Prevention of azoxymethane-induced intestinal tumors by a crude ethyl acetate-extract and tryptanthrin extracted from Polygonum tinctorium Lour.
The effect of a crude ethyl acetate (AcOEt)-extract and tryptanthrin extracted from the Indigo plant (Polygonum tinctorium Lour.) on azoxymethane (AOM)-induced intestinal tumors was examined in F344 rats. The rats were given subcutaneous (s.c.) injections of either AOM (15 mg/kg body weight (b.w.)) once a week for 3 weeks to induce atypical crypt foci (ACF) as a known cancer precursor, or AOM (7.5 mg/kg b.w.) once a week for 10 weeks to induce intestinal tumors. The rats were also administered the AcOEt-extract (500 mg/kg b.w.) or tryptanthrin (50 mg/kg b.w.) orally, 5 days a week, for 7 or 30 weeks, starting two days before the first administration of AOM. All rats were killed 4 or 20 weeks after the last treatment. In the short-term experiment, the incidence of ACE and atypical crypts (AC) in the groups receiving the AcOEt-extract and tryptanthrin was significantly lower than in the control group. In the tumor-inducing experiment, intestinal tumor incidence in the tryptanthrin group was lower than in the AOM-control group (5% versus 26%), and small intestine tumor incidence in the AcOEt-extract and tryptanthrin groups were lower than in the AOM-control group (0% and 0% versus 23%). These results show that the AcOEt-extract of Indigo and tryptanthrin have cancer chemopreventive activity.
Koya-Miyata
S
S
Hayashibara Biochemical Laboratories Inc., Fujisaki Institute, Okayama, Japan. fujisaki@hayashibara.co.jp
Kimoto
T
T
Micallef
M J
MJ
Hino
K
K
Taniguchi
M
M
Ushio
S
S
Iwaki
K
K
Ikeda
M
M
Kurimoto
M
M
D000085:Acetates / Q000737:chemistry; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001397:Azoxymethane / Q000037:antagonists & inhibitors / Q000633:toxicity; D002273:Carcinogens / Q000037:antagonists & inhibitors / Q000633:toxicity; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology; D019664:Polygonaceae / Q000737:chemistry*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000517:prevention & control; D011799:Quinazolines / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344
D000085:Acetates; D016588:Anticarcinogenic Agents; D002273:Carcinogens; D010936:Plant Extracts; D011799:Quinazolines; C046243:tryptanthrine; C007650:ethyl acetate; D001397:Azoxymethane