Cocoa‐rich diet prevents azoxymethane‐induced colonic preneoplastic lesions in rats by restraining oxidative stress and cell proliferation and inducing apoptosis

Abstract

Cocoa is a rich source of bioactive compounds with potential chemopreventive ability but up to date its effectiveness in animal models of colon carcinogenesis has not been addressed. Herein, we investigated the in vivo effect of a cocoa-rich diet in the prevention of azoxymethane (AOM)-induced colon cancer and the mechanisms involved. Our results showed that cocoa feeding significantly reduced AOM-induced colonic aberrant crypt foci formation and crypt multiplicity. Oxidative imbalance in colon tissues seems to be prevented by cocoa as indicated by reduced oxidation markers levels and increased enzymatic and non-enzymatic endogenous defences. Cocoa-rich diet also exhibited antiproliferative effects by decreasing the levels of extracellular regulated kinases, protein kinase B and cyclin D1 together with pro-apoptotic effects evidenced by reduced Bcl-x(L) levels and increased Bax levels and caspase-3 activity. Our findings provide the first in vivo evidence that a cocoa-rich diet may inhibit the early stage of colon carcinogenesis probably by preventing oxidative stress and cell proliferation and by inducing apoptosis

Cocoa-rich diet ameliorates hepatic insulin resistance by modulating insulin signaling and glucose homeostasis in Zucker diabetic fatty rats

“…This reduction of body weight is in agreement with previous studies [26,27], and it has been attributed to the cocoa polyphenolic fraction and its ability to reduce fat adipose tissue. Additionally, the lack of effect of the cocoa-rich diet on food intake observed in this study excludes the possibility that cocoa enhances glucose tolerance simply by reducing food intake, as previously shown for its main flavanol, epicatechin and a cocoa extract [17,20].…”

Potential for preventive effects of cocoa and cocoa polyphenols in cancer

“…More recently, the chemopreventive ability of a cocoa rich-diet on colon carcinogenesis has been studied in detail in male Wistar rats using the well-defined azoxymethane (AOM)-induced colon cancer model (Rodrıiguez-Ramiro et al, 2011). Administration of the colon-specific carcinogen AOM to rodents provokes the development of aberrant crypt foci, pre-neoplastic lesions in the colon that may progress into cancer later on (Pritchard and Grady, 2011).…”

Effects of Dark Chocolate on Azoxymethane-Induced Colonic Aberrant Crypt Foci

“…AOM-treated rats had lower 48-h food intake (39.73 ± 2.29 g vs. 42.89 ± 1.14 g) (P = 0.029) and final body weight (402.4 ± 9.01 g vs. 425.9 ± 6.57g) (P = 0.008) as compared to saline group. There were no differences in final body weight or weight gain among the diet groups (data not shown).…”