Effect of Protein Hydrolysates from Germinated Soybean on Cancerous Cells of the Human Cervix: An In Vitro Study

Abstract

Consumption of soybeans can reduce the risk of different types of cancer. Little is known about the effect of germination on the anticancer properties of soya. This study was done to determine if germination improves the anticancer properties of soybean protein through generation of amino acids or bioactive peptides. Soybean was germinated for 0, 2, 3, 4, 5, and 6 days and proteins were isolated from the seeds. Isolates with and without ethanol-soluble phytochemicals were hydrolyzed with digestive enzymes and their effect on growth in HeLa and C-33 (epidermoid cervical carcinoma) and HaCaT (non-cancerous human keratinocytes) cells were evaluated with the Alamar Blue method. Germination induced degradation of the alpha and alpha' fractions of beta-conglycinin and acid fraction of glycinin, generating low molecular weight peptides. Degrees of hydrolysis ranged from 73-77%. Hydrolysates inhibited the growth of HeLa cells and C-33 at concentrations exceeding 1.25 mg/ml. Major inhibition was observed with the hydrolysate germinated for 2 days and containing ethanolsoluble phytochemicals (IC(50) 2.15 and 2.27 mg/ml for HeLa and C-33, respectively). Interestingly, hydrolysate cytoxicity for normal cells was minimal in comparison to cancer cells.

Effect of Germinated Soybean Protein Hydrolysates on Adipogenesis and Adipolysis in 3T3-L1 Cells

“…This was due to natural proteolysis during germination [23], and also to changes in protein structure which facilitated enzyme access to the protein. Similar results have been reported by Mora-Escobedo et al [11].…”

“…Peptides smaller than 1 kDa inhibited adipogenesis in the early differentiation stage, but the mechanism of action behind the phenomenon is not yet completely understood [33]. Germination produces several low-molecular weight peptides [11], which may explain the higher adipogenesis inhibition observed in the present study with hydrolysates from soybeans germinated for longer times (5 and 6 days).…”

“…Seed Germination Germination was carried out according to Mora-Escobedo et al [11] at 27°C in the dark. Germinated seeds were harvested at different intervals (0 to 6 days), lyophilized and ground.…”

Bioactive Peptides from Legumes as Anticancer Therapeutic Agents

“…To assess if BPs are produced naturally during gastrointestinal digestion, in vitro digestions are commonly carried out with proteases (pepsin, trypsin, chymotrypsin, and pancreatin). Researchers have also performed enzymatic hydrolysis with microbial or plant enzymes, such as alcalase, flavourzyme, papain and bromelain, to obtain bioactive sequences [6,[11][12][13][14][15].…”

“…This process generates changes in the secondary metabolite distribution and mobilizes the reserve proteins stored in the cotyledon protein bodies, producing intermediate molecular weight peptides. Mora-Escobedo, et al [15] showed that germination can improve the anti-proliferative effect of soybean protein on HeLa and C-33 cervical cancer cells. Peptides generated during germination can alter cell signaling pathways and cause apoptosis.…”