Phytosterol Extract Decreases the Oxidative Damage in the Brains of Diabetic db/db Mice.

Introduction: Hypercaloric diets induce oxidative stress, and consequently induce hyperglycemia and type 2 diabetes mellitus (T2DM). Thus, oxidative stress is significantly increased in T2DM, leading to oxidative damage to brain, which might contribute to cognitive deficits and neurodegenerative diseases. Therefore, reducing the oxidative stress is important to preserving cognitive functions, and it has been suggested that phytosterols may reduce the oxidative stress. Objective: The objective of the present study was to determine the effects of phytosterols derived from corn on oxidative damage in the cerebellum, frontal cortex, and hippocampus of diabetic db/db mice. Materials and Methods: A phytosterol extract was isolated from yellow corn (Zea mays L.) and 100 mg/kg of the extract was administrated daily to diabetic mice for 8 weeks. At the end of the treatment period, tissues were isolated to determine the levels of oxidized lipid and protein. Results: The phytosterol treatment increased body weight in diabetic db/db mice, but this treatment did not have any effects on body weight in wild-type mice. Moreover, the phytosterol treatment decreased levels of oxidized lipids in the cerebellum, frontal cortex, and hippocampus, and also decreased the levels of oxidized proteins in the cerebellum and frontal cortex in diabetic db/db mice. Conclusion: These important results show that phytosterol treatment can reduce oxidative damage in the brains of diabetic mice.

One-pot green synthesis of gold and silver nanoparticles using Rosa canina L. extract.

This study reports a green, simple, and fast method for the synthesis of gold and silver nanoparticles using natural antioxidant compounds. The aqueous extract from dried rosehips (pseudofruit of Rosa canina L.) was used as a reducing and capping agent of HAuCl4 and AgNO3 during the noble metal colloid synthesis at room temperature and no other chemical reagent was used. The high antioxidant activity of the plant extract was proven by 2,2-diphenyl-1-picrylhydrazyl assay by a spectrophotometric method. The formation of stable gold and silver nanoparticles was observed by UV-visible spectroscopy and the evolution of their characteristic surface plasmon resonance band was followed over several days. Transmission electron microscopy confirmed the formation of quasi-spherical nanoparticles with mean diameters 26 and 34 nm, for gold and silver nanoparticles, respectively; XRD revealed an FCC crystalline structure for both gold and silver NPs. The effects of concentrations of noble metal precursor and plant extract solution on the formation, stabilization and size of nanoparticles are discussed, as well as some applications of these colloids.

Variability and composition of calcium oxalate crystals in embryos-seedlings-adult plants of the globose cacti Mammillaria uncinata.

The morphology and elemental composition of crystals in embryos, seedlings and adult plants of the globose cacti Mammillaria uncinata were studied. Samples of mature fruits and adult plants were collected. To obtain embryos and seedlings, seeds from mature fruits were germinated under laboratory conditions. Both embryos and seedlings as well as stem and root of the adult plants were processed by conventional microtechniques and tissue macerations to isolate the individual crystals. The crystal morphology was evaluated by light and scanning electron microscopy while its chemical composition was analyzed by energy dispersive spectroscopy, IR and Raman spectroscopy. The results demonstrated the occurrence of calcium oxalate crystals in the three stages of plant growth. Solitary and small crystals are present in embryos and seedlings in contrast crystals are aggregates or conglomerates in the adult plants. The compositional analysis showed that seedling crystals contain carbon (50.37%), oxygen (45.29%) and calcium (3.36%) while in adult plants the percentage has changed to carbon (12.54%), oxygen (53.06%) and calcium (34.38%). In the IR spectrum, the vibration bands around 1321 and 1621 cm-1 are attributed to the calcium oxalate in the dihydrate state (weddellite), the Raman peak at 1475 cm-1 shows also that crystals correspond to the pure state of calcium oxalate dihydrate state. The crystal size was also different for seedlings and adult plants, mean values varied from 12.11 to 13.38 µm for width and length, respectively in seedlings and from 65.10 to 73.90 µm, in adult plants. It is concluded that the elemental composition, size and morphology of crystals in M. uncinata depend on the growth stage, as it happens in other plant species.

Raman spectroscopy study of calcium oxalate extracted from cacti stems.

