title: Human colon and liver cancer cell proliferation inhibition by peptide hydrolysates derived from heat-stabilized defatted rice bran.
abstract: Rice bran, an economical, underutilized coproduct of rough rice milling, was used to produce peptide hydrolysates, which were investigated for anticancer activity. Protein hydrolysates prepared by Alcalase hydrolysis under optimized conditions were treated further to obtain gastrointestinal (GI)-resistant peptide hydrolysates. They were fractionated into >50, 10-50, 5-10, and <5 kDa sizes and evaluated for inhibitory activity on proliferation of human colon (Caco-2) and liver (HepG2) cancer cell lines by Trypan blue dye exclusion assay. GI-resistant <5 and 5-10 kDa sized peptide fractions inhibited growth of Caco-2 cells by 80%, and the <5 kDa fraction inhibited growth of HepG2 cells by approximately 50% compared to controls and nonresistant fractions. An MTS cell titer assay confirmed antiproliferative effects of the peptide fractions. The results demonstrated that 5-10 and <5 kDa sized GI-resistant fractions promoted significant (p < 0.05) inhibitory activities on both cancer cell lines compared to controls. More investigations are needed to show such value-added effects on the technofunctional and sensorial properties of the food protein and peptide matrices.
authors.affiliation: Department of Food Science, University of Arkansas, Fayetteville, Arkansas 72704, USA.
authors.forename: Arvind
authors.initials: A
authors.lastname: Kannan
authors.forename: Navam
authors.initials: N
authors.lastname: Hettiarachchy
authors.forename: Michael G
authors.initials: MG
authors.lastname: Johnson
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Nannapaneni
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000188:drug therapy*; D006131:Growth Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006358:Hot Temperature; D006801:Humans; D006868:Hydrolysis; D008113:Liver Neoplasms / Q000188:drug therapy*; D012275:Oryza / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D011492:Protein Hydrolysates / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D006131:Growth Inhibitors; D010455:Peptides; D011492:Protein Hydrolysates