Impact of green and black tea extracts on swimming performance and caudal fin regeneration in adult zebrafish (Danio rerio) following amputation

This study investigates the effects of green tea and black tea extracts on swimming performance and caudal fin regeneration in adult zebrafish (Danio rerio) following caudal fin amputation. Zebrafish were treated with either tea extract for 14 days, with applications administered three times daily. Swimming performance was assessed against water currents. Results indicated that green tea-treated fish exhibited the greatest resistance to water flow, primarily occupying the high-force zone during a 15-minute exercise session, while black tea-treated fish were mostly found in middle and lower zones. Cumulative distribution analysis showed that green tea-treated fish maintained their positions in stronger current zones significantly longer than both black tea and control groups (p < 0.0001). Conversely, control fish displayed the highest area of caudal fin regeneration, significantly surpassing both tea-treated groups. Green tea-treated fish showed the least regeneration area, though differences from black tea were not statistically significant. These findings challenge previous studies suggesting that green tea enhances tissue regeneration. The pro-apoptotic effects of green tea's primary component, epigallocatechin gallate (EGCG), may have limited its regenerative potential despite its antioxidant properties. This research highlights the complex relationship between tea polyphenols, swimming performance, and tissue regeneration, suggesting that while both green and black tea can enhance physiological performance, their effects vary based on the interplay between antioxidative benefits and apoptosis-inducing mechanisms.