical (Sigma-Aldrich, Saint Louis, MO, USA) according to Gião et al. [41 (link)]. For the reactions, 30 μL of each filtered and duly diluted extract were mixed with 3000 μL ABTS^•+ radical. After 6 min, the absorbance was measured at 734 nm with a spectrophotometer in spectrophotometric units (Metash, Shanghai, China) using ultra-pure water as a blank. The ABTS^•+ antiradical activity was calculated using Trolox solutions (Sigma-Aldrich, Buchs, Switzerland) with different concentrations in a range of 500–2000 μmol. Results were expressed as µmol Trolox equivalents per gram (μmol TE/g).