The antihypertensive effect and mechanisms of bioactive peptides from Ruditapes philippinarum fermented with Bacillus natto in spontaneously hypertensive rats

Abstract In our previous study, the clams (Ruditapes philippinarum) were inoculated with Bacillus natto and fermented to produce peptides (RBPs) with high ACE inhibitory effect in vitro. In this study, we continued to explore the anti-hypertensive effect and potential mechanisms of RBPs in vivo. The results showed that RBPs significantly reduced both systolic and diastolic blood pressure and alleviated the damage of kidney, thoracic aorta and heart of spontaneously hypertensive rats after 8 weeks of treatment. Meanwhile, RBPs could also inhibit the expression of RAS signaling pathway, maintained the secretion balance of NO/ET-1 in vascular endothelial cells and inhibited the cardiac TGF-β/Smad pathway. Most notably, RBPs could also improve the gut microbiota by decreasing the ratio of Firmicutes and Bacteroidetes and increasing the relative abundance of certain genera, like Ruminococcaceae_UCG-014. The data suggested that RBPs could be used as functional food ingredient for the improvement of hypertension.