De. Corpet et G. Parnaud, Polyethylene-glycol, a potent suppressor of azoxymethane-induced colonic aberrant crypt foci in rats, CARCINOGENE, 20(5), 1999, pp. 915-918
Bulking fibers and high water intake may decrease colon carcinogenesis in r
ats, and the risk of colorectal cancer in humans. We speculated that a non-
fermented polymer, polyethylene-glycol (PEG) 8000, which increases stool mo
isture, might protect rats against colon carcinogenesis. Thirty female F344
rats were given a single injection of azoxymethane (20 mg/kg), and 7 days
later randomized to AIN76 diets containing PEG (to provide 3 g/kg body wt/d
ay), or no PEG (control). Diets were given ad libitum for 105 days, then co
lon carcinogenesis was assessed by the aberrant crypt foci (ACF) test. ACF
were scored blindly by a single observer. Dietary feeding of PEG almost sup
pressed ACF larger than one crypt, and strikingly decreased the total numbe
r of ACF per rat. PEG-fed rats had 100 times less large ACF than controls (
0.8 and 83 respectively, P = 0.00001), PEG-fed rats had 20 times less total
ACF than control (six and 107 AGE/rat, respectively; P < 0.0001). Two trea
ted rats had no detectable ACF. PEG is 10 times more potent than other chem
opreventive agents in this model. Since PEG is generally recognized as safe
, its cancer-preventive features could be tested in humans.