Cyclooxygenase (COX) inhibitors have suppressive effects on several types of
cancer cells including
prostate cancer. In this study, we considered the potential COX-inhibitory activity of a unique anti-inflammatory
herbal preparation (
Zyflamend; New Chapter, Inc., Brattleboro, VT) and analyzed its effects on the human
prostate cancer cell line LNCaP. COX inhibitory activity of
Zyflamend was determined by a spectrophotometric-based assay using purified ovine COX-1 and COX-2
enzymes. Effects of
Zyflamend on LNCaP cell growth and apoptosis in vitro were assessed by cell counting, Western blot detection of
poly ADP-ribose polymerase (PARP) cleavage, and measurement of
caspase-3 activity in treated and control
cell extracts. Western blotting techniques were conducted to determine the effects of this
herbal preparation on the expression of the cell signaling
proteins, p21,
androgen receptor (AR), phospho-
protein kinase C (pPKC)(alpha/beta), and phospho (p)Stat3. The phospohorylation status of several signal transduction
phosphoproteins was profiled using a high-throughput
phosphoprotein screening assay in treated cells and compared to controls.
Zyflamend dramatically decreased COX-1 and COX-2 enzymatic activity. Elevated p21 expression coincided with attenuated cell growth following treatment of LNCaP cells with
Zyflamend. PARP cleavage fragments were evident, and
caspase-3 activity was upregulated over the control indicating the ability of
Zyflamend to induce apoptosis of these cells.
Androgen receptor expression levels declined by 40%, and decreases were observed in the active forms of Stat3 and PKC(alpha/beta) in
Zyflamend-treated LNCaP cells.
Zyflamend inhibited both COX-1 and COX-2 enzymatic activities, suppressed cell growth, and induced apoptosis in LNCaP cells. However, our data suggests that the effects are likely due to COX-independent mechanisms potentially involving enhanced expression of p21 and reduced expression of AR, pStat3, and pPKC(alpha/beta).