Protection of Kaempferol on Oxidative Stress-Induced Retinal Pigment Epithelial Cell Damage

Triptonide protects retinal cells from oxidative damage via activation of Nrf2 signaling

Age‑related macular degeneration (AMD) is an ocular disease that threatens the visual function of older adults worldwide. Key pathological processes involved in AMD include oxidative stress, inflammation and choroidal vascular dysfunction. Retinal pigment epithelial cells and Müller cells are most susceptible to oxidative stress. Traditional herbal medicines are increasingly being investigated in the field of personalized medicine in ophthalmology. Triptonide (Tn) is a diterpene tricyclic oxide, the main active ingredient in the extract from the Chinese herbal medicinal plant Tripterygium wilfordii, and is considered an effective immunosuppressant and anti‑inflammatory drug. The present study investigated the potential beneficial role of Tn in retinal oxidative damage in order to achieve personalized treatment for early AMD. An oxidative stress model of retinal cells induced by H2O2 and a retinal injury model of mice induced by light and N‑Methyl‑D‑aspartic acid were constructed. In vitro, JC‑1 staining, flow cytometry and apoptosis assay confirmed that low concentrations of Tn effectively protected retinal cells from oxidative damage, and reverse transcription‑quantitative PCR and western blotting analyses revealed that Tn reduced the expression of retinal oxidative stress‑related genes and inflammatory factors, which may depend on the PI3K/AKT/mTOR‑induced Nrf2 signaling pathway. In vivo, by retinal immunohistochemistry, hematoxylin and eosin staining and electroretinogram assay, it was found that retinal function and structure improved and choroidal neovascularization was significantly inhibited after Tn pretreatment. These results suggested that Tn is an efficient Nrf2 activator, which can be expected to become a new intervention for diseases such as AMD, to inhibit retinal oxidative stress damage and pathological neovascularization.

Natural products for the treatment of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a chronic retinal disease that significantly influences the vision of the elderly.

PURPOSE

There is no effective treatment and prevention method. The pathogenic process behind AMD is complex, including oxidative stress, inflammation, and neovascularization. It has been demonstrated that several natural products can be used to manage AMD, but systematic summaries are lacking.

STUDY DESIGN AND METHODS

PubMed, Web of Science, and ClinicalTrials.gov were searched using the keywords "Biological Products" AND "Macular Degeneration" for studies published within the last decade until May 2023 to summarize the latest findings on the prevention and treatment of age-related macular degeneration through the herbal medicines and functional foods.

RESULTS

The eligible studies were screened, and the relevant information about the therapeutic action and mechanism of natural products used to treat AMD was extracted. Our findings demonstrate that natural substances, including retinol, phenols, and other natural products, prevent the development of new blood vessels and protect the retina from oxidative stress in cells and animal models. However, they have barely been examined in clinical studies.

CONCLUSION

Natural products could be highly prospective candidate drugs used to treat AMD, and further preclinical and clinical research is required to validate it to control the disease.

Natural plant medications for the treatment of retinal diseases: The blood-retinal barrier as a clue

BACKGROUND

Retinal diseases significantly contribute to the global burden of visual impairment and blindness. The occurrence of retinal diseases is often accompanied by destruction of the blood‒retinal barrier, a vital physiological structure responsible for maintaining the stability of the retinal microenvironment. However, detailed summaries of the factors damage the blood‒retinal barrier and treatment methods involving natural plant medications are lacking.

PURPOSE

To comprehensively summarize and analyze the protective effects of active substances in natural plant medications on damage to the blood-retina barrier that occurs when retinal illnesses, particularly diabetic retinopathy, and examine their medicinal value and future development prospects.

METHODS

In this study, we searched for studies published in the ScienceDirect, PubMed, and Web of Science databases. The keywords used included natural plant medications, plants, natural herbs, blood retinal barrier, retinal diseases, diabetic retinopathy, age-related macular degeneration, and uveitis. Chinese herbal compound articles, non-English articles, warning journals, and duplicates were excluded from the analysis.

RESULTS

The blood‒retinal barrier is susceptible to high glucose, aging, immune responses, and other factors that destroy retinal homeostasis, resulting in pathological changes such as apoptosis and increased vascular permeability. Existing studies have shown that the active compounds or extracts of many natural plants have the effect of repairing blood-retinal barrier dysfunction. Notably, berberine, puerarin, and Lycium barbarum polysaccharides exhibited remarkable therapeutic effects. Additionally, curcumin, astragaloside IV, hesperidin, resveratrol, ginsenoside Rb1, luteolin, and Panax notoginseng saponins can effectively protect the blood‒retinal barrier by interfering with distinct pathways. The active ingredients found in natural plant medications primarily repair the blood‒retinal barrier by modulating pathological factors such as oxidative stress, inflammation, pyroptosis, and autophagy, thereby alleviating retinal diseases.

CONCLUSION

This review summarizes a series of plant extracts and plant active compounds that can treat retinal diseases by preventing and treating blood‒retinal barrier damage and provides reference for the research of new drugs for treating retinal diseases.

Global trends in oxidative stress in the Retina: A bibliometric analysis of 2013-2023

Background

Oxidative stress plays a significant role in the pathogenesis of many retinal diseases. However, only a few systematic bibliometric studies have been conducted. This study aims to visualize research hotspots and developmental trends in oxidative stress in the retina from 2013 to 2023 by analyzing bibliometric data.

Methods

We retrieved papers on oxidative stress in the retina published between 2013 and 2023 from the Web of Science Core Collection. The data were visually analyzed using CiteSpace and VOSviewer software.

Results

The total number of 2100 publications were included in the analysis. An overall increasing trend in the number of publications is observed between 2013 and 2023. Chinese publications were the most contributive, but United States publications were the most influential. Shanghai Jiao Tong University was the most active and prolific institution. Antioxidants was the most productive journal, while Oxidative Medicine and Cellular Longevity were the journals with the most-cited articles. Kaarniranta K, from Finland, was the most productive and influential author. Examination of co-cited references revealed that researchers in the field are primarily focused on investigating the molecular mechanisms, preventive strategies, and utilization of antioxidants to address retinal oxidative damage. Diabetic retinopathy, endothelial growth factor, retinitis pigmentosa, retinal degeneration, antioxidant response, retinal ganglion cells, and genes are the research hotspots in this field. Metabolism, sodium iodate, and system are at the forefront of research in this field.

Conclusion

Attention toward retinal oxidative stress has increased over the past decade. Current research focuses on the mechanisms of retinal diseases related to oxidative stress and the experimental study of antioxidants in retinal diseases, which may continue to be a trend in the future.

Immunomodulatory effects of Kaempferol on microglial and Macrophage cells during the progression of diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) stands as a prevalent secondary complication of diabetes, notably Type 1 Diabetes Mellitus (T1D), characterized by immune system involvement potentially impacting the retinal immune response mediated by microglia. Early stages of DR witness blood-retinal barrier permeabilization, facilitating peripheral immune cell interaction with the retinal immune system. Kaempferol (Kae), known for its potent anti-inflammatory activity, presents a promising avenue in DR treatment by targeting the immune mechanisms underlying its onset and progression. Our investigation delves into the molecular intricacies of innate immune cell interaction during DR progression and the attenuation of inflammatory processes pivotal to its pathology.

METHODS

Employing in vitro studies, we exposed HAPI microglial and J774.A1 macrophage cells to pro-inflammatory stimuli in the presence or absence of Kae. Ex vivo and in vivo experiments utilized BB rats, a T1D animal model. Retinal explants from BB rats were cultured with Kae, while intraperitoneal Kae injections were administered to BB rats for 15 days. Quantitative PCR, Western blotting, immunofluorescence, and Spectral Domain - Optical Coherence Tomography (SD-OCT) facilitated survival assessment, cellular signaling analysis, and inflammatory marker determination.

RESULTS

Results demonstrate Kae significantly mitigates inflammatory processes across in vitro, ex vivo, and in vivo DR models, primarily targeting immune cell responses. Kae administration notably inhibits proinflammatory responses during DR progression while promoting an anti-inflammatory milieu, chiefly through microglia-mediated synthesis of Arginase-1 and Hemeoxygenase-1(HO-1). In vivo, Kae administration effectively preserves retinal integrity amid DR progression.

CONCLUSIONS

Our findings elucidate the interplay between retinal and systemic immune cells in DR progression, underscoring a differential treatment response predominantly orchestrated by microglia's anti-inflammatory action. Kae treatment induces a phenotypic and functional shift in immune cells, delaying DR progression, thereby spotlighting microglial cells as a promising therapeutic target in DR management.

