Puerarin Regulates Blood Pressure Through Endothelial TRPV4 Channels Rearch Mechanism

The prevalence of hypertension is increasing year by year in China,but its therapeutic and control rates are still at a low level.It is of great significance to conduct pharmacological research on hypertension.Studies have confirmed that Pueraria lobata has powerful cardioprotective activity and has received much attention in the field of prevention and treatment for hypertension.Pueraria lobata is rich in isoflavones,of which puerarin is the most important natural active ingredient.Puerarin has a variety of pharmacological activities,but less research has put attention on vascular endothelial function,which is one of the main factors affecting blood pressure,so it is worth to investigate the effect of Puerarin on blood pressure via on vascular endothelium.In the present study,we found that transient receptor potential vanilloid 4（TRPV4）is an efficient ion channel in vascular endothelial cells that regulates cellular Ca²⁺concentration and it is an important ion channel for vasodilation and contraction,and has a significant role in the regulation of vascular function homeostasis.In this study,we first revealed the activation of TRPV4 channel by geranium at molecular,cellular and tissue levels,respectively.After that,we constructed a high-salt mouse model and a high-fat mouse model by dietary induction,and monitored blood pressure during the modeling period to determine the hypertensive state after modeling,so as to investigate the regulatory role between gerberoside and hypertension associated with metabolic syndrome and to reveal the related antihypertensive mechanism.The main results are as follows.1.Molecular docking experiments showed that puerarin can bind to TRPV4 protein.Based on human embryonic kidney 293（HEK 293）overexpressing TRPV4 protein,calcium influx experiments were performed to determine EC₅₀(concentration for 50%of maximal effect was 16.97μM.Whole-cell patch-clamp experiments showed that this concentration could induce TRPV4 channel-mediated Ca²⁺currents.Afterwards,calcium influx experiments were carried out on isolated mouse mesenteric artery primary endothelial cells,and the results showed that puerarin could induce Ca²⁺influx with a concentration-dependent manner.Related experiments combining TRPV4 knockout mice(TRPV4^-/-)and TRPV4-specific inhibitor HC-067047 found that puerarin-induced Ca²⁺influx based on TRPV4 channels.2.At the tissue level,puerarin was found to regulate endothelium-dependent vasodilation through TRPV4 channel-mediated IK_Ca/SK_Capathways.3.In high-salt diet-induced hypertension model mice,puerarin（30 mg/Kg）was administered orally for 4 weeks,and it was found that puerarin could slow down the high-salt diet-induced increase in blood pressure.4.In the high-fat diet-induced model mice,puerarin（40 mg/Kg）was administered orally for 8 weeks,and it was found that puerarin could retard blood pressure of DIO-induced and ameliorate the function of vascular endothelial cells.In this study,we firstly determined that Puerarin could activate TRPV4 channels and cause endothelial cell-dependent vasodilation.Secondly,by constructing high-salt diet or diet-induced-fat hypertension models,it was found that puerarin has a certain antihypertensive effect.Finally,it was found that puerarin mainly improves the function of endothelial cells by regulating the function of TRPV4 channel,thereby improving hypertension.From both physiological and pathological states,it was found that puerarin can protect blood pressure in metabolic diseases by regulating TRPV4 channel.