Esculetin and idebenone ameliorate galactose-induced cataract in a rat model

Idebenone Antagonizes P53-Mediated Neuronal Oxidative Stress Injury by Regulating CD38-SIRT3 Protein Level

Idebenone, an antioxidant used in treating oxidative damage-related diseases, has unclear neuroprotective mechanisms. Oxidative stress affects cell and mitochondrial membranes, altering Adp-ribosyl cyclase (CD38) and Silent message regulator 3 (SIRT3) protein expression and possibly impacting SIRT3's ability to deacetylate Tumor protein p53 (P53). This study explores the relationship between CD38, SIRT3, and P53 in H2O2-injured HT22 cells treated with Idebenone. Apoptosis was detected using flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining after determining appropriate H2O2 and Idebenone concentrations.In this study, Idebenone was found to reduce apoptosis and decrease P53 and Caspase3 expression in H2O2-injured HT22 cells by detecting apoptosis-related protein expression. Through bioinformatics methods, CD38 was identified as the target of Idebenone, and it further demonstrated that Idebenone decreased the expression of CD38 and increased the level of SIRT3. An increased NAD+/NADH ratio was detected, suggesting Idebenone induces SIRT3 expression and protects HT22 cells by decreasing apoptosis-related proteins. Knocking down SIRT3 downregulated acetylated P53 (P53Ac), indicating SIRT3's importance in P53 deacetylation.These results supported that CD38 was used as a target of Idebenone to up-regulate SIRT3 to deacetylate activated P53, thereby protecting HT22 cells from oxidative stress injury. Thus, Idebenone is a drug that may show great potential in protecting against reactive oxygen species (ROS) induced diseases such as Parkinson's disease, and Alzheimer's disease. And it might be able to compensate for some of the defects associated with CD38-related diseases.

Nanomaterial-Based Sensors for Coumarin Detection

Sensors are widely used owing to their advantages including excellent sensing performance, user-friendliness, portability, rapid response, high sensitivity, and specificity. Sensor technologies have been expanded rapidly in recent years to offer many applications in medicine, pharmaceuticals, the environment, food safety, and national security. Various nanomaterial-based sensors have been developed for their exciting features, such as a powerful absorption band in the visible region, excellent electrical conductivity, and good mechanical properties. Natural and synthetic coumarin derivatives are attracting attention in the development of functional polymers and polymeric networks for their unique biological, optical, and photochemical properties. They are the most abundant organic molecules in medicine because of their biological and pharmacological impacts. Furthermore, coumarin derivatives can modulate signaling pathways that affect various cellular processes. This review covers the discovery of coumarins and their derivatives, the integration of nanomaterial-based sensors, and recent advances in nanomaterial-based sensing for coumarins. This review also explains how sensors work, their types, their pros and cons, and sensor studies for coumarin detection in recent years.

Protective effects of esculetin against doxorubicin-induced toxicity correlated with oxidative stress in rat liver: In vivo and in silico studies

Doxorubicin (DOX) is widely used in cancer treatment but the dose-related toxicity of DOX on organs including the liver limit its use. Therefore, there is great interest in combining DOX with natural compounds with antioxidant properties to reduce toxicity and increase drug efficacy. Esculetin is a natural coumarin derivative with biological properties encompassing anti-inflammatory and antioxidant activities. In light of these properties, this study was meticulously crafted to investigate the potential of esculetin in preventing doxorubicin (DOX)-induced hepatotoxicity in Sprague-Dawley rats. The rats were divided into a total of six groups: control group, DOX group (administered DOX at a cumulative dose of 5 mg/kg intraperitoneally every other day for 2 weeks), E50 group (administered 50 mg/kg of esculetin intraperitoneally every day), E100 group (administered 100 mg/kg of esculetin intraperitoneally every day) and combined groups (DOX + E50 and DOX + E100) in which esculetin was administered together with DOX. The treatments, both with DOX alone and in combination with E50, manifested a reduction in catalase (CAT mRNA) levels in comparison to the control group. Notably, the enzymatic activities of superoxide dismutase (SOD), CAT, and glutathione peroxidase (GPx) witnessed significant decreases in the liver of rats treated with DOX. Moreover, DOX treatment induced a statistically significant elevation in malondialdehyde (MDA) levels, coupled with a concurrent decrease in glutathione (GSH) levels. Additionally, molecular docking studies were conducted. However, further studies are needed to confirm the hepatoprotective properties of esculetin and to precisely elucidate its mechanisms of action.

