Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC) cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20–25)4, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90%) in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC.

Oral squamous cell carcinoma is the fifth most common epithelial cancer in the world, and its current clinical treatment has both low efficiency and poor selectivity. Cationic amphipathic peptides have been proposed as new drugs for the treatment of different types of cancer. The main goal of the present work was to determine the potential of LfcinB(20–25)4, a tetrameric peptide based on the core sequence RRWQWR of bovine lactoferricin LfcinB(20–25), for the treatment of OSCC. In brief, OSCC was induced in the buccal pouch of hamsters by applying 7,12-Dimethylbenz(a)anthracene, and tumors were treated with one of the following peptides: LfcinB(20–25)4, LfcinB(20–25), or vehicle (control). Lesions were macroscopically evaluated every two days and both histological and serum IgG assessments were conducted after 5 weeks. The size of the tumors treated with LfcinB(20–25)4 and LfcinB(20–25) was smaller than that of the control group (46.16±4.41 and 33.92±2.74 mm3 versus 88.77±10.61 mm3, respectively). Also, LfcinB(20–25)4 caused acellularity in the parenchymal tumor compared with LfcinB(20–25) and vehicle treatments. Furthermore, our results demonstrated that both LfcinB(20–25)4 and LfcinB(20–25) induced higher degree of apoptosis relative to the untreated tumors (75–86% vs 8%, respectively). Moreover, although the lowest inflammatory response was achieved when LfcinB(20–25)4 was used, this peptide appeared to induce higher levels of IgG antibodies relative to the vehicle and LfcinB(20–25). In addition the cellular damage and selectivity of the LfcinB(20–25)4 peptide was evaluated in vitro. These assays showed that LfcinB(20–25)4 triggers a selective necrotic effect in the carcinoma cell line. Cumulatively, these data indicate that LfcinB(20–25)4 could be considered as a new therapeutic agent for the treatment of OSCC.

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The global spread of the ectoparasitic mite Varroa destructor has promoted the spread and virulence of highly infectious honey bee viruses. This phenomenon is considered the leading cause for the increased number of colony losses experienced by the mite-susceptible European honey bee populations in the Northern hemisphere. Most of the honey bee populations in Central and South America are Africanized honey bees (AHBs), which are considered more resistant to Varroa compared to European honey bees. However, the relationship between Varroa levels and the spread of honey bee viruses in AHBs remains unknown. In this study, we determined Varroa prevalence and infestation levels as well as the prevalence of seven major honey bee viruses in AHBs from three regions of Colombia. We found that although Varroa exhibited high prevalence (92%), its infestation levels were low (4.5%) considering that these populations never received acaricide treatments. We also detected four viruses in the three regions analyzed, but all colonies were asymptomatic, and virus prevalence was considerably lower than those found in other countries with higher rates of mite-associated colony loss (DWV 19.88%, BQCV 17.39%, SBV 23.4%, ABPV 10.56%). Our findings indicate that AHBs possess a natural resistance to Varroa that does not prevent the spread of this parasite among their population, but restrains mite population growth and suppresses the prevalence and pathogenicity of mite-associated viruses.

A common denominator that affects the production areas is the dramatic loss of fertility and thus, the natural productive capacity of soils through a sustained process of erosion. The problem of soil loss was largely due to improper production practices, such as monoculture, chemical fertilizers, pesticides, intensive farming, genetically modified seeds, among others. Agroecological alternative allows recovery of soils, compost making, and its quality depends of largely microbial diversity associated with it. The aim of the work focused on microbial characterization of different mixtures of agricultural waste in order to determine quality parameters. Through a randomized block design, six different mixes were evaluated in the village of Fusagasugá (Colombia). The OM, OC, macro and micronutrients chemical indicators were obtained from the soil laboratory at the University of Tolima, for microbial characterization macroscopic and microscopy techniques were used in the Laboratory of Microbiology of the University of Cundinamarca. Principal Component Analysis (PCA), Canonical Correspondence Analysis (CCA) incorporating with the Partial Least Squares (PLS) was made. XLSTAT statistical package (2009.3.02) was used. The most important microorganisms were, Streptomyces, Arthrobacter, Aspergillus and Penicillium genera. Treatments that presented the best quality in relation to chemical and microbiological variables were mixtures containing double burden of animal, especially hens and pig manure.