Raw data from the study "Chemopreventive effects of consumption of table olives on 1,2-dimethylhydrazine-induced preneoplastic lesions in rat colon"

Table olives are a rich dietary source of pentacyclic triterpenes (PT) and polyphenols (P), many of which have demonstrated significant antiproliferative and proapoptotic activities. This study aimed to evaluate the effect of this food on the early stages of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) at 20 mg/kg. Male Sprague-Dawley rats (7 weeks of age) were administered either water or a suspension of Arbequina table olives (AO; 3.85 g/kg) by gavage at 10 mL/kg for 49 days. Each group was then divided into two subgroups that received subcutaneous injections of the carcinogen (DMH+/Olives- and DMH+/Olives+) or the solvent (DMH-/Olives- and DMH-/Olives+) on days 8, 15, and 22 as previously established (Alfaras et al., 2010; Juan et al., 2019). Body weight, as well as food and water consumption were measured weekly. The content of polyphenols and pentacyclic triterpenes were analysed in Arbequina table olives by LC-MS following the method previously described (Moreno-González et al., 2020). After 49 days of supplementation with AO, animals were subjected to terminal anaesthesia, prior to sample collection 17-19h following the last oral administration. Plasma and colon content were processed following liquid-liquid extraction and the concentrations of polyphenols and pentacyclic triterpenes were determined by LC-MS as described previously (Lozano-Mena et al., 2016; Kundisová et al., 2020). The colon was excised and divided into three segments of similar length, namely, proximal, medial and distal. Aberrant crypt foci were determined in the colon following the method described by Bird (1987), whereas mucin depleted foci were assessed as indicated by Caderni et al. (2003). Alfaras et al., J. Agric. Food Chem., 58, 8104–8109, 2010.Bird, Cancer Lett., 37, 147-151, 1987.Caderni et al., Cancer Res., 63, 2388-2392, 2003.Juan et al., Molecules, 24, 1266, 2019.Kundisová et al., J. Agric. Food Chem., 68, 10213-10222, 2020.Lozano-Mena et al., Mol. Nutr. Food Res., 60, 2053-2064, 2016.Moreno-González et al., LWT-Food Sci. Technol., 126, 109310, 2020.