Glioblastoma represents one of the most dangerous malignant tumours, due to its specific localization in the brain and treatment. In most of cases, the treatment is surgical, followed by radiation and chemotherapy. The prognosis for patients remains dismal, with 7–8 months of median progression-free survival, a median overall survival below 15 months, and a 5-year survival rate of only 6.8% (1). Nowadays, much attention is paid to the prevention and treatment of tumors using natural products. The antioxidants protect cells against oxidative stress, which is directly involved in ageing processes and in the pathogenesis of cardiovascular, neurodegenerative and neoplastic diseases. Taraxacum officinale (TO) F. H. Wigg or Dandelion due to its rich content of biologically active ingredients has been commonly used in traditional medicine. The TO roots (TOR) are rich in phenolic and terpene compounds, sesquiterpene lactones, fructosans, inulin etc. The antioxidant activity of TO depends on several factors: the climate, the type of soil, the plant part, the solvent used, as well as the duration of extraction (2). Shutz et al. (2005) evaluated the content of flavonoids and phenolic acids by high-performance liquid chromatography (HPLC). The most abundant was found chicoric acid (CRA), that is a dicaffeoyltartaric acid (3). The main mechanism of action exhibited by TO were related to CRA: antivirus, antioxidant, anti-inflammatory, obesity prevention and neuroprotection effects (4). The CRA effectiveness in case of tumors remains unclear. Fulga et al. (2022) described the action of TO extracts on tumor glial cell line, U-138 MG, where the extract of roots made in 80% ethanol had the greatest effect (5).