Oxidative Medicine and Cellular Longevity

Myocardial infarction (MI) is irreversible damage to the myocardial tissue caused by prolonged ischemia/hypoxia, subsequently leading to loss of contractile function and myocardial damage. However, after a perilous period, ischemia-reperfusion (IR) itself causes the generation of oxygen free radicals, disturbance in cation homeostasis, depletion of cellular energy stores, and activation of innate and adaptive immune responses. The present study employed Abatacept (ABT), which is an anti-inflammatory drug, originally used as an antirheumatic response agent. To investigate the cardioprotective potential of ABT, primarily, the dose was optimized in a chemically induced model of myocardial necrosis. Thereafter, ABT optimized the dose of 5 mg/kg s.c. OD was investigated for its cardioprotective potential in a surgical model of myocardial IR injury, where animals (n = 30) were randomized into five groups: Sham, IR-C, Telmi10 + IR (Telmisartan, 10 mg/kg oral OD), ABT5 + IR, ABT perse. ABT and telmisartan were administered for 21 days. On the 21st day, animals were subjected to LAD coronary artery occlusion for 60 min, followed by reperfusion for 45 min. Further, the cardioprotective potential was assessed through hemodynamic parameters, oxidant–antioxidant biochemical enzymatic parameters, cardiac injury, inflammatory markers, histopathological analysis, TUNEL assay, and immunohistochemical evaluation, followed by immunoblotting to explore signaling pathways. The statistics were performed by one-way analysis of variance, followed by the Tukey comparison post hoc tests. Noteworthy, 21 days of ABT pretreatment amended the hemodynamic and ventricular functions in the rat models of MI. The cardioprotective potential of ABT is accompanied by inhibiting MAP kinase signaling and modulating Nrf-2/HO-1 proteins downstream signaling cascade. Overall, the present work bolsters the previously known anti-inflammatory role of ABT in MI and contributes a mechanistic insight and application of clinically approved drugs in averting the activation of inflammatory response.

The extracellular signal-regulated kinase (ERK) MAPK pathway is dysregulated in various human cancers and is considered an attractive therapeutic target for cancer. Therefore, several inhibitors of this pathway are being developed, and some are already used in the clinic. We have previously identified an anticancer compound, ACA-28, with a unique property to preferentially induce ERK-dependent apoptosis in melanoma cells. To comprehensively understand the biological cellular impact induced by ACA-28, we performed a global gene expression analysis of human melanoma SK-MEL-28 cells exposed to ACA-28 using a DNA microarray. The transcriptome analysis identified nuclear factor erythroid 2-related factor 2 (Nrf2), a master transcription factor that combats oxidative stress, as the most upregulated genetic pathway after ACA-28 treatment. Consistently, ACA-28 showed properties to increase the levels of reactive oxygen species (ROS) as well as Nrf2 protein, which is normally repressed by proteasomal degradation and activated in response to oxidative stresses. Furthermore, the ROS scavenger N-acetyl cysteine significantly attenuated the anticancer activity of ACA-28. Thus, ACA-28 activates Nrf2 signaling and exerts anticancer activity partly via its ROS-stimulating property. Interestingly, human A549 cancer cells with constitutively high levels of Nrf2 protein showed resistance to ACA-28, as compared with SK-MEL-28. Transient overexpression of Nrf2 also increased the resistance of cells to ACA-28, while knockdown of Nrf2 exerted the opposite effect. Thus, upregulation of Nrf2 signaling protects cancer cells from ACA-28-mediated cell death. Notably, the Nrf2 inhibitor ML385 substantially enhanced the cell death-inducing property of ACA-28 in pancreatic cancer cells, T3M4 and PANC-1. Our data suggest that Nrf2 plays a key role in determining cancer cell susceptibility to ACA-28 and provides a novel strategy for cancer therapy to combine the Nrf2 inhibitor and ACA-28.

Background. Neurological disorders like Alzheimer’s disease (AD) and Parkinson’s disease (PD) manifest through gradually deteriorating cognitive functions. An encouraging strategy for addressing these disorders involves the inhibition of precursor-cleaving enzyme 1 (BACE1). Objectives. In the current research, a virtual screening technique was employed to identify potential BACE1 inhibitors among selected herbal isolates. Methods. This study evaluated 79 flavonoids, anthraquinones (AQs), and cinnamic acid derivatives for their potential blood–brain barrier (BBB) permeability. Using the AutoDock 4.0 tool, molecular docking analysis was conducted to determine the binding affinity of BBB permeable compounds to the BACE1 active site. Molecular dynamics (MD) simulations were performed to assess the stability of the docked poses of the most potent inhibitors. The interactions between the most effective plant-based inhibitors and the residues within the BACE1 catalytic site were examined before and after MD simulations. Results. Ponciretin, danthron, chrysophanol, and N-p-coumaroyltyramine were among the highest-ranking BACE1 inhibitors, with inhibition constant values calculated in the nanomolar range. Furthermore, during 10 ns simulations, the docked poses of these ligands were observed to be stable. Conclusion. The findings propose that ponciretin, danthron, chrysophanol, and N-p-coumaroyltyramine might serve as potential choices for the treatment of AD and PD, laying the groundwork for the creation of innovative BACE1 inhibitors.

