Dietary lipids management: are there any benefits from the prevention and treatment of 4T1 murine breast carcinoma?

This study investigated the effect of vegetable and fish oils with different n-3 / n-6 PUFAS ratios on the lipoprotein profile and on the development of murine breast cancer 4T1. Female Balb/c mice (6-7 weeks) received diets containing 4.0% fat during seven weeks. On the fourth week, animals were inoculated into the posterior left flank with 2.5 × 106 4T1 cells. Body weight and food intake were registered and the profile serum lipoproteins was determined. Tumor volume, histopathological and immunohistochemical studies, myeloperoxidase and N-acetylglucosaminidase activities, TNF-α, hemoglobin and VEGF levels were analysed. The highest n-3 / n-6 ratio was found in fish oil (15.8:1), followed by linseed (2.4:1), canola (1:2.1) and soybean (1:9.4) oils. Body weight, food and caloric intake, lipoprotein profile, tumor weight, tumor evolution and histopathological analysis were not different. Canola oil increased cell proliferation when compared to soybean oil, and fish oil changed the inflammatory response and increased VEGF in tumors compared to other groups. The type of fatty acid and the high ratio of n-3 / n-6 PUFAs in the diet influenced cell proliferation and inflammation in the tumor differentially, highlighting the increase of neutrophils and VEGF levels in animals fed on fish oil.

Brazilian green propolis modulates inflammation, angiogenesis and fibrogenesis in intraperitoneal implant in mice.

BACKGROUND: Chronic inflammatory processes in the peritoneal cavity develop as a result of ischemia, foreign body reaction, and trauma. Brazilian green propolis, a beeswax product, has been shown to exhibit multiple actions on inflammation and tissue repair. Our aim was to investigate the effects of this natural product on the inflammatory, angiogenic, and fibrogenic components of the peritoneal fibroproliferative tissue induced by a synthetic matrix. METHODS: Chronic inflammation was induced by placing polyether-polyurethane sponge discs in the abdominal cavity of anesthetized Swiss mice. Oral administration of propolis (500/mg/kg/day) by gavage started 24 hours after injury for four days. The effect of propolis on peritoneal permeability was evaluated through fluorescein diffusion rate 4 days post implantation. The effects of propolis on the inflammatory (myeloperoxidase and n-acetyl-ß-D-glucosaminidase activities and TNF-α levels), angiogenic (hemoglobin content-Hb), and fibrogenic (TGF-ß1 and collagen deposition) components of the fibrovascular tissue in the implants were determined 5 days after the injury. RESULTS: Propolis was able to decrease intraperitoneal permeability. The time taken for fluorescence to peak in the systemic circulation was 20±1 min in the treated group in contrast with 15±1 min in the control group. In addition, the treatment was shown to down-regulate angiogenesis (Hb content) and fibrosis by decreasing TGF-ß1 levels and collagen deposition in fibroproliferative tissue induced by the synthetic implants. Conversely, the treatment up-regulated inflammatory enzyme activities, TNF-α levels and gene expression of NOS2 and IFN-γ (23 and 7 fold, respectively), and of FIZZ1 and YM1 (8 and 2 fold) when compared with the untreated group. CONCLUSIONS: These observations show for the first time the effects of propolis modulating intraperitoneal inflammatory angiogenesis in mice and disclose important action mechanisms of the compound (downregulation of angiogenic components and activation of murine macrophage pathways).

The gastric ulcer protective and healing role of cysteine proteinases from Carica candamarcensis.

Latex from Caricaceae contains proteolytic enzymes localized in the fruit, which are used ethnopharmacologically to treat digestive disorders. Some of these proteins display proliferative properties when probed with mammalian cells, suggesting a role in the reconstruction of wounded tissue. We tested the efficacy of a proteolytic fraction derived from Carica candamarcensis, designated as P1G10 in experimental rodent models, to protect and heal chemically induced gastric ulcers. The protective effect of oral administration of P1G10 fraction was analyzed in indomethacin-treated Wistar animals. The healing effect of P1G10 was studied following sub-serous injection of acetic acid in a Wistar rat model. The results show that P1G10 between 0.1 and 10 mg/kg protect indomethacin but not ethanol-induced gastric ulcers. The maximal protection attained was 67% with 10 mg/kg of P1G10. The healing rate by 10 mg/kg of P1G10 using the acetic acid ulcerogenic model is similar to that of omeprazole (10 mg/kg) or ranitidine (100 mg/kg). The effect of P1G10 at 10 mg/kg seems to be mediated by an increase in the mucus content by 25% and stimulation of angiogenesis by 64% in a manner similar to growth factors. These results confirm the protective and healing role of proteinases from C. candamarcensis.