Purified alkaloid extract of Scutellaria barbata inhibits proliferation of hepatoma HepG-2 cells by inducing apoptosis and cell cycle arrest at G2/M phase

Abstract

Scutellaria barbata was widely used as an antitumor agent in traditional Chinese medicine. However, its antitumor 
components and mechanism remained unclear. In the present study, the effects of purified alkaloid extract of 
Scutellaria barbata (PAESB) on the cultured hepatoma HepG-2 cells were investigated. 3-(4,5-Dimethylthiazol-2-Yl)
2,5-Diphenyltetrazolium Bromide (MTT) assay showed that PAESB could inhibit the proliferation of HepG-2 cells in a 
dose- and time-dependent manner. Annexin V-FITC and propidium iodide (PI) staining showed that PAESB had a 
positive effect on apoptosis of HepG-2 cells. After treatment by PAESB (0.75 mg/ml) for 48 h, the HepG-2 cells 
apoptosis rate (25.12±0.91%) had statistical significance as compared with the negative group (2.97±0.49%) (P<0.01). 
Among the various phases of cell cycle, significant increase in the percentage of G2/M phase occurred after treated 
with PAESB (0.75 mg/ml) for 48 h by comparison with the corresponding values for HepG-2 cells without PAESB 
(P<0.01). These results indicated that PAESB exhibited potential anticancer activity against hepatoma HepG-2 cells 
through induction of apoptosis and G2/M phase cell cycle arrest.