We made a comparative study of kimchis prepared with different ingredients. Cancer preventive kimchi (CPK) and anticancer kimchi (ACK) were already developed by enhancing the chemopreventive activities proved by various experiments in our laboratory. Kimchis were fermented for 4 weeks at 5℃, and tested pH, texture, microbial count, sensory evaluation, identifying bioactive flavonoides using LC-MS, DPPH radical-scavenging activity MTT assay and RT-PCR using HT-29 human colon carcinoma cells. During 5 weeks of fermentation, CPK and ACK showed higher pH and lower acidity than standardized kimchi (SK). ACK showed lower rate of total aerobic bacterial count than SK and CPK, while the counts of lactic acid bacteria were similar in SK, CPK and ACK. In sensory evaluation test, SK received the highest overall acceptability score; followed by CPK and ACK as the same score. CPK and ACK contained some bioactive flavonoids, especially isoramnetin-3-O-glucoside and isorhamnetin were identified in ACK. In DPPH assay, ACK showed 88% of antioxidation, and 86% CPK, 73% SK and 59% commercial kimchi (CK) in the order (p<0.05). In MTT assay on HT-29 human colon carcinoma cells, ACK showed 83% of in vitro anticancer effect, however, CPK exhibited 82%, SK 77% and CK 68%. ACK also significantly reduced mRNA expressions of iNOS, COX-2 and Bcl-2 in the HT-29 human colon carcinoma cells (p<0.05). In addition, Bax, p21 and p53 expressions of ACK treatment significantly increased compared to the other groups(p<0.05).
We evaluated the preventive effect of kimchis prepared with different ingredients on azoxymethane(AOM) / dextran sulfate sodium(DSS) induced colitis-associated colon cancer(CAC). Mice (Balb/c, male) were first given single intraperitoneal injection of AOM (10 mg/kg). Starting 2 and 5 weeks after the injection, mice received 2% of DSS in the drinking water for 7 days. After injection of 2 weeks, methanolic extracts from CK, SK, CPK and ACK were orally administrated for the next 4 weeks. High dose of ACK significantly decreased the ratio of colon weight/length (36.18±5.92 mg/cm), and showed the least tumor numbers (14.1±2.8) than other groups (p<0.05). Histological observation suggested that ACK suppressed mucosal damages. In pro-inflammatory cytokines(IL-6, TNF-α, IL-12, IL-17A and IFN-γ) levels in serum and colon tissue, all kimchi treated groups decreased the expressions significantly(p<0.05). Especially, the margins of the reduction in high dose of ACK expressions were the highest. ACK also significantly reduced mRNA and protein expressions of iNOS and COX-2 in the colon tissue (p<0.05). In addition, p21 and p53 expressions of ACK treatment significantly increased compared to the other groups(p<0.05). Those results suggest that kimchi has a preventive effect on AOM/DSS-induced CAC in Balb/c mice, especially anti-cancer kimchi possibly be used as a health functional food to prevent colon cancer.