Effects of adlay on azoxymethane-induced colon carcinogenesis in rats

Chun Kuang Shih, Wenchang Chiang, Min Liang Kuo

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)


Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) is a grass crop used in traditional Chinese medicine and as a nutritious food. It has been reported that adlay has anti-inflammatory and anti-tumor activity. Cyclooxygenase-2 (COX-2) is an inducible enzyme functionally related to both inflammation and colon carcinogenesis and is the target of many chemopreventive agents. This study investigated the effect of adlay on colon carcinogenesis and COX-2 expression. In a short-term experiment, male F344 rats were fed diets containing different doses of dehulled adlay and received the colon-specific carcinogen, azoxymethane (AOM), by intraperitoneal injection. All rats were killed after 5 weeks of feeding, and the colons were examined for the preneoplastic lesion, aberrant crypt foci (ACF). Dietary dehulled adlay at levels of 10%, 20%, or 40% significantly reduced the numbers of ACF and aberrant crypts. Dehulled adlay reduced the number of ACF of different sizes but did not affect the crypt multiplicity. Most ACF were found in the middle and distal colons; dehulled adlay significantly suppressed the formation of ACF in the middle colon. In a long-term experiment, male F344 rats were fed diets containing different doses of dehulled adlay and injected with AOM. All rats were killed after 52 weeks of feeding, and colons were examined for tumors and COX-2 protein expression. The results indicated that dehulled adlay did not inhibit colon tumors in spite of a slight suppressing effect in the proximal colon. Rats fed diets containing 20% dehulled adlay had less COX-2 protein expression in both proximal and distal colon tumors. The inconsistent effects between COX-2 protein expression and tumor outcome may be due to regional differences in the colon and the malignancy of the tumors. These findings suggest that dehulled adlay suppresses early events in colon carcinogenesis but not the formation of tumors.

Original languageEnglish
Pages (from-to)1339-1347
Number of pages9
JournalFood and Chemical Toxicology
Issue number8
Publication statusPublished - Aug 2004


  • Aberrant crypt foci
  • ACF, aberrant crypt foci
  • Adlay
  • AOM, azoxymethane
  • Azoxymethane
  • Colon cancer
  • COX-2, cyclooxygenase-2
  • Cyclooxygenase-2
  • PBS, phosphate-buffered saline

ASJC Scopus subject areas

  • Food Science
  • Toxicology


Dive into the research topics of 'Effects of adlay on azoxymethane-induced colon carcinogenesis in rats'. Together they form a unique fingerprint.

Cite this