Lupeol, a dietary
triterpene, present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anti-
cancer activities both in vitro and in vivo. However, the precise mechanism involved remains largely unknown. The present study is conducted to investigate the anti-
cancer activity and the underlying mechanisms of
lupeol on human
pancreatic cancer proliferating cell nuclear antigen 1 (PCNA-1) cells in vitro and in vivo.
Lupeol significantly inhibited the proliferation of the cells in dose- and time-dependent manners and induced apoptosis as well as cell cycle arrest in G0/G1 phase by upregulating P21 and P27 and downregulating
cyclin D1. The expression of apoptosis-related
proteins in cells was evaluated by western blot analysis, and we found that
lupeol induced cell apoptosis by decreasing the levels of p-AKT and p-ERK. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of
lupeol in PCNA-1 cells, demonstrating the important role of AKT in this process. More importantly, our in vivo studies showed that administration of
lupeol decreased
tumor growth in a dose-dependent manner. Immunohistochemistry analysis demonstrated the downregulation of p-AKT and p-ERK in
tumor tissues following
lupeol treatment, consistent with the in vitro results. Therefore, these findings indicate that
lupeol can inhibit cell proliferation and induce apoptosis as well as cell cycle arrest of PCNA-1 cells and might offer a therapeutic potential advantage for human
pancreatic cancer chemoprevention or
chemotherapy.