Anticancer Effects of Taraxacum via Cell Cycle Arrest, Necrosis, Apoptosis, and Endoplasmic Reticulum Stress

Dandelion (Taraxacum species) is a wild plant with over 2500 species. Flavonoids, phenolic compounds, saponins, sesquiterpenes, and sugars have been detected in the organs of Taraxacum, and for centuries it has been used in traditional medicine for the relief and treatment of various diseases. However, details of its working mechanism remain unclear. Bioactive compounds in herbal extracts generally have low yields, which makes their isolation and purification intensive in terms of time and cost. Here, to assess their versatility and safety, we applied aqueous extracts of two species of Taraxacum, T. mongolicum and T. formosanum, including extracts of both fresh and dried T. formosanum, to compare their potential antitumor effects on HeLa human cervical cancer cells, three liver cancer cell lines, and one normal liver cell line. After being treated with a lower dose of Taraxacum, the upregulation of subG1 and S populations, as well as increased levels of p-eIF2[Formula: see text]-to-eIF2[Formula: see text] ratio, were observed in HeLa cells, whereas the downregulation of S population and the absence of mRNA expressions were detected in HeLa cells when being treated with a higher dose of Taraxacum. These results indicated that Taraxacumcould induce apoptosis and endoplasmic reticulum stress while suppressing proliferation, transcription, colony formation, migration, and invasion. What's more, we also found that the effects of fresh T. formosanum were much stronger than that of T. mongolicumin HeLa cells. Based on these results, we suggest that T. formosanum may contain specific compound(s) that are potentially useful for cancer therapy. However, much work remains to identify these effective compounds for the future application of Taraxacumto cancer therapy.