The prevention of epigallocatechin gallate on colon preneoplastic lesion / 中华消化杂志

ABSTRACT

Objective To investigate wheter epigallocatechin gallate (EGCG) could prevent the information of abrant crypt loci (ACF) induced by isoquinoline (IQ)and its possible mechanisms. Methods Sixty male BALB/cA nude immunological deficit mice were divided into five groups. Except control group, the other four groups were received IQ to induce ACF. The rats in low, medium and high dose groups were received 5, 10 and 20 mg/kg of EGCG,respectively. The mice were sacrificed six weeks later. Hematoxylin-eosin (HE) staining and 0.2% methylene blue staining were used to observe the routine histology and ACF, respectively. Immunohistochemistry (IHC) was used to detect Nrf2 protein level and RT-PCR was used to detect Nrf2 and UGT1A10 mRNA levels in colon tissue. Results The body weights of model group decreased significantly compared to high-dose group (21.70±0.13 vs. 24.37±0.07, P<0.01). Compared to model group, the degree of atypical hyperplasia and even canceration of colon mucus and the number of total ACF and total AC in high-dose group were decreased significantly (18.00±7.51 vs. 64.20±45.18, P<0.05;63.90±18.58 vs. 168. 80±35.34, P<0.01). The protein level of Nrf2 increased (0.3114±0.0037 vs. 0.1660±0.0021, P<0.01). The mRNA levels of Nrf2 and UGT1A10 in high-dose group was increased (both P value<0.01). Conclusions EGCG has protective effect on IQ induced preneoplastic lesions through reducing the number of ACF. This effect may be caused partly through the signal pathway Nrf2-UGT1A10.