Jian Ni

Branch retinal vein occlusion (BRVO) is a retinal vascular disorder characterized by ischemia and hypoxia. These pathological conditions contribute to retinal pigment epithelial (RPE) cell injury through oxidative stress and ferroptosis. However, whether baicalin (BC) protects against hypoxia-induced RPE injury remains unclear. CoCl₂-induced hypoxic ARPE-19 cells were used to evaluate the protective effects and potential mechanisms of BC. BC improved cell viability and reduced LDH release under hypoxic conditions. BC markedly suppressed hypoxia-induced inflammatory responses, as evidenced by reduced p65 and ICAM-1 expression and decreased release of pro-inflammatory cytokines. Moreover, BC alleviated oxidative stress by reducing ROS and MDA accumulation and restoring SOD and GSH activity. BC attenuated mitochondrial dysfunction, accompanied by restoration of mitochondrial membrane potential, oxygen consumption rate (OCR), and ATP production. Transmission electron microscopy (TEM) results further confirmed the protective effect of BC on mitochondrial integrity. Mechanistically, BC suppressed ferroptosis by reducing intracellular Fe²⁺ accumulation and lipid peroxidation, accompanied by downregulation of TFR1, ACSL4, and p53, as well as upregulation of SLC7A11 and GPX4. These findings suggest that BC protects ARPE-19 cells against hypoxia-induced injury through preservation of mitochondrial function and inhibition of ferroptosis.

Objectives: This study aimed to develop curcumin nanoparticles (Cur@PCL-PEG-MF/cRGDfc) with retinal-targeting capability and to evaluate their biological effects and pharmacological mechanisms in vitro. Methods: After synthesis of the carrier framework, metformin (MF) and cRGDfc were conjugated to the carrier material using the carbodiimide method and Michael addition reaction, respectively. Subsequently, self-assembled nanoparticles were formed from the carrier and curcumin under specific conditions. The materials were characterized by spectroscopy, chromatography, elemental analysis, energy-dispersive spectroscopy and X-ray diffraction. The efficacy of the formulation was evaluated in two cell lines, ARPE-19 and HUVEC-T1. In addition, the pharmacological mechanism was explored using transcriptome sequencing as a complementary approach. Key Findings: Self-assembled nanoparticles were successfully prepared by combining the two modified carrier materials, PCL-PEG-MF and PCL-PEG-cRGDfc, with curcumin. The nanoparticles exhibited an encapsulation efficiency of 78.09%, a particle size of 162.33 nm, and a zeta potential of −23.28 mV and displayed a spherical morphology. They showed sustained release in simulated physiological conditions and stronger affinity for ARPE-19 cells under oxidative stress. Nearly 100% of the nanoparticles were internalized by the cells, which was accompanied by reduced ROS and LDH release and decreased DNA fragmentation. In addition, the nanoparticles inhibited neovascularization by reducing VEGF-A release, thereby potentially protecting the retina in macular degeneration and reducing choroidal hemorrhage. Further analyses showed that curcumin and its nanoformulations significantly reduced the expression of inflammatory factors such as IL-1β and IL-18, lowered the protein levels of Caspase-1, GSDMD-N, and NLRP3, and increased AMPK levels. Conclusions: Using PCL-PEG as the carrier framework, MF and cRGDfc were conjugated to construct a curcumin-loaded nanoparticle with retinal-targeting capability. This nanoparticle, characterized by a small particle size, sustained release, and targeted delivery to retinal pigment epithelium (RPE) cells under oxidative stress, alleviated oxidative stress-induced damage. Its therapeutic effect may be mediated, at least in part, by interference with the AMPK/mTOR pathway and activation of the NLRP3/Caspase-1/GSDMD pathway.

The incidence of primary liver cancer is increasing annually, with extremely high mortality and suboptimal therapeutic outcomes. The inefficient presentation of tumor antigens and low infiltration of specific cytotoxic T lymphocytes (CTLs) result in insufficient immunogenicity, which limits the efficacy of immunotherapy. Despite the popularity of immune checkpoint inhibitors (ICIs), insufficient immune activation means only a small subset of hepatocellular carcinoma (HCC) patients exhibit clinical responses to ICIs, showing significant inter-individual variability. The activation of the cyclic GMP-AMP synthase(cGAS)- stimulator of interferon genes(STING) pathway initiates the expression of type I interferons (IFNs) and inflammatory cytokines, promoting the formation of a pro-inflammatory environment at the tumor site. This pathway enhances anti-tumor immune responses by facilitating antigen processing and presentation, T cell priming and activation, and remodeling of the immunosuppressive microenvironment. Our research found that cucurbitacin B (CuB), a natural component derived from traditional Chinese medicine, had significant anti-hepatocellular carcinoma properties and exerted anti-tumor effects through the cGAS-STING pathway. Specifically, CuB regulated ferroptosis by down-regulating the expression of Solute Carrier Family 7 Member 11 (SLC7A11) and Glutathione Peroxidase 4 (GPX4) and upregulating the expression of Transferrin Receptor Protein 1 (TFR1) and Long-chain Acyl-CoA Synthetase 4 (ACSL4). These actions involved lipid substrates, iron ion homeostasis, and antioxidant defense systems. The release of mitochondrial DNA (mtDNA) triggered by ferroptosis activated the cGAS-STING immune signaling pathway, leading to the up-regulation of cGAS, phosphorylated STING (p-STING), phosphorylated TANK-binding kinase 1 (TBK1), phosphorylated Interferon regulatory factor3 (IRF3), and Interferon-β (IFN-β). This cascade activation pattern provides new insights into the drug treatment of tumors.

