bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2025.12.28.696576

Ergothioneine: Evaluation of a Novel Antioxidant for Targeting Ocular Oxidative Stress

He, R.·Ding, W.·Cao, J.·Guo, C.·Li, X.·Xiao, G.
View original source ↗Export metadata ↓

Abstract

PurposeTo evaluate L-Ergothioneine (EGT), a naturally occurring amino acid and endogenous antioxidant, as a novel therapeutic agent for oxidative stress-related ocular diseases. This evaluation specifically aimed to address the challenge of targeted ocular delivery by assessing EGT s antioxidant potency, stability, ocular tolerance, and crucially, its ability to reach the posterior segment (fundus) via topical administration. MethodsThis study evaluated EGT as a novel ocular antioxidant by examining its radical scavenging capacity (DPPH assay compared to glutathione, astaxanthin, and coenzyme Q10), stability (at 40{degrees}C/75% relative humidity for six months using HPLC), ocular tolerance (using a New Zealand rabbit model), and fundus delivery efficiency (topical D9-EGT eye drops quantified by LC-MS/MS). ResultsEGT demonstrated significantly superior radical scavenging activity, exhibiting 6.4-fold and 46-fold higher rates than glutathione and coenzyme Q10, respectively, at 50 ppm. It also showed excellent stability, retaining over 97% of its initial concentration after six months, and caused no ocular irritation at any tested concentration (score 0). Importantly, topical administration of EGT resulted in effective fundus delivery, with peak concentrations reached at 0.5 hours post-application (1181 {+/-} 56 ng/g), confirming successful penetration through corneal and scleral barriers. These findings establish EGT as a potent, multi-mechanistic antioxidant characterized by high stability, ocular safety, and exceptional posterior segment penetrance via non-invasive eye drops. ConclusionThese findings establish EGT as a potent, multi-mechanistic antioxidant characterized by high stability, ocular safety, and exceptional posterior segment penetrance via non-invasive eye drops. By overcoming key delivery limitations, EGT presents a promising therapeutic strategy for oxidative stress-related ocular diseases such as age-related macular degeneration and diabetic retinopathy. Further studies are warranted to evaluate its long-term efficacy and clinical translation potential.

Source connections

Explore related subjects

pharmacology and toxicologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

He, R., Ding, W., Cao, J., Guo, C., Li, X., Xiao, G.. 2025-12-28. Ergothioneine: Evaluation of a Novel Antioxidant for Targeting Ocular Oxidative Stress. https://doi.org/10.64898/2025.12.28.696576

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Context and exposure history shape insecticide sensitivity in Drosophila melanogaster

Current insecticide toxicology still lacks an integrated understanding of how lethal and sublethal exposure shape organismal performance across biologically and environmentally relevant contexts. In particular, insecticide susceptibility may vary with physiological state, environmental conditions, and recent exposure history, factors that are only partially captured by standardized toxicity assessments. Here, using Drosophila melanogaster, we systematically compared responses to three insecticides with distinct modes of action - acetamiprid, chlorantraniliprole, and deltamethrin - across developmental stages, sexes, adult ages, and ambient temperatures. Insecticide sensitivity varied substantially across these conditions, with temperature modulating toxicity in a compound-dependent manner. Notably, deltamethrin caused substantial lethality at concentrations more than 10,000-fold below approved field application rates. Beyond these context-dependent differences in acute toxicity, sublethal pre-exposure to each insecticide rapidly reduced lethality during a subsequent challenge with the same compound, with increased tolerance already detectable after 24 h. Importantly, these exposure conditions that enhanced insecticide tolerance were associated with reduced resistance to environmental challenges, including heat and nutrient starvation, revealing a potential trade-off in organismal stress resilience. Acetamiprid exposure further altered reproductive performance in a concentration-dependent manner, with higher exposure reducing egg production while increasing developmental success among the resulting offspring, such that the number of offspring reaching adulthood remained largely unchanged. Together, these findings demonstrate that insecticide susceptibility is highly context dependent and can be rapidly modified by recent exposure history. We identify short-term, compound-specific, and potentially costly tolerance as an underappreciated consequence of insecticide exposure and highlight the importance of incorporating biological context, environmental conditions, and sublethal exposure history into pesticide risk assessment.