Chaga mushroom (Inonotus obliquus) contains bioactive metabolites and has been used to treat various ailments, including cancer. Similarly, marine microalgae are considered a sustainable food supplement with anticancer and antioxidant properties. This study investigated the cytotoxicity of different extracts prepared from I. obliquus and microalgae using cultured human and canine cancer cell lines (MCF-7, HepG2, HOS, D-17, and DH-82). MTS cell viability assay was used to study the cytotoxicity of I. obliquus and microalgae extracts, and a synergy matrix effect was used to study the combined effect of the extracts. Isobologram analysis and the highest single agent synergy model were applied to study and validate the synergy between the extracts from I. obliquus and microalgae. Ethanol-based extraction and supercritical water extract significantly inhibited the growth of various mammalian cancer cells compared to aqueous extracts. Osteosarcoma cells were more susceptible to the supercritical extracts of I. obliquus and chlorophyll-free and sugar-free ethanol extracts of microalgae. A combination of ethanol-based I. obliquus extract and chlorophyll-free microalgae extract resulted in a synergistic interaction with various tested cancer cells. This study provides experimental evidence supporting the potential therapeutic application of I. obliquus and microalgae extracts with a synergistic effect to inhibit the growth of various mammalian cancer cells. Additional in vivo studies are required to fully explore possible therapeutic applications of these unique mixtures to be used in treating cancers.

The global prevalence of chronic obstructive pulmonary disease (COPD) has increased over the last decade and has emerged as the third leading cause of death worldwide. It is characterized by emphysema with prolonged airflow limitation. COPD patients are more susceptible to COVID-19 and increase the disease severity about four times. The most used drugs to treat it show numerous side effects, including immune suppression and infection. This review discusses a narrative opinion and critical review of COPD. We present different aspects of the disease, from cellular and inflammatory responses to cigarette smoking in COPD and signaling pathways. In addition, we highlighted various risk factors for developing COPD apart from smoking, like occupational exposure, pollutants, genetic factors, gender, etc. After the recent elucidation of the underlying inflammatory signaling pathways in COPD, new molecular targeted drug candidates for COPD are signal-transmitting substances. We further summarize recent developments in biomarker discovery for COPD and its implications for disease diagnosis. In addition, we discuss novel drug targets for COPD that could be explored for drug development and subsequent clinical management of cardiovascular disease and COVID-19, commonly associated with COPD. Our extensive analysis of COPD cause, etiology, diagnosis, and therapeutic will provide a better understanding of the disease and the development of effective therapeutic options. In-depth knowledge of the underlying mechanism will offer deeper insights into identifying novel molecular targets for developing potent therapeutics and biomarkers of disease diagnosis.

Microglia are activated following cerebral ischemic insult. P-glycoprotein (P-gp) is an efflux transporter on microvascular endothelial cells and upregulated after cerebral ischemia. This study evaluated the effects and possible mechanisms of P-gp on microglial polarization/activation in mice after ischemic stroke. P-gp-specific siRNA and adeno-associated virus (p-AAV) were used to silence and overexpress P-gp, respectively. Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) were performed in mice and cerebral microvascular endothelial cells (bEnd.3) in vitro, respectively. OGD/R-injured bEnd.3 cells were cocultured with mouse microglial cells (BV2) in Transwell. Influences on acute ischemic stroke outcome, the expression of inflammatory cytokines, and chemokines and chemokines receptors, microglial polarization, glucocorticoid receptor (GR) nuclear translocation, and GR-mediated mRNA decay (GMD) activation were evaluated via reverse transcription real-time polymerase chain reaction, western blot, or immunofluorescence. Silencing P-gp markedly alleviated experimental ischemia injury as indicated by reduced cerebral infarct size, improved neurological deficits, and reduced the expression of interleukin-6 (IL-6) and IL-12 expression. Silencing P-gp also mitigated proinflammatory microglial polarization and the expression of C-C motif chemokine ligand 2 (CCL2) and its receptor CCR2 expression, whereas promoted anti-inflammatory microglia polarization. Additionally, P-gp silencing promoted GR nuclear translocation and the expression of GMD relative proteins in endothelial cells. Conversely, overexpressing P-gp via p-AAV transfection offset all these effects. Furthermore, silencing endothelial GR counteracted all effects mediated by silencing or overexpressing P-gp. Elevated P-gp expression aggravated inflammatory response and brain damage after ischemic stroke by augmenting proinflammatory microglial polarization in association with increased endothelial CCL2 release due to GMD inhibition by P-gp.