Growth Inhibition by Caffeic Acid, One of the Phenolic
Constituents of Honey, in HCT 15 Colon Cancer Cells
Previous work from our laboratory showed that the mechanism
of crude-honey induced apoptosis in colon cancer cells. Since phenolic
constituents of honey were attributed to its apoptosis-inducing ability, we
studied caffeic acid, one of the phenolic constituents of honey, induced effect
on colon cancer cells.
Antiproliferative effect of caffeic acid was estimated using
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. MTT
assay signified the antiproliferative nature of caffeic acid against the HCT 15
colon cancer cells.
A time-dependent inhibition of colony formation was evident
with caffeic acid treatment. Cell-cycle analysis of caffeic acid- (CA-) treated
cells indicated increasing accumulation of cells at sub-G(1) phase.
Photomicrograph images of treated cells showed membrane blebbing and cell
shrinkage. Yo-pro-1 staining of caffeic-acid-treated cells confirmed apoptosis
in dose- and time-dependent manner. Increasing ROS generation and reduction in
the mitochondrial membrane potential were also accompanied in the caffeic
acid-induced apoptosis.
This work will promote caffeic acid as a likely candidate in
the chemoprevention of colon cancer.