Induction of apoptosis by the aqueous extract of Rubus coreanum in HT-29 human colon cancer cells.
OBJECTIVE
The incompletely ripened fruit of Rubus coreanum (IRFRC) has been used in traditional herbal medicine to manage various diseases. To explore the possibility that IRFRC has chemopreventive effects, we examined whether or not extracts of IRFRC inhibits HT-29 cell growth and explored the mechanism for this effect.


METHODS
We cultured HT-29 cells in the presence of the aqueous or ethanol extract of IRFRC. DNA synthesis was estimated by 5-bromo-2'-deoxyuridine incorporation. We measured apoptosis using a DNA fragmentation assay and Annexin V staining. We used western blot analyses to determine the cleavage of caspases and poly (adenosine diphosphate-ribose) polymerase.


RESULTS
Aqueous extract of IRFRC substantially inhibited viable HT-29 cell number in a dose-dependent manner, whereas ethanol extract had only a minimal effect. Aqueous extract inhibited DNA synthesis and induced apoptosis of HT-29 cells in a dose-dependent manner. Aqueous extract induced cleavage of caspase-3, -7, and -9 and induced the activity of caspase-3 and cleavage of poly (adenosine diphosphate-ribose) polymerase.


CONCLUSIONS
We have shown that aqueous extract of IRFRC inhibits cell proliferation and stimulates apoptosis in HT-29 cells, and that this may be mediated by its ability to activate the caspase-3 pathway. It remains to be determined whether the aqueous extract of IRFRC has chemopreventive activities in animal models.
Kim
Eun Ji
EJ
Silver Biotechnology Research Center, Hallym University, Chuncheon, Korea.
Lee
Yong-Jin
YJ
Shin
Hyun-Kyung
HK
Park
Jung Han Yoon
JH
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000473:pathology / Q000517:prevention & control*; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D005638:Fruit / Q000737:chemistry*; D019073:HT29 Cells; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D027824:Rosaceae / Q000737:chemistry*
D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases