BBR induces apoptosis in HepG2 cell through an Akt‐ASK1‐ROS‐p38MAPKs‐linked cascade

Abstract

Berberine (BBR) has indicated significant antimicrobial activity against a variety of organisms including bacteria, viruses, and fungi. The mechanism by which BBR initiates apoptosis remains poorly understood. In the present study, we demonstrated that BBR exhibited significant cytotoxicity in human hepatoma HepG2 cells. Herein, we investigated cytotoxicity mechanism of BBR in HepG2 cells. The results showed that the induction of apoptosis in HepG2 cells by BBR was characterized by DNA fragmentation, an increased percentage of annexin V, and the activation of caspase-3. The expressions of Bcl-2 protein and pro-caspase-3 were reduced by BBR in HepG2 cells. However, Bax protein was increased in the cells. BBR-induced apoptosis was preceded by increased generation of reactive oxygen species (ROS). NAC treatment, a scavenger of ROS, reversed BBR-induced apoptosis effects via inhibition of Bax activation and Bcl-2 inactivation. BBR-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of MAP Kinases (JNK and p38 MAPK), ASK1, Akt, and p53. Furthermore, SB203580, p38 inhibitor, reduced the apoptotic effect of BBR, and blocks the generation of ROS and NO as well as activation of Bax. We found that the treatment of HepG2 cells with BBR triggers generation of ROS through Akt phosphorylation, resulting in dissociation of the ASK1-mediated activation of JNK and p38 pathways.

Berberine sensitizes TRAIL-induced apoptosis through proteasome-mediated downregulation of c-FLIP and Mcl-1 proteins

“…It was reported that BBR induced the ROS-mediated apoptosis and downregulated the expression of Bcl-2 protein in HepG2 cells, which were prevented by NAC treatment (17). We also found that treatment with BBR induced ROS generation and that pretreatment with NAC prevented BBR plus TRAIL-induced apoptosis.…”

“…It has been reported that BBR increases ROS production in various cancer cells (10,17,18). Therefore, we examined whether ROS generation might be involved in BBR plus TRAILinduced apoptosis.…”

Tetrandrine induces apoptosis by activating reactive oxygen species and repressing Akt activity in human hepatocellular carcinoma

“…Studies have found that Akt and ROS could interact with each other in the pathway. 32,42,43 We have shown here that the decrease of Akt activity is regulated by ROS generation in the tetrandrine-induced HCC cell apoptosis (Fig. 5).…”

Synergistic antitumor activity of withaferin A combined with oxaliplatin triggers reactive oxygen species-mediated inactivation of the PI3K/AKT pathway in human pancreatic cancer cells

“…Studies have reported AKT activation can increase production of intracellular ROS in apoptosis induction and that ROS generation could repress AKT signaling [32,33]. To investigate the relationship between ROS generation and AKT inhibition in combination treatment-induced apoptosis, western blot analyses were carried out to examine AKT activity in the presence of the ROS scavenger NAC.…”