Brief Reports
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 28, 2005; 11(32): 5044-5046
Published online Aug 28, 2005. doi: 10.3748/wjg.v11.i32.5044
Inositol hexaphosphate-induced enhancement of natural killer cell activity correlates with suppression of colon carcinogenesis in rats
Zheng Zhang, Yang Song, Xiu-Li Wang
Zheng Zhang, Xiu-Li Wang, Department of Biochemistry and Molecular Biology, Qingdao University Medical College, Qingdao 266021, Shandong Province, China
Yang Song, Nutrition and Food Sanitation Institution, Qingdao University Medical College, Qingdao 266021, Shandong Province, China
Author contributions: All authors contributed equally to the work.
Supported by the Health Bureau Foundation of Province Shandong, No. 1999CA2CBA2
Correspondence to: Yang Song, Nutrition and Food Sanitation Institution, Qingdao University Medical College, Qingdao 266021, Shandong Province, China. qdsongyang@126.com
Telephone: +86-532-2991029
Received: November 23, 2004
Revised: January 23, 2005
Accepted: January 26, 2005
Published online: August 28, 2005
Abstract

AIM: To investigate the anti-neoplastic effect of inositol hexaphosphate (InsP6 or phytic acid) on dimethylhydrazine (DMH)-induced colon tumor in rats and its effect on blood natural killer (NK) cell activity.

METHODS: Healthy Wistar rats, 4 wk old, were divided into control group (fed with common food) and InsP6 group (fed with common food+2% sodium inositol hexaphosphate in the drinking water), 15 rats in each group. Both groups were injected with 1,2-dimethylhydrazine subcutaneously (20 mg/kg body weight) once a week for 20 wk. Rats were killed after 21 wk. The whole large intestine was isolated to determine the general condition of tumors and to test blood NK cell activity by lactate-dehydrogenase-release assay.

RESULTS: Administration of InsP6 significantly increased blood NK cell activity in DMH-induced colorectal tumor in rats. InsP6 group had a smaller tumor size on average and a smaller number of tumors than the control group. Its mortality was also higher than that in control. However, the variables of body weight and tumor incidence were not significantly different between the two groups.

CONCLUSION: InsP6 can increase blood NK cell activity in DMH-induced colon tumor in rats and inhibit tumor growth and metastasis in rats.

Keywords: Inositol hexaphosphate; Phytic acid; Natural killer cell activity; Colon cancer