Antioxidant and Anticancer Activities of Walnut (Juglans regia L.) Protein Hydrolysates Using Different Proteases

Plant Foods Hum Nutr. 2016 Dec;71(4):402-409. doi: 10.1007/s11130-016-0576-z.


Walnut (Juglans regia L.) contains approximately 20-25 % protein with abundant essential amino acids. The enzymatic hydrolysate of Persian walnut (Chandler) seed proteins was prepared by incubation with three different proteases, including pancreatic chymotrypsin and trypsin, and a microbial enzyme proteinase K. The hydrolysates were found to possess excellent antioxidant capacities. The peptide fractions scavenged the 2, 2'-anizo-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radicals and inhibited the activity of reactive oxygen species. Walnut protein hydrolysates were also tested, for the first time, against the viability of human breast (MDA-MB231) and colon (HT-29) cancer cell lines. MTT, [3-(4, 5dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide], assay was used to assess in vitro cancer cell viability upon treatment with the peptide fractions. The peptide fractions showed cell growth inhibition of 63 ± 1.73 % for breast cancer and 51 ± 1.45 % for colon cancer cells. Thus, a direct correlation between antioxidant and anticancer activities of walnut peptide fractions exists and supports their potential therapeutic benefit.

Keywords: Anticancer; Antioxidant; Bioactive peptides; Protease; Walnut proteins.

MeSH terms

  • Antineoplastic Agents / analysis
  • Antineoplastic Agents / pharmacology*
  • Antioxidants / analysis
  • Antioxidants / pharmacology*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • HT29 Cells
  • Humans
  • Juglans / chemistry*
  • Nuts / chemistry*
  • Peptide Hydrolases / metabolism*
  • Plant Proteins / chemistry
  • Plant Proteins / pharmacology
  • Protein Hydrolysates / analysis
  • Protein Hydrolysates / pharmacology*
  • Reactive Oxygen Species / metabolism


  • Antineoplastic Agents
  • Antioxidants
  • Plant Proteins
  • Protein Hydrolysates
  • Reactive Oxygen Species
  • Peptide Hydrolases