Glioblastoma is an aggressive type of CNS tumor. The aim was to evaluate the antitumor activity of Taraxacum officinale (TO) extracts on U-138 MG glial cells and correlate it with the concentration of chicoric (ChA), chlorogenic (CGA), and caftaric (CA) acids (mg/mL) in the extract. TO dry leaves were extracted with DMSO (dimethyl sulfoxide) and ethanol of different concentrations. The concentration of acids was determined by liquid chromatograph (Agilent 1260 with DAD). The viability of U-138 MG cells was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) test (% of viable cells). The activity of TO was compared with that of doxorubicin. The best antitumor activity was shown by TO extracts prepared with DMSO (110,000 µg/L—17.3 ± 8%, which contained ChA—8976 × 10⁻⁶ mg/mL, CGA—316.8 × 10⁻⁶ mg/mL, CA—1628 × 10⁻⁶ mg/mL), with 50% ethanol (150,000 µg/L—13.7 ± 3.2%, containing ChA—52,500 × 10⁻⁶ mg/mL, CGA—1746 × 10⁻⁶ mg/mL, CA—8460 × 10⁻⁶ mg/mL) and with 80% ethanol (40,000 µg/L—16.1 ± 9%, containing ChA—904 × 10⁻⁶ mg/mL, CGA—114.4 × 10⁻⁶ mg/mL, CA—70.4 × 10⁻⁶ mg/mL). TO extract activity was close to that of doxorubicin. In conclusion, the TO antitumor activity depends on the type of extractant and its concentration, as well as on the content of cinnamic acids.

The evaluation of the antioxidant activity of plants has been an important issue taking into account its importance on human health. Natural antioxidants protec t cells against oxidative stress, which can damage the cellular components. Taraxacum officinale (TO) leaves (TOL) and roots (TOR) has been commonly used in traditional medicine due to biologically active ingredients. This plant is rich in substances with high antioxidant activity (flavonoids, phenolic acids, coumarins, vitamins etc.). Glutathione represents the most abundant thiol of cells with important functions in the antioxidant system. Until now, there are no comprehensive data about TO extracts action on glutathione content.The objective of the study was to report the influence of TOL and TOR ethanolic extracts on the glutathione content of erythrocytes. TOL and TOR were harvested from a natural habitat of Republic of Moldova. The dry plants were extracted using ethanol as solvent (10, 20, 25, 40, 50 and 80% (v/v)). As source of glutathione were red blood cells (RBC) of healthy persons. As a result we determined that TO exhibits a modulatory action on glutathione content. The highest (28.03±1.14 µM/g. Hb) content of GSH was determined due to action of roots extracts made on ethanol of 20%, the lowest (10.88±0.83 µM/g. Hb) in case of leaves extracted on alcohol of 20%. Opposite, the lowest (5.92±0.72 µM/g. Hb) amount of GSSG was determined as a result of action of radicular extracts made on ethanol of 20%. The highest (11.46±3.27 µM/g. Hb) concentration of GSSG was determined by influence of roots extracts on ethanol of 50%.In conclusion, Taraxacum officinale exhibits a strong antioxidant activity. This plant has ability to prevent and treat the damage of cells caused by oxidative stress process, by actioning on glutathione system. This activity depends of ethanol concentrations and plant’s part.

Background. The oxygen is the ultimate electron acceptor in the electron flow system that produces energy. Problems appears when the electron flow becomes uncoupled thus, generating free radicals. While the majority of processes require oxygen, the last is a highly reactive molecule that can damage cells by producing reactive oxygen species, such as hydroxyl radical, superoxide radical, hydrogen peroxide and hypochlorous acid, all together defined as triggers of oxidative stress. The last is involved in many types of pathologies, such as cancer, atherosclerosis and rheumatic arthritis. Antioxidants can stop formation of free radical by giving hydrogen atoms or scavenging them. The antioxidant can be defined any molecule capable of preventing or blocking oxidation of lipids, proteins and nucleic acids. The reduced glutathione (GSH), as well enzymes, glutathione peroxidase (GPO), glutathione reductase (GR) and glutathione S-transferase (GST) represent antioxidants which prevent the formation of new free radicals, converting them into less harmful molecules. The present study was conducted to assess the antioxidant activity of Taraxacum officinale (TO) ethanolic extracts with different bioactive contents. This experiment was conducted with extracts prepared from dandelion (Taraxacum officinale F. H. Wigg) leaves. A series (10%, 20%, 25%, 40%, 50% and 80%) of ethanolic extracts were made. The influence of TO extracts on RBC’s GPO, GR, GST, glutathione (GSSG, GSH and total-GSH) and thiols (native and total) was evaluated by measuring absorbance spectrophotometrically. Conclusions. Taraxacum officinale ethanolic extracts exhibit a strong antioxidant activity. This plant is capable of preventing damage of cells during oxidative stress process, by using different targets of glutathione system. But, this activity depends of ethanol concentrations, maybe due to different bioactive content.

Oxidative stress (OS), caused by an imbalance between reactive oxygen species (ROS) and antioxidant defenses, is implicated in aging and the pathogenesis of cardiovascular, neurodegenerative, and neoplastic diseases. One of the key enzymatic defenses against oxidative damage is catalase (CAT), which decomposes hydrogen peroxide into water and oxygen, thus protecting cells from oxidative injury. Red blood cells (RBCs) / erythrocytes, due to their high oxygen exposure and hemoglobin content, are particularly vulnerable to oxidative stress. Natural antioxidants derived from plants have attracted significant attention for their potential to mitigate oxidative stress and enhance cellular antioxidant defenses. Taraxacum officinale (TO), commonly known as dandelion, has been widely used in traditional medicine for its anti-inflammatory, hepatoprotective, and antioxidant properties. The chemical composition of TO varies by plant part: roots are rich in phenolic compounds, terpenes, sesquiterpene lactones, fructans, and inulin, while leaves contain flavonoids, phenolic acids, coumarins, and vitamins, particularly vitamin A. Previous studies indicate that the antioxidant activity of TO depends on multiple factors: including the plant part, extraction solvent, and extraction duration. Despite its welldocumented antioxidant properties, the effects of TO extracts on RBC antioxidant enzymes, especially catalase, remain underexplored. Investigating these effects could provide insights into its therapeutic potential for oxidative stress-related disorders. The present study aimed to evaluate and compare the effects of alcoholic extracts from TO roots and leaves on catalase activity in human erythrocytes, contributing to a better understanding of its cellular antioxidant mechanisms.