Tags

Type your tag names separated by a space and hit enter

Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate/isoflavone diet.
Prostate 2000; 45(2):101-5P

Abstract

BACKGROUND

Epidemiological surveys recorded that men in the Orient (Japan and China) consuming diets high in soy food were at low risk of developing clinical prostate cancer, compared to a relatively high risk among men in the West who consumed diets low in soy food. Soybeans contain phytoestrogens (isoflavones) with many recorded anticancer mechanisms. The Lobund-Wistar (L-W) rat is a unique model system: approximately 30% develop metastasizing adenocarcinomas spontaneously in the anterior prostate-seminal vesicle complex (P-SV), from which the tumors expand into the dorsolateral lobes. L-W rats are inherently predisposed, possibly by unusually high levels of circulating testosterone (T), to develop P-SV tumors which are T-dependent in the early stages and T-independent in advanced stages of tumorigenesis.

METHODS

L-W rats were fed two diets from age 2-24 months: 1) natural ingredient diet L-485 (Harlan TekLad Diets, Madison, WI) containing soy meal, or 2) a modified starch-casein diet in which soy protein isolate/isoflavones (SPII) replaced casein as a source of protein.

RESULTS

At age 24 months, 3 of 99 (3%) rats on diet SPII and 30 of 100 (30%) rats on diet L-485 developed spontaneous P-SV cancers. Rats on the SPII diet manifested a significant reduction of circulating T, approaching physiological levels. Failure of the rats on diet L-485 to prevent P-SV cancer development suggests that soy meal contained a factor(s) that blocked the antiandrogenic action of the phytoestrogen.

CONCLUSIONS

The spontaneous development of P-SV cancers was significantly prevented in L-W rats consuming the SPII diet from age 2-24 months, possibly through an agonist effect of the soy-derived phytoestrogens.

Authors+Show Affiliations

Lobund Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA. Morris.Pollard.3@nd.eduNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11027408

Citation

Pollard, M, and W Wolter. "Prevention of Spontaneous Prostate-related Cancer in Lobund-Wistar Rats By a Soy Protein Isolate/isoflavone Diet." The Prostate, vol. 45, no. 2, 2000, pp. 101-5.
Pollard M, Wolter W. Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate/isoflavone diet. Prostate. 2000;45(2):101-5.
Pollard, M., & Wolter, W. (2000). Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate/isoflavone diet. The Prostate, 45(2), pp. 101-5.
Pollard M, Wolter W. Prevention of Spontaneous Prostate-related Cancer in Lobund-Wistar Rats By a Soy Protein Isolate/isoflavone Diet. Prostate. 2000 Oct 1;45(2):101-5. PubMed PMID: 11027408.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate/isoflavone diet. AU - Pollard,M, AU - Wolter,W, PY - 2000/10/12/pubmed PY - 2001/2/28/medline PY - 2000/10/12/entrez SP - 101 EP - 5 JF - The Prostate JO - Prostate VL - 45 IS - 2 N2 - BACKGROUND: Epidemiological surveys recorded that men in the Orient (Japan and China) consuming diets high in soy food were at low risk of developing clinical prostate cancer, compared to a relatively high risk among men in the West who consumed diets low in soy food. Soybeans contain phytoestrogens (isoflavones) with many recorded anticancer mechanisms. The Lobund-Wistar (L-W) rat is a unique model system: approximately 30% develop metastasizing adenocarcinomas spontaneously in the anterior prostate-seminal vesicle complex (P-SV), from which the tumors expand into the dorsolateral lobes. L-W rats are inherently predisposed, possibly by unusually high levels of circulating testosterone (T), to develop P-SV tumors which are T-dependent in the early stages and T-independent in advanced stages of tumorigenesis. METHODS: L-W rats were fed two diets from age 2-24 months: 1) natural ingredient diet L-485 (Harlan TekLad Diets, Madison, WI) containing soy meal, or 2) a modified starch-casein diet in which soy protein isolate/isoflavones (SPII) replaced casein as a source of protein. RESULTS: At age 24 months, 3 of 99 (3%) rats on diet SPII and 30 of 100 (30%) rats on diet L-485 developed spontaneous P-SV cancers. Rats on the SPII diet manifested a significant reduction of circulating T, approaching physiological levels. Failure of the rats on diet L-485 to prevent P-SV cancer development suggests that soy meal contained a factor(s) that blocked the antiandrogenic action of the phytoestrogen. CONCLUSIONS: The spontaneous development of P-SV cancers was significantly prevented in L-W rats consuming the SPII diet from age 2-24 months, possibly through an agonist effect of the soy-derived phytoestrogens. SN - 0270-4137 UR - https://www.unboundmedicine.com/medline/citation/11027408/Prevention_of_spontaneous_prostate_related_cancer_in_Lobund_Wistar_rats_by_a_soy_protein_isolate/isoflavone_diet_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0270-4137&date=2000&volume=45&issue=2&spage=101 DB - PRIME DP - Unbound Medicine ER -