Ergothioneine Mitigates Telomere Shortening under Oxidative Stress Conditions

Shortened telomeres are associated with aging and age-related diseases. Oxidative stress is thought to be a major contributor to telomere shortening, and antioxidants may be able to mitigate these effects. Ergothioneine is a naturally occurring amino acid with potent antioxidant properties. In order to investigate ergothioneine's effects on telomere length, we cultured primary human fibroblasts under standard and oxidative (10 µM H₂O₂) conditions and treated cells with 0.04, 0.1, 0.3, or 1.0 mg/ml ergothioneine for 8 weeks. Telomere length measurements were performed using high-throughput quantitative fluorescent in situ hybridization (HT Q-FISH). Treatment with ergothioneine transiently increased relative telomerase activity after 24 h (p < 0.05 for all concentrations). Under oxidative conditions, ergothioneine treatment resulted in significantly longer median telomere length and 20^th percentile telomere length, and significantly reduced the percentage of short telomeres (<3 kilobase pairs) for all treatment concentrations after 8 weeks. Telomere shortening rate was also reduced. Overall, ergothioneine demonstrated beneficial effects by decreasing the rate of telomere shortening and preserving telomere length under oxidative stress conditions. Our data support a potential role for ergothioneine in oxidative stress-related conditions and healthy aging.