Activation of Nrf2/HO-1 signaling: An important molecular mechanism of herbal medicine in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress

Introduction

Recently, Nrf2/HO-1 has received extensive attention as the main regulatory pathway of intracellular defense against oxidative stress and is considered an ideal target for alleviating endothelial cell (EC) injury.

Objectives

This paper aimed to summarized the natural monomers/extracts that potentially exert protective effects against oxidative stress in ECs.

Methods

A literature search was carried out regarding our topic with the keywords of “atherosclerosis” or “Nrf2/HO-1” or “vascular endothelial cells” or “oxidative stress” or “Herbal medicine” or “natural products” or “natural extracts” or “natural compounds” or “traditional Chinese medicines” based on classic books of herbal medicine and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, GoogleScholar, BaiduScholar, and others. Then, we analyzed the possible molecular mechanisms for different types of natural compounds in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress. In addition, perspectives for possible future studies are discussed.

Results

These agents with protective effects against oxidative stress in ECs mainly include phenylpropanoids, flavonoids, terpenoids, and alkaloids. Most of these agents alleviate cell apoptosis in ECs due to oxidative stress, and the mechanisms are related to Nrf2/HO-1 signaling activation. However, despite continued progress in research on various aspects of natural agents exerting protective effects against EC injury by activating Nrf2/HO-1 signaling, the development of new drugs for the treatment of atherosclerosis (AS) and other CVDs based on these agents will require more detailed preclinical and clinical studies.

Conclusion

Our present paper provides updated information of natural agents with protective activities on ECs against oxidative stress by activating Nrf2/HO-1. We hope this review will provide some directions for the further development of novel candidate drugs from natural agents for the treatment of AS and other CVDs.

Natural substance rutin versus standard drug atorvastatin in a treatment of metabolic syndrome-like condition

Background

Metabolic syndrome is a cluster of metabolic risk factors. The clear causes of its development are not known yet and there is no comprehensive treatment of this disease. There is a trend to use natural substances in the treatment of various diseases, but their effects need to be well explored. We decided to test effect of rutin compared to the effect of the standard drug atorvastatin.

Methods

As a model of metabolic syndrome we used males of hypertriacylglycerolemic rats in combination with high-fat-high-fructose diet. Rutin (100 mg/kg) and atorvastatin (50 mg/kg) were administered orally daily for 5 weeks.

Results

We determined biochemical parameters from blood: HDL-cholesterol, LDL-cholesterol, total cholesterol, triacylglycerols. Relaxation and contraction response of aorta was measured to determine vessel dysfunctions and possible predisposition to cardiovascular disease. The negative influence on cognitive functions could be associated with the development of metabolic cognitive syndrome. Therefore we aimed to monitor spatial memory by Morris water maze test. Both rutin and atorvastatin had a tendency to decrease levels of serum triacylglycerols, but only atorvastatin significantly reduced levels od LDL-cholesterol and increased HDL-cholesterol levels. Both compounds significantly reduced the phenylephrine-induced contractile response of the aorta and improved the relaxation response. Further, treated animals learned better compared to untreated rats in the Morris water maze.

Conclusion

Based on our results we can assume that atorvastatin and rutin had positive effect on spatial memory and vessel reactivity. Atorvastatin optimized lipid profile of blood serum.

Involvement of Rho GTPases and their regulators in the pathogenesis of hypertension

Proper regulation of arterial blood pressure is essential to allow permanent adjustment of nutrient and oxygen supply to organs and tissues according to their need. This is achieved through highly coordinated regulation processes controlling vascular resistance through modulation of arterial smooth muscle contraction, cardiac output, and kidney function. Members of the Rho family of small GTPases, in particular RhoA and Rac1, have been identified as key signaling molecules playing important roles in several different steps of these regulatory processes. Here, we review the current state of knowledge regarding the involvement of Rho GTPase signaling in the control of blood pressure and the pathogenesis of hypertension. We describe how knockout models in mouse, genetic, and pharmacological studies in human have been useful to address this question.