An antiageing telomere-protective effect of superoxide dismutase-rich <i>Tetraselmis chui</i> in human cells

<b>Background:</b> A <i>Tetraselmis chui</i>-derived ingredient exhibiting a high superoxide dismutase (SOD) activity (TSOD) has previously been shown to act as a cellular health promoter, activating cellular antioxidant and anti-inflammatory mechanisms, and protecting DNA from damage, among other bioactivities. To date, the potential of TSOD to protect telomeric DNA from shortening has not been studied. <b>Aim:</b> In this study, potential protective effects of TSOD on telomere length were evaluated in neonatal human fibroblasts both under standard and oxidative conditions induced by H₂O₂. <b>Methods:</b> Based on cytotoxicity tests, three different dilutions of a phosphate-buffered saline extract of TSOD (TSOD_A: 1/160, TSOD_B: 1/320, TSOD_C: 1/640) were assessed after four and eight weeks of treatment using the proprietary telomere analysis technology. <b>Results:</b> Under standard culture conditions, no significant differences in telomere-related variables were observed between control and treated cells after 4 weeks. However, by week 8, cells treated with TSOD_A exhibited a higher 20^th percentile compared to the untreated control. Under oxidative stress conditions, both TSOD_A and TSOD_C significantly increased both median telomere length and 20^th percentile, and reduced critically short telomeres (< 3 kbp) and the telomere shortening rate. Notably, TSOD_A maintained these significant differences also after 8 weeks of exposure. <b>Conclusion:</b> Taken together, these results demonstrated a protective effect of TSOD on telomere length in human cells, supporting the potential of TSOD to combat the deleterious effects of telomere shortening, thus promoting healthy ageing and longevity.