No abstract

Mammary cancer is the most frequent type of tumor in the female canine. Treatments are mainly limited to surgery and chemotherapy; however, these tumors may develop clinical recurrence, metastasis and chemoresistance. The existence of a subpopulation of cancer cells with stemness features called cancer stem-like cells, may explain in part these characteristics of tumor progression. The statins, potent blockers of cholesterol synthesis, have also shown antitumor effects on cancer mammary cells, changes mediated by a decrease in the isoprenylation of specific proteins. Few studies have shown that simvastatin, a lipophilic statin, sensitizes cancer stem-like cells eliminating drug resistance. The aim of the present study was to evaluate the effects of simvastatin on spheres derived from CF41.Mg canine mammary tumor cells, which were characterized by phenotypic and functional analyses. Spheres exhibited characteristics of stemness, primarily expressing a CD44⁺/CD24⁻/low phenotype, displaying auto-renewal and relative chemoresistance. Exposure to simvastatin induced a decrease in the sphere-forming capacity and cell viability, accompanied by a concentration- and time-dependent increase in caspase-3/7 activity. In addition, modulation of β-catenin and p53 expression was observed. Simvastatin triggered a synergistic effect with doxorubicin, sensitizing the spheres to the cytotoxic effect exerted by the drug. Invasiveness of spheres was decreased in response to simvastatin and this effect was counteracted by the presence of geranylgeranyl pyrophosphate. Our results suggest that simvastatin targets canine mammary cancer stem-like cells, supporting its therapeutical application as a novel agent to treat canine mammary cancer.

Structured Lipids are generally constituents of functional foods. Growing demands for SL are based on a fuller understanding of nutritional requirements, lipid metabolism, and improved methods to produce them. Specifically, this work was aimed to add value to avocado oil by producing dietary triacylglycerols (TAG) containing medium-chain fatty acids (M) at positions sn-1,3 and long-chain fatty acids (L) at position sn-2. These MLM-type structured lipids (SL) were produced by interesterification of caprylic acid (CA) (C8:0) and avocado oil (content of C18:1). The regiospecific sn-1,3 commercial lipases Lipozyme RM IM and TL IM were used as biocatalysts to probe the potential of avocado oil to produce SL. Reactions were performed at 30–50°C for 24 h in solvent-free media with a substrate molar ratio of 1∶2 (TAG:CA) and 4–10% w/w enzyme content. The lowest incorporation of CA (1.1% mol) resulted from Lipozyme RM IM that was incubated at 50°C. The maximum incorporation of CA into sn-1,3 positions of TAG was 29.2% mol. This result was obtained at 30°C with 10% w/w Lipozyme TL IM, which is the highest values obtained in solvent-free medium until now for structured lipids of low-calories. This strategy opens a new market to added value products based on avocado oil.

The target site of action of probiotics is the intestine. They must be surviving the stomach acidic condition before reaching the target site. Three probiotic bacteria were microencapsulated in sodium alginate beads using a sophisticated microencapsulation technology provided by BÜCHI B-390. This study reports the tolerance of the different microencapsulated Lactobacillus at low pH using simulated gastric juice, comparing it with the tolerance of free bacteria. The three microencapsulated strains displayed time-dependent acid sensitivity at pH values under 3.0. At pH 2.0, a dramatic reduction in bacterial survival occurred after 5 min, with only L. casei surviving after 30 min, with 75% survival. At pH 2.5 microencapsulated L. casei survived for 90 , L. reuteri survived for 60 and L. bulgaricus survived for only 30 min, respectively. The microencapsulation technology used in this study may effectively protect Lactobacillus from gastric conditions and permit comparisons between strains.

Background: Polycosanols derived from plant species have traditionally been used in medicine as antiproliferative agents for treating various viruses (primarily the herpes simplex virus). However, few studies have studied their effects on hyperproliferative cell lines. In this work, the antiproliferative capacity of polycosanols from tall-oil pitch, obtained from black liquor soaps in the kraft pulping process of cellulose (specifically from Pinus radiata, Pinus taede, and Eucalyptus globulus), was evaluated on CHO-K1 and CRL-1974 human melanoma cell lines. Results: The proliferative capacities and cell viabilities were measured for 72 and 140 h, respectively. Treatment with docosanol produced differential effects on the CHO-K1 and human melanoma cells and significantly affected their proliferation rates, but not their cell viabilities. Tetracosanol produced a significant negative effect on the proliferation of human melanoma cells, and this effect was less than that caused by docosanol. However, it had no effect on the proliferation of CHO-K1 cells and did not induce any significant effect on the viability of the studied cell lines. Conclusion: Docosanol and tetracosanol induced antiproliferative effects on the studied cell lines and exhibited significantly greater effects on the oncogenic cell lines. Prior to this study, the capacity of these polycosanols has never been investigated. Future studies will be necessary to determine their mechanisms of action on these cell systems.