Pharmacological Potential of Kaempferol, a Flavonoid in the Management of Pathogenesis via Modulation of Inflammation and Other Biological Activities

Natural products and their bioactive compounds have been used for centuries to prevent and treat numerous diseases. Kaempferol, a flavonoid found in vegetables, fruits, and spices, is recognized for its various beneficial properties, including its antioxidant and anti-inflammatory potential. This molecule has been identified as a potential means of managing different pathogenesis due to its capability to manage various biological activities. Moreover, this compound has a wide range of health-promoting benefits, such as cardioprotective, neuroprotective, hepatoprotective, and anti-diabetic, and has a role in maintaining eye, skin, and respiratory system health. Furthermore, it can also inhibit tumor growth and modulate various cell-signaling pathways. In vivo and in vitro studies have demonstrated that this compound has been shown to increase efficacy when combined with other natural products or drugs. In addition, kaempferol-based nano-formulations are more effective than kaempferol treatment alone. This review aims to provide detailed information about the sources of this compound, its bioavailability, and its role in various pathogenesis. Although there is promising evidence for its ability to manage diseases, it is crucial to conduct further investigations to know its toxicity, safety aspects, and mechanism of action in health management.

The mechanisms of natural products for eye disorders by targeting mitochondrial dysfunction

The human eye is susceptible to various disorders that affect its structure or function, including glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitochondrial dysfunction has been identified as a critical factor in the pathogenesis and progression of eye disorders, making it a potential therapeutic target in the clinic. Natural products have been used in traditional medicine for centuries and continue to play a significant role in modern drug development and clinical therapeutics. Recently, there has been a surge in research exploring the efficacy of natural products in treating eye disorders and their underlying physiological mechanisms. This review aims to discuss the involvement of mitochondrial dysfunction in eye disorders and summarize the recent advances in the application of natural products targeting mitochondria. In addition, we describe the future perspective and challenges in the development of mitochondria-targeting natural products.

Identification of active compounds in Vernonia anthelmintica (L.) willd by targeted metabolome MRM and kaempferol promotes HaCaT cell proliferation and reduces oxidative stress

Introduction: Vernonia anthelmintica (L.) Willd. is a traditional treatment for vitiligo in Xinjiang. However, its therapeutic mechanism remains unclear owing to its complex composition and limited research on its chemical profile. Methods: We employed a targeted metabolome approach, combining selective reaction monitoring/multiple response monitoring (SRM/MRM) with high-performance liquid chromatography and MRM mass spectrometry to quantitatively analyze the flavonoid constituents of Vernonia anthelmintica. We also used network pharmacology and molecular docking to identify potential vitiligo-linked compounds and targets of V. anthelmintica seeds. Additionally, we assessed HaCaT cell proliferation by AAPH-induced, alongside changes in SOD activity and MDA content, following treatment with V. anthelmintica components. Finally, flow cytometry was used to detect apoptosis and ROS levels. Results and Discussion: We identified 36 flavonoid compounds in V. anthelmintica seeds, with 14 compounds exhibiting druggability. AKT1, VEGFA, ESR1, PTGS2, and IL2 have been identified as key therapeutic target genes, with PI3K/AKT signaling being an important pathway. Notably, kaempferol, one of the identified compounds, exhibited high expression in network pharmacology analysis. Kaempferol exhibited a strong binding affinity to important targets. Further, kaempferol enhanced HaCaT cell viability, inhibited apoptosis, reduced MDA levels, suppressed ROS activity, and upregulated SOD activity, increase the expression of cellular antioxidant genes, including HO-1, GCLC, GCLM, Nrf2, NQO1 and Keap1, providing significant protection against oxidative stress damage in vitro. Here, we present the first comprehensive study integrating SRM/MRM approaches and network analysis to identify active flavonoid compounds within V. anthelmintica (L.) Willd. Moreover, we revealed that its active ingredient, kaempferol, offers protection against AAPH-induced damage in keratinocytes, highlighting its potential as a clinical resource.

Kaempferol: Paving the path for advanced treatments in aging-related diseases

Aging-related diseases (ARDs) are a major global health concern, and the development of effective therapies is urgently needed. Kaempferol, a flavonoid found in several plants, has emerged as a promising candidate for ameliorating ARDs. This comprehensive review examines Kaempferol's chemical properties, safety profile, and pharmacokinetics, and highlights its potential therapeutic utility against ARDs. Kaempferol's therapeutic potential is underpinned by its distinctive chemical structure, which confers antioxidative and anti-inflammatory properties. Kaempferol counteracts reactive oxygen species (ROS) and modulates crucial cellular pathways, thereby combating oxidative stress and inflammation, hallmarks of ARDs. Kaempferol's low toxicity and wide safety margins, as demonstrated by preclinical and clinical studies, further substantiate its therapeutic potential. Compelling evidence supports Kaempferol's substantial potential in addressing ARDs through several mechanisms, notably anti-inflammatory, antioxidant, and anti-apoptotic actions. Kaempferol exhibits a versatile neuroprotective effect by modulating various proinflammatory signaling pathways, including NF-kB, p38MAPK, AKT, and the β-catenin cascade. Additionally, it hinders the formation and aggregation of beta-amyloid protein and regulates brain-derived neurotrophic factors. In terms of its anticancer potential, kaempferol acts through diverse pathways, inducing apoptosis, arresting the cell cycle at the G2/M phase, suppressing epithelial-mesenchymal transition (EMT)-related markers, and affecting the phosphoinositide 3-kinase/protein kinase B signaling pathways. Subsequent studies should focus on refining dosage regimens, exploring innovative delivery systems, and conducting comprehensive clinical trials to translate these findings into effective therapeutic applications.

Wearable Magnetoelectric Stimulation for Chronic Wound Healing by Electrospun CoFe2O4@CTAB/PVDF Dressings

Magnetoelectric stimulation is a promising therapy for various disorders due to its high efficacy and safety. To explore its potential in chronic skin wound treatment, we developed a magnetoelectric dressing, CFO@CTAB/PVDF (CCP), by electrospinning cetyltrimethylammonium bromide-modified CoFe2O4 (CFO) particles with polyvinylidene fluoride. Cetyltrimethylammonium bromide (CTAB) serves as a dispersion surfactant for CFO, with its quaternary ammonium cations imparting antibacterial and hydrophilic properties to the dressing. Electrospinning polarizes polyvinylidene fluoride (PVDF) molecules and forms a fibrous membrane with flexibility and breathability. With a wearable electromagnetic induction device, a dynamic magnetic field is established to induce magnetostrictive deformation of CFO nanoparticles. Consequently, a piezoelectric potential is generated on the surface of PVDF nanofibers to enhance the endogenous electrical field in the wound, achieving a cascade coupling of electric-magnetic-mechanical-electric effects. Bacteria and cell cultures show that 2% CTAB effectively balances antibacterial property and fibroblast activity. Under dynamic magnetoelectric stimulation, the CCP dressing demonstrates significant upregulation of TGF-β, FGF, and VEGF, promoting L929 cell adhesion and proliferation. Moreover, it facilitates the healing of diabetic rat skin wounds infected with Staphylococcus aureus within 2 weeks. Histological and molecular biology evaluations confirm the anti-inflammatory effect of CTAB and the accelerated formation of collagen and vessel by electrical stimulation. This work provides insights into the application of magnetoelectric stimulation in the healing of chronic wounds.

Melatonin protects photoreceptor cells against ferroptosis in dry AMD disorder by inhibiting GSK-3B/Fyn-dependent Nrf2 nuclear translocation

BACKGROUND

Ferroptosis is a type of non-apoptotic cell death that relies on iron ions and reactive oxygen species to induce lipid peroxidation. This study aimed to determine whether ferroptosis exists in the pathogenesis of dry age-related macular degeneration (AMD) and to confirm that melatonin (MLT) suppresses the photoreceptor cell ferroptosis signaling pathway.

METHODS

We exposed 661W cells to sodium iodate (NaIO3) in vitro and treated them with different concentrations of MLT. In vivo, C57BL/6 mice were given a single caudal vein injection of NaIO3, followed by an intraperitoneal injection of MLT, and eyeballs were taken for subsequent trials.

RESULTS

We found that NaIO3 could induce photoreceptor cell death and lipid peroxide accumulation, and result in changes in the expression of ferroptosis-related factors and iron maintenance proteins, which were treated by MLT. We further demonstrated that MLT can block Fyn-dependent Nrf2 nuclear translocation by suppressing the GSK-3β signaling pathway. In addition, the therapeutic effect of MLT was significantly inhibited when Nrf2 was silenced.

CONCLUSIONS

Our findings provide a novel insight that NaIO3 induces photoreceptor cell ferroptosis in dry AMD and suggest that MLT has therapeutic effects by suppressing GSK-3β/Fyn-dependent Nrf2 nuclear translocation.

Therapeutic Effect and Mechanism Prediction of Fuzi-Gancao Herb Couple on Non-alcoholic Fatty Liver Disease (NAFLD) based on Network Pharmacology and Molecular Docking

BACKGROUND

Fuzi-Gancao herb couple is one of the most common herb couples involved in the TCM formula, which was used for the treatment of chronic diseases. The herb couple has a hepatoprotective effect. However, its main components and therapeutic mechanism are not yet clear. This study aims to elucidate the therapeutic effect and mechanism of the Fuzi-Gancao herb couple on NAFLD from animal experiments, network pharmacology, and molecular docking.

