Design and synthesis of novel SCM-198 analogs as cardioprotective agents: Structure-activity relationship studies and biological evaluations

Application of Compounds with Anti-Cardiac Fibrosis Activity: A Review

Coronary heart disease, hypertension, myocarditis, and valvular disease cause myocardial fibrosis, leading to heart enlargement, heart failure, heart rate failure, arrhythmia, and premature ventricular beat, even defibrillation can increase the risk of sudden death. Although cardiac fibrosis is common and widespread, there are still no effective drugs to provide adequate clinical intervention for cardiac fibrosis. In this review article, we classify the compounds for treating cardiac fibrosis into natural products, synthetic compounds, and patent drugs according to their sources. Additionally, the structures, activities and signaling pathways of these compounds are discussed. This review provides insight and could provide a reference for the design of new anti-cardiac fibrosis compounds and the new use of older drugs.

Leonurine improves atherosclerosis by activating foam cell autophagy and metabolic remodeling via METTL3-mediated AKT1S1 mRNA stability modulation

BACKGROUND

Atherosclerosis (AS) is the most prevalent cardiovascular disease and remains the major contributor to death and mortality globally. Leonurine (LEO) is a unique alkaloid compound with protective effects on the cardiovascular system. However, the exact mechanisms underlying its cardiovascular-protecting action are still not fully elucidated. The methyltransferase 3 (METTL3), the catalytic core of the N6-methyladenosine modification (m6A) methyltransferase complex, has been shown to inhibit autophagy and exacerbate the process of AS via regulation of m6A modification of mRNA.

PURPOSE

We aimed to determine whether the inhibited effect of LEO on AS is related to METTL3-mediated AKT1S1 stability.

METHODS

The apolipoprotein E (ApoE) knockout mice was subjected to a high-fat diet (HFD), and THP-1 derived macrophages was exposed to oxidized low-density lipoprotein (ox-LDL), to establish the animal and cellular models of AS, respectively.

RESULTS

We found that LEO effectively improved AS and reduced the plaque area and inflammation via diminishing macrophage lipid accumulation and remodeling the lipid metabolism profile. LEO activated ox-LDL-induced macrophage autophagy, enhancing lipid metabolism decrease, according to the lipidomic and molecular biology analyses. Additionally, LEO caused a marked increase in autophagy marker levels in mouse models with advanced AS. Furthermore, we found that LEO reactivated autophagy and reversed lipid accumulation by suppressing METTL3 expression. The m6A-seq from ox-LDL-induced macrophages showed that a total of five autophagy-related mRNA transcripts (AKT1S1, AKT1, RB1CC1, CFLAR, and MTMR4) were altered, and AKT1S1 was significantly upregulated by LEO. Mechanistically, LEO-mediated regulation of METTL3 decreased AKT1S1 expression by attenuating its mRNA stability. Silencing AKT1S1 inhibited LEO-METTL3 axis-mediated autophagy and enhanced lipid accumulation in ox-LDL-induced macrophages.

CONCLUSION

The study first revealed that LEO exerts anti-atherosclerotic effect by activating METTL3-mediated macrophage autophagy in vivo and in vitro. The mechanism of LEO was further found to be the enhancement of METTL3-mediated AKT1S1 stability to activate autophagy thereby reducing lipid accumulation. This study provides a new perspective of natural medicines on the treatment of AS via an epigenetic manner.

