Effect of beta-Carotene on the development of the solid Ehrlich tumor in mice.
The effect of beta-Carotene on the development of the solid Ehrlich tumor in BALB/c mice was investigated. Male mice received orally, on alternate days, three different doses of beta-Carotene (1, 3.5 or 7 mg/100 g) or corn oil as the control. This protocol started 14 days before tumor inoculation (1.75 x 10(5) cells) into mouse footpad and lasted until 10 days after. The tumor growth was evaluated by daily measurement of the footpad thickness, and the tumor mass was evaluated morphometrically. The proliferation rate of tumor was investigated by counting PCNA (proliferating cell nuclear antigen) positive nuclei in the 10th day of the tumor development. Histopathological examination of the lymphoid tissue: thymus, spleen and popliteal lymph node were also performed. beta-Carotene treatment, at dose 3.5 mg/100 g, increased the tumor growth, proliferative rate and the relative weight of popliteal lymph nodes, showing up an adverse effect only when this intermediate dose was used. No effects were obtained when the smaller (1,0 mg/100 g) or the higher (7.0 mg/100 g) doses were used. These results suggest that depending on the dose, beta-Carotene may determine an undesirable effect upon the tumor growth. This should be taken into account in chemopreventive experiments and human applications.
Salgado Oloris
Sílvia Catarina
SC
Laboratory of Experimental Oncology, Department of Pathology, Faculty of Veterinary Medicine and Zootechny, University of São Paulo, Av. Prof Dr. Orlando Marques de Paiva, no. 87, CEP 05508-900, -SP, São Paulo, Brazil.
Dagli
Maria Lúcia Zaidan
ML
Guerra
José Luiz
JL
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003314:Corn Oil / Q000494:pharmacology; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009336:Necrosis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D016196:S Phase; D013997:Time Factors; D019207:beta Carotene / Q000494:pharmacology*
D018809:Proliferating Cell Nuclear Antigen; D019207:beta Carotene; D003314:Corn Oil