METHODS

60 Male C57BL/6 mice (20 g ± 2 g) were randomly divided into six groups including the blank group (n=10) and NALFD group (n=50). The mice of the NALFD group were fed with a high-fat diet for 20 weeks to establish the NAFLD model and the NALFD mice were randomly divided into five groups including positive group (berberine), model group and F-G groups with three dosages (0.257, 0.514, 0.771 g/kg) (n=10). After 10 weeks of administration, the serum was collected for the analysis of ALT, AST, LDL-c, HDL-c, and TC, and liver tissues were collected for pathological analysis. The TCMAS database was used to collect the main components and targets of the Fuzi-Gancao herb couple. The GeneCards database was used to collect NAFLD-related targets, and the key targets were obtained by intersecting with herbal targets. The diseasecomponent- target relationship diagram was constructed by Cytoscape 3.9.1. The obtained key targets were imported into the String database to obtain the PPI network, and imported into the DAVID database for KEGG pathway analysis and GO analysis. Finally, the key targets and key gene proteins were imported into Discovery Studio 2019 for molecular docking verification.

RESULTS

In this study, H-E staining indicated the pathological changes of liver tissue in Fuzi- Gancao groups were significantly improved, and the levels of AST, ALT, TC, HDL-c, and LDL-c in serum of Fuzi-Gancao groups decreased in a dose-dependent manner, compared with the model group. 103 active components and 299 targets in the Fuzi-Gancao herb couple were confirmed in the TCMSP database and 2062 disease targets in NAFLD were obtained. 142 key targets and 167 signal pathways were screened, such as the AGE-RAGE signaling pathway in diabetic complications, HIF-1 signaling pathway, IL-17 signaling pathway, TNF signaling pathway, and so on. The main bioactive ingredients of Fuzi-Gancao herb couple in the treatment of NAFLD are quercetin, kaempferol, naringenin, inermine, (R)-norcoclaurine, isorhamnetin, ignavine, 2,7-Dideacetyl-2,7- dibenzoyl-taxayunnanine F, glycyrol mainly involving IL6, AKT1, TNF, TP53, IL1B, VEGFA and other core targets. Molecular docking analysis indicated that there is a good affinity between the key components and the key targets.

CONCLUSION

This study preliminarily explained the main components and mechanism of the Fuzi- Gancao herb couple in the treatment of NAFLD and provided an idea for subsequent research.

A multifunctional chitosan composite aerogel based on high density amidation for chronic wound healing

The management of chronic wounds remains a challenging clinical problem worldwide, mainly because of secondary infections, excessive oxidative stress, and blocked angiogenesis. Aerogel is a novel material with high porosity and specific surface area that allows gas exchange and rapid absorption of a large amount of exudate as well as loading bioactive molecules. Therefore, functional aerogel can be an ideal material for chronic wound treatment. The multifunctional aerogel (CG-DA-VEGF) was prepared by a simple and eco-friendly freeze-drying process combined with harmless EDC/NHS as crosslinking agents using chitosan and dopamine-grafted gelatin as raw materials. The physicochemical characterization revealed that the CG-DA-VEGF aerogel had excellent water absorption, water retention, and mechanical properties, and could release VEGF continuously and stably. In vitro experiments demonstrated that the CG-DA-VEGF aerogel exhibited effective antioxidant and antibacterial properties, as well as superb cytocompatibility. In vivo experiments further confirmed that the CG-DA-VEGF aerogel could significantly improve angiogenesis and re-epithelialization, and promote collagen deposition, thus accelerating wound healing with excellent biosafety. These results suggest that the as-prepared CG-DA-VEGF aerogel may be adopted as a promising multifunctional graft for the treatment of chronic wounds.

Alleviate oxidative stress in diabetic retinopathy: antioxidant therapeutic strategies

OBJECTIVES

This review outlines the function of oxidative stress in DR and discusses therapeutic strategies to treat DR with antioxidants.

METHODS

Published papers on oxidative stress in DR and therapeutic strategies to treat DR with antioxidants were collected and reviewed via database searching on PubMed.

RESULTS

The abnormal development of DR is a complicated process. The pathogenesis of DR has been reported to involve oxidative stress, despite the fact that the mechanisms underlying this are still not fully understood. Excessive reactive oxygen species (ROS) accumulation can damage retina, eventually leading to DR. Increasing evidence have demonstrated that antioxidant therapy can alleviate the degeneration of retinal capillaries in DR.

CONCLUSION

Oxidative stress can play an important contributor in the pathogenesis of DR. Furthermore, animal experiments have shown that antioxidants are a beneficial therapy for treating DR, but more clinical trial data is needed.

Mechanism and ingredients prediction of Radix Salviae-Angelicae Sinensis Radix-Lycii Fructus-Rehmanniae Radix Praeparata-Ginkgo Folium for retinitis pigmentosa therapy using network pharmacology and molecular docking analysis

Background

Radix Salviae (Danshen)-Angelicae Sinensis Radix (Danggui)-Lycii Fructus (Gouqizi)-Rehmanniae Radix Praeparata (Shudihuang)-Ginkgo Folium (Yinxinye) (RALRG) are commonly used herbs in China that have shown positive effects on retinitis pigmentosa (RP). However, little research has been performed on the impact of RALRG and RP. Herein, this study aimed to predict the mechanism and potential components of RALRG in treating RP.

Methods

The ingredients of RALRG were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP); the potential targets of RP and RALRG were obtained from TCMSP, GeneCards, and the Online Mendelian Inheritance in Man (OMIM) database. A protein-protein interaction (PPI) network was constructed to visualize PPIs. The functional enrichment was performed with the R program. A visual RALRG-RP-pathway pharmacology network was established by Cytoscape 3.9.1. Molecular docking was used to perform molecular docking and calculate the binding affinity.

Results

A total of 132 effective active ingredients in RALRG with 248 target genes were screened; 92 intersection target genes were acquired from the intersection of RP- and RALRG-related genes. Gene Ontology (GO) enrichment indicated that these intersection targets were mainly involved in oxidative stress, metal ion response, and chemical stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the PI3K-AKT, cellular senescence, and MAPK signaling pathways were closely related to the therapy of RP. In addition, a potential pharmacology network for RALRG-RP-pathway was constructed. AKT1 and JUN were considered the primary targets. Luteolin, quercetin, and kaempferol were identified as the vital three active ingredients.

Conclusions

RALRG was found to be the main regulator for oxidative stress and PI3K/AKT signaling pathways. Luteolin, quercetin, and kaempferol were three promising complementary ingredients for RP treatment. This study may provide a theoretical basis for applying RALRG to screen potential drugs for RP.

Jin-Gui-Shen-Qi Wan ameliorates diabetic retinopathy by inhibiting apoptosis of retinal ganglion cells through the Akt/HIF-1α pathway

BACKGROUND

Jin-Gui-Shen-Qi Wan (JGSQ) has been used in China for thousands of years to treat various ailments, including frequent urination, blurred vision, and soreness in the waist and knees. It has traditional therapeutic advantages in improving eye diseases.

AIM OF THE STUDY

Clinical studies have confirmed the therapeutic efficacy of JGSQ in improving diabetes and vision; however, its efficacy and pharmacological effects in treating diabetic retinopathy (DR) remain unclear. Therefore, the aim of this study was to investigate the specific pharmacological effects and potential mechanisms of JGSQ in improving DR through a db/db model.

MATERIALS AND METHODS

db/db mice were given three different doses of orally administered JGSQ and metformin for 8 weeks, and then PAS staining of the retinal vascular network patch, transmission electron microscopy, H&E staining, and TUNEL staining were performed to determine the potential role of JGSQ in improving DR-induced neuronal cell apoptosis. Furthermore, network pharmacology analysis and molecular docking were carried out to identify the main potential targets of JGSQ, and the efficacy of JGSQ in improving DR was evaluated through western blotting and immunofluorescence staining, revealing its mechanism of action.

RESULTS

According to the results from H&E, TUNEL, and PAS staining of the retinal vascular network patch and transmission electron microscopy, JGSQ does not have an advantage in improving the abnormal morphology of vascular endothelial cells, but it has a significant effect on protecting retinal ganglion cells from apoptosis. Through network pharmacology and molecular docking, AKT, GAPDH, TNF, TP53, and IL-6 were identified as the main core targets of JGSQ. Subsequently, through western blot and immunofluorescence staining, it was found that JGSQ can inhibit HIF-1α, promote p-AKT expression, and inhibit TP53 expression. At the same time, inhibiting the release of inflammatory factors protects retinal ganglion cells and improves apoptosis in DR.

CONCLUSION

These results indicated that in the db/db DR mouse model, JGSQ can inhibit the expression of inflammatory cytokines and protect retinal ganglion cells from apoptosis, possibly by modulating the Akt/HIF-1α pathway.

Medicinal Plants Used for Eye Conditions in Mexico-A Review

Medicinal plants have been historically significant for treating common human diseases in Mexico. Although some ethnobotanical research exists, limited ethnomedicinal data has documented medicinal plants employed for eye health. This review focuses on ethnomedicinal information and preclinical and clinical studies regarding medicinal plants used in Mexico for treating symptoms associated with eye conditions. An electronic database search was conducted by consulting scientific articles, books about Mexican herbal medicine, and academic theses. This work recorded 69 plant species belonging to 26 plant families, especially plants from the Crassulaceae family, which are used as remedies for irritation and infections in the eye. Eight of these medicinal plants have been the subject of preclinical studies using ocular models, and one medicinal plant has been tested in clinical trials. The evidence of pharmacological effects indicates the promising therapeutic potential of these medicinal plants for developing new treatments for eye conditions. However, toxicological studies are necessary to ensure safe application to the eye, particularly as traditional medicine continues to be relied upon worldwide. In addition, this review highlights the need to perform ethnobotanical and phytochemical studies in Mexico regarding the medicinal flora used as remedies for eye conditions.

