Schisandrin C targets Keap1 and attenuates oxidative stress by activating Nrf2 pathway in Ang II-challenged vascular endothelium

Schisandrin C prevents regorafenib-induced cardiotoxicity by recovering EPHA2 expression in cardiomyocytes

Regorafenib, an oral multikinase inhibitor of angiogenic, stromal, and oncogenic receptor tyrosine kinases, has been approved for the treatment of metastatic colorectal cancer, gastrointestinal stromal tumors, and hepatocellular carcinoma by the US Food and Drug Administration and European Medicines Agency. However, regorafenib-induced cardiotoxicity increases the risk of mortality. Despite reports that regorafenib can cause mitochondrial dysfunction in cardiomyocytes, the molecular mechanism of regorafenib-induced cardiotoxicity is much less known and there is an urgent need for intervention strategies. Here, we treated mice with vehicle or 200 mg/kg regorafenib daily for 42 d by gavage or treated cardiomyocyte lines with 8, 16, or 32 μM regorafenib, and we found that regorafenib could cause apoptosis, mitochondrial injury, and DNA damage in cardiomyocytes. Mechanistically, regorafenib can reduce the expression of EPHA2, which inhibits AKT signaling, leading to cardiomyocyte apoptosis and cardiotoxicity. In addition, we showed that recovering EPHA2 expression via plasmid-induced overexpression of EPHA2 or schisandrin C, a natural product, could prevent regorafenib-induced cardiotoxicity. These findings demonstrated that regorafenib causes cardiomyocyte apoptosis and cardiac injury by reducing the expression of EPHA2 and schisandrin C could prevent regorafenib-induced cardiotoxicity by recovering EPHA2 expression, which provides a potential management strategy for regorafenib-induced cardiotoxicity and will benefit the safe application of regorafenib in clinic.

The promising antioxidant effects of lignans: Nrf2 activation comes into view

Lignans are biologically active compounds widely distributed, recognized, and identified in seeds, fruits, and vegetables. Lignans have several intriguing bioactivities, including anti-inflammatory, antioxidant, and anticancer activities. Nrf2 controls the expression of many cytoprotective genes. Activation of Nrf2 is a promising therapeutic approach for treating and preventing diseases resulting from oxidative injury and inflammation. Lignans have been demonstrated to stimulate Nrf2 signaling in a variety of in vitro and experimental animal models. The review summarizes the findings of fourteen lignans (Schisandrin A, Schisandrin B, Schisandrian C, Magnolol, Honokiol, Sesamin, Sesamol, Sauchinone, Pinoresinol, Phyllanthin, Nectandrin B, Isoeucommin A, Arctigenin, Lariciresinol) as antioxidative and anti-inflammatory agents, affirming how Nrf2 activation affects their pharmacological effects. Therefore, lignans may offer therapeutic candidates for the treatment and prevention of various diseases and may contribute to the development of effective Nrf2 modulators.

Endothelial deubiquinatase YOD1 mediates Ang II-induced vascular endothelial-mesenchymal transition and remodeling by regulating β-catenin

Hypertension is a prominent contributor to vascular injury. Deubiquinatase has been implicated in the regulation of hypertension-induced vascular injury. In the present study we investigated the specific role of deubiquinatase YOD1 in hypertension-induced vascular injury. Vascular endothelial endothelial-mesenchymal transition (EndMT) was induced in male WT and YOD1-/- mice by administration of Ang II (1 μg/kg per minute) via osmotic pump for four weeks. We showed a significantly increased expression of YOD1 in mouse vascular endothelial cells upon Ang II stimulation. Knockout of YOD1 resulted in a notable reduction in EndMT in vascular endothelial cells of Ang II-treated mouse; a similar result was observed in Ang II-treated human umbilical vein endothelial cells (HUVECs). We then conducted LC-MS/MS and co-immunoprecipitation (Co-IP) analyses to verify the binding between YOD1 and EndMT-related proteins, and found that YOD1 directly bound to β-catenin in HUVECs via its ovarian tumor-associated protease (OTU) domain, and histidine at 262 performing deubiquitination to maintain β-catenin protein stability by removing the K48 ubiquitin chain from β-catenin and preventing its proteasome degradation, thereby promoting EndMT of vascular endothelial cells. Oral administration of β-catenin inhibitor MSAB (20 mg/kg, every other day for four weeks) eliminated the protective effect of YOD1 deletion on vascular endothelial injury. In conclusion, we demonstrate a new YOD1-β-catenin axis in regulating Ang II-induced vascular endothelial injury and reveal YOD1 as a deubiquitinating enzyme for β-catenin, suggesting that targeting YOD1 holds promise as a potential therapeutic strategy for treating β-catenin-mediated vascular diseases.

