Abstract 1841: Dietary morin suppresses colitis-associated colorectal carcinogenesis in rats

Abstract A flavonol, morin, found in almonds, mill, fig and other moraceae which are used as dietary agents and also as herbal medicine. Morin acts as a potent antioxidant, xanthine oxidase inhibitor, PKC inhibitor, cell proliferation inhibitor, apoptosis inducer, modulator of LOX and COX activities. Based on our previous studies on chemopreventive ability of morin in tongue and colon carcinogenesis (Carcinogenesis 20: 1477-84, 1999; Int J Cancer 83: 381-6, 1999; Oncol Rep 6:1333-40, 1999), we aimed to determine possible inhibitory potential of this compound in colitis-associated colon carcinogenesis in rats initiated with AOM and promoted by DSS. Male F344 rats initiated with a single s.c. injection of AOM (20 mg/kg bw) were promoted by 1.5% DSS in their drinking water for 7 days. They were then given a basal diet containing 50, 250 and 1000 ppm of morin for 17 weeks. At wk 20, the development of colonic adenocarcinoma was significantly inhibited by feeding with morin at a dose level of 1000 ppm (45% incidence, p=0.0141; and 0.73 +/- 1.01 multiplicity, p<0.05), when compared to the AOM/DSS group (93% incidence and 2.36 +/- 1.95 multiplicity). The incidence and multiplicity of adenocarcinomas in the rats received 50 ppm (60% incidence and 1.20 +/- 1.23 multiplicity) and 250 ppm (64% incidence and 1.09 +/- 1.04 multiplicity) of morin in diet were also smaller than that of the AOM and DSS group, but the differences were insignificant. The treatments inhibited colonic inflammation, and also modulated proliferation, apoptosis, and expression of several pro-inflammatory cytokines, such as NF-kappaB, Stat3, TNF-alpha and IL-1beta in the adenocarcinomas. Feeding with morin lowered tissue polyamine levels of colonic mucosa. Our findings indicate that dietary morin is able to inhibit colitis-related colon carcinogenesis in rats. Also, our model provides knowledge applicable to prevent inflammation-associated colon cancer in humans. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1841. doi:10.1158/1538-7445.AM2011-1841