Bioquímica y Farmacia

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Actividad antibacteriana de aceites esenciales solos y en combinación con antibióticos sintéticos frente a Pseudomonas aeruginosa
(Universidad de Cuenca, 2023-08-29) Coronel Tenesaca, Mateo Sebastián; Piña Calle, Camila Estefanía; Moscoso Romo, María Paz
Pseudomonas aeruginosa is a gram-negative bacillus that belongs to the ESKAPE group, which includes the main bacteria classified as a priority in the development of new antimicrobial agents due to the increasing antimicrobial resistance. The production of biofilms and intrinsic resistance to antibiotics are natural resistance mechanisms of P. aeruginosa against conventional pharmacotherapy. This bacterium has been linked to infections in immunocompromised patients, particularly those who are hospitalized, due to the development of biofilms on catheters, artificial respirators, or prosthetic devices. In this study, essential oils were obtained from two medical plants, Clinopodium nubigenum (tipo) y Cymbopogon citratus (lemon grass) through hydro- distillation. Subsequently, the antimicrobial activity was determined against Pseudomonas aeruginosa ATCC 27853, using the broth microdilution method, and the potential synergism effect with conventional antibiotics was assessed using the checkerboard method. The results of this dissertation demonstrate that both essential oils have activity against the mentioned bacteria, with Clinopodium nubigenum (tipo) essential oil an activity of 4096 μg/mL and Cymbopogon citratus (lemon grass) at 1024 μg/mL. Regarding the synergism activity, Clinopodium nubigenum (tipo) essential oil and Ciprofloxacin showed a synergistic effect, with a reduction in the Minimum Inhibitory Concentration (MIC) to 1/512 (8 μg/mL) and to 1/4 (0.03125 μg/mL) respectively. On the other hand, the data obtained from Cymbopogon citratus (lemon grass) essential oil showed an indifference effect with the antibiotic evaluated.
Cuantificación de la actividad antibacteriana de aceites esenciales frente a Escherichia coli ATCCC 25922 y Escherichia coli portadora de betalactamasas de espectro extendido
(Universidad de Cuenca, 2023-01-11) Avila Guallpa, Joseline Karina; Guzmán Gaona , Ángela Cynthia; Vanegas Jácome, David Enrique
Antibiotic resistance due to the production of the extended-spectrum β-lactamases (ESBL) by Escherichia coli has become a threat to public health. For this reason, the use of essential oils (EOs) is considered a new therapeutic alternative to counteract this problem. The most widely used method to determine the antimicrobial activity of EOs is the plate microdilution technique, which allows to determinate the inhibitory concentration (IC) at 50 % and 90 %, from the measurement of turbidity in a microplate reader. However, this generates a high margin of error in bacterial quantification, which is why it is recommended to use cell viability indicators such as 3- (4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and resazurin. In the present study, the antibacterial activity (IC 50 % and IC 90 %) of nine EOs against E. coli ATCC 25922 and ESBL-producing E. coli was evaluated with the microdilution technique using indicators such as MTT and resazurin in order to analyzewhich indicator is ideal for the quantification of the activity. Commercial EOs from Cinnamon cassia, Citrus limonum, Mentha spicata, Pogostemon cablin, Cymbopogonflexuosos and EOs obtained from the hydrodistillation of Clinopodium nubigenum, Aloysia citriodora, Pimpinella anisum and Zingiber officinale were used. Essential oils from A. citriodora, M. spicata, C. cassia, Z. officinale, C. flexuosos and C. nubigenum were estimated to have antibacterial activity against E. coli ATCC 25922and ESBL-producing E. coli, different to C. limonum, P. cablin and P. anisum. In addition, it was determined that the technique using MTT at a wavelength of 450 nm presents a lower percentage of coefficient of variation than resazurin at a wavelength of 560 to 590 nm.
Evaluación de la variación geográfica de la composición del aceite esencial de Ruta graveolens proveniente de los cantones de Cuenca y Morona
(Universidad de Cuenca, 2021-12-16) Galarza Crespo, Max Andrés; Sacaquirin Jiménez, Ramón Esteban; Ortiz Ulloa, Silvia Johana
Ruta graveolens, known as rue, is a plant of the Rutaceae family, native to Europe and introduced to America in the Middle Ages. Its essential oil is composed of terpenes and terpenoids such as: flavonoids, coumarins, furancomarins and mainly ketones. In addition, the essential oil of R. graveolens has been attributed several biological properties such as antimicrobial activity against pathogenic bacteria species (Gram positive and Gram negative), as well as insecticidal and anticancer activity. In this work, the composition of Ruta graveolens’ essential oil obtained from different geographical areas, in the cantons of Cuenca and Morona, were evaluated. The analysis was performed using an optimized method for gas chromatography with flame ionization detection (GC-FID). In the optimization of the method, it was observed that a major area of chromatographic peaks was obtained at an injection temperature of 160 °C. However, a better resolution is obtained at 220 °C and, to cover the wide range of boiling temperatures of the possible components of the essential oil, subsequent analyzes were continued at this temperature. The main components of the essential oil of Ruta graveolens identified were 2-nonanone and 2-undecanone, both in the specimens from the Cuenca canton and those from the Morona canton. When comparing the general composition of the oils of the specimens from both cantons, a significant difference was observed attributed to the variations by the geographical area where the samples were collected.
Evaluación del potencial de los aceites esenciales de albahaca (Ocimum basilicum), caléndula (Calendula officinalis) y manzanilla (Matricaria chamomilla) y sus mezclas como fotoprotectores
(2019-03-11) Tacuri Lucero, Mayra Johanna; Cazar Ramírez, María Elena
The increase of the incidence of radiation solar in the biosphere due to the weakening of the ozone layer in decades recent generates the need of protect the skin against the negative effects of the radiation UV:, erythema, hiperpigmentación, photo greening and skin cancer. In this project is evaluated the ability of absorption ultraviolet of essential oils obtained of the parts of the leaves of basil (Ocimum basilicum), flowers of calendula (Calendula officinalis) and flowers of chamomile (Matricaria chamomilla). The factor of protection is determined according to the method of Mansur. After that, I did mixtures of the oils in study, with the purpose of evaluate possible effects synergy in the factor of protection solar. The factors of protection solar in the pure essential oils is determined in this manner: 3.14 for O. basilicum, 2.55 for M. chamomilla and 5.02 for C. officinalis. The mixtures 50:50 O. basilicum: M. chamomilla, M. chamomilla: C. officinalis, y O. basilicum: M. chamomilla present values of protection solar of 4.02, 4.4 y 5.7, respectively. The ternary mixture 33% O. basilicum: M. chamomilla: C. officinalis generates FPS of 7.2. The methodology of this study can be applied to select substances of natural origin in the development of new formulas of sunscreens with the bioactive principles
La ruda: obtención de la esencia y estudio de la acción farmacológica de la misma
(1963-11-11) Sánchez Orellana, Rómulo; González Moscoso, Marcelo; Donoso Montesinos, Carlos

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Browsing Bioquímica y Farmacia by Subject "Aceites esenciales"