Prostate cancer cells stop growing when treated with grape seed extract

NewsRx.com


09-08-06

Prostate cancer (PCA) cells stop growing when treated with grape seed extract (GSE).

"The anti-cancer efficacy of GSE against PCA via its anti-proliferative, pro-apoptotic and anti-angiogenic activities in both cell culture and animal models have recently been described by us. GSE is a complex mixture containing gallic acid (GA), catechin (C), epicatechin (EC) and several oligomers (procyanidins) of C and/or EC, some of which are esterified to GA," investigators in the United States report.

According to R. Veluri and colleagues, University of Colorado, "To determine which components are most active against PCA, an ethyl acetate extract of GSE was separated by reverse-phase high-performance liquid chromatography (HPLC) into three fractions. Fraction 1 was far more effective than others in causing growth inhibition and apoptotic death of human PCA DU145 cells.

"Of the components in this fraction, GA showed a very strong dose- and time-dependent growth inhibition and apoptotic death of DU145 cells, but C and procyanidins B1 (EC-C dimer), B2 (EC-EC dimer) and B3 (C-C dimer) were nearly ineffective. Mechanistic studies demonstrated a strong caspase-9, caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavages by GA in DU145 cells."

"Procyanidin oligomers eluting in HPLC fractions 2 and 3 were obtained in larger quantities by separating GSE into eight fractions (I-VIII) on a gel filtration column. All fractions were analyzed by HPLC-UV and negative-ion electrospray mass spectrometry. Fractions I-III contained the active compound GA and inactive components C, EC, B1 and B2. Fraction IV contained other dimers and a dimer-GA ester and was also less active than GSE in DU145 cells," researchers reported.

They said, "Fractions V-VIII, however, caused significant growth inhibition and apoptosis with the highest activity present in the later fractions that contained procyanidin trimers and GA esters of dimers and trimers. Together, these observations identify GA as one of the major active constituents in GSE.

"Several procyanidins, however, and especially the gallate esters of dimers and trimers also may be efficacious against PCA and merit further investigation."

Veluri and colleagues published their study in Carcinogenesis (Fractionation of grape seed extract and identification of gallic acid as one of the major active constituents causing growth inhibition and apoptotic death of DU145 human prostate carcinoma cells. Carcinogenesis, 2006;27(7):1445-1453).

For additional information, contact C. Agarwal, University of Colorado, Health Science Center, School Pharmacy, Dept. of Pharmaceutical Science, 4200 E 9th Avenue, Box C238, Denver, CO 80262, USA.

The publisher of the journal Carcinogenesis can be contacted at: Oxford University Press, Great Clarendon St., Oxford OX2 6DP, England.