A Relook into the Flavonoid Chemical Space of Moringa oleifera Lam. Leaves through a Combination of LC-MS and Molecular Networking

Moringa oleifera Lam. is a functional tree that is known to produce a variety of metabolites with purported pharmacological activities. It is frequently called the "miracle tree" due to its utilization in numerous nutraceutical and pharmacological contexts. This study was aimed at studying the chemical space of M. oleifera leaf extracts through molecular networking (MN), a tool that identifies metabolites by classifying them based on their MS-based fragmentation pattern similarities and signals. In this case, a special emphasis was placed on the flavonoid composition. The MN unraveled different molecular families such as flavonoids, carboxylic acids and derivatives, lignin glycosides, fatty acyls, and macrolactams that are found within the plant. In silico annotation tools such as network annotation propagation (NAP) and DEREPLICATOR, an unsupervised substructure identification tool (MS2LDA), and MolNet enhancer were also explored to further compliment the classic molecular networking output within the Global Natural Product Social (GNPS) site. In this study, common flavonoids found within Moringa oleifera were further annotated using MS2LDA. Utilizing computational tools allowed for the discovery of a wide range of structurally diverse flavonoid molecules within M. oleifera leaf extracts. The expansion of the flavonoid chemical repertoire in this plant arises from intricate glycosylation modifications, leading to the creation of structural isomers that manifest as isobaric ions during mass spectrometry (MS) analyses.

Oxidative Model of Retinal Neurodegeneration Induced by Sodium Iodate: Morphofunctional Assessment of the Visual Pathway

Sodium iodate (NaIO3) has been shown to cause severe oxidative stress damage to retinal pigment epithelium cells. This results in the indirect death of photoreceptors, leading to a loss of visual capabilities. The aim of this work is the morphological and functional characterization of the retina and the visual pathway of an animal model of retinal neurodegeneration induced by oxidative stress. Following a single intraperitoneal dose of NaIO3 (65 mg/kg) to C57BL/6J mice with a mutation in the Opn4 gene (Opn4-/-), behavioral and electroretinographic tests were performed up to 42 days after administration, as well as retinal immunohistochemistry at day 57. A near total loss of the pupillary reflex was observed at 3 days, as well as an early deterioration of visual acuity. Behavioral tests showed a late loss of light sensitivity. Full-field electroretinogram recordings displayed a progressive and marked decrease in wave amplitude, disappearing completely at 14 days. A reduction in the amplitude of the visual evoked potentials was observed, but not their total disappearance. Immunohistochemistry showed structural alterations in the outer retinal layers. Our results show that NaIO3 causes severe structural and functional damage to the retina. Therefore, the current model can be presented as a powerful tool for the study of new therapies for the prevention or treatment of retinal pathologies mediated by oxidative stress.

microRNA-96 targets the INS/AKT/GLUT4 signaling axis: Association with and effect on diabetic retinopathy

Background

miR-96-5p is a highly expressed microRNA in the retina of subjects with diabetes. The INS/AKT/GLUT4 signaling axis is the main cell signaling pathway of glucose uptake in cells. Here, we investigated the role of miR-96-5p in this signaling pathway.

Methods

Expression levels of miR-96-5p and its target genes were measured under high glucose conditions, in the retina of streptozotocin-induced diabetic mice, in the retina of AAV-2-eGFP-miR-96 or GFP intravitreal injected mice and in the retina of human donors with diabetic retinopathy (DR). MTT, wound healing, tube formation, Western blot, TUNEL, angiogenesis assays and hematoxylin-eosin staining of the retinal sections were performed.

Results

miR-96-5p expression was increased under high glucose conditions in mouse retinal pigment epithelial (mRPE) cells, in the retina of mice receiving AAV-2 carrying miR-96 and STZ-treated mice. Expression of the miR-96-5p target genes related to the INS/AKT/GLUT4 signaling pathway was reduced following miR-96-5p overexpression. mmu-miR-96-5p expression decreased cell proliferation and thicknesses of retinal layers. Cell migration, tube formation, vascular length, angiogenesis, and TUNEL-positive cells were increased.

Conclusions

In in vitro and in vivo studies and in human retinal tissues, miR-96-5p regulated the expression of the PIK3R1, PRKCE, AKT1, AKT2, and AKT3 genes in the INS/AKT axis and some genes involved in GLUT4 trafficking, such as Pak1, Snap23, RAB2a, and Ehd1. Because disruption of the INS/AKT/GLUT4 signaling axis causes advanced glycation end product accumulation and inflammatory responses, the inhibition of miR-96-5p expression could ameliorate DR.

Construction and evaluation of an antioxidant synergistic system containing vitamin C and vitamin E

AIMS

The aim of this study is to develop a liposome that could exert unparalleled antioxidant effects. In the present study, a vitamin C (VC)/vitamin E (VE)-co-loaded multivesicular liposome (VCVE-MVL) was constructed.

METHODS

Vitamins were encapsulated in soybean phosphatidylcholine (SPC) and cholesterol (CHO) by multi-emulsification method. The concentration of VC was determined by Fast Blue method. The concentration of VE was determined by high performance liquid chromatography (HPLC). Vitamin antioxidant capacity in vitro and in vivo was determined using β-carotene bleaching.

RESULTS

VCVE-MVL with particle diameter of 848.55 ± 0.29 nm and SPAN of 0.16 ± 0.11 were obtained. The encapsulation efficiency of VC reached 48.51% (w/w)±0.15. Compared with VC/VE solution, VCVE-MVL had a higher permeation efficiency. In addition, the in vitro and ex-vivo antioxidant tests verified the adequate antioxidant activity of VCVE-MVL.

CONCLUSIONS

In conclusion, the antioxidant synergistic system we constructed and demonstrated its potential applications in the cosmetics industry.

Role of flavonoids in age-related macular degeneration

A common eye disorder known as age-related macular degeneration (AMD) eventually results in blindness and vision loss. AMD has a complicated and poorly understood aetiology. The main pathological processes associated with AMD include oxidative damage, inflammation, and neovascularization. Flavonoids are naturally occurring bioactive substances with extensive distribution and antioxidant, anti-inflammatory, and neovascularization inhibitory properties. Several in vitro and in vivo AMD-related models pertinent to vision and this ocular ailment have been used to assess the mechanisms of action of various flavonoids. This article will discuss the research progress of flavonoids in AMD, especially the characteristics and mechanism of flavonoids in treating AMD.

Pharmacological network analysis of the functions and mechanism of kaempferol from Du Zhong in intervertebral disc degeneration (IDD)

Background

Senescence and apoptosis of the nucleus pulposus cells (NPCs) are essential components of the intervertebral disc degeneration (IDD) process. Senescence and anti-apoptosis treatments could be effective ways to delay or even stop disc degeneration. IDD has been treated with Eucommia ulmoides Oliver (Du Zhong, DZ) and its active ingredients. However, the roles and mechanisms of DZ in NPC apoptosis and senescence remain unclear.

Methods

Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to select the main active ingredients of DZ with the threshold of oral bioavailability (OB) ​≥ ​30% and drug-likeness (DL) ​≥ ​0.2. GSE34095 contained expression profile of degenerative intervertebral disc tissues and non-degenerative intervertebral disc tissues were downloaded for different expression genes analysis. The disease targets genes of IDD were retrieved from GeneCards. The online tool Metascape was used for functional enrichment annotation analysis. The specific effects of the ingredient on IL-1β treated NPC cell proliferation, cell senescence, reactive oxygen species (ROS) accumulation and cell apoptosis were determined by CCK-8, SA-β-gal staining, flowcytometry and western blot assays.

Results

A total of 8 active compounds of DZ were found to meet the threshold of OB ​≥ ​30% and DL ​≥ ​0.2 with 4151 drug targets. After the intersection of 879 IDD disease targets obtained from GeneCards and 230 DEGs obtained from the IDD-related GSE dataset, a total of 13 hub genes overlapped. According to functional enrichment annotation analysis by Metascape, these genes showed to be dramatically enriched in AGE-RAGE signaling, proteoglycans in cancer, wound healing, transmembrane receptor protein tyrosine kinase signaling, MAPK cascades, ERK1/2 cascades, PI3K/Akt signaling pathway, skeletal system, etc. Disease association analysis by DisGeNET indicated that these genes were significantly associated with IDD, intervertebral disc disease, skeletal dysplasia, and other diseases. Active ingredients-targets-signaling pathway networks were constructed by Cytoscape, and kaempferol was identified as the hub active compound of DZ. In the IL-1β-induced IDD in vitro model, kaempferol treatment significantly improved IL-1β-induced NPC cell viability suppression and senescence. In addition, kaempferol treatment significantly attenuated IL-1β-induced ROS accumulation and apoptosis. Furthermore, kaempferol treatment partially eliminated IL-1β-induced decreases in aggrecan, collagen II, SOX9, and FN1 levels and increases in MMP3, MMP13, ADAMTS-4, and ADAMTS-5. Moreover, kaempferol treatment significantly relieved the promotive effects of IL-1β stimulation upon p38, JNK, and ERK1/2 phosphorylation. ERK1/2 inhibitor PD0325901 further enhanced the effect of kaempferol on the inhibition of ERK1/2 phosphorylation, downregulation of MMP3 and ADAMTS-4 expression, and upregulation of aggrecan and collagen II expressions.