pharmacology and toxicology↗
bioRxiv2026

Aquaporin-9 and aquaporin-10 but not aquaporin-3 confer susceptibility to dimethylarsinic acid genotoxicity in human cells

Human metabolism converts inorganic arsenic to the pentavalent methylated species MMA(V) and DMA(V), the forms most people excrete, and the forms long read as the end of a detoxification pathway. Whether a transporter sets how much of these metabolites reaches the genome has not been tested in a mammalian cell. We expressed human AQP3, AQP7, AQP9 or AQP10 in HEK293T and MRC5-SV40 cells and measured gamma-H2AX by flow cytometry across dose series of As(V), MMA(V) and DMA(V), pairing every aquaporin with a GFP-Tubulin control and an untransfected mock acquired in the same replicate. As(V) was inactive in HEK293T cells and only weakly active in MRC5-SV40 cells to 20 micromolar, and both methylated species damaged DNA only in the millimolar range, DMA(V) being the more potent of the two in both cell lines. Against that weak baseline, AQP9 and AQP10 raised DMA(V)-induced gamma-H2AX in HEK293T cells by roughly 17 percentage points over the matched control, more than doubling the damage the same exposure produced in control cells, whereas AQP3 and AQP7 changed it not at all. AQP9 alone remained active with MMA(V). The ranking held in MRC5-SV40 fibroblasts at one-sixth the size, and within single wells the damage rose with the amount of AQP9 a cell carried while the control was flat. Aquaglyceroporins therefore discriminate among arsenic species, and AQP9 and AQP10 turn a weakly genotoxic metabolite into a substantially more genotoxic one.

pharmacology and toxicology↗
bioRxiv2026

Quantitative Systems Pharmacology Model for Trop-2 Targeting Antibody-Drug Conjugate in Triple-Negative Breast Cancer

TROP2-targeted antibody-drug conjugates (ADCs) have demonstrated promising clinical activity in triple-negative breast cancer (TNBC) as monotherapies; however, therapeutic benefit varies among patients. Combination strategies pairing TROP2-targeted ADCs with immune checkpoint inhibitors are also being investigated. Elucidating the mechanistic drivers of ADC monotherapy variability and enabling the rational development of combination regimens require computational frameworks that integrate ADC pharmacology with tumor-immune interactions. A quantitative systems pharmacology (QSP) model is presented that incorporates an ADC module into our established immuno-oncology model for TNBC. The module captures ADC and payload pharmacokinetics and pharmacodynamics. TNBC heterogeneity is represented by two tumor cell clones with high and low TROP2 expression, informed by prior characterizations, and differential sensitivity to the ADC payload is incorporated as an intrinsic property of each clone. Although generalizable, the model was applied to the TROP2-targeted ADC sacituzumab govitecan (SG, TRODELVY). A virtual patient cohort was generated using Latin hypercube sampling and calibrated against objective response rate (ORR) data from SG Phase I/II TNBC basket trial. The model predicted an ORR of 33.2% consistent with ASCENT study (NCT02574455). Simulations suggest TROP2-mediated delivery contributes modestly to SG efficacy with tumor exposure driven largely by systemically released SN-38 payload being sufficient to induce cytotoxicity. Tumor heterogeneity emerged as a key determinant of response with ORR increasing as the fraction of payload-sensitive clones increased. Overall, this QSP framework for TROP2-targeted ADCs accounts for TNBC heterogeneity and is extendable to other ADCs and targets enabling interrogation of ADC mechanisms of action in conjunction with tumor-immune interactions.

pharmacology and toxicology↗