Background Colorectal cancer (CRC) is a major public health problem, with almost 1.8 million newly diagnosed cases and about 881,000 deaths annually. Chamomile (Matricaria chamomilla) is a well-documented medicinal herb that possesses anti-inflammatory and anti-carcinogenic properties. This study aimed to unravel the effect of aqueous chamomile extract against 1,2-dimethylhydrazine(DMH)-induced CRC in mice. Methods Male Balb/c mice received a weekly intraperitoneal injection of DMH (20 mg/kg body weight) for 12 weeks. Chamomile extract (150 mg/kg body weight/5 days/week p.o.) was administered at the initiation and post-initiation stages of carcinogenesis. Polyps count, histopathological analysis, real-time polymerase chain reaction (RT-PCR) analysis of Wnt signaling genes, ELISA of cyclooxygenase-2 (COX-2), and enzyme assay for inducible nitric oxide synthase (iNOS) were performed. Results Chamomile extract modulated the Wnt pathway in colonic tissues, where it significantly downregulated Wnt5a, β-catenin, T cell factor (Tcf4), lymphoid enhancer factor 1 (Lef1), c-Myc and Cyclin D1 expression levels, while it upregulated adenomatous polyposis coli (APC) and glycogen synthase kinase (GSK3β) expression levels. This extract significantly reduced COX-2 levels and iNOS activities. Polyps count and histopathological analysis provided supportive evidence for the biochemical and molecular analyses. Conclusions Chamomile can act as a potent dietary chemopreventive agent against DMH-induced CRC.
Keywords: 1,2-dimethylhydrazine; COX-2; Wnt signaling; chamomile; colorectal cancer; iNOS.