Oridonin interferes with simple steatosis of liver cells by regulating autophagy.

Oridonin has significant liver-protective effects, but its effect on liver steatosis has not been reported. We investigated the effects of oridonin on liver steatosis by cell cultures. The optimal experimental concentration of oridonin was determined through cytotoxicity experiments. A simple steatosis liver cell model was induced using free fatty acids (FFA). After adding oridonin to the FFA-induced cell model for 24 h, the lipid droplets and triglyceride (TG) content in the cells were measured by Oil Red O staining and TG kits. The expressions of autophagy-related markers (cyclin dependent kinases inhibitor 1a (p21), Beclin-1, microtubule-associated protein light chain 3 (LC3)-I and LC3-II, protein kinase B (AKT), phosphorylated-AKT (p-AKT), AMP-activated protein kinase (AMPK), and phosphorylated-AMPK (p-AMPK)) were detected by Western blot. Based on the results, the cell model was further treated by autophagy inhibitor 3-methyladenine (3-MA) to determine the degree of steatosis and the expressions of autophagy-related factors. Oridonin at a concentration higher than 10 µmol/L caused cytotoxicity to the cells. Adding 10 µmol/L oridonin to the FFA-induced cell model effectively reduced lipid droplets and TG content in the cells. Oridonin up-regulated p21, Beclin-1 and LC3-II expressions, but down-regulated those of p62 and LC3-I. Also, oridonin increased the ratios of LC3-II/LC3-I and p-AMPK/AMPK, but reduced that of p-AKT/AKT. With the addition of 3-MA, the effect of oridonin on reducing steatosis was partially reversed, and the autophagy was inhibited. This study found that oridonin can activate autophagy, thereby preventing simple steatosis of liver cells.

Oridonin enhances the anti-tumor activity of gemcitabine towards pancreatic cancer by stimulating Bax- and Smac-dependent apoptosis.

BACKGROUND: Oridonin has been shown to exhibit potent anti-tumor activity, but the exact mechanisms underlying this activity remains unclear. Here, we investigated whether oridonin could synergistically enhance the activity of gemcitabine against BxPC-3 pancreatic cancer cells. METHODS: CCK-8 assays were conducted to determine cell viability. The cellular morphology was observed under light microscope and compared with normal cell. Apoptotic cells were quantified by flow cytometry. RT-PCR, Western blot analysis and immunohistochemical methods were employed to analyze related-gene and protein expression. A xenograft tumor model was conducted whereby BxPC-3 cells were introduced into nude mice to detect anti-tumor effects in vivo. RESULTS: In vitro, oridonin inhibited the proliferation of BxPC-3 and Panc-1 cells cells in a concentration and time dependent manner. In addition, oridonin dose-dependently induced Panc-1 cellular morphology changes. Besides, In BxPC-3 cells oridonin potentiated gemcitabine-induced apoptosis. oridonin induced Bax translocation from cytosolic to mitochondrial compartments. This was accompanied by the release of the apoptogenic protein Smac and inhibition of its downstream target XIAP. These effects were further enhanced by combined treatment with oridonin and gemcitabine. In vivo, both oridonin alone and in combination with gemcitabine significantly suppressed tumor growth in a Bax- and Smac-dependent manner. CONCLUSIONS: Oridonin can potentiate the effects of gemcitabine through Bax- and Smac-dependent mitochondrial signaling pathways in BxPC-3 pancreatic cancer cells. Therefore, oridonin has the potential to be used clinically in the treatment of pancreatic cancer.