Scutellarin exerts anticancer effects on human leukemia cells via induction of Sub-G1 cell cycle arrest, apoptosis and also inhibits migration and invasion by targeting Raf/MEK/ERK signalling pathway.

Objective: Leukemia accounts for a significant mortality across the globe every year. The main objective of the present research work was directed towards studying the anticancer effects of scutellarin-a plant flavone, against K562 human leukemia cells, along with examining its effects on cellular apoptosis, cell cycle, cell migration and cell invasion as well as Raf/MEK/ERK signalling pathway.

Methods: Cell viability of K562 leukemia cells was evaluated by WTS-1 assay, while apoptotic effects induced by scutellarin in K562 cells were examined by fluorescence microscopy, flow cytometry, and western blot methods. Effects on cell cycle were measured by flow cytometry. Transwell Matrigel assay was performed to evaluate whether scutellarin induces inhibition of cell migration and cell invasion effects in K562 cells.

Results: Scutellarin was shown to suppress the viability of the K562 cells dose-dependently with an IC50 of 6 μM. Further, scutellarin was shown to induce apoptosis which was initially exhibited by DAPI and annexin-V/propidium iodide (PI) staining and then confirmed by western blot in which it was shown to trigger regulation of Bax and downregulation of Bcl-2 in K562 human leukemia cells. Scutellarin also induced G0/G1 cell cycle arrest which was accompanied by suppression of cell migration and invasion. Scutellarin also led to the decline of the expression of p-Raf, p-MEK1/2 and p-ERK1/2 in a concentration-dependent manner.

Conclusions: In conclusion, scutellarin could inhibit the growth of K562 human leukemia cells by inducing apoptosis, cell cycle arrest, inhibition of cell migration and invasion and downregulating the expressions of p-Raf, p-MEK1/2 and p-ERK1/2.