Flavonoids in safflower extract reduce cisplatin-induced damage to human follicle dermal papilla cells by inhibiting DNA damage and Rad17/Chk1/Cdc25C signaling

Background: Cisplatin is a chemotherapeutic agent commonly used clinically for the treatment of various human cancers. Patients often reduce the use of cisplatin due to its side effects, which in turn affects its treatment. This study explored the mechanism of action of safflower extract as an adjuvant traditional Chinese medicine for chemotherapy. Methods: Primary human follicle dermal papilla cells (HFDPCs) were used as target cells for cisplatin-induced damage to hair cells. Western blotting was used to investigate the molecular targets of cisplatin and safflower extract in causing HFDPCs damage. Cell survival and cell cycle were analyzed by mitochondrial staining reagent WST-1 and propidium iodide. Results: Cisplatin could reduce the viability of HFDPCs without causing cell death. Cisplatin increased the level of phospho-Rad17 in HFDPCs and activated the Chk1/Cdc25C signaling to reduce the expression of Cdc2 protein, thereby arresting the cells in the G2/M phase. The combination of safflower extract and the flavonoids could effectively inhibit the signal transduction of Rad17/Chk1/Cdc25 in cisplatin-treated cells and reduce the cell population in the G2/M phase. Finally, we also confrmed that safflower extract could effectively inhibit the damage to HFDPCs caused by cisplatin, mainly at the level of reducing the DNA damage caused by cisplatin. Conclusions: Safflower extract can be used as an adjuvant Chinese medicine for chemotherapy to reduce the damage caused by chemotherapy to normal hair follicle cells.