Allicin sensitizes hepatocellular cancer cells to anti-tumor activity of 5-fluorouracil through ROS-mediated mitochondrial pathway

J Pharmacol Sci. 2016 Aug;131(4):233-40. doi: 10.1016/j.jphs.2016.04.017. Epub 2016 Apr 22.

Abstract

Drug resistance and hepatic dysfunction are the two major factors that limit the application of chemotherapy for hepatocellular carcinoma (HCC). It has been reported that allicin has the hepatic protective effect and antitumor activity. Hence allicin may be an ideal enhancer to chemotherapy regimen of HCC. In the present study, we demonstrated that allicin enhanced 5-fluorouracil (5-FU) inducing cytotoxicity in HCC cells. In vivo experiment, combined treatment group with allicin (5 mg/kg/d; every two days for 3 weeks) and 5-FU (20 mg/kg/d; 5 consecutive days) showed a dramatic inhibitory effect on the growth of HCC xenograft tumors in nude mice. The co-treatment group showed highly apoptotic level compared with 5-FU treated alone. Cells combined treatment with allicin and 5-FU increased intracellular reactive oxygen species (ROS) level, reduced mitochondrial membrane potential (ΔΨm), activated caspase-3 and PARP, and down-regulated Bcl-2 compared with DMSO, allicin and 5-FU treated alone. Moreover, the increase of activated caspase-3 and PARP was blocked by the ROS inhibitor antioxidant N-acetyl cysteine (NAC). In conclusion, this is the first study to demonstrate that allicin sensitized HCC cells to 5-FU induced apoptosis through ROS-mediated mitochondrial pathway. These results provided evidences for the combination used of allicin and 5-FU as a novel chemotherapy regimen in HCC.

Keywords: 5-Fluorouracil; Allicin; Apoptosis; Hepatocellular carcinoma.

MeSH terms

  • Acetylcysteine / pharmacology
  • Animals
  • Antineoplastic Combined Chemotherapy Protocols
  • Apoptosis / drug effects
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Caspase 3 / metabolism
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Disulfides
  • Drug Synergism
  • Fluorouracil / antagonists & inhibitors
  • Fluorouracil / pharmacology*
  • Humans
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology*
  • Membrane Potential, Mitochondrial / drug effects
  • Mice
  • Mitochondria / drug effects*
  • Poly (ADP-Ribose) Polymerase-1 / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Reactive Oxygen Species / metabolism*
  • Sulfinic Acids / antagonists & inhibitors
  • Sulfinic Acids / pharmacology*
  • Xenograft Model Antitumor Assays

Substances

  • Disulfides
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • Sulfinic Acids
  • allicin
  • Poly (ADP-Ribose) Polymerase-1
  • Caspase 3
  • Fluorouracil
  • Acetylcysteine