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Natural products as non-covalent and covalent modulators of the KEAP1/NRF2 pathway exerting antioxidant effects

By controlling several antioxidant and detoxifying genes at the transcriptional level, including NAD(P)H quinone oxidoreductase 1 (NQO1), multidrug resistance-associated proteins (MRPs), UDP-glucuronosyltransferase (UGT), glutamate-cysteine ligase catalytic (GCLC) and modifier (GCLM) subunits, glutathione S-transferase (GST), sulfiredoxin1 (SRXN1), and heme-oxygenase-1 (HMOX1), the KEAP1/NRF2 pathway plays a crucial role in the oxidative stress response. Accordingly, the discovery of modulators of this pathway, activating cellular signaling through NRF2, and targeting the antioxidant response element (ARE) genes is pivotal for the development of effective antioxidant agents. In this context, natural products could represent promising drug candidates for supplementation to provide antioxidant capacity to human cells. In recent decades, by coupling in silico and experimental methods, several natural products have been characterized to exert antioxidant effects by targeting the KEAP1/NRF2 pathway. In this review article, we analyze several natural products that were investigated experimentally and in silico for their ability to modulate KEAP1/NRF2 by non-covalent and covalent mechanisms. These latter represent the two main sections of this article. For each class of inhibitors, we reviewed their antioxidant effects and potential therapeutic applications, and where possible, we analyzed the structure-activity relationship (SAR). Moreover, the main computational techniques used for the most promising identified compounds are detailed in this survey, providing an updated view on the development of natural products as antioxidant agents.

A Review of Extraction and Purification, Biological Properties, Structure-Activity Relationships and Future Prospects of Schisandrin C: A Major Active Constituent of Schisandra Chinensis

Since ancient times, China has used natural medicine as the primary way to combat diseases and has a rich arsenal of natural medicines. With the progress of the times, the extraction of bioactive molecules from natural drugs has become the new development direction for natural medicines. Among the numerous natural drugs, Schisandrin C (Sch C), derived from Schisandra Chinensis (Turcz.) Baill. It has excellent potential for development and has been shown to possess various pharmacological properties, including hepatoprotective, antitumor and anti-inflammatory activities. Based on the biological properties of hepatoprotection, scholars have explored Sch C and its synthetic products in depth; some studies have shown that pentosidine has the effect of improving the symptoms of liver fibrosis and reducing the concentration of alanine transaminase (ALT) and aspartate aminotransferase (AST) in the serum of rats, which is an essential inspiration for the development of anti-liver fibrosis drugs. But more in vivo and ex vivo studies still need to be included. This paper focuses on Sch C's extraction and synthesis, biological activities and drug development progress. The future application prospects of Sch C are discussed to perfect its development work further.

Exploring the therapeutic potential of natural compounds for Alzheimer's disease: Mechanisms of action and pharmacological properties

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease.

Simultaneous Extraction and Determination of Lignans from Schisandra chinensis (Turcz.) Baill. via Diol-Based Matrix Solid-Phase Dispersion with High-Performance Liquid Chromatography

The quality of Schisandra chinensis (Turcz.) Baill. (S. chinensis) is principally attributed to lignan compounds. In this paper, a simple and rapid strategy for simultaneous extraction and determination of 10 lignans from S. chinensis was established through matrix solid-phase dispersion (MSPD) assisted by diol-functionalized silica (Diol). The experimental parameters for MSPD extraction were screened using the response surface methodology (RSM). Diol (800 mg) was used as a dispersant and methanol (MeOH, 85%, v/v) as an eluting solvent (10 mL), resulting in a high extraction efficiency. MSPD extraction facilitated the combination of extraction and purification in a single step, which was less time-consuming than and avoided the thermal treatment involved in traditional methods. The simultaneous qualification and quantification of 10 lignans was achieved by combining MSPD and high-performance liquid chromatography (HPLC). The proposed method offered good linearity and a low limit of detection starting from 0.04 (schisandrin C) to 0.43 μg/mL (schisantherin B) for lignans, and the relative standard deviation (RSD, %) values of precision were acceptable, with a maximum value of 1.15% (schisantherin B and schisanhenol). The methodology was successfully utilized to analyze 13 batches of S. chinensis from different cultivated areas of China, which proved its accuracy and practicability in the quantitative analysis of the quality control of S. chinensis.

