Toxicity evaluation of traditional and organic yerba mate (Ilex paraguariensis A. St.-Hil.) extracts

Yerba mate (Ilex paraguariensis A. St.-Hil.) is an important source of biologically active compounds with pharmacological potential. The aim of this study was to examine the toxicity of different extracts obtained from either traditional or organic cultivated yerba mate in vitro and in vivo. Aqueous, ethanolic and methanolic extracts were obtained from commercial samples of yerba mate and total phenolic content was determined employing Folin-Ciocalteau reagent. The aqueous extracts presented higher content of total phenols, compared to ethanolic and methanolic extracts, and also demonstrated lower cytotoxicity, which is the basis for testing were carried out only using aqueous extracts. The main phenolic acids found in traditional aqueous (TA) extract were chlorogenic, gallic and protocatechuic acids. Gallic and hydroxybenzoic acids were detected in aqueous cultivated organic (OA) extract. Pretreatment with OA extract (100 mu g/ml, 1 hr) was cytoprotective against rotenone-induced toxicity (1 mu M). For in vivo toxicity assay, zebrafish embryos were exposed to OA or TA extracts (10-160 mu g/ml) at 4 hr post fertilization. TA extract decreased embryos survival in a concentration-dependent manner, reduced the hatching rate at 40 mu g/ml, increased edema frequency at 80 mu g/ml and altered body curvature at 120 mu g/ml. Further, TA extract produced locomotor disorders at concentrations equal to or greater than 10 mu g/ml. In contrast, OA extract exhibited no apparent toxic effect on organogenesis and behavior up to 100 mu g/ml. In summary, the OA cultivated extract showed the lowest cytotoxicity in vitro, enhanced reduction in rotenone-induced toxicity, and produced less toxicity in zebrafish embryos compared to the TA extract.

Automated summary

The study found that organic cultivated yerba mate extract showed lower cytotoxicity in vitro compared to traditional extract, had a protective effect against rotenone-induced toxicity, and exhibited less toxicity in zebrafish embryos.