Abstract 907: Chemopreventive effects of a non-camellia tea against azoxymethane -induced precancerous colorectal lesions in male rats
Authors: He Chunnian , Bi Wu , Zhang L. Harris , Cao Li , Xiao Pei-Gen 
Published: August 2015

Tea (the leaves from Camellia plants) is one of the most popular beverages in the world; substantial evidence supports its success in the prevention of carcinogenesis and other chronic diseases in animal models. Plants other than Camellia have been widely used as tea as well in various cultures. We have systematically collected and identified over 30 species of frequently used Non-Camellia teas, which have been consumed at least 300 years in China or other nations. Recently, non-Camellia teas have attracted much attentions due to high potentials of preventing and treating metabolic and inflammatory diseases, as well as cancers. Epidemiologic studies report that tea consumption significantly reduces risk of colorectal cancer (CRC). We here reported in vivo preventive effects of the Ku-jin-cha (KJC) tea for CRC. KJC tea is a kind of “Non-Camellia tea” prepared from leaves of the plant Acer ginnala and popularly used in some Chinese regions for thousands of years. KJC contains high levels of anti-inflammatory and anti-oxidative compounds such as ginnalins. However, the potential chemopreventive effect of KJC remains unknown. Here, we investigated modulatory effects of KJC on colon carcinogenesis using the rat azoxymethane (AOM) induced precancerous colorectal lesion model.

Wistar rats (male, 4∼5 weeks old) were randomly divided into 4 groups (Control, KJC, AOM and AOM+KJC, 10 rats/group) and were fed either normal water or experimental water containing KJC for 12 weeks. After one week of water or KJC drinking, all rats except the Control Group were injected with 15 mg/kg AOM (s.c., once weekly for 3 weeks). At 16∼17 weeks of age, urine and sera were collected for metabolomic analysis using UPLC-QTOF/MS (ultra-HPLC coupled with time-of-flight mass spectrometry). Rats were sacrificed at the end of KJC administration, and colorectums collected for evaluation of aberrant crypt (AC), aberrant crypt foci (ACF) and Crypts/focus. Spleens, thymuses and bloods were also taken for immunological analysis. Our results show that the numbers of AC, ACF and Crypts/focus in rats of the KJC+AOM Group were significantly decreased, versus rats of the AOM Group (p &lt; 0.01). No ACF was found in rats without AOM injection. In addition, significant metabolic alterations were observed in the groups with KJC. Although KJC administration did not cause marked weight changes of spleens and thymuses, the effect of KJC on levels of inflammatory cytokines and mediators were also examined. Our results indicated that KJC significantly inhibited AOM-induced colonic ACF formation, suggesting that KJC might have a chemopreventive effect against colon carcinogenesis at least in the initiation stage of CRC. Furthermore, KJC may exert the chemopreventive effects on ACF formation by changing metabolic pathways and modulating immunity and inflammatory responses. This warrants further studies on the cellular and molecular mechanisms of KJC tea.

Citation Format: Chunnian He, Wu Bi, L. Harris Zhang, Li Cao, Pei-Gen Xiao. Chemopreventive effects of a non-camellia tea against azoxymethane -induced precancerous colorectal lesions in male rats. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 907. doi:10.1158/1538-7445.AM2015-907