Toxicological effect of Brazilian bamboo extracts in zebrafish larvae

Zebrafish (Danio rerio) has been considered as a promising model for in vivo screening of bioactive molecules of plant extracts [1]. Bamboos possess a diversity of medicinal properties [2]. This study aimed to analyze the toxicological effect of the aqueous extracts from Olyra glaberrima (OG) and Filgueirasia arenicola (FA) on the locomotion of zebrafish larvae. Dried leaves were powdered and submitted to infusion. Embryos were exposure to freeze-dried extracts (0.1, 0.5 and 1.0 mg/mL) immediately after fertilization for seven days. Daily the survival rate was recorded. Animals were individually submitted for a session of exploratory behavior analyses. Total distance traveled (cm), mean speed (cm/s), time mobile (s), and absolute turn angle (°) were considered the main parameters of exploration of a new environment and for the evaluation of movements. After that, larvae were submitted to avoidance-escape behavior from a visual stimulus. The number of larvae in the non-stimulus area during the session was considered indicative of deficits in the avoidance response [3]. There was a delayed larvae hatching rate for the treated animals [Fig. 1]. The lowest survival rate was observed after exposure to 1.0 mg/mL OG. At the exploratory analysis, 1.0 mg/mL OG and 0.1 mg/mL FA induced a significant decrease in total distance traveled and mean speed. Only 1.0 mg/mL OG increased erratic movements. There were no changes in the larvae avoidance response after bamboo extracts treatment. It was possible to conclude that extracts of both species in their highest concentration showed a toxicological effect in zebrafish larvae.

Fig. 1 (A) Larvae percent survival: FA 0.1, FA 1.0, OG 0.5 and OG 1.0 mg/mL differed from the control group (p ≤ 0.05). (B) Percentage of hatching rate: FA 0.5, FA 1.0, OG 0.1, 0.5 and 1.0 differed from the control group (p ≤ 0.0001). (C) Exploratory parameters: FA 0.1 and OG 1.0 showed significant differences from the control group. For all analyses, One-way ANOVA was used, followed by a post-hoc Tukey’s test. * represents significant difference p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001 and **** p ≤ 0.0001 in relation to control.

• References

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