ABSTRACT
ABSTRACT This project's purpose was to evaluate the healing effects of chitosan (CS) hydrogels loaded with extracts from Aloe vera (CS+AV) and Calendula officinalis (CS+CO) on wounds of diabetic and non-diabetic Wistar rats. A total of 24 rats were used; animals were randomly divided into three diabetic and three non-diabetic groups (one control and two treated groups) and monitored for 13 days. A biopsy on the wound site was recovered to assess the collagen and n-acetyl glucosamine content. The wound area ratio was reduced since day 1 on both non-diabetic treated groups. A similar effect was observed on the diabetic group treated with CS+AV, while the diabetic group treated with CS+CO showed a reduction in wound area compared to the diabetic control until day 11 after being wounded. Collagen and n-acetyl glucosamine content were higher in every treated group. Further studies are needed to clarify the underlying mechanisms through which they promote wound healing. These results suggest that the hydrogels prepared are potential material to be used as wound dressings.
RESUMEN El propósito de este proyecto fue evaluar los efectos curativos de los hidrogeles de quitosano con extractos de Aloe vera (CS + AV) y Calendula officinalis (CS + CO) en heridas en ratas Wistar diabéticas y no diabéticas. Se utilizaron un total de 24 ratas; los animales fueron divididos aleatoriamente en tres grupos diabéticos y tres no diabéticos (un grupo control y dos tratados) y se monitorearon durante 13 días. Se recuperó una biopsia del sitio de la herida para evaluar el contenido de colágeno y n-acetilglucosamina. El área de la herida se redujo desde el día 1 en ambos grupos no diabéticos tratados. Se observó un efecto similar en el grupo diabético tratado con CS + AV, mientras que el grupo diabético tratado con CS + CO mostró una reducción del área de la herida en comparación al control diabético hasta el día 11 después de la creación de la herida. El contenido de colágeno y n-acetilglucosamina fue mayor en todos los grupos tratados. Se necesitan más estudios para aclarar los mecanismos subyacentes a través de los cuales estos tratamientos promueven la cicatrización de heridas. Estos resultados sugieren que los hidrogeles preparados son materiales con potencial para usarse como apósitos para heridas.
ABSTRACT
Resumen EL asma es una enfermedad relacionada con estrés oxidativo. Los practicantes de la medicina alternativa han usado plantas que tienen altas concentraciones de polifenoles en el tratamiento de pacientes con asma. Este artículo revisa la administración de antioxidantes no vitamínicos en pacientes con asma, con insistencia en los polifenoles. Se realizó una búsqueda en Google Scholar y en la base de datos de RIMA de Astra Zeneca con las palabras clave y frases "asthma and flavonoids", "antioxidant therapy in asthma" "resveratrol and asthma" y "polyphenols and asthma". Se priorizó la búsqueda de estudios experimentales en modelos animales y de estudios en humanos. Existe tendencia a aceptar los efectos favorables de los polifenoles en pacientes con asma. La mayor parte de la información es más consistente en trabajos experimentales realizados en animales que cuando se comparan entre sí los pocos estudios clínicos en humanos. La interpretación de los estudios a partir de experiencias con la dieta tiene el inconveniente que el tipo y concentración de polifenoles cambia entre poblaciones y depende de regiones geográficas. Es recomendable diseñar estudios con gran cantidad de personas para evaluar la contribución de la terapia con polifenoles en sujetos con asma en profilaxis y en manejo de crisis y en terapias para el control de la enfermedad a largo plazo.
Abstract Asthma is a disease related to oxidative stress. Practitioners of alternative medicine have used plants that have high concentrations of polyphenols in the treatment of patients with asthma. This paper reviews the use of non-vitamin antioxidants in asthma, with emphasis in polyphenols. A search was made in Google Scholar and in the RIMA database of Astra Zeneca with the keywords and phrases "asthma and flavonoids", "antioxidant therapy in asthma", "resveratrol and asthma" and "polyphenols and asthma". We prioritized the search for experimental studies in animal models and studies with humans. There is a tendency to accept the favorable effects of polyphenols in asthma. Most of the information is more consistent in experimental work on animals than when comparing experiences among the few clinical studies in humans. The interpretation of studies from dietary experiences has the drawback that the type and concentration of polyphenols changes between populations and depends on geographical regions. It is advisable to design studies with a large number of people to evaluate the contribution of polyphenols in subjects with asthma in prophylaxis, crisis management and long-term disease control therapies.
ABSTRACT
Abstract Stress tolerance is a key attribute that must be considered when using yeast cells for industrial applications. High temperature is one factor that can cause stress in yeast. High environmental temperature in particular may exert a natural selection pressure to evolve yeasts into thermotolerant strains. In the present study, three yeasts (Saccharomyces cerevisiae, MC4, and Kluyveromyces marxianus, OFF1 and SLP1) isolated from hot environments were exposed to increased temperatures and were then compared with a laboratory yeast strain. Their resistance to high temperature, oxidative stress, and antioxidant response were evaluated, along with the fatty acid composition of their cell membranes. The SLP1 strain showed a higher specific growth rate, biomass yield, and biomass volumetric productivity while also showing lower duplication time, reactive oxygen species (ROS) production, and lipid peroxidation. In addition, the SLP1 strain demonstrated more catalase activity after temperature was increased, and this strain also showed membranes enriched in saturated fatty acids. It is concluded that the SLP1 yeast strain is a thermotolerant yeast with less oxidative stress and a greater antioxidant response. Therefore, this strain could be used for fermentation at high temperatures.