Kiloni, S.; Ali, A.; Dunshea, F.; Cottrell, J.; Caceres-Velez, P. R.; Jusuf, P. R.

Plant-derived bioactive compounds are recognised for their antioxidant potential and benefit for human diseases, including age-related diseases caused by oxidative stress. However, their antioxidant composition and safety profiles remain insufficiently understood. This study integrates phytochemical profiling, antioxidant evaluation, and in vivo toxicological assessment of Warrigal spinach (Tetragonia tetragonioides) and Kensington Pride mango (Mangifera indica). Spinach exhibited greater antioxidant capacity, and higher total phenolic and flavonoid content than mango: TPC (14.2 +/- 0.6 mg GAE/g vs 1.30 +/- 0.07 mg GAE/g) and TFC (9.61 +/- 0.39 mg QE/g vs 0.08 +/- 0.0 mg QE/g). LC-ESI-QTOF-MS/MS identified 187 metabolites dominated by flavonoids (53.5%) and phenolic acids (16%), with spinach showing greater chemical diversity. Quantitative analysis revealed higher levels of hydroxycinnamic acids and flavonoid glycosides in spinach, whereas mango contained distinct metabolites, including mangiferin and pyrogallol. Zebrafish embryo / larval assays demonstrated high safety margins, with LC50 values of 478.8 mg/L (spinach) and >480 mg/L (mango). At 480 mg/L spinach displayed developmental abnormalities and malformations. These findings demonstrate that antioxidant capacity is linked to phenolic composition, but does not predict toxicity. Thus, integrated phytochemical and safety evaluation for extracts with complex compound mixtures are critical to identify botanicals suitable for future drug development.