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

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Jambolan ( Syzygium cumini (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 ( Danio rerio ) 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 in vitro 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. • Jambolan extract is rich in phenolic compounds, anthocyanins, and antioxidants. • LC50 values were 118.4 µg/ml for embryos and 68.86 µg/ml for adult zebrafish. • No cardiovascular or neurological toxicities were observed in concentrations below LC50. • Jambolan extract shows nonmonotonic concentration-response curve.