Oxidant effects and toxicity of Croton campestris in Drosophila melanogaster

Context: Croton campestris A. St.-Hil. (Euphorbiaceae) is a species native to Northeast Brazil used by traditional communities for the treatment of a variety of health problems. However, potential toxicological effects of this plant are unknown. Objective: The potential toxicity of the hydroalcoholic extract of C. campestris leaves on Drosophila melanogaster insect model, additionally with phytochemical constitution and cellular mechanisms mediating the action of extract were analysed in this study. Materials and methods: Constituents of the extract were evaluated by HPLC. In vitro antioxidant potential of extract was analysed by DPPH, ABTS and FRAP. Flies injected culture medium mixed with extract (0.1-50mg/mL) for 72 h. After, ROS production was evaluated by DCF-DA oxidation. Phosphorylation of MAPK signalling pathway was investigated by Western blotting method. Activity of antioxidant enzymes was analysed in homogenates. Results: Major components of the extract include quercetin (38.11 +/- 0.06mg/g), caffeic acid (20.06 +/- 0.17 mg/g) and kaempferol (15.45 +/- 0.05mg/g). Consumption of the extract impaired locomotor performance and induced fly death of flies (LC50 of 26.51mg/mL). Augmented ROS formation and SOD, CAT and GST activity were observed from 0.1mg/mL. JNK and p38 kinases phosphorylation was modulated and Paraquat-induced toxicity was augmented by extract. Discussion and conclusion: Our data show important toxicological effects of C. campestris leading to increased mortality and impaired locomotor performance accompanied by induction of cell stress markers in flies. The study draws attention to the indiscriminate use of plant extracts.