Water-soluble extract of clove inhibits in vitro and in vivo growth of colon cancer by inducing autophagy

摘要

OBJECTIVE Cloves(Syzygium aromaticum L.)have been used as both a spice and a traditional Chinese medicinal herb for thousands of years. However, relatively little is known about its potential anticancer activity and mechanisms.In this study,we investigated the in vitro and in vivo anti-tumor effects and mechanisms of water extract of cloves(WEC)against colorectal cancer. METHODS MTS assay and Colony-formation assay were used to detect the anti-tumor activity of WEC on HT-29 cells.The in vivo anti-tumor effect of WEC was detected in a subcutaneous transplantation tumor model of human HT-29 cells.Autophagy was detected by flow cytometry and the expressions of autophagy related proteins(Beclin-1 and LC-3a/b)were determined by western blot. RESULTS MTS result showed that WEC significantly inhibited the viability of HT-29 cells,with the IC50values of 150 μg·mL-1.The colony-formation assay showed that the WEC significantly suppressed colon cancer cells proliferation.WEC also exhibited significant antitumor activity in tumor bearing nude mice. Flow cytometry result showed that WEC significantly induced autophagy, and the averaged relative values of fluorescence intensity were 206,251,341 and 356 in cells treated with 0,100,150 and 200 μg·mL-1WEC for 48 h.Western blot result showed that WEC treatment significantly increased Beclin-1 expression and ratios of LC3-II/LC3-I. CONCLUSION These result showed that WEC inhibited the growth of colon tumor both in vitro and in vivo, which might be related with autophagy induction, and WEC has potential to be developed as a novel anticancer agent for the treatment of colon cancer.