The Natural Polyphenol Epigallocatechin Gallate Protects Intervertebral Disc Cells from Oxidative Stress

Figure 2

As an antioxidant, EGCG inhibited senescence-associated β-galactosidase accumulation. (a) EGCG exhibited increasing 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity between 10 and 100 μM, which confirmed its antioxidant properties. Ascorbic acid in the same concentration was used as positive control (). ((b)–(d)) Oxidative stress was induced with 50 μM H₂O₂ for 2 hours and cellular senescence was measured during the following 10 days. 10 μM EGCG inhibited SA β-gal accumulation when added to the oxidative stress phase, when its antioxidant activity was confirmed (). (c) 10 μM EGCG added to the recovery phase did not influence SA β-gal accumulation compared to the H₂O₂-only group (). (d) EGCG combined in both phases (5 + 5 μM) did not significantly inhibit SA β-gal accumulation, although a trend is visible (). Asterisks indicate statistical significance at (ANOVA, Tukey post hoc).

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