title: Lack of protective effects of zinc gluconate against rat colon carcinogenesis.
abstract: Zinc has been proposed as a promising chemopreventive candidate against colon cancer. However, few studies on the potential beneficial effects of this trace element on cancer chemoprevention are available. The present study was designed to investigate the potential modifying influence of zinc gluconate (ZnGly) on the initiation step of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH). Male Wistar rats received orally ZnGly (15 mg elemental zinc/kg, 3 times per wk) 2 wk before and during DMH treatment (3 × 40 mg/kg, once a wk). The animals were euthanized at the end of 4th and 16th wk. Colons were analyzed for aberrant crypt foci (ACF) and tumor development. Blood and colon zinc levels, cell proliferation, and apoptosis indexes in colonic crypts were analyzed 24 h after the last DMH administration. Oral treatment with ZnGly did neither alter the number of ACF nor the indexes of cell proliferation and apoptosis in the colonic mucosa. The incidence and multiplicity of colon tumors induced by DMH and their histopathological patterns were not modified by previous treatment with ZnGly. These findings indicate a lack of chemopreventive action of zinc gluconate supplementation on the initiation step of rat colon carcinogenesis induced by DMH.
authors: Department of Pathology, Botucatu Medical School, UNESP, Sao Paulo State University, Sao Paulo, Brasil.
authors: Flávia Regina Moraes
authors: FR
authors: da Silva
authors: Marcos Correa
authors: MC
authors: Dias
authors: Luis Fernando
authors: LF
authors: Barbisan
authors: Maria Aparecida Marchesan
authors: MA
authors: Rodrigues
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000633:toxicity; D058739:Aberrant Crypt Foci / Q000188:drug therapy; D000284:Administration, Oral; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003106:Colon / Q000187:drug effects / Q000473:pathology; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D019587:Dietary Supplements; D005942:Gluconates / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016588:Anticarcinogenic Agents; D005942:Gluconates; D019813:1,2-Dimethylhydrazine; C030691:gluconic acid