Influence of fresh garlic (Allium sativum L.) juice on zebrafish (Danio rerio) embryos developmental effects

A higher sensitivity and the cytotoxic effects of garlic have been previously reported on culture cells. No studies, however, have investigated the developmental toxicity of fresh garlic in zebrafish model. In this study freshly made garlic juice, which chemically is a combination of sulphur containing compounds, was evaluated to investigate the developmental toxicity during a 5-day assay using zebrafish embryos, starting from 2 h post fertilization. The results showed that toxicity endpoints such as the hatching rate, survival rate, malformation rate and growth rate had a significant dose-response relationship with increasing concentrations of garlic juice. The average hatching rate and time to hatch of zebrafish exposed to lower concentrations (0.001% and less) were significantly increased around 48-60 h of treatment (P < 0.05), strongly emphasizing the acceleration of hatchability caused by garlic juice. Mortality was also increased with exposure to garlic, exhibiting the maximal toxicity after 12 h of exposure to the concentration of 0.08%. A significant reduction in the heart rate by 35.5% was recorded due to the higher concentrations of juice (above 0.01%) starting form 36-hour exposure (P < 0.05). Growth retardation, pericardial oedema with heart malformations, deformity of yolk, lack of pigmentation and body malformation have been noticed at the concentration of 0.03% starting from 48 h of exposure. No severe malformations in any of the experimental zebrafish were produced at concentrations less than 0.01% of garlic juice. The results indicate that developing zebrafish are sensitive to garlic juice and further studies are required to investigate the molecular basis of the observed effects that garlic constituents exert upon aquatic vertebrates.