LC-ESI-MS/MS analysis of secondary metabolites of different St. John's wort (Hypericum perforatum) extracts used as food supplements and evaluation of developmental toxicity on zebrafish (Danio rerio) embryos and larvae

•Chlorogenic acid, hyperocide, rutin and hyperforin were obtained in higher quantities.•Toxicity doses of SJW extracts used as nutritional supplements were determined.•SJW at doses of 10 µg/mL and below may be harmless to use as food supplement.•Caspase-3 expression was not observed in brain tissues of zebrafish larvae in SJW1-SJW3.