Leonurine pretreatment protects the heart from myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (I/R), an important complication of reperfusion therapy for myocardial infarction, is characterized by hyperactive oxidative stress and inflammatory response. Leonurine (4-guanidino-n-butyl syringate, SCM-198), an alkaloid extracted from Herbaleonuri, was previously found to be highly cardioprotective both in vitro and in vivo. Our current study aimed to investigate the effect of SCM-198 preconditioning on myocardial I/R injury in vitro and in vivo, respectively, as well as to decipher the mechanism involved. Rats were pretreated with SCM-198 before subjected to 45 min of myocardial ischemia, which was followed by 24 h of reperfusion. Primary neonatal rat cardiac ventricular myocytes (NRCMs) were exposed to hypoxia (95% N2 + 5% CO2) for 12 h, and then to 12 h reoxygenation so as to mimic I/R. The enzymatic measurements demonstrated that SCM-198 reduced the release of infarction-related enzymes, and the hemodynamic and echocardiography measurements showed that SCM-198 restored cardiac functions, which suggested that SCM-198 could significantly reduce infarct size, maintaining cardiomyocyte morphology, and that SCM-198 pretreatment could significantly reduce cardiomyocytes apoptosis. Moreover, we demonstrated that SCM-198 could exert a cardioprotective effect by reducing reactive oxygen species (ROS) level and Akt phosphorylation while reducing the phosphorylation of p38 and JNK. In addition, the upregulation of p-Akt, Bcl-2/Bax induced by SCM-198 treatment were blocked by PI3K inhibitor LY294002, and the total protein level of Akt was not affected by SCM-198 pretreatment. Our experimental results indicated that SCM-198 could have a cardioprotective effect on I/R injury, which confirmed the utility of SCM-198 preconditioning as a strategy to prevent I/R injury.

Natural products in drug discovery and development: Synthesis and medicinal perspective of leonurine

Natural products, those molecules derived from nature, have been used by humans for thousands of years to treat ailments and diseases. More recently, these compounds have inspired chemists to use natural products as structural templates in the development of new drug molecules. One such compound is leonurine, a molecule isolated and characterized in the tissues of Herb leonuri. This molecule has received attention from scientists in recent years due to its potent anti-oxidant, anti-apoptotic, and anti-inflammatory properties. More recently researchers have shown leonurine to be useful in the treatment of cardiovascular and nervous system diseases. Like other natural products such as paclitaxel and artemisinin, the historical development of leonurine as a therapeutic is very interesting. Therefore, this review provided an overview of natural product discovery, through to the development of a potential new drug. Content will summarize known plant sources, the pathway used in the synthesis of leonurine, and descriptions of leonurine’s pharmacological properties in mammalian systems.

Oxidative Injury in Ischemic Stroke: A Focus on NADPH Oxidase 4

Ischemic stroke is a leading cause of disability and mortality worldwide. Thus, it is urgent to explore its pathophysiological mechanisms and find new therapeutic strategies for its successful treatment. The relationship between oxidative stress and ischemic stroke is increasingly appreciated and attracting considerable attention. ROS serves as a source of oxidative stress. It is a byproduct of mitochondrial metabolism but primarily a functional product of NADPH oxidases (NOX) family members. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is most closely related to the formation of ROS during ischemic stroke. Its expression is significantly upregulated after cerebral ischemia, making it a promising target for treating ischemic stroke. Several drugs targeting NOX4, such as SCM-198, Iso, G-Rb1, betulinic acid, and electroacupuncture, have shown efficacy as treatments of ischemic stroke. MTfp-NOX4 POC provides a novel insight for the treatment of stroke. Combinations of these therapies also provide new approaches for the therapy of ischemic stroke. In this review, we summarize the subcellular location, expression, and pathophysiological mechanisms of NOX4 in the occurrence and development of ischemic stroke. We also discuss the therapeutic strategies and related regulatory mechanisms for treating ischemic stroke. We further comment on the shortcomings of current NOX4-targeted therapy studies and the direction for improvement.

Leonurine, a potential drug for the treatment of cardiovascular system and central nervous system diseases

Leonurus japonicus Houtt., a traditional Chinese herbal medicine, is often used as a gynecological medicine with the effect of promoting blood circulation, regulating menstruation, clearing heat, and detoxificating. As the most important alkaloid in L. japonicus, leonurine has a wide range of biological activities, such as antioxidation, anti-inflammation, and anti-apoptosis. Cardiovascular system and central nervous system diseases are arrogant killers that threaten human lives and health around the world, but many drugs for treating them have certain side effects. This paper reviews the potential therapeutic effects of leonurine on cardiovascular system and central nervous system diseases, summarizes the previous research progress, and focuses on its therapeutic effect in various diseases. Although leonurine plays a prominent role in the treatment of cardiovascular system and central nervous system diseases, there are still some shortages, such as low bioavailability, weak transmembrane ability, and poor fat solubility. Therefore, the structure modification of leonurine may solve these problems and provide reference value for the development of new drugs. At present, leonurine is in clinical trial, and it is hoped that our summary will help to provide guidance for its future research on the basic science and clinical application.