Toxicological Assessment of Stevia and Its Products on Zebrafish Larvae

Background: Stevia plant is known as a natural sweetener whose antioxidant and insulinotropic properties have been proven in various studies. Examining the toxicity of this plant and its related products is considered a necessity due to the increased demand and its consumption in today's societies. Methods: In this research, three stevia substances such as stevia plant leaves, stevia powder, and tea bags sweetened with stevia were used to evaluate the toxicity. After preparing a ۱۰۰% solution, concentrations of ۱۰۰ mg/L to ۲۰۰۰۰ mg/L were prepared from each of them using E۳ solution. Then, each of the concentrations prepared in ۲۰ wells of ELISA plates was exposed to a healthy and fertilized zebrafish egg, and the last ۴ wells of each plate filled with E۳ solution as a negative control solution were also exposed to healthy and fertilized eggs. Results: The experiment continued for ۹۶ hours. Every ۲۴ hours, the larvae were examined with a stereomicroscope for morphological changes and abnormalities (chronic toxicity) and also for mortalities (acute toxicity). According to the rules of OECD ۲۳۶, in the negative control group, at the end of ۹۶ hours of study, more than ۸۰% of the larvae should be healthy, which this condition was completely fulfilled in this study. Finally, it was found that the concentration of ۲۰,۰۰۰ mg/L of all three substances tested has ۱۰۰% mortality for zebrafish larvae during ۹۶ hours. At concentrations ۱۰,۰۰۰ mg/L and above, significant morphological changes were shown compared to the control group. The average lethal concentration for each of the tested substances was calculated by SPSS software. Conclusion: In this study, which used natural and other stevia derivatives in various dilutions, it was determined that stevia is generally considered a safe substance because in studies conducted on zebrafish larvae, no acute or chronic toxicity was observed.

کلیدواژه ها:

stevia ، zebrafish larvae ، acute toxicity ، chronic toxicity ، lethal dose