Targeting oxidative stress as a preventive and therapeutic approach for cardiovascular disease

Cardiovascular diseases (CVDs) continue to exert a significant impact on global mortality rates, encompassing conditions like pulmonary arterial hypertension (PAH), atherosclerosis (AS), and myocardial infarction (MI). Oxidative stress (OS) plays a crucial role in the pathogenesis and advancement of CVDs, highlighting its significance as a contributing factor. Maintaining an equilibrium between reactive oxygen species (ROS) and antioxidant systems not only aids in mitigating oxidative stress but also confers protective benefits on cardiac health. Herbal monomers can inhibit OS in CVDs by activating multiple signaling pathways, such as increasing the activity of endogenous antioxidant systems and decreasing the level of ROS expression. Given the actions of herbal monomers to significantly protect the normal function of the heart and reduce the damage caused by OS to the organism. Hence, it is imperative to recognize the significance of herbal monomers as prospective therapeutic interventions for mitigating oxidative damage in CVDs. This paper aims to comprehensively review the origins and mechanisms underlying OS, elucidate the intricate association between CVDs and OS, and explore the therapeutic potential of antioxidant treatment utilizing herbal monomers. Furthermore, particular emphasis will be placed on examining the cardioprotective effects of herbal monomers by evaluating their impact on cardiac signaling pathways subsequent to treatment.

Gasdermin D affects aortic vascular smooth muscle cell pyroptosis and Ang II-induced vascular remodeling

Vascular smooth muscle cells (VSMCs) are primarily responsible for vasoconstriction and the regulation of blood pressure1. Pyroptosis, a particular form of regulated cell death, is involved in multiple vascular injuries, including hypertensive vascular dysfunction. This pyroptotic cell death is mediated by the pore-forming protein of Gasdermin D (GSDMD). This study was designed to examine the direct effect of GSDMD on smooth muscle cell pyroptosis and vascular remodeling. Findings revealed that GSDMD was activated in Angiotensin (Ang) II- treated aortas. We then showed that genetic deletion of Gsdmd reduced vascular remodeling and aorta pyroptosis induced by Ang II in vivo. Aberrant expression of GSDMD by recombinant AAV9 virus carrying Gsdmd cDNA aggravated the level of pyroptosis in aortas of Ang II mice. Gain- and loss-of- function analysis further confirmed that GSDMD regulated the pyroptosis of murine aortic vascular smooth muscle cells (MOVAS) in an in vitro model of tumor necrosis factor (TNF)-α treatment, which was achieved by transfecting expressing plasmid or siRNA, respectively. Overall, this study provided evidence supporting the active involvement of GSDMD in smooth muscle cell pyroptosis and Ang II-induced mice vascular injury. This finding lends credence to GSDMD as a potential therapeutic target for hypertensive vascular remodeling via inhibiting pyroptosis.

Cardioprotective Potential of Berries of Schisandra chinensis Turcz. (Baill.), Their Components and Food Products

Schisandra chinensis (S. chinensis) berries, originally a component of traditional herbal medicine in China, Korea, and other east Asian countries, are also valuable agents in modern phototherapy. S. chinensis berry preparations, including extracts and their chemical components, demonstrate anti-cancer, hepatoprotective, anti-inflammatory, and antioxidant properties, among others. These valuable properties, and their therapeutic potential, are conditioned by the unique chemical composition of S. chinensis berries, particularly their lignan content. About 40 of these compounds, mainly dibenzocyclooctane type, were isolated from S. chinensis. The most important bioactive lignans are schisandrin (also denoted as schizandrin or schisandrol A), schisandrin B, schisantherin A, schisantherin B, schisanhenol, deoxyschisandrin, and gomisin A. The present work reviews newly-available literature concerning the cardioprotective potential of S. chinensis berries and their individual components. It places special emphasis on the cardioprotective properties of the selected lignans related to their antioxidant and anti-inflammatory characteristis.