To find markers that distinguish the different Cactaceae species, by using near infrared Raman spectroscopy and scanning electron microscopy, we studied the occurrence, in the stem, of solid deposits in five Cactaceae species (Coryphantha clavata, Ferocactus latispinus, Opuntia ficus-indica, O. robusta, and O. strepthacantha) collected from their natural habitats from a region of México. The deposits in the tissues usually occurred as spheroidal aggregates, druses, or prismatic crystals. From the Raman spectra, the crystals were identified either as calcium oxalate monohydrate (CaC2O4·H2O) or calcium oxalate dihydrate (CaC2O4·2H2O). Opuntia species (subfamily Opuntioideae) showed the presence of CaC2O4·H2O, and the deposition of CaC2O4·2H2O was present in C. clavata and F. latispinus (subfamily Cactoideae, Cacteae tribe). As a punctual technique, Raman spectroscopy seems to be a useful tool to identify crystal composition. In addition to allowing the analysis of crystal morphology, this spectroscopic technique can be used to identify Cactaceae species and their chemotaxonomy.

Epidermal and hypodermal characteristics in North American Cactoideae (Cactaceae).

Dermal and hypodermal anatomical features of 70 species representing 21 genera of North American Cactoideae were studied. Results show that all species examined have parallelocytic stomata and anticlinal wall surface varies from straight to undulate. Cuticle thickness is mostly narrow (1-10 microm) contrary to the general opinion that cuticle is thick in most cacti; however, few species such as Ariocarpus fissuratus and several species of Pachycereus show a distinctive thick cuticle. More than 80% of the species studied have a single-layered epidermis. Papillae occur in eight species belonging to four genera. Notable papillae are a feature shared by all members of Peniocereus subg. Peniocereus. Other species show a bullate surface produced by irregular patches of secondary epidermal cell divisions. Commonly, the hypodermis is composed of more than two cell layers with distinctive collenchymatous walls as reported in many South American species. Silica bodies, prismatic crystals, druses, sphaerocrystals, and tannins are the most common cellular inclusions that distinguish several genera and appear to have taxonomic value. However, a more thorough search in species of Cephalocereus, Coryphantha, Echinocereus, Mammillaria, Neobuxbaumia, Pilosocereus, and Turbinicarpus is needed to support the previous assertion.

Características morfo-anatómicas y metabolismo fotosintético en plántulas de stenocereus queretaroensis (cactaceae): su significado adaptativo / Morpho-anatomical features and photosynthetic metabolism in stenocereus queretaroensis seedlings (cactaceae): their adaptive value

Se estudiaron los caracteres morfo-anatómicos y del metabolismo fotosintético en plántulas de Stenocereus queretaroensis (Weber) Buxb. para examinar dichos atributos durante su ontogenia. Más de 500 plántulas fueron sembradas en semilleros y durante los tres primeros meses fueron recolectadas cada semana; posteriormente cada mes hasta completar 56 semanas para registrar los cambios morfo-anatómicos. Parte de las plántulas se colectaron cada 3h durante 24h en los intervalos señalados y almacenaron en N2 líquido para estimar la concentración de ácido (protones titulables) por unidad de peso fresco. Las plántulas tuvieron un tallo de 3.6cm de altura con siete costillas y raices de la misma longitud a las 56 semanas; al año los cotiledones se marchitaron. El eje hipocótilo-raíz, al igual que el tallo, tuvo epidermis simple y estomas escasos; la hipodermis también fue de un estrato y difiere del tallo adulto. El cámbium vascular se diferenció en plántulas de un año, el xilema secundario se diferencia del tallo adulto por la presencia de traqueidas de banda ancha y ausencia de fibras. Los protones titulables mostraron fluctuaciones irregulares en las primeras semanas de crecimiento, sin embargo, la acidez incrementó con la edad de las plántulas. En la semana 56 se incrementó a partir de las 18:00 y continuó hasta un valor máximo de 45,19µmolH+.g-1 de tejido a las 06:00 mostrando el patrón típico de metabolismo ácido de las crasuláceas. El rápido crecimiento de las raíces, la presencia de traqueidas de banda ancha y los escasos estomas se interpretaron como adaptaciones para evitar al desecación