Effect of garlic on tumor invasion and metastatic potential in induced colon carcinogenesis in rats : histopathological and immunohistochemical study

Abstract EN

Background and Aim: Preventive intervention of colorectal cancer has become essential as a major portion of the population may develop the disease at some points during their lives.

Diet and nutrition play an important role during this multi-step colon carcinogenic process.

Inhibitory activity of garlic was tested on Dimethylhydrasin (DMH) induced colon carcinogenesis in Sprague-Dawley rats.

Methods: Experimental study was done to investigate the mechanism of garlic action on occurrence of colon neoplasia and liver metastasis as well as the expression of cyclooxygenase-2 (COX-2), matrix metalloproteinase (MMP-2) and CD34 was analyzed in the colonic mucosa.

Results: On histopathological examination of colon and liver of the investigated animals, the first (normal control) as well as the fourth group (receiving garlic only) revealed no pathological lesions.

In the 2nd group (taking DMH only), colon neoplasia was detected in 21/21 (100%) of animals and liver metastasis in 10/21 (47.6%) while, in the 3rd group (receiving DMH and garlic), the tumor occurrence was detected in 16/32 (50%) of animals with no liver metastasis.

Following treatment with garlic, significant suppression of COX-2, MMP-2 expressions (p<0.01) was detected with respect to the carcinogen group.

As regards angiogenesis in DMH treated animals, CD34 expression was mostly of grades III and IV compared to grades 1 and II in combined DMH and garlic treated group.

Conclusion: It could be concluded that the observed modulatory influences of garlic at the level of suppression of COX-2, MMP-2 and CD34 during DMH induced colon carcinogenesis suggest that the dietary intake of garlic has a chemopreventive and inhibitory effects through the multi-step carcinogenesis.