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.

Doxorubicin-loaded nanocarriers: A comparative study of liposome and nanostructured lipid carrier as alternatives for cancer therapy.

Nowadays cancer is one of the most common causes of deaths worldwide. Conventional antitumor agents still present various problems related to specificity for tumor cells often leading to therapeutic failure. Nanoscale particles are considered potential alternative to direct access of drugs into tumor cells, therefore increasing the drug accumulation and performance. The aim of this study was to evaluate the antitumor activity of doxorubicin (DOX)-loaded nanostructured lipid carriers (NLC) versus liposomes against a breast cancer animal experimental model. NLC-DOX and liposomes-DOX were successfully prepared and characterized. Tumor-bearing mice were divided into five groups (blank-NLC, blank-liposome, DOX, NLC-DOX, liposome-DOX). Each animal received by the tail vein four doses of antitumoral drugs (total dose, 16mg/kg), every 3 days. Antitumor efficacy was assessed by measuring 1) tumor volume, calculating the inhibitory ratio (TV-IR, see after) and 2) acquiring scintigraphic images of the tumor using doxorubicin radiolabeled with technetium-99m as an imaging tumor probe. Liposome-DOX and free DOX did not showed differences in the tumor mean volume, whereas NLC-DOX proved to be the best treatments in controlling the tumor growth. NLC-DOX showed an inhibition ration (TV-IR) of 73.5% while free DOX and liposome-DOX decreased TV-RI of 48.8% and 68.0%, respectively. Tumor was clearly visualized in controls, DOX, and liposome-DOX groups. Yet, regarding the NLC-DOX group, tumor was barely identified by the image, indicating antitumor efficacy. Moreover, both NLC and liposomes proved to be able to delay the occurrence of lung metastasis. In conclusion, results of this study indicated that NLC-DOX might be an alternative strategy to achieve an efficient antitumor activity.

Skin-healing activity and toxicological evaluation of a proteinase fraction from Carica candamarcensis.

Previous studies demonstrated that proteinases from latex of C. candamarcensis act as mitogens on fibroblast and epithelial cells and a subsequent report showed their protective, angiogenic and wound healing effects on gastric ulcers. In this study, we present evidence of skin healing activity by the group of proteinases known as P1G10. By using a hairless mouse model, we compared the healing effect following topical application of various concentrations of P1G10. The data confirm that healing actions take place between 0.1 and 1%, without adverse local irritation or systemic toxicological action after a prolonged period of use. The wound healing effect is unaltered when P1G10 is previously inhibited with iodoacetamide. The low permeation of the hydrosoluble formulation Polawax(®) supports the maintenance of the drug at the site of application. These results extend the healing properties of these groups of enzymes in situations of dermatological trauma and open the way to future clinical applications.

Wound-healing activity of a proteolytic fraction from Carica candamarcensis on experimentally induced burn.

Carica candamarcensis is a species from the Caricaceae family whose immature fruit contains latex with large amounts of cysteine proteinases. In prior studies, we isolated two of these enzymes displaying mitogenic activity when incubated with L929 fibroblastic cells. One of the fractions containing these enzymes (P1G10) was shown to enhance wound healing of skin and to accelerate healing of chemically induced gastric ulcer. In this study we evaluate the effect of P1G10 on heat-induced, third-degree burn using a rodent model. The results show that 0.1% P1G10 accelerates epithelisation while the effect of 1% or 0.01% P1G10 is not significantly different to 1% silver sulphadiazine, 2% papain or the hydrosoluble vehicle used as control. In a double-blind randomised experiment comparing the healing response of 0.1%, 1% and the vehicle alone, we confirmed the enhanced healing property of P1G10. Histological analysis of burn-tissue sections following treatment with P1G10 support these observations. These results extend the healing properties of these groups of enzymes to a different type of trauma and open the way to future clinical applications.