Djulis (Chenopodium Formosanum) Prevents Colon Carcinogenesis via Regulating Antioxidative and Apoptotic Pathways in Rats

Abstract

Djulis is a cereal crop rich in polyphenols and dietary fiber that may have nutraceutical activity to prevent colon cancer. This study was designed to examine the preventive effect of djulis on colon carcinogenesis in rats treated with 1,2-dimethylhydrazine (DMH). Rats were fed different AIN-93G-based diets: groups N and DMH were fed AIN-93G diet and groups LD, MD, and HD were fed AIN-93G diet containing 5, 10, and 20% djulis, respectively. All rats except for group N were injected with DMH to induce colon carcinogenesis. After 10 weeks, rats were sacrificed and colon and liver tissues were collected for analysis. The results showed that djulis-treated rats had significantly lower numbers of colonic preneoplastic lesions, aberrant crypt foci (ACF), sialomucin-producing (SIM)-ACF, and mucin-depleted foci. Djulis treatment increased superoxide dismutase and catalase activities in colon and liver. Djulis also reduced p53, Bcl-2, and proliferating cell nuclear antigen expressions and increased Bax and caspase-9 expressions. Besides, phenolic compounds and flavonoids were found rich in djulis. These results demonstrate the chemopreventive effect of djulis on carcinogen-induced colon carcinogenesis via regulating antioxidative and apoptotic pathways in rats. Djulis may have the potential to be developed as a valuable cereal product for chemoprevention of colon cancer.

Keywords: antioxidant; apoptosis; chemoprevention; colon cancer; djulis; preneoplastic lesions.

Figure 1

The representatives of aberrant crypt foci (ACF) with one AC (a), ACF with two AC (b), ACF with four AC (c), ACF with six AC (d), sulfomucin-producing ACF (SUM-ACF) (e), ACF with not more than 85% SIM-producing or 85% SUM-producing cells were defined as mixed-type (MIX)-ACF (f), sialomucin-producing ACF (SIM-ACF) (g) and mucin-depleted foci (MDF) (h) in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in male F344 rats. The original magnification is 100 ×.

Figure 2

Effects of djulis on p53 (a), proliferating cell nuclear antigen (PCNA) (b), Bax (c), Bcl-2 (d), Bax/Bcl-2 (e), and caspase-9 (f) expressions of the distal colon mucosa of male F344 rats. The bar represents the mean ± SD (n = 3–5). Bars with the different letter are significantly different from one another as determined by a one-way ANOVA followed by Duncan’s multiple-range test, p < 0.05. All rats except those in group N were administered 1,2-dimethyl hydrazine (DMH). N, AIN-93G diet; DMH, AIN-93G diet; LD, AIN-93G diet containing 5% djulis; MD, AIN-93G diet containing 10% djulis; HD, AIN-93G diet containing 20% djulis.