Carbohydrate content and antioxidative potential of the seed of three edible indica rice (Oryza sativa L.) cultivars.

Rice (Oryza sativa L.) grains or seeds are known to lose much of their nutrient and antioxidant contents, following polishing. The current study was undertaken to evaluate and compare the carbohydrate content and antioxidant parameters in the unpolished and polished seeds of three edible indica rice cultivars, namely Swarna (SW), the most popular indica rice cultivar in India and aromatic or scented cultivars Gobindobhog (GB) and Pusa Basmati (PB). While both the sucrose and starch content was the maximum in PB seeds (both unpolished and polished), the amylose content was the highest in SW polished seeds. SW polished seeds were superior as compared to GB and PB cultivars in terms of total antioxidant capacity, DPPH radical scavenging and Fe(II) chelation potential, as well as the highest lipoxygenase (LOX) inhibition or H2O2 scavenging potential, probably due to the maximum accumulation of total phenolics and flavonoids, the two important antioxidants. The reducing power ability was, however, identical in both SW and GB polished seeds. The PB polished seeds were more potent in superoxide and hydroxyl scavenging, whereas GB in nitric oxide (NO) scavenging. The common observation noted after polishing of seeds was the reduction in the level of carbohydrates and antioxidant potential, though the extent of reduction varied in the three cultivars. The only exception was GB, where there was no alteration in NO scavenging potential even after polishing. Our study showed the better performance of SW polished seeds with respect to higher amylose content and majority of the tested parameters governing antioxidant capacity and radical scavenging potential, thus highlighting the greater dietary significance of SW over the other two cultivars.

Ácido linoleico conjugado (ALC), metabolismo de lípidos y enfermedad cardiovascular / Conjugated linoleic acid (ALC), lipid metabolism and cardiovascular disease

High density lipoproteins (HDL) have been inversely related with the risk of cardiovascular diseases and are considered antiatherogenic factors. The vascular protective effect of HDL is associated to the reverse cholesterol transport, where the sterol is mobilized from peripheral tissues to the liver by HDL and redistributed to circulation or delivered through the bile as free cholesterol or transformed into bile acids. In the last years it has been demonstrated that conjugated linoleic acid (CLA), an omega-6 fatty acid from ruminants, which is a mixture of positional and geometric isomers of linoleic acid, has hipolipidemic and antiatherogenic properties in animal models. However, the precise effect of CLA on HDL metabolism and the mechanisms involved in these actions have yet not been elucidated. The present work reviews the scientific literature about the possible role of CLA as an antiatherogenic factor by controlling the reverse cholesterol transport.

Las lipoproteínas de alta densidad (HDL) han sido correlacionadas inversamente con el riesgo de enfermedad cardiovascular ya que se considera que constituyen un factor de protección antiateroesclerótico. El efecto protector vascular de las HDL se asocia con la vía de transporte reverso de colesterol, proceso por el cual el esterol es movilizado desde los tejidos periféricos hacia el hígado a través de las HDL plasmáticas para ser redistribuido a la circulación, o para su remoción hacia la bilis como colesterol propiamente tal o transformado en sales biliares. Por otro lado, en los últimos a±os el ácido linoleico conjugado (ALC), un acido graso derivado de la serie omega-6 proveniente de animales rumiantes y cuya mezcla está mayoritariamente formada por los isómeros geométricos y posicionales del ácido linoleico (cis 9 trans 11 y trans 10 cis 12), ha demostrado tener propiedades hipolipemiantes y antiaterogénicas en varios modelos animales. Sin embargo, su efecto preciso sobre el metabolismo de HDL y los posibles mecanismos de acción involucrados aún no ha sido dilucidado. El presente trabajo realiza una revisión de la literatura científica en relación al rol antiaterosclerótico que puede tener el consumo de ALC a través del control del trasporte reverso del colesterol.

Controle da adipogênese por ácidos graxos: [revisão] / Control of adipogenesis by fatty acids: [review]

A obesidade é um dos principais problemas de saúde pública. Indivíduos obesos são mais suscetíveis a desenvolver doenças cardiovasculares e diabetes melito tipo 2. A obesidade resulta do aumento no tamanho e no número de adipócitos. O balanço entre adipogênese e adiposidade determina o grau de obesidade do indivíduo. Adipócitos maduros secretam adipocinas, tais como TNFα, IL-6, leptina e adiponectina, e lipocina, o ácido palmitoleico ω-7. A produção de adipocinas é maior na obesidade, o que contribui para o estabelecimento de resistência periférica à insulina. O conhecimento dos eventos moleculares que regulam a diferenciação dos pré-adipócitos e de células-tronco mesenquimais em adipócitos (adipogênese) é importante para o entendimento da gênese da obesidade. A ativação do fator de transcrição PPARγ é essencial na adipogênese. Certos ácidos graxos são ligantes de PPARγ e podem, assim, controlar a adipogênese. Além disso, alguns ácidos graxos atuam como moléculas sinalizadoras em adipócitos, regulando sua diferenciação ou morte. Dessa forma, a composição lipídica da dieta e os agonistas de PPARγ podem regular o balanço entre adipogênese e morte de adipócitos e, portanto, a obesidade.

Obesity is one of the major Public Health problems. Obese individuals are more susceptible to develop cardiovascular diseases and type 2 diabetes mellitus. The obesity results from the increase in size and number of the adipocytes. The balance between adipogenesis and adiposity determines the degree of obesity. Mature adipocytes secrete adipokines, such as TNFα, IL-6, leptine and adiponectin, and lipokine, the palmitoleic acid ω-7. The production of adipokines is increased in obesity, contributing to the onset of peripheral insulin resistance. The knowledge about the molecular events that regulate the differentiation of pre-adipocytes and mesenchymal stem cells into adipocytes (adipogenesis) is important for the comprehension of the genesis of obesity. Activation of transcription factor PPARγ plays an essential role in the adipogenesis. Certain fatty acids are PPARγ ligands and can control adipogenesis. Moreover, some fatty acids act as signaling molecules regulating their differentiation into adipocytes or death. Accordingly, the lipid composition of the diet and PPARγ agonists can regulate the balance between adipogenesis and death of adipocytes and, therefore, the obesity.