Dietary inclusion of cyanobacteria Arthrospira (Spirulina platensis) spp. decreases the aggravating effect of hemin from red meat in a rat colorectal carcinogenesis model

Colorectal cancer (CRC) risk, associated with a high intake of red/processed meat, may be related to hemin. A potential chemopreventive agent, Arthrospira (Spirulina platensis) spp. (AP) is a cyanobacteria employed as a functional food with the potential to reduce malnutrition in developing countries. Thus, we assessed the effects of dietary AP against hemin-promoting effects in a dimethylhydrazine (DMH)-induced colorectal carcinogenesis model. Male Sprague-Dawley rats were allocated into five groups. G1–G4 received four subcutaneous DMH injections (40 mg/kg body weight, twice a week for 2 weeks) and G5 received DMH vehicle. At weeks 4 to 16, groups were fed a balanced diet (BD, G1 and G5), BD containing 2 % AP (20 g powder/kg chow, G2), BD containing hemin (0.32 g/kg chow, G3) or BD containing hemin+2 % AP (G4), respectively. Hemin group (G3) increased aberrant crypt foci (ACF) development, malondialdehyde (MDA), and Nox-1 levels and reduced glutathione (GSH) and GSH-Px levels in colonic mucosa when compared to DMH group (G1). In contrast, the dietary hemin+2 % AP regimen (G4), reduced both preneoplastic lesion development and MDA levels while increased GSH levels, compared to the DMH+hemin group (G3). Dietary AP may reduce hemin-promoting effects by modulating oxidative stress and ACF lesions.