Xuezhikang alleviates lipid accumulation via AMPK activation in hepatocellular steatosis model

Abstract Xuezhikang (XZK) is an extract of Chinese red yeast rice. It has multiple protective effects in cardiovascular systems. However, the underlying mechanism by which XZK affects free fatty acid (FFA)-induced lipogenesis in hepatocellular steatosis model is still unknown. Herein, we investigated this mechanism in HepG2 cells. The HepG2 cells were treated with palmitate acid (PA) to induce lipogenesis. Then the PA-induced HepG2 cells were subsequently treated with XZK. After 24 h of treatment, we determined the intracellular triglyceride (TG) contents and average areas of lipid droplets. To study the involvement of AMPK signaling pathway, we pre-treated the PA-induced HepG2 cells with Compound C, an AMPK inhibitor, before XZK treatment. Expressions of p-AMPK and AMPK were determined by Western blot. The results showed that XZK decreased TG content and lipid accumulation in hepatocellular steatosis model. Compound C abolished the effects of XZK. These results demonstrated for the first time that XZK protects hepatocytes against lipid accumulation induced by free fatty acids. Its effects may be mediated by the activation of AMPK pathway.

Concordancia entre analistas de laboratorios de latinoamérica para la determinación de la apariencia de grano de arroz pulido mediante el uso de imágenes digitales

La determinación de la apariencia del grano de arroz es un aspecto clave para evaluar su calidad. Generalmente, este análisis es realizado de manera visual empleando analistas expertos, sin embargo debido a la naturaleza subjetiva de su determinación, los resultados pueden ser divergentes. Con el objetivo de evaluar la concordancia entre analistas de laboratorios latinoamericanos de calidad de arroz en la determinación de la apariencia del grano de arroz pulido con ayuda de imágenes digitalizadas, se realizó un ensayo interlaboratorio con diez analistas e imágenes de 90 granos, capturadas mediante scanner de alta resolución. Los granos fueron clasificados en cuatro categorías incluyendo grano traslúcido, grano yesoso, grano panza blanca y granos dañados. La categorización fue analizada mediante la moda, frecuencia, concordancia relativa y coeficiente de concordancia Kappa. Adicionalmente, se elaboró una galería referencial de imágenes de granos típicos de cada categoría, basada en la frecuencia de modas. Los resultados revelaron un valor de Kappa de 0,49 que corresponde a una reproducibilidad moderada, atribuida a la subjetividad del análisis visual de las imágenes. Los resultados evidencian la necesidad de uniformizar criterios de evaluación entre analistas para mejorar la confiabilidad en la determinación de la apariencia de granos de arroz.

Concordance among analysts from Latin-american laboratories for rice grain appearance determination using a gallery of digital images. The appearance of rice grain is a key aspect in quality determination. Mainly, this analysis is performed by expert analysts through visual observation; however, due to the subjective nature of the analysis, the results may vary among analysts. In order to evaluate the concordance between analysts from Latin-American rice quality laboratories for rice grain appearance through digital images, an inter-laboratory test was performed with ten analysts and images of 90 grains captured with a high resolution scanner. Rice grains were classified in four categories including translucent, chalky, white belly, and damaged grain. Data was categorized using statistic parameters like mode and its frequency, the relative concordance, and the reproducibility parameter kappa. Additionally, a referential image gallery of typical grain for each category was constructed based on mode frequency. Results showed a Kappa value of 0.49, corresponding to a moderate reproducibility, attributable to subjectivity in the visual analysis of grain images. These results reveal the need for standardize the evaluation criteria among analysts to improve the confidence of the determination of rice grain appearance.

Elevada diversidade genética interpopulacional em Oryza glumaepatula Steud. (Poaceae) avaliada com microssatélites / High interpopulational genetic diversity of Oryza glumaepatula Steud. (Poaceae) assessed with microsatellites

Marcadores microssatélites foram usados para caracterizar a diversidade genética entre e dentro de sete populações naturais de Oryza glumaepaula. Seis dessas populações são originárias da bacia hidrográfica da Amazônia e uma do rio Paraguai no Pantanal Matogrossense. Utilizando sete locos de microssatélites, observou-se diversidade genética intrapopulacional média de 1,98 alelos por loco, 56,2 por cento de locos polimórficos, Ho = 0,026 e He = 0,241. Elevada diferenciação interpopulacional foi observada pelo índice de fixação de Wright e pelo parâmetro de divergência de Slatkin (F ST = 0,715 e R ST = 0,595, respectivamente), bem como elevado nível de endogamia total (F IT = 0,963), em grande parte influenciada pelo sistema reprodutivo (F IS = 0,858). Verificou-se que nenhuma população estava em equilíbrio de Hardy-Weinberg, devido ao predomínio da autofertilização, o que também pôde ser verificado pela taxa média aparente de cruzamentos: t a = 0,055. Consequentemente, o fluxo gênico entre populações foi praticamente nulo o que contribuiu para o elevado nível de divergência interpopulacional. De modo geral, as taxas de cruzamento foram muito baixas ou nulas nas populações da Amazônia. Entretanto, a população PG-3 do Rio Paraguai, originária do Pantanal Matogrossense, apresentou taxa de cruzamento mais elevada (13,2 por cento), indicando sistema reprodutivo misto com predomínio de autogamia. Como a diversidade intrapopulacional foi baixa, os resultados indicam que a amostragem de elevado número de populações é a estratégia mais adequada para a conservação ex situ desta espécie. Para a conservação in situ, com base na riqueza alélica, recomenda-se como prioridade as populações PG-3, TA-3, SO-17 e NE-7, originárias das bacias hidrográficas dos Rios Paraguai, Tapajós, Solimões e Negro, respectivamente.

