Antioxidant Activity and Cytotoxicity of Taraxacum Hispanicum Aqueous and Ethanolic Extracts on Hepg2 Cells

Plants belonging to the genus Taraxacum have been used in traditional medicine. Nowadays, extracts of these plants have been reported for the treatment of diseases, including liver disorders. Increasing interest and research on these plants also revealed its potential for treating cancer. This study aims to evaluate the antioxidant activity and cytotoxic properties of crude extracts from aerial parts of Taraxacum hispanicum H.Lindb, against human hepatocarcinoma (HepG2). Material and methods: Evaluation of the antioxidant properties was performed using DPPH in vitro test, superoxide scavenging assay and Fe2+ chelating activity. MTT assay was used to determine metabolic activity, for 24 and 48 hours. Results: For antioxidant capacity of the ethanolic extract (overall the one with the best results), IC50 values were 62.4 ± 6.7 μg/ml (DPPH radical scavenging activity) 53.9 ± 10.3 μg/ml (Fe2+ chelating activity) and 2.0 ± 0.3 μg/ml (superoxide scavenging assay). The aqueous and ethanolic extracts had different effects on HepG2 cell viability. Aqueous extract induced cell cytotoxicity in a time and dose-dependent manner, leaving only 52.6% viable cells at a concentration of 200 μg/ml, after 48 h. An increase in the cell viability was seen in the ethanolic extract, from 24 h to 48 h at higher concentrations. Conclusions: Ethanolic extract of T. hispanicum was the most promising, presenting anti-oxidative capacity and only the aqueous extract of the plant presented more relevant cytotoxicity over HepG2 cell line. These activities may be related with the extract phenolic content. However, further studies are needed to elucidate the main mechanisms responsible for these potential effects.