María Adriana Núñez-González

Miconia sp. Increases mRNA Levels of PPAR Gamma and Inhibits Alpha Amylase and Alpha Glucosidase.

Diabetes mellitus is a public health problem worldwide. For this reason, ethanolic extract of Miconia sp. from Oaxaca, Mexico, was selected in search of an alternative against this disease. The effect of Miconia sp. on mRNA expression of PPARγ on cell line 3T3-L1, its effect on alpha amylase and alpha glucosidase, lipid accumulation during adipogenesis, and cell viability on VERO cells were evaluated. The mRNA levels of PPARγ increased on 1.393 ± 0.008 folds, lipid accumulation was increased by 29.55% with Miconia sp. extract and 34.57% with rosiglitazone, and α-amylase and α-glycosidase were inhibited with IC50 values from 28.23 ± 2.15 μg/mL and 1.95 ± 0.15 μg/mL, respectively; the IC50 on antiproliferative activity on VERO cells was 314.54 ± 45.40 μg/mL. In case of α-amylase and α-glycosidase assays, IC50 (inhibitory concentration 50) refers to necessary extract amounts to inhibit 50% of enzymatic activity. On the other hand, on antiproliferative activity, IC50 (inhibitory concentration 50) refers to necessary extract amounts to inhibit 50% of cell proliferation. It was concluded that the compounds present in Miconia sp. ethanolic extract increase mRNA expression of PPARγ, inhibit α-amylase and α-glucosidase, and increase lipid accumulation. It constitutes an alternative as adjuvant in diabetes mellitus treatment; therefore, we recommend continuing identifying the compounds responsible for its promising in vivo antidiabetic activity.

Performance and nutrient digestion of lambs fed incremental levels of wild cactus (Opuntia leucotrichia)

In a performance trial, 50 intact Rambouillet×Dorper male lambs (19±2.8 kg), were randomly assigned to experimental diets containing 0, 10, 20, 30 or 40%, Opuntia leucotrichia (O. leucotrichia; dry matter basis). At day 91 animals were slaughtered for carcass and meat quality evaluation. In trial two, five ruminal cannulated Rambouillet male rams were used in a digestion study. Dry matter intake, average daily gain and feed efficiency of lambs decreased (P<0.05) generally with increasing levels of O. leucotrichia. Carcass dressing was increasing as O. leucotrichia was augmented. Water intake decreased as consumption of O. leucotrichia increased. Crude protein was digested higher (P<0.05) in lambs fed 40% diet than other lambs. Ruminal pH and ammonia-N were not significantly different among treatments. Inclusion of O. leucotrichia on feedlot lamb diets is a good option for production systems if this resource is available.

Study of the fortification with bean and amaranth flours in nixtamalized maize tortilla

The aim of this study was to compare the physicochemical, rheological and textural tortillas of nixtamalized maize flour fortified with common bean (Phaseolus vulgaris) and amaranth (Amaranthus spp.) flours in three different proportions (3F7A, 5F5A and 7F3A) with respect to commercial maize flour (TR). Also, their effect on growth was assessed by a bioassay of two generations with Wistar rats. Treatments obtained similar efficiencies to TR, plus a significant increase in the protein. They showed a similar behavior in water absorption capacity (WAC) and rollability, crucial factors to the proper development of the dough and its acceptation, respectively. Furthermore, the treatments presented a significant difference (p < 0.05) in bioassay, showing 3F7A similar behavior between casein control. The formulations developed in this research, primarily 3F7A, are a viable option for bioavailable protein-fortified tortillas, rich in lysine, that show textural and rheological properties analogous to regular tortilla.

Physicochemical Changes and Resistant-Starch Content of Extruded Cornstarch with and without Storage at Refrigerator Temperatures

Effects of extrusion cooking and low-temperature storage on the physicochemical changes and resistant starch (RS) content in cornstarch were evaluated. The cornstarch was conditioned at 20%–40% moisture contents and extruded in the range 90–130 °C and at screw speeds in the range 200–360 rpm. The extrudates were stored at 4 °C for 120 h and then at room temperature. The water absorption, solubility index, RS content, viscoelastic, thermal, and microstructural properties of the extrudates were evaluated before and after storage. The extrusion temperature and moisture content significantly affected the physicochemical properties of the extrudates before and after storage. The RS content increased with increasing moisture content and extrusion temperature, and the viscoelastic and thermal properties showed related behaviors. Microscopic analysis showed that extrusion cooking damaged the native starch structure, producing gelatinization and retrogradation and forming RS. The starch containing 35% moisture and extruded at 120 °C and 320 rpm produced the most RS (1.13 g/100 g) after to storage at low temperature. Although the RS formation was low, the results suggest that extrusion cooking could be advantageous for RS production and application in the food industry since it is a pollution less, continuous process requiring only a short residence time.

Actividad biológica de proteínas y péptidos

Las proteinas y peptidos son motivo de estudio en diversas disciplinas dado que se ha demostrado que no unicamente presentan actividad estructural, sino que pueden presentar actividad biologica favorable para el ser humano o para la planta. En este sentido, han sido reportadas numerosas actividades para estos metabolitos desde una antimicrobiana contra bacterias Gram positivas, Gram negativas, fungicida, hasta inmunomoduladores y anticancerigenos, sin olvidar mencionar que poseen algunos otros usos en el area de la salud. Recientemente se han empleado herramientas proteomicas para el desarrollo de estudios en donde se logra la caracterizacion de algunas proteinas y peptidos expresados por genomas, permitiendo establecer las interacciones entre estos metabolitos y esclarecer sus funciones, aunado a la posible identificacion de marcadores para diagnostico de enfermedades. El desarrollo de dichos estudios resulta prometedor para el uso potencial de estos metabolitos como nuevos farmacos, debido a las multiples actividades biologicas ya reportadas.