Fresh garlic juice versus aged garlic extract. Determination of lethal concentration (LC20 and LC50) values on zebrafish (Danio rerio) embryos and larvae

Developmental abnormalities due to fresh garlic (Allium sativum L.) juice exposure have been previously reported on zebrafish (Danio rerio) embryos. Freshly made garlic juice (FGJ) containing allicin as a main ingredient and aged garlic extract (AGE) containing mainly S-allyl-L-cysteine were evaluated to investigate the lethality during a 5-day assay using zebrafish embryos, starting from 2 hours post fertilization (hpf), in a static system at an garlic concentration range of 0.00001-0.1%. In addition, lethality comparison between embryos and 3 days of post fertilization (dpf) larvae was performed. The results indicate that the mortality rate is positively correlated to the concentration of FGJ. Lethal concentration for the 24-h LC20 and 24-h LC50 in zebrafish embryos exposure was determined as 0.034% and 0.021%. The corresponding values for larval forms were significantly higher, 0.081% and 0.073% (P < 0.01), suggesting a greater sensitivity of developing embryos to FGJ treatment, as well as no protection from an embryo’s chorion. Below the FGJ concentrations of 0.02% (for embryos) and 0.06% (for larvae), no increase in mortality was observed over the entire exposure time. The mortality of AGE-treated embryos did not differ significantly (P = 0.571) from the control regardless of exposure duration and AGE concentration. The overall results indicate that zebrafish embryos constitute a reliable model for testing the developmental toxicity of garlic, and that different types of garlic preparations have different pharmacologic properties.