Antimutagenicity of Murdannia loriformis in the Salmonella mutation assay and its inhibitory effects on azoxymethane-induced DNA methylation and aberrant crypt focus formation in male F344 rats.
An 80% ethanol extract of Murdannia loriformis, a Thai medicinal plant, was examined for antimutagenic activity and cancer chemopreventive activity. In the Salmonella mutation assay, the extract showed antimutagenicity against 2-amino-3-methylimidazo [4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, 2-amino-6-methyldipyrido [1,2-a:3',2'-d] imidazole, 2-aminodipyrido[1,2-a:3',2'-d]imidazole, 2-aminoanthracene, 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide, N-methyl-N'-nitro-N-nitrosoguanidine and methylazoxymethanol acetate and reduced their mutagenicities to 31.4-67.9% at the dose of 10 mg/plate. However, it did not inhibit the mutagenicities of 2-amino-9H-pyrido[2,3-b]indole, 2-amino-3-methyl-9 H-pyrido[2,3-b]indole, benzo[a]pyrene,N-ethyl-N'-nitro-N-nitrosoguanidine and 1-nitropyrene. The extract itself showed no mutagenicity. The chemopreventive activity of M. loriformis was examined using azoxymethane (AOM)-induced aberrant crypt focus (ACF) formation in the colon of F344 rats. The extract at doses of 0.1-1.0 g/kg wt significantly inhibited ACF formation in the initiation stage (21-51%), although it was more effective at a lower dose. In the post-initiation stage, the extract also tended to inhibit ACF formation (12-27%) and significantly decreased the number of larger ACFs that have more than 3 aberrant crypts per focus. The extract inhibited the formation of O6-methylguanine and N7-methylguanine in the colonic mucosa and muscular layers but not or increased in the liver. These results indicate that M. loriformis extract has antimutagenic activity toward various known mutagens and that it inhibits AOM-induced ACF formation both in the initiation and post-initiation stages in the rat colon.
Intiyot
Yaowarate
Y
Department of Bacteriology, University of Tokushima School of Medicine, Kuramoto-cho, Tokushima 770-8503, Japan.
Kinouchi
Takemi
T
Kataoka
Keiko
K
Arimochi
Hideki
H
Kuwahara
Tomomi
T
Vinitketkumnuen
Usanee
U
Ohnishi
Yoshinari
Y
D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001397:Azoxymethane / Q000009:adverse effects / Q000037:antagonists & inhibitors*; D003106:Colon / Q000187:drug effects* / Q000473:pathology; D003110:Colonic Neoplasms / Q000517:prevention & control; D019175:DNA Methylation / Q000187:drug effects*; D006147:Guanine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000473:pathology; D019684:Magnoliopsida; D008297:Male; D009152:Mutagenicity Tests; D009153:Mutagens / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D011916:Rats, Inbred F344; D012486:Salmonella typhimurium / Q000235:genetics*
D016587:Antimutagenic Agents; D000970:Antineoplastic Agents; D009153:Mutagens; D010936:Plant Extracts; D006147:Guanine; C008449:O-(6)-methylguanine; D001397:Azoxymethane