Almond protein hydrolysate fraction modulates the expression of proinflammatory cytokines and enzymes in activated macrophages

• Published in: Food & function Vol. 4; no. 5; p. 777
• Main Authors: Udenigwe, Chibuike C, Je, Jae-Young, Cho, Young-Sook, Yada, Rickey Y
• Format: Journal Article
• Language: English
• Published: England 30-04-2013
• Subjects: Amino Acids - analysis; Animals; Cell Line, Tumor; Cyclooxygenase 2 - metabolism; Electrophoresis, Polyacrylamide Gel; Gene Expression; Inflammation - drug therapy; Interleukin-1beta - metabolism; Interleukin-6 - metabolism; Lipopolysaccharides - adverse effects; Lipopolysaccharides - metabolism; Macrophages - drug effects; Macrophages - metabolism; Mice; Nitric Oxide - biosynthesis; Nitric Oxide Synthase Type II - metabolism; Protein Hydrolysates - analysis; Protein Hydrolysates - pharmacology; Prunus - chemistry; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 2042-650X
• DOI: 10.1039/c3fo30327f

Simulated gastrointestinal treatment of almond proteins with pepsin and pancreatic proteases resulting in 16.6% degree of hydrolysis or 1.33 milliequivalent leucine per g protein yielded a hydrolysate that modulated excessive nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages. After fractionation, a resulting fraction of molecular size > 5 kDa retained the nitric oxide modulatory effect observed initially in the crude hydrolysate. The high molecular size fraction was found to modulate levels of proinflammatory cytokines, interleukin (IL)-6, IL-1β, and tumour necrosis factor (TNF)-α in the activated cells. Immunoblotting analysis indicated that the hydrolysate fraction decreased the expression levels of inflammatory enzyme indicators, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 in the activated cells. RT-PCR analysis showed that treatment of the activated cells with the hydrolysate fraction resulted in the inhibition of relative gene expressions of proinflammatory IL-6, IL-1β, TNF-α, iNOS and COX-2. These results indicate a potential application of almond protein hydrolysates against inflammatory conditions, and will contribute to delineating the possible contributions of proteins to health benefits attributed to almond consumption.