Get access

The effect of probiotic-fermented soy milk on enhancing the NO-mediated vascular relaxation factors


Tsung-Yu Tsai, Department of Food Science, Fu Jen Catholic University, Taipei, Taiwan. E-mail:


BACKGROUND: Soy milk is one of the common soy-based foods in Asia. In this study the effects of soy milk fermented with selected probiotics on nitric oxide (NO)-mediated vascular relaxation factors in cell model systems were investigated.

RESULTS: Soy milk fermented with Lactobacillus plantarum TWK10 or Streptococcus thermophilus BCRC 14085 for 48 h showed a greater transformation of glucoside isoflavones to aglycone isoflavones (P < 0.05). An increase in aglycone isoflavones in ethanol extracts from fermented soy milk stimulated NO production and endothelial NO synthase (eNOS) activity in human umbilical vein endothelial cells. It also had a stimulating effect on superoxide anion scavenging and prostaglandin E2 production. In addition, it enhanced mRNA expression of the E-prostanoid 4 receptor in rat thoracic aorta smooth muscle cells. Moreover, a small amount of Oequation image induced by water extracts from fermented soy milk at low concentration (1 mg mL−1) increased the content of calcium ions and activated eNOS, thereby promoting NO production and the coupling state of eNOS.

CONCLUSION: Soy milk fermented with selected probiotics promotes the relaxation factors of vascular endothelial cells and can be applied in the development of functional foods. © 2012 Society of Chemical Industry