Conclusion

Kaempferol has been regarded as the major active compound of DZ, protecting NPCs from IL-1β-induced damages through promoting cell viability, inhibiting cell senescence and apoptosis, increasing ECM production, and decreasing ECM degradation. MAPK signaling pathway may be involved.

The translational poteintial of this article

This study provides in vitro experimental data support for the pharmacological effects of kaempferol in treating IDD, and lays a solid experimental foundation for its future clinical application in IDD treatment.

Physiologically-obtainable polyphenol exposures modulate reactive oxygen and nitrogen species signaling in the C2C12 model of skeletal muscle ageing

Age-related frailty is a significant health and social care burden, with limited treatment options. There is a lack of suitable cell culture model for screening large numbers of test compounds to identify those which promote healthy skeletal muscle function. This paper describes the characterization of reactive oxygen and nitrogen species (RONS) signalling changes in young and aged myoblasts and myotubes using C₂C₁₂ cells, and the application of aged cultures to assess the effect of dietary polyphenols on RONS signalling. Aged myoblasts and myotubes showed significantly increased reactive oxygen species (p < 0.01 and p < 0.001 respectively), nitric oxide (p < 0.05 for myoblasts and myotubes), and lipid peroxidation (p < 0.05 for myoblasts and myotubes). Nine polyphenols were assessed in aged myoblasts and myotubes using concentrations and incubation times consistent with known pharmacokinetic parameters for these compounds. Although several polyphenols were seen to reduce single markers of RONS signalling, only kaempferol and resveratrol significantly reduced multiple markers in both cell models. Modulation of enzymatic antioxidant activities was assessed as a possible mechanism of action, although superoxide dismutase and catalase activities were significantly reduced in aged (versus young) myotubes (p < 0.01 and p < 0.05 respectively), no effect of polyphenol treatment on these enzyme activities were observed. Overall, this research has shown the utility of the C₂C₁₂ model (myoblasts and myotubes) for screening compounds in aged muscle, and that resveratrol and kaempferol (using pharmacokinetically-informed exposures) can modulate RONS signalling in skeletal muscle cells after an acute exposure.

Mini-αA Upregulates the miR-155-5p Target Gene CDK2 and Plays an Antiapoptotic Role in Retinal Pigment Epithelial Cells during Oxidative Stress

Background

Age-related macular degeneration (AMD) is the leading cause of serious vision loss in the elderly. Regulating microRNA (miRNA) gene expression offers exciting new avenues for treating AMD. This study aimed to investigate whether miRNAs and their target genes play an antiapoptotic role during oxidative stress-induced apoptosis of retinal pigment epithelial (RPE) cells via mini-αA.

Methods

ARPE-19 cells were treated with 3.5 mM NaIO3 for 48 h to establish a retinal degeneration model. Cells were treated with mini-αA (10, 15, and 20 μM) for 4 h. miR-155-5p was knocked down and overexpressed. Cell viability and apoptosis were measured using the Cell Counting Kit-8 assay and flow cytometry, respectively. The reactive oxygen species level was detected by flow cytometry. miR-155-5p target genes were predicted via bioinformatics. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed for miR-155-5p target genes. A quantitative real-time polymerase chain reaction was performed to detect miRNAs and cell cycle-related target genes. Western blotting was performed to measure the levels of apoptotic pathway genes encoding Bcl-2, Bax, cleaved caspase-3, and cyclin-dependent kinase 2 (CDK2). Dual-luciferase reporter gene assay was performed to verify the targeted binding relationship between miR-155-5p and CDK2.

Results

NaIO3 can induce oxidative damage and promote apoptosis. Conversely, mini-αA had inhibitory effects and could reverse the oxidative damage and apoptosis triggered by NaIO3 in the retinal degeneration model. The expression of miR-155-5p was upregulated in cells treated with NaIO3 and was downregulated after mini-αA treatment. Furthermore, miR-155-5p can target the following cell cycle-related and proliferation-related genes: CDK2, CDK4, CCND1, and CCND2. Moreover, our study indicated that miR-155-5p was involved in the antioxidative damage and antiapoptotic effects of mini-αA via CDK2 regulation.

Conclusions

miR-155-5p promotes the antioxidative damage and antiapoptotic effects of mini-αA during oxidative stress-induced apoptosis of RPE cells via CDK2 regulation. This study provides a new therapeutic target for AMD.

Endoplasmic reticulum as a target in cardiovascular diseases: Is there a role for flavonoids?

Flavonoids are found in natural health products and plant-based foods. The flavonoid molecules contain a 15-carbon skeleton with the particular structural construction of subclasses. The most flavonoid's critical subclasses with improved health properties are the catechins or flavonols (e.g., epigallocatechin 3-gallate from green tea), the flavones (e.g., apigenin from celery), the flavanones (e.g., naringenin from citrus), the flavanols (e.g., quercetin glycosides from berries, onion, and apples), the isoflavones (e.g., genistein from soya beans) and the anthocyanins (e.g., cyanidin-3-O-glucoside from berries). Scientific data conclusively demonstrates that frequent intake of efficient amounts of dietary flavonoids decreases chronic inflammation and the chance of oxidative stress expressing the pathogenesis of human diseases like cardiovascular diseases (CVDs). The endoplasmic reticulum (ER) is a critical organelle that plays a role in protein folding, post-transcriptional conversion, and transportation, which plays a critical part in maintaining cell homeostasis. Various stimuli can lead to the creation of unfolded or misfolded proteins in the endoplasmic reticulum and then arise in endoplasmic reticulum stress. Constant endoplasmic reticulum stress triggers unfolded protein response (UPR), which ultimately causes apoptosis. Research has shown that endoplasmic reticulum stress plays a critical part in the pathogenesis of several cardiovascular diseases, including diabetic cardiomyopathy, ischemic heart disease, heart failure, aortic aneurysm, and hypertension. Endoplasmic reticulum stress could be one of the crucial points in treating multiple cardiovascular diseases. In this review, we summarized findings on flavonoids' effects on the endoplasmic reticulum and their role in the prevention and treatment of cardiovascular diseases.

Kaempferol ameliorates palmitate-induced lipid accumulation in HepG2 cells through activation of the Nrf2 signaling pathway

OBJECTIVES

Kaempferol (KMF), has beneficial effects against hepatic lipid accumulation. In this study, we aimed to investigate molecular mechanism underlying the protective effect of KMF on lipid accumulation.

METHODS

HepG2 cells were treated with different concentrations of KMF and 0.5 mM palmitate (PA) for 24  h. The mRNA and protein levels of genes involved in lipid metabolism were evaluated using real-time PCR and western blot. The expression of Nrf2 was silenced using siRNA.

RESULTS

Data indicated that KMF (20 μM) reversed PA-induced increased triglyceride (TG) levels and total lipid content. These effects were accompanied by down-regulation of the mRNA and protein levels of lipogenic genes (FAS, ACC and SREBP1), and up-regulation of genes related to fatty acid oxidation (CPT-1, HADHα and PPARα). Kaempferol significantly decreased the levels of the oxidative stress markers (ROS and MDA) and enhanced the activities of antioxidant enzymes SOD and GPx in PA-challenged cells. Luciferase analysis showed that KMF increased the transactivation of Nrf2 in hepatocytes. The results also revealed that KMF-mediated activation of Nrf2 target genes was suppressed by Nrf2 siRNA. Furthermore, Nrf2 siRNA abolished the KMF-induced reduction in ROS and MDA levels in PA treated cells. In addition, the inhibitory effect of KMF on TG levels and the mRNA and protein levels of FAS, ACC and SREPB-1 were significantly abolished by Nrf2 inhibition. Nrf2 inhibition also suppressed the KMF-induced activation of genes involved in β oxidation (CPT-1 and PPAR-α).

CONCLUSION

The results suggest that KMF protects HepG2 cells from PA-induced lipid accumulation via activation of the Nrf2 signaling pathway.

