Figure 4.

Berberine inhibited expression of cell cycle proteins involved in regulation of the G₂/M phase in HTB-94 cells. HTB-94 cells were untreated (0) or treated with 100 µM berberine for the indicated times (10 or 30 min or 1, 3, 6, 12, or 24 h). (A) Expression of cyclin B1, cdc2, cdc25c, phosphorylated retinoblastoma tumor-suppressor protein (pRb), Rb, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was determined by Western blot analysis. GAPDH was used as loading control. (B) The relative amounts of cyclin B1, cdc2, cdc25c, and pRb were quantified by a densitometric analysis (ImageJ). The Western blot data represent the results of a typical experiment, and the graphical data are expressed as mean values ± standard deviation. *p < 0.05 compared to the control.