Toxicity Assessment of Catechins on Representative Aquatic Organisms and Terrestrial Plant

Catechins, renowned for their health benefits, have unexamined environmental impacts. This study assessed the toxicity of crude catechin and catechin hydrate on invertebrate larvae, plant, and microalgae. The survival rates of <i>Daphnia magna</i> Straus and <i>Artemia salina</i> L. were monitored every 24 h over a three-day period. The germination rate and radicle length of <i>Lactuca sativa</i> L. was measured every 24 h for four days. Inhibitory effects were evaluated in both freshwater and seawater cultures of <i>Chlorella vulgaris</i> Beijerinck, with cell density recorded every 24 h and yield inhibition calculated after 96 h. Results indicated that increasing catechin concentration and exposure duration decreased the survival rate of <i>D. magna</i> and <i>A. salina</i>. <i>Daphnia magna</i> was more sensitive to catechins than <i>A. salina</i>, with 24 h lethal concentration 50 (LC-50) values of 1174 µg/mL compared to 1895 µg/mL for crude catechin, and 54 µg/mL compared to 153 µg/mL for catechin hydrate. The germination rate and radicle length of <i>L. sativa</i>, along with the cell density of <i>C. vulgaris</i>, decreased with increasing catechin concentration, but remained higher even after prolonged exposure. At low catechin concentrations, <i>C. vulgaris</i> cell density exceeded control levels. This study demonstrates that catechins in aquatic environments can significantly impact ecosystems. At certain concentrations, catechins are toxic and potentially lethal to aquatic organisms. Conversely, at lower concentrations, catechins may promote microalgal growth, suggesting a fertilizing effect. Understanding these dynamics is crucial for maintaining the stability of aquatic ecosystems.