Gasdermin D mediates doxorubicin-induced cardiomyocyte pyroptosis and cardiotoxicity via directly binding to doxorubicin and changes in mitochondrial damage

Doxorubicin (Dox), as a widely used anthracycline antitumor drug, can cause severe cardiotoxicity. Cardiomyocyte death and inflammation are involved in the pathophysiology of Dox-induced cardiotoxicity (DIC). Gasdermin D (GSDMD) is known as a key executioner of pyroptosis, which is a pro-inflammatory programmed cell death. We aimed to investigate the impact of GSDMD on DIC and systematically reveal its underlying mechanisms. Our findings indicated that Dox induced cardiomyocyte pyroptosis in a GSDMD-dependent manner by utilizing siRNA or overexpression-plasmid technique. We then generated GSDMD global knockout mice via CRISPR/Cas9 system and found that GSDMD deficiency reduced Dox-induced cardiomyopathy. Dox induced the activation of inflammatory caspases, which subsequently mediated GSDMD-N generation indirectly. Using molecular dynamics simulation and cell-free systems, we confirmed that Dox directly bound to GSDMD and facilitated GSDMD-N-mediated pyroptosis. Furthermore, GSDMD also mediated Dox-induced mitochondrial damage via Bnip3 and mitochondrial perforation in cardiomyocytes. These findings provide fresh insights into the mechanism of how Dox-engaged GSDMD orchestrates adverse cardiotoxicity and highlight the prospects of GSDMD as a potential target for DIC.

Nrf2-Mediated Dichotomy in the Vascular System: Mechanistic and Therapeutic Perspective

Nuclear factor-erythroid 2-related factor 2 (Nrf2), a transcription factor, controls the expression of more than 1000 genes that can be clustered into different categories with distinct functions ranging from redox balance and metabolism to protein quality control in the cell. The biological consequence of Nrf2 activation can be either protective or detrimental in a context-dependent manner. In the cardiovascular system, most studies have focused on the protective properties of Nrf2, mainly as a key transcription factor of antioxidant defense. However, emerging evidence revealed an unexpected role of Nrf2 in mediating cardiovascular maladaptive remodeling and dysfunction in certain disease settings. Herein we review the role of Nrf2 in cardiovascular diseases with a focus on vascular disease. We discuss the negative effect of Nrf2 on the vasculature as well as the potential underlying mechanisms. We also discuss the clinical relevance of targeting Nrf2 pathways for the treatment of cardiovascular and other diseases.

Bee bread attenuates the progression of atherosclerosis by activating Nrf2/Keap1 and modulating TNF-α/NF-κβ-associated mast cell migration and a mitochondrial-dependent apoptotic pathway in the obese rat model

This study explores the anti-atherosclerotic effects of bee bread in the context of oxidative stress, inflammation, and apoptosis phenomena in an obesity animal model, and its vitamin composition. Forty male Sprague-Dawley rats were administered with a normal diet (Normal group) and a high-fat diet (HFD) to induce obesity. After 6 weeks, obese rats that received the HFD were treated either with distilled water (Ob group), bee bread at 0.5 g per kg per day (Ob + Bb group), or orlistat at 10 mg per kg per day (Ob + Or group) concomitant with the HFD for another 6 weeks. Bee bread significantly improved atherosclerotic changes by enhancing the immunoexpressions of Nrf2/Keap1, impeding the immunoexpressions of NF-κβ downstream proteins, and intensifying Bcl-2 upregulation, attributed to the improvement in mast cell adherence and collagen deposition in the aortic wall of the Ob + Bb group. We have demonstrated that the treatment with bee bread attenuates the progression of atherosclerosis through its inhibition of vascular oxidative stress, and retardation of inflammatory reaction and apoptosis in obese rats, indicating its potential therapeutic targets for obesity-related vascular diseases. This could be partly attributed to the components of vitamins such as vitamins A, C and E that are present in bee bread, which need further study for the exact molecular mechanism of action.

Lignans as Pharmacological Agents in Disorders Related to Oxidative Stress and Inflammation: Chemical Synthesis Approaches and Biological Activities

Plant lignans exhibit a wide range of biological activities, which makes them the research objects of potential use as therapeutic agents. They provide diverse naturally-occurring pharmacophores and are available for production by chemical synthesis. A large amount of accumulated data indicates that lignans of different structural groups are apt to demonstrate both anti-inflammatory and antioxidant effects, in many cases, simultaneously. In this review, we summarize the comprehensive knowledge about lignan use as a bioactive agent in disorders associated with oxidative stress and inflammation, pharmacological effects in vitro and in vivo, molecular mechanisms underlying these effects, and chemical synthesis approaches. This article provides an up-to-date overview of the current data in this area, available in PubMed, Scopus, and Web of Science databases, screened from 2000 to 2022.

