Diabetes mellitus (DM) is considered the epidemic of the 21st century. Traditional medicine uses plants to treat DM; many of these have hypoglycemic effects in both animal models and diabetic patients. Our objective was to evaluate the hypoglycemic activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on diabetic rats. The methanolic extracts of the plants under study were obtained by Soxhlet extraction. Toxicity was evaluated on Artemia salina; the antioxidant potential was evaluated using the DPPH technique. Hypoglycemic capacity at doses of 250 and 500 mg/kg was tested on Wistar rats with diabetes induced by alloxan (120 mg/kg). The toxicity on A. salina was null for the extracts of B. officinalis and P. sanctum, moderate for T. americana, and highly toxic for C. nuttalliae. The relevant extract of T. americana var. mexicana showed antioxidant activity. Three plants of the studied plants showed hypoglycemic activity: Tilia Americana (p=0.0142), Borago officinalis (p=0.0112), and Piper sanctum (p=0.0078); P. sanctum was the one that showed the greatest reduction in glucose levels at a lower dose.

No abstract

Depending on the morphology of the natural fibers, they can be used as reinforcement to improve flexural strength in cement-based composites or as aggregates to improve thermal conductivity properties. In this last aspect, hemp, coconut, flax, sunflower, and corn fibers have been used extensively, and further study is expected into different bioaggregates that allow diversifying of the raw materials. The objective of the research was to develop plant-based concretes with a matrix based on Portland cement and an aggregate of Agave salmiana (AS) leaves, obtained from the residues of the tequila industry that have no current purpose, as a total replacement for the calcareous aggregates commonly used in the manufacturing of mortars and whose extraction is associated with high levels of pollution, to improve their thermal properties and reduce the energy demand for air conditioning in homes. Characterization tests were carried out on the raw materials and the vegetal aggregate was processed to improve its compatibility with the cement paste through four different treatments: (a) freezing (T/C), (b) hornification (T/H), (c) sodium hydroxide (T/NaOH), and (d) solid paraffin (T/P). The effect of the treatments on the physical properties of the resulting composite was evaluated by studying the vegetal concrete under thermal conductivity, bulk density, and compressive strength tests with a volumetric ratio between the vegetal aggregate and the cement paste of 0.36 and a water/cement ratio of 0.35. The hornification treatment showed a 15.2% decrease in the water absorption capacity of the aggregate, resulting in a composite with a thermal conductivity of 0.49 W/mK and a compressive strength of 8.66 MPa, which allows its utilization as a construction material to produce prefabricated blocks.

No abstract

México es un país que se encuentra en zona tropical cálida con alta intensidad de radiación ultravioleta, la cual puede inducir alteraciones graves a nivel dérmico. El presente trabajo consistió en determinar la actividad fotoprotectora de los extractos metanólicos de Opuntia megacantha, Cistus incatus, Opuntia imbricata, Equisetum hyemale y el extracto clorofórmico de Euphorbia tirucalli. El factor de protección solar (FPS) de dichos extractos se determinó mediante el método in vitro descrito por Mansur utilizado bezofenona-3 como control positivo, mientras que el contenido de fenoles totales se determinó de acuerdo con el método descrito por Magalhães y colaboradores, con ligeras modificaciones. Se encontró que los extractos de dichas plantas tienen un potencial fotoprotector, debido a que se obtuvieron valores de FPS de 11.79, 11.22, 9.83 y 6.4 con O. megacantha, C. incatus, E. hyemale y E. tirucalli respectivamente; estos valores se encuentran asociados a la presencia de flavonoides y/o taninos en su perfil fitoquímico. Por otro lado, la variabilidad del FPS de estos extractos se relacionó con su contenido en polifenoles totales, siendo los valores 108.52, 146.28, 34.68, 53.4 μg EAG/mg de las plantas anteriormente mencionadas respectivamente. La presencia de otros fitoquímicos tales como sesquiterpenos, terpenos y estroles nos llevó a concluir que dichos extractos, además de ser fotoprotectores prometedores, podrían tener otras actividades biológicas frente a otros tipos de afecciones tópicas.