Research

Effect of different levels of dietary zinc on development of chemically induced oral cancer in rats.

Wallenius K, Mathur A, Abdulla M

Four-week-old female rats distributed among three experimental groups were fed a 0.23 (zinc-deficient), 0.77 (zinc-adequate) or 3.06 (zinc-supplemented) mmol zinc/kg diet and oral cancer was induced by repeated application of the water-soluble carcinogen 4-nitroquinoline N-oxide (4NQO) to the palatal mucosa. The clinical development of oral cancer differed significantly among the three groups (P less than 0.05). In rats fed the zinc-supplemented diet, the macroscopic oral cancer appeared early and the survival time was shorter than in either of the other groups. It was concluded that a zinc-supplemented diet accelerates, and a zinc-deficient diet retards the development of chemically induced oral cancer in rats.

PMID: 107135, UI: 79150166

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10713 5&dopt=Abstract

Influence of zinc on onset and progression of oral carcinogenesis in rats.

Mathur A, Wallenius K, Abdulla M

Three-week-old female rats were fed 0.09 (zinc-deficient), 0.77 (zinc-adequate) or 3.98 (zinc-supplemented) mmol zinc/kg diet in three experimental groups and the palatal mucosa was painted with the water-soluble carcinogen 4-nitroquinoline N-oxide (4NQO) three times a week for 20 weeks. The zinc-supplemented diet seemed to retard the induction of carcinogenesis, whereas a low-zinc diet had the opposite effect. Once initial cellular changes had been induced the supplementary zinc seemed to accelerate their further advancement. Zinc-deficiency in animals fed a copper/zinc low-zinc diet was reflected in the plasma and liver zinc levels as well as in the copper/zinc ratio. The development of cancer was accompanied by a decrease in plasma zinc and an increase in the plasma copper/zinc ratio as well as in the liver zinc. These changes were most remarkable in the zinc-supplemented group.

PMID: 118633, UI: 80105932

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11863 3&dopt=Abstract

Assessment of sub-clinical zinc-deficiency for carcinogenetic and other long-term studies in rats.

Mathur A, Wallenius K, Abdulla M

PMID: 110296, UI: 79208747

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=110296&dopt=Abstract