Microsatellite markers were used to characterize the genetic diversity within and among seven natural populations of Oryza glumaepaula. Six of these populations originated from the hydrographic basin of the Amazon and one from Rio Paraguay in the Pantanal Matogrossense. Using seven microsatellite loci, the following intrapopulation genetic diversity parameters were estimated on average: 1.98 alleles per locus, 56.2 percent polymorphic loci, Ho = 0.026 and He = 0.241. High interpopulational differentiation was noticed by examining Wright's fixation index and Slatkin's divergence parameter (F ST = 0.715 and R ST = 0.595, respectively), as well as a high level of total inbreeding (F IT = 0.963), greatly influenced by the mating system (F IS = 0.858). No population was in Hardy-Weinberg equilibrium, due to the prevailing autogamic mating behavior, as also indicated by the average apparent outcrossing rate observed: t a = 0.055. Consequently, among populations gene flow was practically absent, which has contributed to the high interpopulational genetic divergence. In general, very low or null outcrossing rates were found in the Amazonian populations. However, population PG-3 from Rio Paraguay, originated from Pantanal Matogrossense, showed a higher outcrossing rate (13.2 percent), indicating a mixed mating system with the predominance of self-fertilization. Since intrapopulation diversity was low, results indicate that sampling a large number of populations is the most appropriate strategy for the ex situ conservation of this species. For in situ conservation, taking in consideration the allelic richness, the following populations are indicated as priority: PG-3, TA-3, SO-17, and NE-7, from the hydrographic basins of the rivers Paraguay, Tapajos, Solimoes and Negro, respectively.

Ultrastructure of the wild rice Oryza grandiglumis (Gramineae) in Costa Rica

Oryza grandiglumis is a wild species of rice endemic to tropical America. This species was first found in 1998 in the wetlands of Caño Negro, located in the northern part of Costa Rica. Twenty five plants of O. grandiglumis were processed for scanning electron microscope. An ultrastructural description of the leaf blade, ligule, auricles, spikelet and caryopsis, with an emphasis on structures of taxonomic value. The leaf blade has a characteristic cuticular wax pattern, composed of dense rod-like structures, and is surrounded by papillae, zipper-like silica cells, abundant bulky prickle trichomes, and hooked trichomes. The blade's edge has three rows of hooked prickle trichomes of various sizes. The auricles wrapped the culm, with long attenuated trichomes at the edges; the base was surrounded by oblong cells. The ligule is a blunt membrane covered by short prickle trichomes. Spikelet morphology is characteristic of the Poaceae family, but the sterile lemmas were nearly as long as the fertile lemmas, and they have an unique crown-like structure of lignified spines between the rachilla and the fertile lemmas. Comparison with Brazilian specimens of O. grandiglumis revealed little differences in the ultrastructural characteristics.

El arroz silvestre Oryza grandiglumis es endémico de América. Se localiza en la zona norte de Costa Rica, principalmente en el humedal de Caño Negro y del Río Medio Queso. Es una planta vigorosa y grande. Su nombre deriva del gran tamaño de las lemas estériles (glumas). Presentamos una descripción ultraestructural de la lámina foliar, lígula, aurículas, espiguilla y cariópside, con énfasis en las estructuras de valor taxonómico, usando el microscopio electrónico de barrido. La lámina foliar se caracteriza por presentar un patrón de cera cuticular en forma de densos bastoncillos. Presenta estomas rodeados de papilas, células de sílice en forma crenada, varias formas de papilas de cera, distribuidas en forma muy regular, y tricomas espinosos abultados en la base y tricomas ganchudos. En el borde de la lámina hay tres hileras de tricomas espinosos ganchudos de diferente tamaño. Las aurículas son envolventes y los bordes presentan tricomas atenuados largos cubiertos en la base por células alargadas. La lígula es truncada y cubierta de tricomas espinosos pequeños. La morfología de la espiguilla es algo similar a las de las otras especies de la familia Poaceae, pero las lemas estériles son casi del mismo tamaño que las fértiles. Además se observó entre la raquilla y las lemas fértiles una corona de espinas lignificadas. Ultraestructuralmente, esta población es similar a las brasileñas.

Structural and histochemical studies on grain-filling in the caryopsis of rice (Oryza sativa L.).

The endosperm and embryo that constitute the filial tissues of rice caryopsis are isolated from the maternal tissues by the absence of any symplastic continuity. Nutrients are transported to the endosperm through a single ovular vascular trace present on the ventral side of the ovary. Initially solute enters through the chalaza into the nucellar projection and then into the endosperm. At later stages transport occurs through the nucellar epidermis, centripetally towards the endosperm. The cell walls of the nucellar epidermis are provided with rib-like thicken ings. A comparison of grain-filling in C3 and C4 cereals suggests that rice has structural features allied to C3 cereals, such as wheat, but with significant differences.