Therapeutic Effects of Coumarins with Different Substitution Patterns

The use of derivatives of natural and synthetic origin has gained attention because of their therapeutic effects against human diseases. Coumarins are one of the most common organic molecules and are used in medicine for their pharmacological and biological effects, such as anti-inflammatory, anticoagulant, antihypertensive, anticonvulsant, antioxidant, antimicrobial, and neuroprotective, among others. In addition, coumarin derivates can modulate signaling pathways that impact several cell processes. The objective of this review is to provide a narrative overview of the use of coumarin-derived compounds as potential therapeutic agents, as it has been shown that substituents on the basic core of coumarin have therapeutic effects against several human diseases and types of cancer, including breast, lung, colorectal, liver, and kidney cancer. In published studies, molecular docking has represented a powerful tool to evaluate and explain how these compounds selectively bind to proteins involved in various cellular processes, leading to specific interactions with a beneficial impact on human health. We also included studies that evaluated molecular interactions to identify potential biological targets with beneficial effects against human diseases.

Proteostasis in aging-associated ocular disease

Vision impairment has devastating consequences for the quality of human life. The cells and tissues associated with the visual process must function throughout one's life span and maintain homeostasis despite exposure to a variety of insults. Maintenance of the proteome is termed proteostasis, and is vital for normal cellular functions, especially at an advanced age. Here we describe basic aspects of proteostasis, from protein synthesis and folding to degradation, and discuss the current status of the field with a particular focus on major age-related eye diseases: age-related macular degeneration, cataract, and glaucoma. Our intent is to allow vision scientists to determine where and how to harness the proteostatic machinery for extending functional homeostasis in the aging retina, lens, and trabecular meshwork. Several common themes have emerged despite these tissues having vastly different metabolisms. Continued exposure to insults, including chronic stress with advancing age, increases proteostatic burden and reduces the fidelity of the degradation machineries including the ubiquitin-proteasome and the autophagy-lysosome systems that recognize and remove damaged proteins. This "double jeopardy" results in an exponential accumulation of cytotoxic proteins with advancing age. We conclude with a discussion of the challenges in maintaining an appropriate balance of protein synthesis and degradation pathways, and suggest that harnessing proteostatic capacities should provide new opportunities to design interventions for attenuating age-related eye diseases before they limit sight.

Idebenone regulates sirt1/Nrf2/TNF-α pathway with inhibition of oxidative stress, inflammation, and apoptosis in testicular torsion/detorsion in juvenile rats

Testicular torsion is an emergency, mainly in newborn and adolescent males, resulting in testicular ischemia. The current study aimed to evaluate the effect of Idebenone (IDE) on testicular torsion/detorsion (T/D) in juvenile rats. Thirty-two rats were randomized into: (1) the sham group: rats received sham operations with no other interventions; (2) the IDE group: rats received idebenone (100 mg/kg, i. p) without T/D; (3) the T/D group: rats underwent torsion for 2 h and detorsion for 4 h; and (4) the IDE+ T/D group: rats received IDE 1 h before T/D. Testicular malondialdehyde (MDA), total nitrite/nitrate (NOx), total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α), caspase-3, sirtuin type 1 (Sirt1), serum interleukin-1β (IL-1β), total cholesterol, and testosterone were measured. Histological changes, nuclear factor (erythroid-derived 2)-like-2 factors (Nrf2), and proliferating cell nuclear antigen (PCNA) immuno-expressions were assessed. T/D displayed an increase in MDA, NOx, TNF-α, caspase-3, IL-1β, and total cholesterol with a significant decrease in TAC, Sirt1, and testosterone and strong positive Nrf2 and negative PCNA immuno-expressions. IDE could improve all oxidative, inflammatory, and apoptotic indicators. Therefore, IDE significantly reduced testicular ischemia-reperfusion injury in the juvenile rat testicular T/D model by limiting oxidative stress, inflammation, and apoptosis via the Sirt1/Nrf2/TNF-α pathway.

