Soy protein functionality and nutrigenomic analysis.

Soy protein has various biological functions, such as cholesterol-lowering effect, anti-obese, in addition to that nutritive value, and may relieve some lifestyle-related diseases, cancer, osteoporosis, menopausal disorder and so on. Because of the cholesterol-lowering effect of soy protein had been studied extremely and internationally for mechanism and clinical proof, the Ministry of Health and Welfare in Japan had approved soy protein product as a food for special health use (FOSHU) in 1994, and also the FDA in the United States also approved the food labeling for that in 1999. Although, some reports suggested that soy protein changes in expression of the genes concerned with lipid metabolism in liver and in adipose tissue, there are few reports that it is concerned with the comprehensive influence of the intake of soy protein on gene expression. The gene expression of liver in soy protein fed animal has been analyzed with the Affymetrix DNA-microarray. About 33% of 8000 genes in soy fed animals differed compared with those of casein fed. After cluster analysis, significant differences were observed in the gene cluster concerned with lipid metabolism, also in the gene related to energy metabolism, transcription factor, and anti-oxidization enzymes.