Grape seed procyanidin extract (GSE) has been reported to exert antineoplastic properties via the inhibition of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) eicosanoid pathways. In addition, ample data link carcinogenesis to inflammatory events involving other major eicosanoid metabolic pathways, including prostacyclin (PGI2) and 15-Hydroxyeicosatetraenoic acid (15-HETE). We therefore evaluated the effects of GSE on prostacyclin synthase (PTGIS)/PGI2 and 15-lipoxigenase-2 (15-LOX-2)/15-HETE productions by human lung premalignant and malignant cells and correlated the findings with anti-proliferative or pro-apoptotic effects of GSE. The effects of GSE on PGI2 and 15-HETE productions by human bronchoalveolar lavage (BAL) cells ex vivo were also determined. We further evaluated the bioactivity of oral administration of leucoselect phytosome (a standardized GSE) in the lungs of subjects participating in a lung cancer chemoprevention trial, by comparing the anti-proliferative effects of co-culturing matched pre- vs. post-treatment BAL fluids with lung premalignant and malignant cells. GSE significantly increased PGI2 (as measured by 6-keto PGF1α) and 15-HETE productions by these cells. Transfections of PTGIS or 15-LOX-2 specific siRNA partially abrogated the anti-proliferative or proapoptotic effects of GSE in lung premalignant and malignant cells, respectively. GSE also increased PTGIS and inhibition of caspase 3 and transfection of 15-LOX-2 siRNA abrogated the GSE-induced apoptosis in A549 cells. In addition, culture supernatants from ex vivo GSE-treated baseline BAL cells, as well as BAL fluids from subjects treated with leucoselect phytosome, significantly decreased proliferations of lung premalignant and malignant cells. Our findings support the continued investigation of GSE as an anti-neoplastic and chemopreventive agent against lung cancer.

This content is only available via PDF.

Article PDF first page preview

Article PDF first page preview