Therapeutic effect of Keap1-Nrf2-ARE pathway-related drugs on age-related eye diseases through anti-oxidative stress

Age-related eye diseases, including cataract, glaucoma, diabetic retinopathy (DR), and age-related macular degeneration (AMD), are the leading causes of vision loss in the world. Several studies have shown that the occurrence and development of these diseases have an important relationship with oxidative stress in the eye. The Keap1-Nrf2-ARE pathway is a classical pathway that resists oxidative stress and inflammation in the body. This pathway is also active in the development of age-related eye diseases. A variety of drugs have been shown to treat age-related eye diseases through the Keap1-Nrf2-ARE (Kelch-like ECH-Associating protein 1- nuclear factor erythroid 2 related factor 2-antioxidant response element) pathway. This review describes the role of oxidative stress in the development of age-related eye diseases, the function and regulation of the Keap1-Nrf2-ARE pathway, and the therapeutic effects of drugs associated with this pathway on age-related eye diseases.

3,5-Dimethoxy-4-hydroxy myricanol attenuated oxidative stress-induced toxicity on cardiomyoblast cells

Myocardial ischemia is the main reason for ischemic heart diseases. Antioxidant treatment is considered as a possible approach to prevent myocardial ischemia injury, because oxidative stress is a key factor triggering it. This study was to investigate the protective effects of 3,5-dimethoxy-4-hydroxy myricanol (DHM) against oxidative stress-induced cytotoxicity on H9c2 cells and further explore its mechanisms. The oxidative stress and inflammatory response markers were detected by H2DCFDA fluorescent measurement, enzyme-linked immunosorbent assay (ELISA), real-time PCR and Western blot. Results showed DHM exerted inhibitory effects against H9c2 cell damage. Furthermore, DHM decreased oxidative stress in H9c2 cells through up-regulating protein expression of heme oxygenase-1 (HO-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Moreover, DHM inhibited inflammatory responses through down-regulating the protein expression of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB). DHM exerted protective activities against oxidative stress-induced cell damage, at least through decreasing oxidative stress and inhibiting inflammatory responses, indicating that DHM have the potential to be developed as therapeutic agents for the treatment of myocardial ischemia.

Novel Short-Chain Quinones to Treat Vision Loss in a Rat Model of Diabetic Retinopathy

Diabetic retinopathy (DR), one of the leading causes of blindness, is mainly diagnosed based on the vascular pathology of the disease. Current treatment options largely focus on this aspect with mostly insufficient therapeutic long-term efficacy. Mounting evidence implicates mitochondrial dysfunction and oxidative stress in the central etiology of DR. Consequently, drug candidates that aim at normalizing mitochondrial function could be an attractive therapeutic approach. This study compared the mitoprotective compounds, idebenone and elamipretide, side-by-side against two novel short-chain quinones (SCQs) in a rat model of DR. The model effectively mimicked type 2 diabetes over 21 weeks. During this period, visual acuity was monitored by measuring optokinetic response (OKR). Vision loss occurred 5–8 weeks after the onset of hyperglycemia. After 10 weeks of hyperglycemia, visual function was reduced by 65%. From this point, the right eyes of the animals were topically treated once daily with the test compounds. The left, untreated eye served as an internal control. Only three weeks of topical treatment significantly restored vision from 35% to 58–80%, while visual acuity of the non-treated eyes continued to deteriorate. Interestingly, the two novel SCQs restored visual acuity better than idebenone or elamipretide. This was also reflected by protection of retinal pathology against oxidative damage, retinal ganglion cell loss, reactive gliosis, vascular leakage, and retinal thinning. Overall, mitoprotective and, in particular, SCQ-based compounds have the potential to be developed into effective and fast-acting drug candidates against DR.

Idebenone: When an antioxidant is not an antioxidant

Idebenone is a well described drug that was initially developed against dementia. The current literature widely portrays this molecule as a potent antioxidant and CoQ₁₀ analogue. While numerous papers seem to support this view, a closer look indicates that the pharmacokinetics of idebenone do not support these claims. A major discrepancy between achievable tissue levels, especially in target tissues such as the brain, and doses required to show the proposed effects, significantly questions our current understanding. This review explains how this has happened and highlights the discrepancies in the current literature. More importantly, based on some recent discoveries, a new framework is presented that can explain the mode of action of this molecule and can align formerly contradictory results. Finally, this new appreciation of the molecular activities of idebenone provides a rational approach to test idebenone in novel indications that might have not been considered previously for this drug.