Toxicological screening of jambolan hydroalcoholic extract (Syzygium cumini (L.) Skeels) in zebrafish (Danio rerio)

Jambolan (<i>Syzygium cumini</i> (L.) Skeels) is an important source of phenolic compounds, especially anthocyanins, known for their biological properties. This study investigated the acute toxicity of jambolan hydroalcoholic extract (JE) in zebrafish (<i>Danio rerio</i>) at different life stages. JE, obtained from freeze-dried fruits, was analyzed by high-performance liquid chromatography (HPLC) and found to be rich in total phenolic compounds (TPC). A total of 15 phenolic compounds were identified in the HPLC extracts, mainly anthocyanins (≈ 82 % of TPC), and JE presented relevant antioxidant properties in <i>in vitro</i> tests. Exposure to concentrations between 50 and 200 µg/ml resulted in increased malformations and mortality in both embryos and adult zebrafish, and doses of 300 and 400 µg/ml were lethal to the animals. Lethal concentrations (LC50) were estimated at 118.4 µg/ml for embryos and 68.86 µg/ml for adults. Despite no significant cardiovascular or neurological toxicities, behavioral impacts were observed at lower concentrations (10 µg/ml), indicating a nonmonotonic concentration-response curve. Our findings suggest that moderate JE doses (around 25 µg/ml) are safe for zebrafish; however, further studies are needed to ensure its safety and efficacy under different health conditions and exposure regimes.