Kaempferol Protects Against Retinal Photoreceptor Degeneration in a Mouse Model of Light-Induced Retinal Injury

Purpose: Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries with little in the way of treatment that prevents progression to end-stage disease. Kaempferol (KF) is a plant-derived dietary flavonoid that has demonstrated as a strong antioxidant showing neuroprotection in stroke models. We hypothesize that KF has protective effects against retinal degeneration and may serve as a therapeutic agent against AMD. Methods: BALB/c albino mice were assigned to 1 of 2 groups: control-treated or KF-treated retinal light injury mice. Mice were exposed to 8,000 lux cool white fluorescent light for 2 h to induce light injury. Control or KF was injected intraperitoneally after light injury for 5 days. Scotopic electroretinography (ERG) was recorded before light injury and 7 days after light injury. The retinal morphology and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed after light injury. Results: ERG a- and b-wave amplitudes were significantly reduced in the retinal light injury group compared with the nonretinal light injury group. Retinal light injury produced markedly thinning of the outer nuclear layer along with significant TUNEL-positive signals. In contrast KF treatments significantly attenuated reduction of ERG a- and b- wave amplitudes and the loss of the outer nuclear layer. Conclusions: KF protects retinal photoreceptors and preserves retinal function against retinal degeneration caused by light injury. These initial findings suggest that KF may represent a novel therapy for retinal degenerative conditions such as AMD.

Investigation of Pharmacological Mechanisms of Yinhua Pinggan Granule on the Treatment of Pneumonia through Network Pharmacology and In Vitro

Yinhua pinggan granule (YHPGKL), a traditional Chinese medical compound, could treat pneumonia. Although previous studies demonstrated the protective and therapeutic effects of YHPGKL on pneumonia, its potential molecular mechanisms and its effective components are still elusive. Herein, we performed a network pharmacology analysis to determine the possible signaling pathways involved in the protective effects of components of YHPGKL. A total of 119 components and 257 target proteins of YHPGKL were identified, among which 117 effective components interacted with 113 proteins related to pneumonia. Then, a compound-effective component-target protein network was established to screen the effective hub components. The top three effective components, namely luteolin, kaempferol, and quercetin, were selected. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of 113 proteins revealed a significant enrichment term associated with host immune and anti-infectious responses. Furthermore, by constructing a protein-protein interaction network between common proteins, ten hub proteins were identified, among which three hub components hit eight proteins. A further molecular docking analysis confirmed that the three effective hub components had a good affinity with six hub proteins. Eventually, the interactions were further visualized and screened on account of an infectious macrophage model in vitro. The results noted that three components could inhibit proinflammatory related hub genes but had no effect on survival-related hub genes. Thus, the three effective hub components and corresponding hub genes may play essential roles in the treatment of YHPGKL on pneumonia.

Wnt inhibitory factor 1 ameliorated diabetic retinopathy through the AMPK/mTOR pathway-mediated mitochondrial function

Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus and will lead to visual impairment. We aim to explore the effects and mechanisms of wnt inhibitory factor 1 (WIF1) in the progression of DR. To establish DR in vitro and in vivo, human retinal pigment epithelium (RPE) cell line ARPE-19 was treated with high-glucose (HG) and diabetic mice models were induced by streptozotocin (STZ), respectively. Different dose of recombinant WIF1 protein was used to treat DR. qRT-PCR and western blotting results demonstrated that WIF1 was downregulated, while VEGFA was upregulated in HG-induced ARPE-19 cells. WIF1 overexpression promoted cell migration. The ARPE-19 cells culture medium treated with WIF1 inhibited retinal endothelial cell tube formation and downregulated VEGFA expression. Moreover, WIF1 decreased the levels of ROS and MDA, while increasing the activity of SOD and GPX. WIF1 increased the ΔΨm in the mitochondria and downregulated the expression of mitochondrial autophagy-related proteins including Parkin, Pink1, LC3-II/LC3-I ratio, cleaved caspase 3, and cyt-c, which ameliorated mitochondrial dysfunction. The in vivo studies further demonstrated the consistent effects of WIF1 in STZ-induced mice. Taken together, WIF1 ameliorated mitochondrial dysfunction in DR by downregulating the AMPK/mTOR pathway.

The transcriptome profile of RPE cells by the fullerenol against hydrogen peroxide stress

Age-related macular degeneration (AMD) causes central vision impairment with increased incidence. In the pathogenesis of AMD, reactive oxygen species (ROS) are associated with RPE cell apoptosis. H₂O₂ is an oxidative toxicant and is used to establish the AMD in vitro model. However, the mechanisms of ROS in H₂O₂-induced AMD are still unclear. Fullerenol, a promising antioxidant of nanomaterials, protects RPE cells from ROS attack. In addition to working as a scavenger, little is known about the antioxidant mechanism of fullerenol in RPE cells. In this study, transcriptome sequencing was performed to examine the global changes in mRNA transcripts induced by H₂O₂ in human ARPE-19 cells. Moreover, we comprehensively investigated the protective effects of fullerenol against H₂O₂-induced oxidative injury by RNA sequencing. Gene Ontology enrichment analysis showed that those pathways related to the release of positive regulation of DNA-templated transcription and negative regulation of apoptotic process were affected. Finally, we found that 12 hub genes were related to the oxidative-protection function of fullerenol. In summary, H₂O₂ affected these hub genes and signaling pathways to regulate the senescence of RPE cells. Moreover, fullerenol is a potent nanomaterial that protects the RPE and would be a promising approach for AMD prevention.

The Association of Oxidative Stress and Reactive Oxygen Species Modulator 1 (ROMO1) with Infertility: A Mini Review

Infertility is one of the disorders that worries many couples around the world, although novel and molecular methods can be used to cure this disease in different stages. One of the factors that causes infertility in men and women is the increased oxidative stress within the cells, which can lead to damage in zygote formation. ROMO1 is one of the most important proteins in the production of reactive oxygen species. This protein can enhance oxidative stress in the cells and body through cellular pathways, such as TNF-α and NF-κB routes, which will eventually lead to many diseases, especially infertility. We engage several international databases by using keywords; ROMO1, Infertility, and Reactive Oxygen Species, and gained a great quantity of information about ROMO1, Infertility, and Oxidative Stress. Although not proven, it is hypothesized that ROMO1 might elevate oxidative stress by activating NF-κB pathway in the cells, furthermore, TNF-α can arouse ROMO1 that can end up with apoptosis and cell death, which consequently can have a lot of disturbing effects on the body, especially the reproductive system. To sum up, revealing the exact cellular and molecular mechanisms of ROMO1-dependent TNF-α and NF-κB pathways in the pathogenesis of infertility might find interesting therapeutic and management strategies for this disorder.

Pharmacological Mechanism of Zuojin Pill for Gastroesophageal Reflux Disease: A Network Pharmacology Study

Background. Although Zuojin Pill (ZJP) is widely used in China as a traditional prescription to treat gastroesophageal reflux disease (GERD), its exact mechanism of action is still unknown. Therefore, we employed network pharmacology (NP), molecular docking (MD), and molecular dynamics simulation (MDS) to investigate the pharmacological mechanisms of ZJP against GERD. Methods. Active compounds and target genes corresponding to ZJP and target genes related to GERD were identified through analysis of publicly available datasets. Subsequently, the obtained data were subjected to further network pharmacological analysis to explore the potential key active compounds, core target genes, and biological processes (BPs) associated with the effect of ZJP against GERD. Finally, the prediction results of NP were validated by MD, and MDS of the optimal core protein-ligand for each component obtained by MD were performed using Gromacs 2020 software. Results. Twelve active components of ZJP were identified to act on 82 target genes associated with GERD, and ZJP might exert an anti-GERD effect through the regulation of BPs such as reactive oxygen species (ROS) metabolism, response to oxidative stress (OS), and ROS, as well as the activation of signaling pathways such as apoptosis, p53 signaling, chemical carcinogenesis-ROS, and HIF-1 signaling pathways. Furthermore, quercetin, kaempferol, and coptisine, the three key components of ZJP were shown to stably bond with the 14 core target genes, including AKT1, MMP2, TP53, EGFR, JUN, CASP3, CXCL8, HIF1α, IL-1β, MYC, PPARG, MMP9, PTGS2, and FOS. Results from MDS showed that PPARG-quercetin and MMP2-quercetin bound more stably. Conclusions. The findings suggest that ZJP alleviates the symptoms of GERD and improves the prognosis by regulating ROS metabolism, thereby reducing the secretion of proinflammatory cytokines like IL-1β, COX-2, CXCL8, and MMPs, regulating the expression of oncogenes such as JUN and FOS, and maintaining the normal expression of tumor suppressor genes such as TP53 and MYC. However, whether the effect of this modulation of ROS metabolism is positive or negative needs to be further verified by pharmacological experiments.

Diabetic retinopathy: Involved cells, biomarkers, and treatments

Diabetic retinopathy (DR), a leading cause of vision loss and blindness worldwide, is caused by retinal neurovascular unit dysfunction, and its cellular pathology involves at least nine kinds of retinal cells, including photoreceptors, horizontal and bipolar cells, amacrine cells, retinal ganglion cells, glial cells (Müller cells, astrocytes, and microglia), endothelial cells, pericytes, and retinal pigment epithelial cells. Its mechanism is complicated and involves loss of cells, inflammatory factor production, neovascularization, and BRB impairment. However, the mechanism has not been completely elucidated. Drug treatment for DR has been gradually advancing recently. Research on potential drug targets relies upon clear information on pathogenesis and effective biomarkers. Therefore, we reviewed the recent literature on the cellular pathology and the diagnostic and prognostic biomarkers of DR in terms of blood, protein, and clinical and preclinical drug therapy (including synthesized molecules and natural molecules). This review may provide a theoretical basis for further DR research.

