Browsing by Author "Salazar, Luis A."
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- ItemBiological stress reactivity as an index of the two polarities of the experience model(2017) Silva, Jaime R.; Vivanco-Carlevari, Anastassia; Barrientos, Mauricio; Martínez, Claudio; Salazar, Luis A.; Krause Jacob, Mariane
- ItemCharacterization of LDLR rs5925 and PCSK9 rs505151 genetic variants frequencies in healthy subjects from northern Chile : Influence on plasma lipid levels(2019) Rojas, Claudio; Ramírez Rivera, Hugo Rodolfo E.; Salazar, Luis A.; Kalergis Parra, Alexis Mikes; Gálvez, Anita S.; Escobar Vera, Jorge
- ItemChemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus(2013) Barrientos, Leticia; Herrera, Christian L.; Montenegro, Gloria; Ortega, Ximena; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolas; Salazar, Luis A.Propolis is a non-toxic natural substance with multiple pharmacological properties including anticancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC) was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 mu g mL(-1)). Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them.
- ItemChemical and botanical characterization of chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus(2013) Barrientos, Leticia; Herrera, Christian L, Montenegro Rizzardini, Gloria; Ortega Fuenzalida, Ximena Alicia; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolás; Salazar, Luis A.
- ItemDiagnóstico del Trabajo en Equipo en Estudiantes de Ingeniería en Chile(2017) Herrera Valencia, Rodrigo Fernando; Muñoz, Felipe Crsitobal; Salazar, Luis A.
- ItemSingle Nucleotide Polymorphisms in Apolipoprotein B, Apolipoprotein E, and Methylenetetrahydrofolate Reductase Are Associated With Serum Lipid Levels in Northern Chilean Subjects. A Pilot Study(2021) Galvez, Anita S.; Ramirez, Hugo; Placencia, Pablo; Rojas, Claudio; Urzua, Ximena; Kalergis, Alexis M.; Salazar, Luis A.; Escobar-Vera, JorgeCharacterization of allelic variants is relevant to demonstrate associations among genetic background and susceptibility to develop cardiovascular diseases, which are the main cause of death in Chile. Association of APOB, APOE, and MTHFR polymorphisms with higher lipid levels and the risk of developing hypertension and cardiovascular diseases have been described. Thus, the aim of this study was to assess genotype distribution and relative allelic frequency of ApoB rs693, ApoE rs7412, ApoE rs429358, MTHFR rs1801131, and MTHFR rs1801133 allelic variants and their effects on lipid profile in young healthy men and women from Northern Chile. A group of 193 healthy subjects were enrolled for this study. Genotyping of rs693 (APOB), rs7412 and rs429358 (APOE), and rs1801131 and rs1801133 (MTHFR) polymorphisms were performed by real time PCR. In addition, lipid profiles were determined and associated to genetic data. The genotype distribution was APOB rs693 (CC = 37%, CT = 41%, and TT = 22%), APOE rs7412/rs429358 (E4 = 0.06, E3 = 0.91, and E2 = 0.03), MTHFR rs1801131 (AA = 57%, AC = 30%, and CC = 13%), and MTHFR rs1801133 (CC = 20%, CT = 47%, and TT = 33%). The association of the genetic variants with plasma lipid levels showed that women, but not men, carrying APOB mutated allele (T) and Apo E4 allele presented lower values of total cholesterol when compared with C/C homozygous genotype or E3 allele, respectively (p < 0.05). In addition, a subgroup analysis revealed that ApoB C/C homozygous women exhibited higher values of HDL-C when compared with men carrying identical genotype (p < 0.01). On the other hand, women carrying E4 allele exhibited lower values of triglycerides when compared with male carrying identical genotype (p < 0.05). Finally, women carrying mutate allele (C) for MTHFR rs1801131 showed lower levels of triglycerides when compared with A/A homozygous genotype (p < 0.05) and lower levels of LDL-C for MTHFR rs1801133 in females carrying (T) allele when compared with males carrying identical genotype (p < 0.05). In summary, the present data showed that APOB, APOE, and MTHFR single nucleotide polymorphisms are associated to lipid levels in a gender-dependent manner among healthy subjects from Northern Chile, especially in women.
- ItemThe antifungal effect of six commercial extracts of Chilean propolis on Candida spp.(2010) Herrera, Christian L.; Alvear, Marysol; Barrientos, Leticia; Montenegro, Gloria; Salazar, Luis A.C. L. Herrera, M. Alvear, L. Barrientos, C. Montenegro, and L. A. Salazar. 2010. The antifungal effect of six commercial extracts of Chilean propolis on Candida spp. Cien. Inv. Agr. 37(1): 75 - 84. Propolis has been used in traditional medicine for many centuries because of its beneficial health properties, including its antimicrobial capacity. Prosthesis stomatitis affects a significant percentage of users of removable dentures; Candida albicans is the most common fungal species associated with the development of this pathology. Thus, the objectives of this study were: a. To evaluate the antifungal activity of six commercial propolis extracts against Candida spp. that was isolated from the oral cavity of removable dentures users, and b. To determine chemical characteristics of the propolis extracts evaluated. Among the results, we note that these concentrations of polyphenols varied between 9 +/- 0.3 and 85 +/- 2.1 mg mL(-1). Chromatographic analysis was able to detect 35 compounds, among which were caffeic acid, myricetin, quercetin, kaempferol, apigenin. pinocembrin, galangin, and caffeic acid phenyl ester (CAPE). All strains tested were inhibited by the liquid extracts of propolis. The MID ranged between 1:40 and 1:1280, and the MIC for C. albicans ranged from 197 mu g mL(-1) to 441 mu g mL(-1). From the results obtained in this investigation, we can conclude that all propolis extracts evaluated are capable of inhibiting the development of Candida spp. However, they show significant differences in the concentration of polyphenols present and in antifungal activity.
- ItemThe antifungal effect of six commercial extracts of Chilean propolis on Candida spp(2010) Herrera, Christian L.; Alvear, Marysol; Barrientos, Leticia; Montenegro Rizzardini, Gloria; Salazar, Luis A.
- ItemThe antifungal effect of six commercial extracts of Chilean propolis on Candida spp..(2010) Herrera, Christian L.; Alvear, Marysol; Barrientos, Leticia; Montenegro, Gloria; Salazar, Luis A.