The present study aimed to investigate the efficacy of Rosmarinus officinalis total methanolic extract on colon cancer- induced in rats. Rats were classified into 5 groups. Group (1) was control. Groups from (2) to (5) were intrarectally injected with N-methylnitrosourea (MNU) for induction of colon cancer then group (2) was left untreated (cancer group); group (3) was treated intraperitoneally with 5-fluorouracil while, groups (4 and 5) were treated orally with 1400 and 2800 mg/kg b.wt. of R. officinalis extract respectively. Cancer group declared significant increase in the expression levels of β-catenin and c-Myc genes in colon tissue. Furthermore, colon cancer induced-rats demonstrated significant increase in colon COX-2, cyclin D1 and survivin expression in colon tissue associated with significant elevation in the circulating levels of all studied biochemical markers. Additionally, histopathological investigation of colon tissue sections in cancer group showed dysplasia and anaplasia in the lining epithelial cells of the glandular structure. In the contrary, treatment of cancer group with 5-fluorouracil or R. officinalis extract showed significant decrease in the expression levels of β-catenin and c-Myc genes. Also, all treated groups exhibited marked decrease in COX-2, cyclin D1 and survivin expression in colon tissue accompanied with a significant reduction in the circulating levels of the all studied biomarkers. As well as, marked improvement in the histological structure of colon tissue was detected. In conclusion, the present study indicated that R. officinalis extract possess promising therapeutic role against colon cancer through their antiinflammatory property, antiproliferative capacity and apoptotic potential.