Luteolin attenuated cisplatin-induced cardiac dysfunction and oxidative stress via modulation of Keap1/Nrf2 signaling pathway

Cardiovascular complications are a well-documented limitation of cancer chemotherapy. Cisplatin-induced cardiotoxicity threatens the health and life of patients, and limits the application of cisplatin. Oxidative stress is the main mechanism underlying cisplatin-induced cardiac toxicity. Luteolin (Lut) has been reported to possess cardioprotective properties by activating nuclear factor-E2-related factor 2 (Nrf2) -mediated antioxidant response. However, the effect of Lut on cisplatin-induced cardiac damage remains unclear. In this study, we revealed that Lut exerted a protective effect against cisplatin-induced cardiac dysfunction and injury in vivo. In HL-1 cells, Lut was observed to dramatically reduce cisplatin-induced apoptosis and oxidative stress by modulating the Kelch-like epichlorohydrin-associated protein 1 (Keap1)/Nrf2 pathway. Altogether, these findings suggested that Lut showed promise in attenuating cisplatin-induced cardiac injury and might be considered a protective drug candidate for chemotherapy-associated cardiovascular complications.

A comprehensive review of ethnopharmacology, phytochemistry, pharmacology, and pharmacokinetics of Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis (called bei-wuweizi in Chinese, S. chinensis) and Schisandra sphenanthera (called nan-wuweizi in Chinese, S. sphenanthera) are two highly similar plants in the Magnoliaceae family. Their dried ripe fruits are commonly used as traditional Chinese medicine in the treatment of coughs, palpitation, spermatorrhea, and insomnia. They also are traditionally used as tonics in Russia, Japan, and Korea.

AIM OF THE REVIEW

S. chinensis and S. sphenanthera are similar in appearance, traditional applications, ingredient compositions, and therapeutic effects. This review, therefore, aims to provide a systematic insight into the botanical background, ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, quality control, and toxicology of S. chinensis and S. sphenanthera, and to explore and present the similarities and differences between S. chinensis and S. sphenanthera.

MATERIALS AND METHODS

A comprehensive literature search regarding S. chinensis and S. sphenanthera was collected by using electronic databases including PubMed, SciFinder, Science Direct, Web of Science, CNKI, and the online ethnobotanical database.

RESULTS

In the 2020 Edition of Chinese Pharmacopoeia (ChP), there were 100 prescriptions containing S. chinensis, while only 11 contained S. sphenanthera. Totally, 306 and 238 compounds have been isolated and identified from S. chinensis and S. sphenanthera, respectively. Among these compounds, lignans, triterpenoids, essential oils, phenolic acid, flavonoids, phytosterols are the major composition. Through investigation of pharmacological activities, S. chinensis and S. sphenanthera have similar therapeutic effects including hepatoprotection, neuroprotection, cardioprotection, anticancer, antioxidation, anti-inflammation, and hypoglycemic effect. Besides, S. chinensis turns out to have more effects including reproductive regulation and immunomodulatory, antimicrobial, antitussive and antiasthmatic, anti-fatigue, antiarthritic, and bone remodeling effects. Both S. chinensis and S. sphenanthera have inhibitory effects on CYP3A and P-gp, which can mediate metabolism or efflux of substrates, and therefore interact with many drugs.

CONCLUSIONS

S. chinensis and S. sphenanthera have great similarities. Dibenzocyclooctadiene lignans are regarded to contribute to most of the bioactivities. Schisandrin A-C, schisandrol A-B, and schisantherin A, existing in both S. chinensis and S. sphenanthera but differing in the amount, are the main active components, which may contribute to the similarities and differences. Study corresponding to the traditional use is needed to reveal the deep connotation of the use of S. chinensis and S. sphenanthera as traditional Chinese medicine. In addition, a joint study of S. chinensis and S. sphenanthera can better show the difference between them, which can provide a reference for clinical application. It is worth mentioning that the inhibition of S. chinensis and S. sphenanthera on CYP3A and P-gp may lead to undesirable drug-drug interactions.

