Delay of Lung Adenocarcinoma (LAC-1) Development in Mice by Dietary Oleic Acid.

Lung cancer is the leading cause of death by cancer, and is a major sanitary concern worldwide. Some nutrients, such as ω-9 fatty acids, have been proposed as anticancer agents. Thus, an olein-enriched diet was assayed in a murine model of lung adenocarcinoma (LAC-1) to evaluate neoplastic and paraneoplastic evolution in BALB/c mice. The organic assimilation of dietary fatty acids was confirmed in liver by gas chromatography. This experimental oleic acid-containing diet increased animal survival and tumour latency (analysed by the Kaplan-Meier method), improving neoplastic evolution and general status, with weak effects on the paraneoplastic syndrome (thymus atrophy, splenomegaly, splenocyte response to mitogen, blood anaemia, and leucocytosis). Tumour lipid oxidation was not involved. Thus, diet enrichment with olein, a natural source of the ω-9 oleic acid, significantly delayed progression of LAC-1 and increased tumour latency and mice survival. These results support its use in nutritional management of cancer, with further studies being encouraged.

A soy-based product fermented by Enterococcus faecium and Lactobacillus helveticus inhibits the development of murine breast adenocarcinoma.

PURPOSE: Soy and its fermented products are considered functional foods. The study objective was to assess three functional food - a non-fermented soy product (NFP), fermented soy product (FSP), fermented soy product enriched with isoflavones (FI) - in terms of their ability to reduce the development of adenocarcinoma in mice, as well their ability on modulating immune system. METHODS: It was observed tumor volume and to verify correlations with the immune system it was measured levels of the cytokines IL-1ß and TNF-α produced by macrophages as well as IFN-γ produced by lymphocytes using ELISA test, and nitric oxide production by macrophages using Griess reagent. RESULTS: All products showed immunological activity, but FSP showed the most effective tumor containment, resulting in smallest tumor volumes. FI animals expressed larger amounts of nitric oxide and IL-1ß and exhibited larger tumor sizes than FSP and NFP animals. CONCLUSIONS: The results suggested that the ingestion of FSP was most efficient in tumor containment, possibly due to a positive modulation of the immune system by when Enterococcus faecium and Lactobacillus helveticus are added to the soy product.

Effect of ω-3 and ω-9 fatty acid rich oils on lipoxygenases and cyclooxygenases enzymes and on the growth of a mammary adenocarcinoma model.

BACKGROUND: Nutritional factors play a major role in cancer initiation and development. Dietary polyunsaturated fatty acids (PUFAs) have the ability to induce modifications in the activity of lipoxygenase (LOX) and cyclooxygenase (COX) enzymes that affect tumour growth. We studied the effect of two diets enriched in 6% Walnut and Peanut oils that are rich in ω-3 and ω9 PUFAs respectively on a murine mammary gland adenocarcinoma as compared with the control (C) that received commercial diet. RESULTS: Peanut oil enriched diet induced an increase in membrane arachidonic acid (AA) content and the cyclooxygenase enzyme derived 12-HHT (p < 0.05) and simultaneously showed decrease in 12-LOX, 15-LOX-2, 15-LOX-1 and PGE activities (p < 0.05) that corresponded to higher apoptosis and lower mitosis seen in this group (p < 0.05). Furthermore, Peanut oil group showed lower T-cell infiltration (p < 0.05), number of metastasis (p < 0.05) and tumour volume (p < 0.05) and longer survival rate compared to other groups. CONCLUSIONS: The results of the present study showed that Peanut oil-enriched diet protects against mammary cancer development by modulating tumour membrane fatty acids composition and LOX and COX enzyme activities.

Differential effects of dietary Oenothera, Zizyphus mistol, and corn oils, and essential fatty acid deficiency on the progression of a murine mammary gland adenocarcinoma.

The modulating effect of dietary enrichment in mistol seed oil (MO) containing 25% of alpha-linolenic acid (ALA), evening primrose oil (EPO) enriched in gamma-linolenic acid (GLA) and corn oil (CO) as sources of omega-6 and omega-9 fatty acids on the growth parameters of one transplantable mammary tumor were compared. Mice fed on different lipid formulae were inoculated with a mammary gland adenocarcinoma and different growth development tumor parameters were recorded. Results showed that corn oil feeding slowed down most of the tumor growth parameters, as did the EPO diet. MO also showed antitumor activity. Olein feeding, which induces an essential fatty acid deficiency (EFAD), increased the incidence and the multiplicity of metastases when compared with the controls. It may be concluded that a diet enriched in omega-6 fatty acids did not behave as a tumor promoter in this mammary gland tumor model. The antitumor activities of EPO and MO are corroborated in present experiments, suggesting that both oils may be of value in nutritional approaches of mammary gland tumor therapies. In addition, present data add further experimental proof about the proposed protumorigenic proneness induced by the EFAD state.

Influence of dietary levels of fat, cholesterol, and calcium on colorectal cancer.

The associations between calcium, fat, and cholesterol intake and risk of colorectal cancer were studied in a case-control study conducted in Uruguay. A total of 282 incident and histologically proven cases of adenocarcinomas of the colon and rectum comprised the case series. Five hundred sixty-four hospitalized controls were selected from the same hospitals from which the cases were drawn. Calcium intake was associated with a significant decrease in the risk of colorectal cancer (odds ratio = 0.41, 95% confidence limit = 0.24-0.69 for the uppermost quartile of intake). The associations were similar for colon and rectal cancer. On the other hand, protein and total fat were associated with significantly increased risk of colorectal cancer. A strong interaction between calcium and fat (and cholesterol) intake was found. According to this interaction, calcium effect was maximal at low levels of dietary fat (and cholesterol intake), whereas fat (and cholesterol intake) showed a positive monotonic increase in risk of colorectal cancer at high levels of calcium intake. This finding should be further investigated in other epidemiologic and experimental studies.