Mechanisms of Qing-Gan Li-Shui Formulation in Ameliorating Primary Open Angle Glaucoma: An Analysis Based on Network Pharmacology

Objective

In this study, we investigated the mechanism of Qing-Gan Li-Shui formulation (QGLSF) in treating primary open glaucoma (POAG) by network pharmacology and in vitro experiments.

Methods

The active pharmaceutical ingredients (APIs) of GLQSF (prepared with Prunella vulgaris, Kudzu root, Plantago asiatica, and Lycium barbarum) were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and Yet Another Traditional Chinese Medicine database (YATCM). The targets of POAG were screened out with GeneCards, OMIM, PharmGKB, Therapeutic Target Database (TTD), and DrugBank databases. The Venny platform was used to summarize the core targets. Topological analysis was performed using Cytoscape3.8.0. A protein-protein interaction network was plotted by STRING online. The key targets were subjected to GO and KEGG enrichment analyses. Finally, the effects of APIs were verified by a model of chloride hexahydrate (CoCl₂)-induced retinal ganglion cells-5 (RGC-5).

Results

The main APIs were selected as quercetin (Que) by network pharmacology. Nine clusters of QGLSF targets were obtained by the PPI network analysis, including AKT-1, TP53, and JUN. KEGG enrichment analysis showed that these targets were mainly involved in the AGE-RAGE signaling pathway. By in vitro experiments, Que promoted cell proliferation. The secretion of AKT-1, TP53, JUN, AGE, and RAGE in the cell culture supernatant decreased, as shown by ELISA. The mRNA levels of AKT-1, TP53, JUN, and RAGE decreased, as shown by RT-PCR. QGLSF may employ the AGE-RAGE signaling pathway to counter POAG.

Conclusion

This study preliminarily elucidates the efficacy and mechanism of QGLSF in the treatment of POAG.

Cuscuta chinensis Lam. Protects Against Light-Induced Retinal Degeneration: Therapeutic Implications for Photoreceptor Degenerative Disorders

Cuscuta chinensis Lam. (CCL) is a medicinal herb widely used in traditional Chinese medicine for the treatment of ophthalmic diseases, including age-dependent vision-threatening retinal degenerative disorders that involve irreversible loss of the first-order retinal neurons, photoreceptors. However, evidence is lacking if CCL is pharmacologically active at protecting against loss of photoreceptors and photoreceptor degeneration-associated retinal structural and functional impairment. The current study thus evaluates the potential photoreceptor protective effects of CCL to better support its clinical applications in the prevention and treatment of photoreceptor degenerative diseases. Non-invasive full-retinal optical coherence tomography, electroretinography, histological examination, immunohistochemistry and real-time qPCR analysis were performed to assess the retinal protective effects of CCL in light-exposed BALB/c mice characterized by photooxidative stress-mediated photoreceptor loss and associated retinal morphological and functional impairment. The results showed that CCL treatment protected against light-induced degeneration of the photoreceptor structure and deterioration of the retinal function. Furthermore, CCL treatment increased the retinal expression of rhodopsin, S-opsin and M-opsin, supporting the protective effects of CCL in both rod and cone photoreceptors. CCL treatment suppressed photoreceptor cell death in the light-exposed retinas. The morphological integrity of the second-order retinal neurons was also preserved as a result of CCL treatment. In addition, CCL treatment attenuated light-induced reactive müller gliosis, microglial activation and inflammation in the retina. In conclusion, the current work demonstrates for the first time that CCL protects against photooxidative stress-mediated degeneration of photoreceptors and associated disturbance of structural, functional and immune homeostasis of the retina. The findings here thus provide novel experimental evidence supporting the clinical application of CCL in the prevention and treatment photoreceptor degenerative diseases.

Mechanism of Ba Zhen Tang Delaying Skin Photoaging Based on Network Pharmacology and Molecular Docking

Purpose

To study the efficacy of Ba Zhen Tang in delaying skin photoaging and its potential mechanism based on network pharmacology and molecular docking.

Methods

First, we screened the active components and targets of Ba Zhen Tang by Traditional Chinese Medicine Database and Analysis Platform (TCMSP) and The Universal Protein Resource (UniProt). The target genes of skin photoaging were obtained from GeneCards and GeneMap database. Then, we analyzed the protein–protein interaction (PPI) by STRING database. The network map was constructed by Cytoscape. Finally, we performed Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis by Metascape database. The molecular docking via Autodock Vina and Pymol. Furthermore, skin photoaging cellular models were established, and the effects of Ba Zhen Tang on ameliorating skin photoaging were investigated.

Results

A total of 160 active ingredients in Ba Zhen Tang and 60 targets of Ba Zhen Tang for delaying skin photoaging were identified. By GO enrichment analysis, 1153 biological process entries, 45 cellular component entries and 89 molecular functional entries were obtained. A total of 155 signal pathways were obtained by KEGG analysis. Ba Zhen Tang is related to MAPK signaling pathway, TNF signaling pathway and AGE-RAGE signaling pathway in diabetic complications, etc., which directly affect the key nodes of photoaging. The molecular docking results showed that there was a certain affinity between the main compounds (kaempferol, quercetin, β-sitosterol, naringenin) and core target genes (PTGS2, CASP3, MAPK1, MAPK3, TP53). Ba Zhen Tang-treated mouse serum inhibited the senescence and p16^INK4a expression of human immortalized keratinocyte (HaCaT) cells irradiated by ultraviolet-B (UVB).

Conclusion

Our study elucidated the potential pharmacological mechanism of Ba Zhen Tang in the treatment of photoaging through multiple targets and pathways. The therapeutic effects of Ba Zhen Tang on skin photoaging were validated in cellular models.

Recent Developments of Nanostructures for the Ocular Delivery of Natural Compounds

Ocular disorders comprising various diseases of the anterior and posterior segments are considered as the main reasons for blindness. Natural products have been identified as potential treatments for ocular diseases due to their anti-oxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, most of these beneficial compounds are characterised by low solubility which results in low bioavailability and rapid systemic clearance thus requiring frequent administration or requiring high doses, which hinders their therapeutic applications. Additionally, the therapeutic efficiency of ocular drug delivery as a popular route of drug administration for the treatment of ocular diseases is restricted by various anatomical and physiological barriers. Recently, nanotechnology-based strategies including polymeric nanoparticles, micelles, nanofibers, dendrimers, lipid nanoparticles, liposomes, and niosomes have emerged as promising approaches to overcome limitations and enhance ocular drug bioavailability by effective delivery to the target sites. This review provides an overview of nano-drug delivery systems of natural compounds such as thymoquinone, catechin, epigallocatechin gallate, curcumin, berberine, pilocarpine, genistein, resveratrol, quercetin, naringenin, lutein, kaempferol, baicalin, and tetrandrine for ocular applications. This approach involves increasing drug concentration in the carriers to enhance drug movement into and through the ocular barriers.

Contribution of Müller Cells in the Diabetic Retinopathy Development: Focus on Oxidative Stress and Inflammation

Diabetic retinopathy is a neurovascular complication of diabetes and the main cause of vision loss in adults. Glial cells have a key role in maintenance of central nervous system homeostasis. In the retina, the predominant element is the Müller cell, a specialized cell with radial morphology that spans all retinal layers and influences the function of the entire retinal circuitry. Müller cells provide metabolic support, regulation of extracellular composition, synaptic activity control, structural organization of the blood–retina barrier, antioxidant activity, and trophic support, among other roles. Therefore, impairments of Müller actions lead to retinal malfunctions. Accordingly, increasing evidence indicates that Müller cells are affected in diabetic retinopathy and may contribute to the severity of the disease. Here, we will survey recently described alterations in Müller cell functions and cellular events that contribute to diabetic retinopathy, especially related to oxidative stress and inflammation. This review sheds light on Müller cells as potential therapeutic targets of this disease.

Long non‑coding RNA MALAT1 is involved in retinal pigment epithelial cell damage caused by high glucose treatment

The present study aimed to explore the role of long non‑coding RNA metastasis associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) in high glucose (HG)‑induced ARPE‑19 cell damage. ARPE‑19 cells were cultured and treated with HG (25 mmol/l glucose). MALAT1 expression was silenced following transfection of small interfering RNA. Cell apoptosis was measured using flow cytometry. The cellular levels of reactive oxygen species (ROS), malondialdehyde and superoxide dismutase activity were all measured to examine oxidative stress. Gene expression levels of MALAT1 were determined by reverse transcription‑quantitative (RT‑q)PCR, while expression of tumor necrosis factor (TNF)‑α, monocyte chemotactic protein 1 (MCP‑1), intercellular cell adhesion molecule 1 (ICAM‑1) and vascular endothelial growth factor (VEGF) was detected using RT‑qPCR and western blotting. MALAT1 expression was markedly increased in ARPE‑19 cells treated with HG. HG treatment caused increased apoptosis and elevated ROS‑induced stress in ARPE‑19 cells and these effects could be partly attenuated by MALAT1 knockdown. Increased gene expression levels of TNF‑α, MCP‑1, ICAM‑1 and VEGF induced by HG were also alleviated by MALAT1 inhibition. Therefore, lncRNA MALAT1 is the key factor in ARPE‑19 cell damage caused by HG and may be a promising therapeutic target for clinical DR therapy. However, further studies are still required to reveal the detailed mechanisms underlying lncRNA MALAT1 function.

