Effects of Lyophilized Black Raspberries on Azoxymethane-Induced Colon Cancer and 8-Hydroxy-2′-Deoxyguanosine Levels in the Fischer 344 Rat

Abstract

This study examined the effects of lyophilized black raspberries (BRB) on azoxymethane (AOM)-induced aberrant crypt foci (ACF), colon tumors, and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in male Fischer 344 rats. AOM was injected (15 mg/kg body wt i.p.) once per week for 2 wk. At 24 h after the final injection, AOM-treated rats began consuming diets containing 0%, 2.5%, 5%, or 10% (wt/wt) BRB. Vehicle controls received 5% BRB or diet only. Rats were sacrificed after 9 and 33 wk of BRB feeding for ACF enumeration and tumor analysis. ACF multiplicity decreased 36%, 24%, and 21% (P < 0.01 for all groups) in the 2.5%, 5%, and 10% BRB groups, respectively, relative to the AOM-only group. Total tumor multiplicity declined 42%, 45%, and 71% (P < 0.05 for all groups). Although not significant, a decrease in tumor burden (28%, 42%, and 75%) was observed in all BRB groups. Adenocarcinoma multiplicity decreased 28%, 35%, and 80% (P < 0.01) in the same treatment groups. Urinary 8-OHdG levels were reduced by 73%, 81%, and 83% (P < 0.01 for all groups). These results indicate that BRB inhibit several measures of AOM-induced colon carcinogenesis and modulate an important marker of oxidative stress in the Fischer 344 rat.

A Phase Ib Study of the Effects of Black Raspberries on Rectal Polyps in Patients with Familial Adenomatous Polyposis

“…Intestinal cell proliferation was reduced in both mouse models by BRBs; however, mucus differentiation was not affected in either model (12). Feeding of BRBs at 5% and 10% of the diet to F-344 rats for 32 weeks after treatment of the rats with the carcinogen, azoxymethane, resulted in a reduction of adenocarcinoma multiplicity of 35% and 80%, respectively (13). In addition, dietary administration of BRBs has been shown to inhibit esophageal, oral cavity, and mammary tumorigenesis in animal models (11).…”

“…Many of these compounds have demonstrated chemopreventive activity, both in vitro and in animal models; for example, ellagic acid and the anthocyanins (11). Two mouse models of colorectal cancer were used to evaluate the effects of BRBs on colorectal tumor development and to investigate the underlying mechanisms (12,13). A 12-week feeding of BRBs significantly inhibited intestinal tumor formation in both models; reducing tumor incidence by 45% and tumor multiplicity by 60% in Apc1638 þ/À mice and tumor incidence and multiplicity by 50% in Muc À/À mice (12).…”

Cancer prevention with freeze-dried berries and berry components

“…A BRB diet was tested to prevent colon cancer development in F344 rats induced by the chemical carcinogen, azoxymethane (AOM) [41] (this model is used extensively to evaluate the effects of putative chemopreventatives, in part because the histopathology of the resulting cancers resembles that of human colon cancer). AOM was administered at 15 mg/kg body weight intraperitoneally once per week for two weeks.…”

Dietary Anthocyanins: Impact on Colorectal Cancer and Mechanisms of Action

“…Animal studies have also reported anticarcinogenic properties of anthocyanins. In induced rat colon cancer cell models they significantly decreased total tumors as well as aberrant crypts (Hagiwara et al, 2001;Hagiwara et al, 2002;Harris et al, 2001;Lala et al, 2006;Magnusson et al, 2003). Cai and colleagues demonstrated that Red grape pomace extract (oenocyanin) interferes with adenoma development in the Apc Min mouse by affecting tumor burden more prominently than tumor number.…”