Suppression of β-catenin and cyclooxygenase-2 expression and cell proliferation in azoxymethane-induced colonic cancer in rats by rice bran phytic acid (PA).

Abstract

BACKGROUND:

Phytic acid (PA) is a polyphosphorylated carbohydrate that can be found in high amounts in most cereals, legumes, nut oil, seeds and soy beans. It has been suggested to play a significant role in inhibition of colorectal cancer. This study was conducted to investigate expression changes of β-catenin and cyclooxygenase-2 (COX-2) and cell proliferation in the adenoma-carcinoma sequence after treatment with rice bran PA by immunocytochemistry.

MATERIALS AND METHODS:

Seventy-two male Sprague-Dawley rats were divided into 6 equal groups with 12 rats in each group. For cancer induction two intraperitoneal injections of azoxymethane (AOM) were given at 15 mg/kg bodyweight over a 2-weeks period. During the post initiation phase, two different concentrations of PA, 0.2% (w/v) and 0.5% (w/v) were administered in the diet.

RESULTS:

Results of β-catenin, COX-2 expressions and cell proliferation of Ki-67 showed a significant contribution in colonic cancer progression. For β-catenin and COX-2 expression, there was a significant difference between groups at p<0.05. With Ki-67, there was a statistically significant lowering the proliferating index as compared to AOM alone (p<0.05). A significant positive correlation (p=0.01) was noted between COX-2 expression and proliferation. Total β-catenin also demonstrated a significant positive linear relationship with total COX-2 (p=0.044).

CONCLUSIONS:

This study indicated potential value of PA extracted from rice bran in reducing colonic cancer risk in rats.

• Authors: Norazalina Saad, Norhaizan Mohd Esa, Hairuszah Ithnin
• Journal: Asian Pacific journal of cancer prevention : APJCP (Asian Pac J Cancer Prev) Vol. 14 Issue 5 Pg. 3093-9 ( 2013) ISSN: 2476-762X [Electronic] Thailand
• PMID: 23803085 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carcinogens
• beta Catenin
• Phytic Acid
• Cyclooxygenase 2
• Azoxymethane

Topics

• Adenoma (chemically induced, metabolism, prevention & control)
• Animals
• Apoptosis (drug effects)
• Azoxymethane (toxicity)
• Blotting, Western
• Carcinogens (toxicity)
• Cell Proliferation (drug effects)
• Colonic Neoplasms (chemically induced, metabolism, prevention & control)
• Cyclooxygenase 2 (chemistry, metabolism)
• Immunoenzyme Techniques
• Male
• Oryza (chemistry)
• Phytic Acid (therapeutic use)
• Rats
• Rats, Sprague-Dawley
• beta Catenin (antagonists & inhibitors, metabolism)