Pyroptosis is a type of programmed cell death (PCD) with pro-inflammatory properties, which is characterized by the swelling with bubbles and the release of LDH and inflammatory cell cytokines. Polyphyllin II (PPII) is the main active ingredient of the Chinese herb Rhizoma Paridis and has been proven to exert high efficacy against a variety of malignant tumors. At present, the anti-tumor research on PPII mainly focuses on apoptosis that is an anti-inflammatory type of PCD, but other potential modes of death cell death and mechanisms of PPII remain to be discovered. Here, we first found that PPII could effectively inhibit the growth of hepatocellular carcinoma (HCC) cells via pyroptosis. After treatment with PPII, the morphology of swelling with bubbles and the formation of pores in the cell membrane in HCC cells were observed, and LDH and cell cytokines (IL-1β, IL-18, IL-6, TNF-α, IFN-β, and IFN-γ) were released. Furthermore, the flow cytometry results showed that PPII could activate oxidative stress by increasing Ca²⁺ influx, thereby promoting the production of ROS to exert anti-tumor effects. RNA sequencing revealed that pyroptosis is closely linked to several signaling pathways, including the MAPK, TNF, Rap1, mTOR, and FoxO pathways, as well as the PD-L1 expression and PD-1 checkpoint pathway. An in vivo study demonstrated that PPII treatment suppressed liver tumor growth in mice by pyroptosis in a dose-dependent manner, and it showed no obvious side effects within a certain range. The Western blot results of tumor tissues revealed that the pyroptosis effect of PPII on liver cancer was associated with the activation of the NLRP3/Caspase1/GSDMD pathway, which upregulates the expression of NLRP3, Cleaved-Caspase 1, GSDMD-N, IL-1β, and IL-18 proteins and downregulates the expression of pro-Caspase 1 and GSDMD proteins. In summary, our findings revealed the pyroptosis effect and mechanism of PPII in HCC cells in vitro and in vivo, suggesting that PPII may be used as a potential pyroptosis inducer for HCC treatment in the future.

This study aimed to establish a method for quantifying baicalin (BC) in rabbit ocular tissues and plasma, and evaluate the pharmacological efficacy and pharmacokinetic properties of BC and BC@HS15/DSPE-PEG2000-L-Val, a novel ocular formulation for dry eye treatment. BC@HS15/DSPE-PEG2000-L-Val or free BC was administered via eye drops to benzalkonium chloride (BAC)-induced dry eye mice. Corneal and conjunctival tissues were assessed for anti-dry eye efficacy. BC concentrations in cornea, conjunctiva, aqueous humor, and ocular plasma were quantified using LC–MS/MS. Noncompartmental pharmacokinetic parameters (AUC, Tmax) were calculated using DAS 2.0 software. The method demonstrated excellent linearity (0.50–500.00 ng/mL, r > 0.9905), precision (RSD < 10%), and accuracy (± 13%). Compared to free BC, BC@HS15/DSPE-PEG2000-L-Val significantly increased tear secretion, reduced MMP-3/MMP-9 expression, and preserved corneal epithelium integrity. In the micelle group, corneal and conjunctival Cmax values were 2.7- and 3.6-fold higher than the solution group, respectively. A sensitive and validated liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed to measure baicalin concentrations in ocular plasma and tissues of rabbits. BC@HS15/DSPE-PEG2000-L-Val for treating dry eye demonstrated significantly superior outcomes. The nano-micelle notably enhanced BC concentration on the ocular surface and effectively prolonged its retention time. Graphical abstract