Discovering the Potential of Natural Antioxidants in Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a multifactorial disease associated with anatomical changes in the inner retina. Despite tremendous advances in clinical care, there is currently no cure for AMD. This review aims to evaluate the published literature on the therapeutic roles of natural antioxidants in AMD. A literature search of PubMed, Web of Science and Google Scholar for peer-reviewed articles published between 1 January 2011 and 31 October 2021 was undertaken. A total of 82 preclinical and 18 clinical studies were eligible for inclusion in this review. We identified active compounds, carotenoids, extracts and polysaccharides, flavonoids, formulations, vitamins and whole foods with potential therapeutic roles in AMD. We evaluated the integral cellular signaling pathways including the activation of antioxidant pathways and angiogenesis pathways orchestrating their mode of action. In conclusion, we examined the therapeutic roles of natural antioxidants in AMD which warrant further study for application in clinical practice. Our current understanding is that natural antioxidants have the potential to improve or halt the progression of AMD, and tailoring therapeutics to the specific disease stages may be the key to preventing irreversible vision loss.

Non-neglectable therapeutic options for age-related macular degeneration: A promising perspective from traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Age-related macular degeneration (AMD) is a chronic neurodegenerative disease which causes irreversible central vision loss among the elderly population. Traditional Chinese Medicine (TCM), including formulas, acupuncture and herbs, has been used in the treatment of AMD for thousands of years and is currently used by many AMD patients around the world.

AIM OF THE REVIEW

A comprehensive, in-depth literature review examining the use of TCM in the treatment of AMD has yet to be compiled. This review will improve current knowledge relating to the use of TCM and will open new avenues of exploration in developing new drugs for the treatment of AMD.

METHODS

A literature search of the PubMed database, Web of Science, Google Scholar and China National Knowledge Infrastructure (CNKI) was performed using relevant terms and keywords related to TCM in the treatment of AMD. Related books, PhD and master's theses were also researched.

RESULTS

The TCM-based interpretation of AMD has been used to establish a theoretical foundation for understanding the effect of TCM formulas and acupuncture on AMD. The possible mechanism of action of common Chinese herbs has also been discussed in detail.

CONCLUSION

TCM is a promising treatment option of AMD patients. However, lack of rigorous scientific evidence has limited the impact and uptake of TCM therapy. Future research should focus on improving understanding of the mechanism of action and bioactive components of TCM therapies.

Mechanisms of Kaempferol in the treatment of diabetes: A comprehensive and latest review

Obesity-insulin resistance-β-cells apoptosis" is an important trilogy of the pathogenesis of type 2 diabetes. With the global pandemic of obesity and diabetes, continuous research and development of new drugs focuses on the prevention of the pathological progress of these diseases. According to a recent study, the natural product kaempferol has excellent antidiabetic effects. Therefore, this review comprehensively summarized the frontier studies and pharmacological mechanisms of kaempferol in the treatment of diabetes. The successful research and development of kaempferol may yield a significant leap in the treatment of diabetes and its complications.

Kaemperfol alleviates pyroptosis and microglia-mediated neuroinflammation in Parkinson's disease via inhibiting p38MAPK/NF-κB signaling pathway

The study aims to investigate whether kaemperfol (KAE) inhibits microglia pyroptosis and subsequent neuroinflammatory response to exert neuroprotective effects, along with the underlying mechanisms. The results showed KAE could ameliorate the behavioral deficits of Parkinson's disease (PD) rats, inhibit the activation of microglia and astrocytes, reduce the loss of TH-positive neurons, down-regulate levels of pyroptosis-related NOD-like receptor family pyrin domain containing 3 (NLRP3), GasderminD-N Term (GSDMD-NT), caspase1, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), interleukin (IL)-1β, and IL-18, and decrease the levels of inflammatory molecules (inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2)) and p38 mitogen-activated protein kinase/nuclear factor-kappaB (p38MAPK/NF-κB) signaling pathway molecules (p38MAPK, p-p38MAPK, NF-κB, and p-NF-κB) in the substantia nigra of PD rats. Further in vitro study indicated that KAE reversed the activation of BV2 cells and down-regulated the expressions of pyrolytic proteins, inflammatory mediators and key molecules in p38MAPK/NF-κB signaling pathway. Collectively, KAE inhibits the microglia pyroptosis and subsequent neuroinflammatory response to exert neuroprotective effects on 6-hydroxydopamine (6-OHDA)-induced PD rats and lipopolysaccharide (LPS)-induced BV2 inflammatory cells through inhibiting p38MAPK/NF-κB signaling pathway.

Natural Biocidal Compounds of Plant Origin as Biodegradable Materials Modifiers

The article presents a literature review of the plant origin natural compounds with biocidal properties. These compounds could be used as modifiers of biodegradable materials. Modification of polymer material is one of the basic steps in its manufacturing process. Biodegradable materials play a key role in the current development of materials engineering. Natural modifiers are non-toxic, environmentally friendly, and renewable. The substances contained in natural modifiers exhibit biocidal properties against bacteria and/or fungi. The article discusses polyphenols, selected phenols, naphthoquinones, triterpenoids, and phytoncides that are natural antibiotics. Due to the increasing demand for biodegradable materials and the protection of the natural environment against the negative effects of toxic substances, it is crucial to replace synthetic modifiers with plant ones. This work mentions industries where materials containing natural modifying additives could find potential applications. Moreover, the probable examples of the final products are presented. Additionally, the article points out the current world's pandemic state and the use of materials with biocidal properties considering the epidemiological conditions.

Mangiferin and Hesperidin Transdermal Distribution and Permeability through the Skin from Solutions and Honeybush Extracts (Cyclopia sp.)-A Comparison Ex Vivo Study

Polyphenolic compounds—mangiferin and hesperidin—are, among others, the most important secondary metabolites of African shrub Cyclopia sp. (honeybush). The aim of this study was to compare the percutaneous absorption of mangiferin and hesperidin from solutions (water, ethanol 50%, (v/v)) and extracts obtained from green and fermented honeybush (water, ethanol 50%, (v/v)). Research was performed with the Bronaugh cells, on human dorsal skin. The mangiferin and hesperidin distributions in skin layers (stratum corneum, epidermis, and dermis) and in acceptor fluid (in every 2, 4, 6, and 24 h) were evaluated by HPLC–Photodiode Array Coulometric and Coulometric Electrochemical Array Detection. The transdermal distribution of hesperidin was also demonstrated by fluorescence microscopy. Results indicated that mangiferin and hesperidin were able to cross the stratum corneum and penetrate into the epidermis and dermis. An advantage of hesperidin penetration into the skin from the water over ethanol solution was observed (451.02 ± 14.50 vs. 357.39 ± 4.51 ng/cm²), as well as in the mangiferin study (127.56 ± 9.49 vs. 97.23 ± 2.92 ng/cm²). Furthermore, mangiferin penetration was more evident from nonfermented honeybush ethanol extract (189.85 ± 4.11 ng/cm²) than from solutions. The permeation of mangiferin and hesperidin through the skin to the acceptor fluid was observed regardless of whether the solution or the honeybush extract was applied. The highest ability to permeate the skin was demonstrated for the water solution of hesperidin (250.92 ± 16.01 ng/cm²), while the hesperidin occurring in the extracts permeated in a very low capacity. Mangiferin from nonfermented honeybush ethanol extract had the highest ability to permeate to the acceptor fluid within 24 h (152.36 ± 8.57 ng/cm²).

Kaempferol inhibits the cell migration of human hepatocellular carcinoma cells by suppressing MMP-9 and Akt signaling

Metastasis is the most prevalent cause of cancer-related deaths and treatment failure in patients with hepatocellular carcinoma (HCC). Kaempferol is a natural flavonol belonging to the subgroup of flavonoids and exhibits potent anticancer activities. This study provides molecular evidence on the anti-invasive and anti-migratory effects of kaempferol on human HCC cells. The anti-invasive effect was investigated by applying kaempferol on two human HCC cell lines (Huh-7 and SK-Hep-1). Kaempferol reduced the invasion and migration of Huh-7 and SK-Hep-1 cells by Boyden chamber invasion assay and wound healing assay, respectively. A protease array analysis showed that Matrix Metalloproteinase-9 (MMP-9) was dramatically downregulated in HCC cells after kaempferol treatment. Gelatin zymography and Western blot assay showed that kaempferol reduced the activities and protein expression of MMP-9, respectively. Kaempferol also sufficiently suppressed the phosphorylation of the Akt expression. Overall, kaempferol inhibited the invasive properties of human HCC cells by targeting MMP-9 and Akt pathways. Hence, kaempferol could be used as an adjuvant therapeutic agent for the treatment of human HCC cells.