Gaussian accelerated molecular dynamics (GaMD): principles and applications

Gaussian accelerated molecular dynamics (GaMD) is a robust computational method for simultaneous unconstrained enhanced sampling and free energy calculations of biomolecules. It works by adding a harmonic boost potential to smooth biomolecular potential energy surface and reduce energy barriers. GaMD greatly accelerates biomolecular simulations by orders of magnitude. Without the need to set predefined reaction coordinates or collective variables, GaMD provides unconstrained enhanced sampling and is advantageous for simulating complex biological processes. The GaMD boost potential exhibits a Gaussian distribution, thereby allowing for energetic reweighting via cumulant expansion to the second order (i.e., "Gaussian approximation"). This leads to accurate reconstruction of free energy landscapes of biomolecules. Hybrid schemes with other enhanced sampling methods, such as the replica exchange GaMD (rex-GaMD) and replica exchange umbrella sampling GaMD (GaREUS), have also been introduced, further improving sampling and free energy calculations. Recently, new "selective GaMD" algorithms including the ligand GaMD (LiGaMD) and peptide GaMD (Pep-GaMD) enabled microsecond simulations to capture repetitive dissociation and binding of small-molecule ligands and highly flexible peptides. The simulations then allowed highly efficient quantitative characterization of the ligand/peptide binding thermodynamics and kinetics. Taken together, GaMD and its innovative variants are applicable to simulate a wide variety of biomolecular dynamics, including protein folding, conformational changes and allostery, ligand binding, peptide binding, protein-protein/nucleic acid/carbohydrate interactions, and carbohydrate/nucleic acid interactions. In this review, we present principles of the GaMD algorithms and recent applications in biomolecular simulations and drug design.

Irigenin alleviates angiotensin II-induced oxidative stress and apoptosis in HUVEC cells by activating Nrf2 pathway

Endothelial dysfunction is closely related to various cardiovascular diseases. Oxidative stress and apoptosis are involved in the progress of endothelial dysfunction. Irigenin (IR) has antioxidative properties. We investigated IR as a novel therapy for angiotensin II (Ang II)-induced endothelial dysfunction and explored the potential mechanisms of IR. After human umbilical vein endothelial cell lines (HUVECs) were treated with Ang II (100, 200, 300 and 400 nmol/L) alone, IR (2.5, 5, 10, 20 and 40 μmol/L) alone or Ang II plus IR for 24 h, HUVECs viability, lactate dehydrogenase (LDH), apoptosis, oxidative stress, apoptosis-related protein and nuclear factor E2-related factor 2 (Nrf2) levels were detected by Cell Counting Kit (CCK)-8 assay, enzyme-linked immunosorbent assay, flow cytometry and western blot. Transfection rate of Nrf2 was detected by western blot. In the next rescue experiment, we used silent Nrf2 (siNrf2) to verify the previous experimental results. Different concentrations' Ang II repressed HUVECs viability and increased LDH release, and different concentrations' IR did not affect HUVECs viability or LDH release. Furthermore, IR elevated cell viability and Nrf2 level, inhibited LDH release, apoptosis, oxidative stress and apoptosis-related protein levels in Ang II-induced HUVECs. More important, siNrf2 suppressed the expression of Nrf2, and siNrf2 abrogated the protective effect of IR on Ang II-induced Nrf2 expression, cell viability, LDH activity, oxidative stress generation and apoptosis-related protein in HUVECs. IR protected HUVECs from Ang II-induced oxidative stress and apoptosis injury by activating Nrf2 pathway.

Pharmacodynamic effects and molecular mechanisms of lignans from Schisandra chinensis Turcz. (Baill.), a current review

Fruit of Schisandra chinensis Turcz. (Baill.) (S. chinensis) is a traditional herbal medicine widely used in China, Korea, and many other east Asian countries. At present, S. chinensis commonly forms Chinese medicinal formulae with other herbal medicines to treat liver disease and neurological disease in clinical. Modern researches indicated that lignans were the main active ingredients of S. chinensis with high content and novel dibenzocyclooctadiene skeletal structure, exhibited considerable antioxidant, anti-inflammatory, and neuroprotective properties. Additionally, some of these lignans also showed certain potentials in anti-cancer, anti-fibrosis, and other effects. In the current review, we summarize literature reported lignans from S. chinensis in the past five years, and highlight the molecular mechanisms of lignans in exerting their biological functions. Also, we point out some deficiencies of existing researches and discuss the future direction of lignans study.