Sarmiento-Machado L.M and Ariane Rocha Bartolomeu A.R received fellowships from the
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)- Finance code 001
and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)-# 2017/26217-7,
respectively.Colorectal cancer is the third most diagnosed cancer worldwide and linked to dietary/lifestyle factors. Arthrospira (Spirulina) platensis (AP)
contains bioactive compounds with beneficial effects in vivo/in vitro. We evaluated the effects of AP feeding against 1,2-dimethylhydrazine
(DMH)-induced colon carcinogenesis. Male Sprague Dawley rats were given subcutaneous injections of DMH (4 × 40 mg/kg body weight)
(G1–G3) or vehicle (G4–G5) twice a week (weeks 3–4). During weeks 1–4, animals were fed a diet containing 1 % (G2) or 2 % (G3–G4)
AP powder (w/w). After this period, all groups received a balanced diet until week 12. Some animals were euthanised after the last DMH
injection (week 4) for histological, immunohistochemical (Ki-67, γ-H2AX and caspase-3) and molecular analyses (real time-PCR for
91 genes), while other animals were euthanised at week 12 for preneoplastic aberrant crypt foci (ACF) analysis. Both AP treatments
(G2–G3) significantly decreased the DMH-induced increase in γ-H2AX (DNA damage) and caspase 3 (DNA damage-induced cell death) in
colonic crypts at week 4. In addition, Cyp2e1 (Drug metabolism), Notch1, Notch2 and Jag1 genes (Notch pathway) and Atm, Wee1,
Chek2, Mgmt, Ogg1 and Xrcc6 genes (DNA repair) were also down-regulated by 2 % AP feeding (G3) at week 4. A significant reduction in
ACF development was observed in both AP-treated groups (G2–G3) at week 12. In conclusion, findings indicate that AP feeding reduced acute
colonic damage after DMH, resulting in fewer preneoplastic lesions. Our study provided mechanistic insights on dietary AP-preventive effects
against early colon carcinogenesis.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)
001Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2017/26217-
