Eugenol, a natural compound available in honey and various plants extracts including cloves and Magnoliae flos, is exploited for various medicinal applications. Since most of the drugs used in the
cancer are apoptotic inducers, the apoptotic effect and anticancer mechanism of
eugenol were investigated against
colon cancer cells. Antiproliferative effect was estimated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-
diphenyl tetrazolium
bromide assay]. Earlier events like
MMP (mitochondrial membrane potential),
thiol depletion and
lipid layer break were measured by using flow cytometry. Apoptosis was evaluated using PI (
propidium iodide) staining, TUNEL (
terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) assay and DNA fragmentation assay. MTT assay signified the antiproliferative nature of
eugenol against the tested
colon cancer cells. PI staining indicated increasing accumulation of cells at sub-G1-phase.
Eugenol treatment resulted in reduction of intracellular non-
protein thiols and increase in the earlier
lipid layer break. Further events like dissipation of
MMP and generation of ROS (
reactive oxygen species) were accompanied in the
eugenol-induced apoptosis. Augmented ROS generation resulted in the DNA fragmentation of treated cells as shown by DNA fragmentation and TUNEL assay. Further activation of PARP (
polyadenosine diphosphate-
ribose polymerase), p53 and
caspase-3 were observed in Western blot analyses. Our results demonstrated molecular mechanism of
eugenol-induced apoptosis in human
colon cancer cells. This research will further enhance
eugenol as a potential chemopreventive agent against
colon cancer.