Cucurbitacin B (CuB), a tetracyclic triterpenoid compound isolated from Cucurbitaceae plants, exhibits inhibitory effects on various tumor cells (e.g., liver, gastric, and colorectal cancer cells). Since the 1970s–1980s, cucurbitacin tablets containing CuB have been used as an adjuvant therapy for chronic hepatitis and primary liver cancer. CuB exerts anticancer effects through multiple mechanisms: inducing apoptosis, cell cycle arrest (G2/M or S phase), autophagy, and cytoskeleton disruption; inhibiting migration, invasion, and angiogenesis (via VEGF/FAK/MMP-9 and Wnt/β-catenin pathways); regulating metabolic reprogramming and immune responses; inducing pyroptosis, ferroptosis, and epigenetic changes; and reversing tumor drug resistance. These effects are associated with signaling pathways like JAK/STAT, PI3K/Akt/mTOR, and FOXM1-KIF20A. To improve its application potential, strategies such as structural modification (e.g., NO donor conjugation), combination therapy (with gemcitabine or cisplatin), and nanomaterial-based delivery (e.g., liposomes and exosome-mimicking nanoparticles) have been developed to enhance efficacy, reduce toxicity, and improve bioavailability. CuB shows broad-spectrum anticancer activity, but further research is needed to clarify the mechanisms underlying its cell-specific sensitivity and interactions with the immune system. This review systematically summarizes the physicochemical properties, anticancer mechanisms, and strategies for applying CuB and suggests future research directions, providing references for scientific research and clinical translation.

Diabetic nephropathy (DN) represents a severe microvascular complication of diabetes mellitus. As a Traditional Chinese Medicine (TCM) with extensive clinical applications, Ligustri Lucidi Fructus (LLF) exhibits significant anti-DN activity. However, the underlying pharmacological mechanisms, crucial components, and targets for LLF in DN treatment remain unclear. By integrating network pharmacology, molecular docking, and molecular dynamics simulations, the bioactive compounds, potential therapeutic targets, and underlying mechanisms of LLF in the treatment of DN were elucidated, followed by biological validation in a palmitic acid (PA)-induced MPC5 podocyte injury model. Among the 383 DN-related LLF targets identified, TNF emerged as a pivotal one, demonstrating potential binding interaction with the active components salidroside (Sal), apigenin (Api), and tormentic acid (TA). Moreover, Gene Expression Omnibus (GEO) database and KEGG enrichment analysis collectively highlighted the cytosolic DNA-sensing pathway. Notably, the cGAS-STING pathway is central to this pathway. Experimental studies further demonstrated that LLF-containing serum exerted a protective effect on MPC5 podocytes through cGAS-STING pathway suppression. Overall, these findings elucidate the pleiotropic mechanisms underlying LLF’s protective effects against DN, integrating compound–target–pathway interactions and thus offering a rationale for further investigation.

Psoriasis, a chronic inflammatory skin disorder, is driven by dysregulated immune responses and keratinocyte dysfunction. Here, we explore the therapeutic potential of Astilbin (AST), a flavonoid with potent anti-inflammatory properties, in modulating ferroptosis and the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in IL-17-stimulated HaCaT keratinocytes. Our psoriatic cell model recapitulated key pathological features, including hyperproliferation, membrane integrity loss, mitochondrial dysfunction, and heightened oxidative stress, alongside elevated proinflammatory cytokine levels. Ferroptosis-related biomarkers were significantly altered, with increased malondialdehyde (MDA) accumulation, reduced glutathione (GSH) levels, iron overload (Fe²⁺), and enhanced lipid peroxidation (detected via C11-BODIPY). Mechanistically, mitochondrial damage triggered cytoplasmic leakage of mitochondrial DNA (mtDNA), activating the cGAS-STING pathway, as evidenced by upregulated pathway-associated protein expression. AST intervention effectively mitigated these pathological changes by suppressing ferroptosis and modulating cGAS-STING signaling. These findings reveal a dual-pathway regulatory mechanism, positioning AST as a promising therapeutic candidate for psoriasis. By elucidating the interplay between ferroptosis and the cGAS-STING pathway, this study provides new insights into psoriatic inflammation and offers a rationale for targeting these pathways in therapeutic strategies.

Hypoxic damage to retinal pigment epithelial (RPE) cells and subsequent neovascularization are key factors in the pathogenesis of branch retinal vein occlusion (BRVO). Naringin (NG), a naturally occurring flavanone glycoside, has demonstrated significant antioxidant and anti-neovascular activities. However, the regulatory effects and mechanisms of NG on ferroptosis in BRVO are yet to be explored. Our study aimed to investigate the protective effects of NG on RPE cells under hypoxic stress and to elucidate the underlying molecular mechanisms. Our findings revealed that NG significantly reduced cytotoxicity induced by cobaltous chloride (CoCl₂) and also inhibited vascular proliferation in the retina, thereby attenuating choroidal neovascularization. NG pretreatment largely countered the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA) triggered by hypoxic damage, while also restoring levels of the antioxidants glutathione (GSH) and superoxide dismutase (SOD). Furthermore, NG pretreatment significantly activated the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and its downstream heme oxygenase-1 (HO-1) and NADPH dehydrogenase (NQO1). In conclusion, NG not only inhibits neovascularization but also alleviates inflammation in RPE cells by modulating the HO-1/GPX4 pathway to inhibit ferroptosis. These findings highlight the potential of NG as a promising therapeutic agent for the treatment of BRVO.