In traditional herbal medicine, the Polyscias fruticosa has been frequently used for the treatment of ischemia and inflammation. Oxidative stress mediated by elevated glutamate levels cause neuronal cell death in ischemia and various neurodegenerative diseases. However, so far, the neuroprotective effects of this plant extract against glutamate-mediated cell death have not been investigated in cell models. The current study investigates the neuroprotective effects of ethanol extracts of Polyscias fruticosa (EEPF) and elucidates the underlying molecular mechanisms of EEPFs relevant to neuroprotection against glutamate-mediated cell death. The oxidative stress-mediated cell death was induced by 5 mM glutamate treatment in HT22 cells. The cell viability was measured by a tetrazolium-based EZ-Cytox reagent and Calcein-AM fluorescent dye. Intracellular Ca²⁺ and ROS levels were measured by fluorescent dyes, fluo-3 AM and 2′,7′-dichlorodihydrofluorescein diacetate (DCF-DA), respectively. Protein expressions of p-AKT, BDNF, p-CREB, Bax, Bcl-2, and apoptosis-inducing factor (AIF) were determined by western blot analysis. The apoptotic cell death was measured by flow cytometry. The in vivo efficacy of EEPF was evaluated using the Mongolian gerbil mouse by surgery-induced brain ischemia. EEPF treatment showed a neuroprotective effect against glutamate-induced cell death. The EEPF co-treatment reduced the intracellular Ca²⁺ and ROS and apoptotic cell death. Furthermore, it recovered the p-AKT, p-CREB, BDNF, and Bcl-2 levels decreased by glutamate. The EEPF co-treatment suppressed the activation of apoptotic Bax, the nuclear translocation of AIF, and mitogen-activated protein kinase (MAPK) pathway proteins (ERK1/2, p38, JNK). Further, EEPF treatment significantly rescued the degenerative neurons in the ischemia-induced Mongolian gerbil in vivo model. EEPF exhibited neuroprotective properties that suppress glutamate-mediated neurotoxicity. The underlying mechanism of EEPF is increasing the level of p-AKT, p-CREB, BDNF, and Bcl-2 associated with cell survival. It has therapeutic potential for the treatment of glutamate-mediated neuropathology.

The aim of this study was to evaluate the pharmacological efficacy of persimmon leaves in two glaucoma models, microbeads-induced ocular hypertension (OHT) and DBA/2 mouse. Thus, we demonstrated that Ethanol Extract of Diospyros kaki (EEDK) reduced elevated intraocular pressure (IOP) in both mouse models of glaucoma by measurements with a tonometer. In particular, we revealed that retinal ganglion cell loss and optic nerve damage caused by IOP elevation were markedly diminished as assessed by TUNEL assay, H&E staining, and fluorescent staining, while the expression of soluble guanylate cyclase (sGCα-1) increased, when EEDK was administered, as revealed by western blot. Moreover, the b-wave magnitude indicating functional scotopic vision was significantly improved in EEDK-administered DBA/2 mice during the 10-week follow-up study, as observed with electroretinography. Collectively, our results suggested that EEDK could be an effective therapeutic and IOP-lowering agent for preventing and treating retinal degenerative diseases such as glaucoma.

Age-related macular degeneration (AMD) is a leading cause of vision impairment in people over the age of 60. Currently, the FDA-approved drugs for AMD have various side effects, and there is a notable lack of drug development for dry AMD. This study aimed to explore the therapeutic effects of mono-ethyl fumarate (MEF) on AMD. MEF effectively protected ARPE-19 cells from cell death induced by a combination of A2E and blue light exposure. In a C57BL/6J mouse model of retinal degeneration caused by sodium iodate, MEF played a role in preserving retinal thickness and maintaining the layered structure of the retina. It was assessed via fundus imaging, optical coherence tomography, and hematoxylin and eosin staining. Treatment with MEF significantly increased the expression of antioxidant proteins such as HO-1, NQO1, and SOD1 in ARPE-19 cells. Additionally, treatment with MEF significantly increased the levels of the antioxidant proteins SOD1 and GPX4 in the mouse retina. Concurrently, it significantly reduced the levels of apoptosis-related factors, such as the Bax/Bcl-2 ratio and Caspase -3 cleavage. These findings suggest that MEF may represent a promising therapeutic candidate for the management of AMD.

Dysregulated extracellular matrix (ECM) deposition and epithelial–mesenchymal transition (EMT) in the trabecular meshwork (TM) contribute to glaucoma-associated fibrotic remodeling, and lysophosphatidic acid (LPA) potently induces these profibrotic responses in human trabecular meshwork (HTM) cells. We investigated whether an ethanolic extract of Diospyros kaki leaves (EEDK) attenuates LPA-induced fibrosis and explored the underlying mechanisms. HTM cells were stimulated with LPA and treated with ethanol-based EEDK extracts. Expression of ECM/fibrosis-related genes (FN1, ACTA2, COL1A1, COL3A1, COL4A1, COL6A2, CCN2) and EMT markers (CDH2, VIM, SNAI1) was assessed, along with cell migration using a wound-healing assay. Upstream regulatory pathways were examined via transcription factor prediction, AP-1 reporter assays, and analyses of MAPK/AP-1 signaling. Among the extracts tested, the 70% ethanol EEDK extract showed the strongest antifibrotic activity, significantly reducing LPA-induced ECM gene/protein expression and inhibiting HTM cell migration in a dose-dependent manner, whereas the 90% ethanol extract showed minimal effects. LPA robustly activated MAPK-dependent AP-1 signaling, and either pharmacologic inhibition of MAPK pathways or treatment with 70% ethanol EEDK comparably suppressed AP-1 activity and decreased downstream ECM/EMT gene expression. Thus, 70% ethanol EEDK mitigates LPA-induced TM fibrosis by inhibiting MAPK/AP-1-mediated transcription, supporting its potential as an antifibrotic strategy for glaucoma.