In vitro and in vivo cytotoxic effect of AntiGan against tumor cells

Abstract

Novel effective chemopreventive agents against cancer are required to improve current therapeutic rates. The aim of the present study was to investigate the anti-carcinogenesis effect of AntiGan, an extract obtained from the European conger eel, Conger conger, in vitro (human tumor cell lines) and in vivo (murine model of colitis) models. The potential apoptogenic activity after 24 h of incubation with 10, 25 and 50 µl/ml AntiGan was reported using growth inhibition and apoptosis activity assays. In vivo studies were performed in mice by inducing colitis with oral administration of 2% dextran sulphate sodium (DSS) for 5 weeks. Apoptosis was observed in HL-60, Hs 313.T, SW-480, Caco-2 and HT-29 cell lines. The highest level of growth inhibition was observed in Caco-2 (66, 75.8 and 88.1%), HT-29 (56, 73 and 87.6%) and SW-480 (38.5, 61.6, 78.6%) for AntiGan doses of 10, 25 and 50 µl/ml, respectively, compared to untreated cells, while the results of the expression of genes associated with apoptosis indicated a downregulation of B-cell lymphoma 2 (Bcl-2) in all cell lines studied. In vivo, morphopathological alterations in the colon were analyzed by immunohistochemical and staining methods. Tumoral markers, including β-catenin, cyclooxygenase 2 and Bcl-2 were expressed in cryptal cells of the dysplastic colonic mucosa, whereas the levels of interferon-γ expression were also increased when no treatment was applied. In the experimental murine model, the optimal concentration of AntiGan for an effective dose-response was 10% in diet. These results suggested that AntiGan displays a powerful anti-inflammatory effect in DSS-induced colitis, acting as a chemopreventive agent against colon carcinogenesis, most likely due to its apoptogenic peptides that contribute to the induction of apoptosis.