Hypocholesterolemic effects of soy protein isolates from soybeans differing in 7S and 11S globulin subunits vary in rats fed a high cholesterol diet

Authors: LIU, SHANSHAN - Northeast Agricultural University, China; LUO, TINGTING - Northeast Agricultural University, China; SONG, YANRU - Ministry Of Agriculture - China; REN, HONGBO - Northeast Agricultural University, China; QIU, ZHENDONG - Heilongjiang Academy Of Agricultural Sciences; MA, CHONGUAN - Northeast Agricultural University, China; TIAN, YUSU - Northeast Agricultural University, China; WU, QI - Northeast Agricultural University, China; WANG, FU - Northeast Agricultural University, China; Krishnan, Hari; YU, WENHUA - Shandong Fuyang Biotechnology Co; YANG, JILIANG - Northeast Agricultural University, China; XU, PENGFEI - Northeast Agricultural University, China; ZHANG, SHUZHEN - Northeast Agricultural University, China; SONG, BO - Northeast Agricultural University, China

Submitted to: Journal of Functional Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2022
Publication Date: 11/23/2022
Citation: Liu, S., Luo, T., Song, Y., Ren, H., Qiu, Z., Ma, C., Tian, Y., Wu, Q., Wang, F., Krishnan, H.B., Yu, W., Yang, J., Xu, P., Zhang, S., Song, B. 2022. Hypocholesterolemic effects of soy protein isolates from soybeans differing in 7S and 11S globulin subunits vary in rats fed a high cholesterol diet. Journal of Functional Foods. 99. Article 105347. https://doi.org/10.1016/j.jff.2022.105347.
DOI: https://doi.org/10.1016/j.jff.2022.105347

Interpretive Summary: Soybeans contain several phytochemicals that promote human health, in part, by helping to reduce cholesterol levels. Several soy protein components are crucial for the reduced cholesterol effect, however, the individual role of various protein subunits in influencing the reduced cholesterol effects of soy protein were not previously explored. In the present study, we have examined the effect of soy protein isolates prepared from genotypes with differing globulin subunit composition on the expression of cholesterol metabolism-related key genes. Our study demonstrates soybean lines lacking the alpha prime and alpha subunits of 7S globulins may lower blood cholesterol levels and promote the levels of good cholesterol (HDL). Our study should benefit US farmers by promoting wider use of select soybean mutant lines in health and food industry.

Technical Abstract: The objective of this study was to determine if genotypes with differing globulin subunit compositions affect the hypocholesterolemic effect (HCE) of soy protein isolates (SPIs). Six SPIs (300 mg/kg/day), which differed in the 11S/7S globulin subunit composition, and fenofibrate (FF) (30 mg/kg/day), a hypocholesterolemic drug, were administered by gavage for 28 days to hypercholesterolemic model rats (HMRs). Blood samples were collected to measure serum lipid parameters. Hepatic histopathologic and lipid biochemical data were collected, and the expression of cholesterol metabolism-related key genes was analyzed. Our results demonstrated that soybeans differing in genotype generate SPIs with marked different HCEs, and the mechanism underlying the various HCEs of SPIs is associated with differential expression of hepatic cholesterol metabolism-related key genes in HMRs. 7S(a'+a)-Null genotype provided a greater effect on increasing HDL-C level, and daily ingestion of SPI-2 (null a, a) might significantly contribute to increase HDL-C level in HMRs.