Evaluation of solvent-dependent yield and toxicity of selected spices using brine shrimp and zebrafish bioassays: Implications for aquaculture applications

Spices are widely used culinary ingredients with notable antioxidant and antibacterial properties. In aquaculture, they function as immunostimulants and natural therapies, enhancing fish health and disease resilience. Nevertheless, certain spices may demonstrate toxicity and pose health risks as medicinal agents in the aquaculture activity. This study evaluated the extraction yield and toxicity of selected spice extracts using brine shrimp lethality test (BSLT) and Zebrafish assay in relation to five different solvents including hexane, ethyl acetate, ethanol, methanol and water. Water had the highest extraction yield, followed by ethyl acetate, methanol, hexane and ethanol. The water extract of bell pepper ( Capsicum annuum ) had the highest extraction yield (64.12%), while the ethanolic extract of cumin ( Cuminum cyminum ) had the lowest (2.38%). Probit regression analysis ( p < 0.05) indicated that all water extracts were non-toxic (LC 50 >1000 μg/mL) in BSLT, while methanol and ethanol extracts were generally more toxic. Hexane extracts displayed lower toxicity, and ethyl acetate extracts exhibited moderate toxicity for most spices. Cumin, turmeric, mace and ajwan have been shown to be more toxic, especially when used as methanol and ethanol solvents in both models whereas, black caraway and almond exhibited lower toxicity, making it more suitable for more investigation as immunostimulant. Zebrafish were more sensitive than brine shrimp, as reflected by lower LC 50 . Overall, the findings of this study emphasize the selection of suitable solvents and spice to maximize extraction yield while minimizing toxicity for potential aquaculture applications. • Spices has antioxidative and antibacterial characteristics, hence improving fish immunity and health in aquaculture settings. • Extraction yield exhibited significant differences between solvents, with water yielding the highest percentage (64.12% in bell pepper) and ethanol yielding the lowest (2.38% in cumin). • Water extracts exhibited non-toxicity (LC 50 > 1000 μg/ml), however methanol and ethanol extracts shown greater toxicity in the majority of spices. • Zebrafish experiments demonstrated superior sensitivity compared to BSLT, highlighting the significance of solvent selection for excellent extraction yield with less toxicity.