Gallic acid, an active constituent of grape seed extract, exhibits anti-proliferative, pro-apoptotic and anti-tumorigenic effects against prostate carcinoma xenograft growth in nude mice.
OBJECTIVE
Gallic acid, a natural agent present in a wide-range of fruits and vegetables, has been of potential interest as an anti-cancer agent; herein, we evaluated its efficacy in androgen-independent DU145 and androgen-dependent-22Rv1 human prostate cancer (PCa) cells.


METHODS
Cell viability was determined by MTT and apoptosis by Annexin V-PI assays. In vivo anti-cancer efficacy was assessed by DU145 and 22Rv1 xenograft growth in nude mice given normal drinking water or one supplemented with 0.3% or 1% (w/v) gallic acid. PCNA, TUNEL and CD31 immunostaining was performed in tumor tissues for in vivo anti-proliferative, apoptotic and anti-angiogenic effects of gallic acid.


RESULTS
Gallic acid decreased cell viability in a dose-dependent manner in both DU145 and 22Rv1 cells largely via apoptosis induction. In tumor studies, gallic acid feeding inhibited the growth of DU145 and 22Rv1 PCa xenografts in nude mice. Immunohistochemical analysis revealed significant inhibition of tumor cell proliferation, induction of apoptosis, and reduction of microvessel density in tumor xenografts from gallic acid-fed mice as compared to controls in both DU145 and 22Rv1 models.


CONCLUSIONS
Taken together, our findings show the anti-PCa efficacy of gallic acid and provide a rationale for additional studies with this naturally-occurring agent for its efficacy against PCa.
Kaur
Manjinder
M
Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045, USA.
Velmurugan
Balaiya
B
Rajamanickam
Subapriya
S
Agarwal
Rajesh
R
Agarwal
Chapla
C
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005707:Gallic Acid / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D014183:Transplantation, Heterologous
D005707:Gallic Acid