britannin and Liver-Neoplasms

Hepatocellular carcinoma is cancer with many new cases and the highest mortality rate. Chemotherapy is the most commonly used method for the clinical treatment of hepatocellular carcinoma. Natural products have become clinically important chemotherapeutic drugs due to their great potential for pharmacological development. Many sesquiterpene lactone compounds have been proven to have antitumor effects on hepatocellular carcinoma.. Britanin is a sesquiterpene lactone compound that can be considered for the treatment of hepatocellular carcinoma. The present study aimed to investigate the antitumor effect of britanin.. BEL 7402 and HepG2 cells were used to study the cytotoxicity and antitumor effects of britanin. Preliminary studies on the nuclear factor kappa B pathway were conducted by western blot analysis. A BEL 7402-luc subcutaneous tumor model was established for the in vivo antitumor studies of britanin. In vivo bioluminescence imaging was conducted to monitor changes in tumor size.. The results of the cytotoxicity analysis showed that the IC50 values for britanin in BEL 7402 and HepG2 cells were 2.702μM and 6.006μM, respectively. The results of the colony formation demonstrated that the number of cells in a colony was reduced significantly after britanin treatment. And the results of transwell migration assays showed that the migration ability of tumor cells was significantly weakened after treatment with britanin. Tumor size measurements and staining results showed that tumor size was inhibited after britanin treatment. The western blot analysis results showed the inhibition of p65 protein expression and reduced the ratio of Bcl-2/Bax after treatment.. A series of in vitro and in vivo experiments demonstrated that britanin had good antitumor effects and provided an option for hepatocellular carcinoma treatment.

Topics: Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Inula; Lactones; Liver Neoplasms; Liver Neoplasms, Experimental; Male; Mice; Mice, Nude; Molecular Structure; Optical Imaging; Sesquiterpenes; Structure-Activity Relationship; Time Factors; Tumor Cells, Cultured

Britannin (Bri), isolated from Inula aucheriana, is a sesquiterpene lactone (SL), a class of secondary metabolites. Previous studies have suggested the anti-cancer potential of Bri; however, the molecular mechanism remains elusive. The present study investigated the effects of Bri on liver cancer progression. Our findings indicated that Bri significantly suppressed the growth of liver cancer cell lines. Mechanistic researches revealed that Bri induced apoptosis through the extrinsic and intrinsic apoptotic pathways, as evidenced by the increase of Caspase-8, -9 and -3 cleavages. In addition, Bri-triggered autophagy in liver cancer cells, supported by the up-regulation of light chain 3 (LC3) II, p62, autophagy-related 5 (ATG5) and Beclin 1, as well as the occurrence of autophagic vacuoles. Importantly, Bri increased AMPK activation, while decreased the activity of its down-streaming signal, mTOR. Of note, suppression of AMP-activated protein kinase (AMPK) activation using its inhibitor, Compound C, could inhibit both apoptosis and autophagy induced by Bri. Furthermore, Bri was found to induce reactive oxygen species (ROS) generation in hepatic cancer cells. Notably, reducing ROS production by its scavenger, N-acetyl cysteine (NAC), could down-regulate p-AMPK levels, while up-regulate the phosphorylated mechanistic target of rapamycin (p-mTOR) expressions, accompanied with the restored cell viability, as well as the reduced apoptosis and autophagy in Bri-treated liver cancer cells. Finally, Bri inhibited the tumor growth in vivo without side effects. In conclusion, our study illustrated that Bri could induce apoptosis and autophagy by activating AMPK regulated by ROS in liver cancer cells, supplying molecular bases for developing Bri into an effective candidate against liver cancer.

Topics: AMP-Activated Protein Kinases; Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Cell Line; Cell Line, Tumor; Enzyme Activation; Humans; Inula; Lactones; Liver Neoplasms; Reactive Oxygen Species; Sesquiterpenes